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Microscopic polyangiitis (MPA) is a small-vessel vasculitis characterised by systemic infiltration, with a primary focus on the renal and pulmonary systems. One of its more lethal pulmonary manifestations is diffuse alveolar haemorrhage (DAH), although the spectrum of lung pathology in MPA is vast and calls for immediate immunosuppressive therapy. Our case looks at an older woman initially presenting with MPA-induced rapid progressive glomerulonephritis. However, she gradually develops an array of vasculitis-related pulmonary insults that necessitate endotracheal intubation, and following a short course of immunosuppression, her lungs undergo a rapid physiological recovery. This case highlights that induction therapy with steroids enhances lung compliance and results in a more profound respiratory recovery in ventilated MPA patients who lack DAH-related pulmonary symptoms., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2025. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Background/aims: This study applied the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) criteria for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) to patients with Behçet's disease (BD) to investigate the proportion and clinical implications of the reclassification to the overlap syndrome of BD and AAV (OS-BD-AAV)., Methods: We included 280 BD patients presenting with ANCA positivity but without medical conditions mimicking AAV at diagnosis. Demographic data, items from the 2014 revised International Criteria for BD and 2022 American College of Rheumatology and European Alliance of Associations for Rheumatology criteria for AAV, ANCA positivity, and laboratory results were recorded as clinical data at diagnosis. A total score ≥ 5 indicated microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA), whereas a total score ≥ 6 indicated a diagnosis of eosinophilic GPA (EGPA)., Results: The overall reclassification rate of OS-BD-AAV was 8.6%. Of the 280 patients, 16 (5.7%) and 8 (2.9%) were reclassified as having OS-BD-MPA and OS-BD-GPA, respectively; none were classified as having OS-BD-EGPA. ANCA, myeloperoxidase-ANCA (P-ANCA), proteinase 3-ANCA (C-ANCA) positivity, hearing loss, and interstitial lung disease (ILD) at diagnosis were more common in patients with OS-BD-AAV than in those without. ANCA positivity and ILD at BD diagnosis contributed to the reclassification of OS-BD-AAV. However, hearing loss was not considered a major contributor to BD due to its possibility of developing as a manifestation of BD., Conclusion: To our knowledge, this is the first study to demonstrate the reclassification rate (8.6%) of patients with BD and ANCA results at diagnosis as OS-BD-AAV.

To explore disease characteristics, renal involvement and induction treatment strategies over the last decades and evaluate relapse rates and renal outcomes in ANCA-associated vasculitides (AAV). We retrospectively analyzed remission, relapse rates and the occurrence of the composite endpoint (comprising death and renal failure) in newly diagnosed AAV cases in four tertial referral centers in Germany and Switzerland diagnosed between 1999 and 2022. Hazard ratios were computed by Cox proportional hazard and Kaplan-Meier curves were plotted to compare therapeutic strategies after propensity-matching. In our cohort of 358 AAV patients, 203 (58.1%) were classified as granulomatosis with polyangiitis (GPA) based on the novel 2022 ACR/EULAR criteria, 139 (38.8%) as microscopic polyangiitis (MPA). The proportion of MPA cases among all AAV patients increased from 28.9% between 1999 and 2013 up to 46.7% thereafter. Cyclophosphamide (CYC) was chosen most frequently for remission induction (74.8% before 2013 and 57.3% thereafter), whereas the use of rituximab (RTX) increased from 5 to 26% within these periods. GPA patients had a higher relapse rate as compared to MPA patients (41.3% vs. 25.9%, p = 0.006). However, in AAV patients with renal involvement, renal events (i.e. end-stage kidney disease or a persistent drop in the estimated glomerular filtration rate (eGFR) below 15 ml/min/1.73 m 2 ) occurred more frequently in MPA patients, particularly under RTX treatment as compared to matched CYC counterparts (11.8% vs. 7.5%, p = 0.011). In our cohort, GPA patients exhibited frequent relapses, advocating for a more intense and extended treatment. MPA patients had lower relapse rates, however, RTX was less effective to prevent renal endpoints in MPA as compared to CYC, highlighting the need to further investigate additional treatment strategies., Competing Interests: Declarations. Conflict of interests: S. Krämer, K. Vogt, T. Schreibing, T. Schmitt, S. Mosberger: no disclosures. T. Rauen, M. Busch, R. Bergner, T. Neumann: received consultancy honoraria from Vifor Pharma. Ethical approval: This retrospective analysis was approved by the involved local ethic committees (Aachen: EK 164/19, St. Gallen: 2020-01350, Jena: 2020-1837-Daten, Ludwigshafen: 2020-14843-Retrospective)., (© 2024. The Author(s).)

Background: This study investigated poor prognostic factors for the relapse of interstitial lung disease (ILD) in patients with microscopic polyangiitis (MPA) after remission induction therapy., Methods: We enrolled patients diagnosed with MPA complicated by ILD according to the Chapel Hill Consensus definition from 2001 to 2023 in multiple institutions in the REVEAL cohort. All patients who were treated with immunosuppressive therapy were followed up, and those who relapsed with ILD were extracted in this study. We explored the risk factors for predicting ILD relapse in patients with MPA-ILD by comparing the demographic, clinical, laboratory, and radiological findings and treatments between the relapsed and non-relapsed groups on admission., Results: Of 243 patients with MPA, 134 (55.1%) with MPA-ILD were enrolled. Among them, 28 (20.9%) relapsed during a mean follow-up of 4.2 years. The initial serum Krebs von den Lungen-6 (KL-6) and surfactant protein-D (SP-D) levels and the prevalence of usual interstitial pneumonia (UIP) pattern were significantly higher in the relapsed group. The biomarkers were also risk factors for relapse in multivariate Cox regression analysis. The best cut-off values of KL-6, SP-D for predicting ILD relapse were 430 U/mL and 89.5 ng/mL, respectively. We created prediction models based on the best cut-off values for KL-6, SP-D, and the presence of the UIP pattern (KSU model). The 10-year relapse rate was significantly different among patients with MPA-ILD stratified by the number of risk factors based on the KSU model. A higher relapse rate was associated with higher all-cause mortality., Conclusions: The initial serum high KL-6 and SP-D levels and the prevalence of the UIP pattern were associated with ILD relapse in patients with MPA-ILD. Our multicentre cohort study indicated that the KSU model, which consists of KL-6 ≥ 430 U/mL, SP-D ≥ 89.5 ng/mL, and the presence of the UIP pattern, is a useful predictor of ILD relapse in patients with MPA after immunosuppressive therapy., Competing Interests: Declarations. Ethics approval and consent to participate: The study was conducted in accordance with the Declaration of Helsinki and its amendments, and it was approved by the Osaka Medical College and the Faculties of Medicine Ethics Committee (approval no. 1529) and by the individual participating centres, including Kyoto University (approval no. R1540) and Osaka Metropolitan University (approval no. 2023-027). The Ethics Committee of Kyoto University waived the requirement for informed consent because of the anonymous nature of the data. Written informed consent was obtained from each patient at the other institutions. Consent for publication: Not applicable. Competing interests: SM has received research grant from Japan Intractable Diseases Research Foundation and Promotion and Mutual Aid Corporation for Private Schools of Japan. TK has received payments for lectures from Abbvie, Bristol-Myers Squibb, Chugai, Eisai, Eli Lilly, Pfizer, and Boehringer Ingelheim. RW receives research grant from AbbVie and speaker’s fee from Asahi Kasei, Chugai, Eli Lilly, GSK, and UCB Japan. RH received research grants from GSK, and speaker fee from Abbvie, Asahi Kasei, Brystol-Meyers Squibb, Eisai, Eli Lilly, GSK, Kissei, and Pfizer. MH received research grants and/or speaker fee from Abbvie, Asahi Kasei, Astellas, Brystol Meyers, Chugai, Eisai, Daiichi Sankyo, Eli Lilly, Novartis Pharma, Tanabe Mitsubishi. TT received research grants and/or speaker fee from Abbvie, Asahi Kasei, Astellas, Brystol-Meyers Squibb, Chugai, Eisai, Eli Lilly, Janssen pharma, Nihon Shinyaku, Mitsubishi-Tanabe, Takeda, and Pfizer. Other authors (AO, DN, YM, MS, TT, AM, KK, TY, WY) do not have any conflict of interest., (© 2024. The Author(s).)

Background: The association between interstitial lung disease (ILD) and microscopic polyangiitis (MPA) has received increasing attention in recent years. However, there are still no studies comparing clinical characteristics and prognoses between MPA-ILD patients and patients with ANCA-negative ILDs. Therefore, the purpose of this study was to analyse a group of patients presenting MPA-ILD matched with patients exhibiting ANCA-negative ILDs to identify differences in their clinical characteristics and survival., Methods: This study retrospectively reviewed the data of 60 patients with MPA-ILD and 60 patients with ANCA-negative ILDs who were matched for age, sex, and patterns on chest high-resolution CT (HRCT) images. The baseline clinical information, laboratory parameters and chest CT data were collected and analysed at each patient's initial diagnosis., Results: Sixty of the 682 (8.8%) ILD patients were diagnosed with MPA-ILD. MPA-ILD patients tended to be older and have higher CRP and ESR levels. ILD antedated MPA in 61.7% (37/60) of the patients, and MPA occurred on average (45.1 ± 33.4) months after the ILD diagnosis. Compared with matched ANCA-negative ILD patients, MPA-ILD patients had higher CRP and serum creatinine levels and lower haemoglobin levels. UIP (63.3%) was the most common chest HRCT pattern, and the proportion of patients with oddly shaped cysts (P = 0.04) was significantly greater in the MPA-ILD group than in the matched ANCA-negative ILD group. The number of MPA-ILD patients was significantly shorter than that of ANCA-negative ILD patients (P = 0.005). Survival analysis revealed that acute exacerbation (AE) of ILD (HR 2.40, 95% CI 1.03-5.59, P = 0.043) and diffuse alveolar haemorrhage (HR 3.42, 95% CI 1.09-10.73, P = 0.036) were independently associated with shorter survival and that receiving glucocorticoids combined with immunosuppressants (HR 0.11, 95% CI 0.03-0.37, P < 0.001) was independently associated with prolonged survival in MPA-ILD patients., Conclusions: The proportion of MPA-ILD patients with total ILD is not low, and ANCA testing of ILD patients is necessary. Oddly shaped cysts with a UIP pattern may be a characteristic chest imaging manifestation of MPA-ILD. The prognosis of MPA-ILD is poor, especially for patients who are older, have DAH, and have experienced AEs., Competing Interests: Declarations. Ethics approval and consent to participate: All the studies were conducted in accordance with the Declaration of Helsinki. Written informed consent from study subjects was waived because of the retrospective design. The cohort study was approved by the institutional review board of the First Affiliated Hospital of Ningbo University and Ningbo Zhenhai People’s Hospital. All the methods were carried out in accordance with relevant guidelines and regulations. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests. Clinical trial number: Not applicable., (© 2024. The Author(s).)

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is a group of life-threatening autoimmune small vessel vasculitis and the prognosis depends heavily on whether a prompt diagnosis is achieved. Autoimmune thyroiditis is the most common autoimmune endocrine disease and could overlap with other autoimmune diseases. It remains elusive whether autoimmune thyroiditis affects the risk of AAV development. We performed a 2-sample Mendelian randomization analysis to explore the true association between autoimmune thyroiditis and microscopic polyangiitis (MPA), a subtype of AAV. Independent single-nucleotide polymorphisms associated with Hashimoto thyroiditis or Grave disease with genome-wide significance were selected as instrumental variables from large genome-wide association study. MPA genome-wide association study summary statistics were obtained from FinnGen consortium. The inverse-variance weighted method was conducted as the primary analysis for estimating the effect of the exposure on the outcome. Mendelian randomization-Egger and the weighted median method were used to confirm the results. We found a causal association between Hashimoto thyroiditis and MPA while no causal effect of Grave disease on MPA. This study contributed a genetic viewpoint to the understanding of the link between autoimmune thyroiditis and AAV., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

A 68-year-old woman was admitted to our hospital because of a rapid progression of renal dysfunction with positive myeloperoxidase antineutrophil cytoplasmic antibody and was diagnosed with rapidly progressive glomerulonephritis associated with microscopic polyangiitis (MPA). Severe right rectus sheath hematoma (RSH) bleeding from the inferior epigastric artery developed after starting hemodialysis, which required 4 transarterial embolizations due to recurrent bleeding. After additional treatment with methylprednisolone pulse therapy and rituximab, no rebleeding occurred. Although the giant hematoma reached the pelvis, it shrank spontaneously without any intervention. Nontraumatic RSH should therefore be considered when treating patients with multiple risk factors.

Although rapidly progressive glomerulonephritis (RPGN) is the main renal phenotype of microscopic polyangiitis (MPA), we aim to clarify the clinical features of slowly progressive MPA. This retrospective observational study included 12 patients diagnosed with MPA in our hospital between January 2012 and February 2022. We investigated the differences in surrogate markers, rate of decline of estimated glomerular filtration rate (eGFR) between the slowly progressive and rapidly progressive MPA groups. Of the 12 patients with MPA, 3 (25.0%) had slowly progressive MPA: MPA within 30% decrease in eGFR 3 months pretreatment, all of whom developed RPGN during the course. Patients with slowly progressive MPA had lower levels of C-reactive protein, myeloperoxidase anti-neutrophil cytoplasmic antibodies, and interleukin-6; higher levels of sialylated carbohydrate antigen KL-6. Slowly progressive MPA is not uncommon in our hospital. A linear relationship was found between slower rate of eGFR decline and lower surrogate markers of disease activity. Some MPA cases have slowly progressive glomerulonephritis leading to RPGN, which may be clinically characterized by low disease activity. It may be useful to measure myeloperoxidase anti-neutrophil cytoplasmic antibody in chronic kidney disease with concomitant urinary abnormalities to diagnose MPA with slowly progressive glomerulonephritis.

Microscopic polyangiitis (MPA) is a form of necrotizing vasculitis affecting the small vessels. Our study is the first study with the objective of describing the difference in clinical presentation of MPA and response to treatment at 6 months based on the age of disease onset. All patients seen at a tertiary vasculitis clinic between 2015 and 2023 with a diagnosis of MPA were included. Patients were divided into an elderly group (age >  = 65 years) and a younger group (age < 65). Comparative analysis was conducted to characterize differences amongst the elderly and younger patients, including differences in organ involvement and clinical presentation, Birmingham Vasculitis Activity Score (BVAS) scores, Vasculitis Damage Index( VDI) scores, and response to treatment at 6 months. Thirty-one patients were included in our study. Younger MPA patients (n = 18) with mean age at diagnosis of 53.17 years were compared with older MPA patients(n = 13) with mean age at diagnosis of 76.08 years. The younger patients had statistically significant higher BVAS scores (p = 0.009), along with higher incidence of renal (p = 0.028), pulmonary (p = 0.0069), and cutaneous (p = 0.026) manifestations at disease onset. Furthermore, amongst the younger population, there was noted statistically significant clinical improvement at 6 months following treatment induction, particularly in the domains of general symptoms (p = 0.011), MSK (p = 0.019), cutaneous (p = 0.011), and pulmonary symptoms (p = 0.04). In contrast, the elderly population presented with a predominant of non-specific constitutional symptoms, with statistically significant improvement in the domain of non-specific general symptoms at 6 months (p = 0.00008). All MPA patients responded well to treatment, with statistically significant improvement amongst younger patients (p = 0.0032), but no statistically significant improvement amongst elderly patients (p = 0.67). Our study findings concluded that MPA's clinical presentation differed by age group. Younger patients had more aggressive vasculitis disease presentation with better response to treatments, whereas, elderly patients had less severe disease presentation with predominant of general symptoms at disease onset. Key Points • MPA clinical presentation differed by age at disease onset. Younger patients presented with more aggressive and classic vasculitis-like presentations, with multi-system organ involvement and statistically significant higher incidence of renal, pulmonary, and cutaneous manifestations. In contrast, elderly patients had a predominant of constitutional and non-specific symptoms with often delayed diagnosis. • All MPA patients responded well to treatment. Amongst the younger population, there was statistically significant improvement in BVAS scores after treatment induction at 6 months; however, there was no statistically significant improvement of BVAS scores in the elderly population. • Future studies are required to further understand the difference in the clinical presentation of MPA based on the age at disease onset, and the implication on disease diagnosis and management., (© 2024. The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR).)

Anti-neutrophil cytoplasmic autoantibody (ANCA) vasculitis has diverse patterns of injury including microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Necrotizing and crescentic glomerulonephritis (NCGN) occurs in all syndromes and as renal limited vasculitis (RLV). Single-dose intravenous ANCA IgG-specific for mouse myeloperoxidase (MPO) causes RLV in mice. Although multiple mouse models have elucidated ANCA-IgG induced necrotizing and crescentic glomerulonephritis (NCGN), pathogenesis of ANCA-induced granulomatosis and vasculitis outside the kidney has not been clarified. To investigate this, we used intravenous MPO-ANCA IgG in the same strain of mice to induce different patterns of lung disease mirroring patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Repeated intravenous MPO-ANCA IgG induced GPA with NCGN, lung capillaritis, arteritis and granulomatosis. Lung leukocyte phenotypes were evaluated by immunohistochemical image analysis and by flow cytometry. ANCA lung capillaritis and microabscesses began within one day and evolved into granulomas in under seven days. Influenza plus single-dose MPO-ANCA IgG induced MPA with NCGN, lung capillaritis and arteritis, but no granulomatosis. Allergic airway disease caused by house dust mites or ovalbumin plus single-dose intravenous MPO-ANCA IgG induced EGPA with eosinophilic bronchiolitis, NCGN, capillaritis, arteritis, and granulomatosis. Thus, our study shows that the occurrence and pattern of lung lesions are determined by the same ANCA IgG accompanied by different synergistic immune factors., (Copyright © 2024 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

ANCA-associated vasculitides (AAV) comprise granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis. All forms may involve different organ systems, yet kidney and lung involvement are common and fatal in many cases. Here, we aimed to determine the predictive value of pulmonary disease manifestation and individual CT findings in AAV patients. Available CT scans and clinical information on mortality, renal outcomes, occurrence of relapses and damage scores were analysed retrospectively from a tertiary rheumatology center in Germany. We included a total of 94 AAV patients (49 with GPA, 41 with MPA). Forty-four patients had lung involvement with available CT scans, 70.5% of which with GPA and 72.7% with renal involvement. Nodule formation and cavities were more frequent among GPA patients, whereas ground-glass opacities (GGO), ILD and pleural effusion were observed predominantly in MPA patients. Over a median follow-up of 37 months, GPA patients had a slightly higher overall mortality, whereas end-stage kidney failure rates were significantly increased in MPA patients. Relapse frequencies were comparable between both entities. The presence of GGO and pleural effusion were associated with higher relapse rates, whereas nodules were negatively correlated with relapses. Notably, RTX-treated patients had less infections as compared to individuals under different therapies. Our data demonstrate the outstanding importance of characteristic CT patterns in AAV diagnosis assessment. Especially certain CT patterns including GGO and pleura effusion may help to identify patients who are at higher risk for relapsing disease., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Infections are a critical concern for patients with microscopic polyangiitis (MPA). This study aimed to identify the risk factors associated with serious infections (SIs) and infection-related mortality in patients with MPA, as well as the effect of glucocorticoid (GC) dose tapering on these outcomes., Methods: This multicentre, retrospective, and observational study utilised data from a cohort of patients with MPA in Japan [Registry of Vasculitis Patients to Establish REAL World Evidence (REVEAL) cohort]. Patients were categorised based on the occurrence of SIs or infection-related deaths, and various characteristics were compared among the groups., Results: Among 182 patients, 66 (36.2%) experienced 129 SIs and 27 (14.8%) developed infection-related deaths. Advanced age, elevated C-reactive protein (CRP) levels, and higher ratio of the GC dose at 3 months to the initial dose were identified as independent risk factors for SIs. Older age was also associated with infection-related deaths. Furthermore, the cumulative incidence of infection-related deaths was significantly higher in patients with a higher ratio of the GC dose at 24 months to the initial dose., Conclusion: Older age, elevated CRP levels, and slower GC dose tapering predispose patients to SIs and infection-related deaths. Strategies, such as rapid GC dose tapering, are anticipated to mitigate the risk of infections., (© Japan College of Rheumatology 2024. Published by Oxford University Press.)

Objectives: To assess self-reported symptoms of neuropathy, disability, pain, health-related quality of life (HR-QOL) and autonomic dysfunction in patients with vasculitis., Methods: Patients with vasculitis (with or without neuropathy) were invited by Vasculitis UK to complete an anonymous online survey., Results: Three hundred and twelve patients (71% female) responded. Median age was 61-70 years. Median duration of vasculitis was 4 years (<2 months to >15 years). Vasculitic types included granulomatosis with polyangiitis (34%), unspecified ANCA-associated vasculitis (13%), microscopic polyangiitis (11%), eosinophilic granulomatosis with polyangiitis (11%), giant cell arteritis (10%), non-systemic vasculitic neuropathy (2%) and other (19%). Many patients reported foot/hand symptoms suggestive of neuropathy, including numbness (64%), pain (54%) or weakness (40%). Two hundred and forty-two patients (78%) met our definition of probable vasculitic neuropathy: diagnosis of neuropathy by vasculitis team OR numbness OR weakness in feet/hands. Only 52% had been formally diagnosed with neuropathy. Compared with 70 patients without neuropathy, neuropathy patients had greater disability measured by the inflammatory Rasch-built Overall Disability Scale (centile mean 63.1 [s.d. 17.3] vs 75.2 [16.7]; P < 0.0001), Inflammatory Neuropathy Cause and Treatment scale (median 2 [interquartile range 1-4] vs 0.5 [0-2]; P < 0.0001) and modified Rankin scale (median 2 [interquartile range 1-3] vs 2 [1-2)]; P = 0.0002); greater pain on an 11-point rating scale (mean 4.6 [s.d. 2.6] vs 3.5 [2.8]; P = 0.0009); and poorer HR-QOL on the EQ5D-3L (summary index mean 0.58 [s.d. 0.29] vs 0.69 [0.28]; P < 0.0001). Two-thirds reported autonomic symptoms (not associated with neuropathy)., Conclusion: Neuropathy is common and associated with significant disability, pain and impaired HR-QOL in patients with systemic vasculitis., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The incidence rate of malignancy in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is higher than that in the general population. Malignancy has been indicated to be a risk factor or inducer of AAV. Herein, we report the case of a healthy 84-year-old man with seronegative microscopic polyangiitis (MPA) after the diagnosis of renal pelvic carcinoma. Four weeks before admission, his estimated glomerular filtration rate (eGFR) was 85 ml/min/1.73 m 2 , and no hematuria or proteinuria was detected. Renal biopsy on admission revealed invasive urothelial carcinoma of the right renal pelvis. On day 15, his eGFR decreased to 30 ml/min/1.73 m 2 without any incitement. The renal specimen extracted via right robot-assisted nephroureterectomy indicated the presence of ANCA-associated glomerulonephritis. On day 37, urinary protein/urinary creatinine level of 6.48 g/gCre, serum albumin level of 2.1 mg/dL, and eGFR of 20 ml/min/1.73 m 2 indicated the presence of nephrotic syndrome. His blood sputum was analyzed via chest computed tomography, which revealed alveolar hemorrhage. Although his myeloperoxidase-ANCA was negative, he was diagnosed with MPA based on the 2022 American College of Rheumatology/European League Against Rheumatism classification criteria. This is the first case report of  MPA or AAV complicated with renal pelvic carcinoma. The clinical indicators demonstrated that renal pelvic carcinoma preceded the onset of MPA. The spatial proximity of both diseases indicated that renal pelvic carcinoma had some influence on MPA development via the mechanism of inflammatory cytokines or neutrophil extracellular traps. Our report may be useful in elucidating the mechanism of MPA development., (© 2024. The Author(s), under exclusive licence to Japanese Society of Nephrology.)

We describe the case of a 76-year-old man affected by pneumoconiosis, secondary to silica dust exposure, who was diagnosed with antineutrophil cytoplasmic antibody (ANCA)-positive microscopic polyangiitis (MPA)-related cervical myelitis. Pneumoconiosis is reported to trigger autoantibody production and the onset of different autoimmune diseases, including ANCA-associated vasculitis (AAV). MPA is an AAV of the small vessels that can often affect the nervous system, although involvement of the spinal cord in the form of myelitis is described as an anecdotal occurrence. Our experience suggests that an autoimmunity workup should be considered for patients with pneumoconiosis who present with neurological symptoms consistent with AAV.

Introduction: This study aimed to explore ocular manifestations in ANCA-associated vasculitis (AAV), focusing on granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA), and microscopic polyangiitis (MPA) and to examine the associations with laboratory parameters and other systemic manifestations., Methods: This retrospective study reviewed data from 533 AAV patients across two major Chinese medical centers from January 2016 to November 2023. Data including diagnosis, cranial manifestations of disease, ocular complications, and laboratory parameters were analyzed. Univariate and multivariable logistic regression analyses assessed associations across disease manifestations. Machine learning models were also utilized to predict the risk of retinal/eye involvement in AAV patients., Results: Among 533 patients (210 GPA, 217 MPA, 99 EGPA, and 7 unclassified AAV), ocular complications were observed in 20.64% of them, with a distribution of 36.67% in GPA, 7.37% in MPA, and 18.18% in EGPA. The most common ocular manifestations included scleritis and retro-orbital mass/dacryocystitis, which were notably prevalent in GPA patients. Retinal involvement was observed in 9.09% of EGPA cases. The machine learning models yielded that eosinophil percentage (EOS%), high-sensitivity C-reactive protein (hsCRP), and CD4 + T cell/CD8 + T cell ratio (T4/T8) can predict retinal involvement. Furthermore, the white blood cell, EOS%, APTT, IgA, hsCRP, PR3-ANCA, and T4/T8 can predict eye involvement., Conclusion: Ocular manifestations are a prevalent complication across all forms of AAV. Predictive models developed through machine learning offer promising tools for early intervention and tailored patient care. This necessitates a multidisciplinary approach, integrating rheumatology and ophthalmology expertise for optimal patient outcomes., (© 2024. The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR).)

Objectives: To evaluate the effectiveness and safety of two different intravenous methylprednisolone (IVMP) pulse doses in patients with severe microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA)., Methods: We emulated a target trial using observational data from the nationwide registry in Japan. Patients with severe glomerulonephritis or diffuse alveolar haemorrhage were selected and pseudo-randomized into three groups using propensity score-based overlap weighting as follows: non-IVMP, IVMP 0.5 g/day and IVMP 1.0 g/day. The primary outcome was all-cause mortality, and the secondary outcomes were composite all-cause mortality and kidney failure, severe relapse and serious infection from 2 to 48 weeks after treatment initiation. To estimate the treatment effects, the Cox proportional hazard model and Fine-Gray subdistribution hazard model were used., Results: In this emulated target trial, of 201 eligible patients (MPA, 175; GPA, 26), 6 (3%) died, 4 (2.0%) had kidney failure, 11 (5.5%) had severe relapse, and 40 (19.9%) had severe infections. Hazard ratios (HR) for IVMP 0.5 g/day and IVMP 1.0 g/day pulse groups compared with non-IVMP pulse were as follows: all-cause mortality 0.46 (95% CI: 0.07, 2.81) and 0.07 (95% CI: 0.01, 0.41), respectively; all-cause mortality/kidney failure 1.18 (95% CI: 0.26, 5.31) and 0.59 (95% CI: 0.08, 4.52), respectively; subdistribution HRs for severe relapse were 1.26 (95% CI: 0.12, 13.70) and 3.36 (95% CI: 0.49, 23.29), respectively; and for serious infection 1.88 (95% CI: 0.76, 4.65) and 0.94 (95% CI: 0.28, 3.13), respectively., Conclusion: IVMP 1.0 g/day pulse may improve 48-week mortality in patients with severe MPA/GPA., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Antineutrophil cytoplasmic antibody-associated vasculitides (AAV) is a group of systemic necrotizing small vessel autoimmune diseases, with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) being the two most common. The co-existence of AAV with different immune-mediated diseases (autoimmune disesases - AID) might affect the clinical presentation of the primary disease. The purpose of the study was to assess the co-existence of AAV with AID and to investigate whether it affects the characteristics and the course of AAV., Methods: A retrospective single-center study was performed to identify patients with a diagnosis of MPA or GPA and concomitant AID, and to investigate their clinical features and characteristics. The group consisted of consecutive unselected AAV patients treated at a large university-based hospital, since 1988 with follow-up until 2022., Results: Among 284 patients diagnosed either with GPA (232) or MPA (52), 40 (14,1%) had co-existing AIDs. The most frequent were: Hashimoto thyroiditis (16 cases), rheumatoid arthritis (8 cases), followed by psoriasis (6 cases), pernicious anemia (3 cases), and alopecia (3 cases). Patients with autoimmune comorbidities had a significantly longer time between the onset of symptoms and the diagnosis (26 vs. 11 months, p < 0.001). Laryngeal involvement (20.0% vs. 9.0%, p = 0,05), peripheral nervous system disorders (35.0% vs. 13.9%, p < 0.001), and neoplasms (20.0% vs. 8.6%, p = 0,044) were more common in patients with AID comorbidities, compared to subjects without AID. In contrast, renal involvement (45.0% vs. 70.9%, p = 0.001) and nodular lung lesions (27.5% vs. 47.5%, p = 0.044) were significantly less frequent in patients with co-morbidities. Following EUVAS criteria, patients with autoimmune co-morbidities had a generalized form of the disease without organ involvement (52.5% vs. 27.2%, p = 0.007), while the others had a higher percentage of generalized form with organ involvement (38.3% vs. 20.0%, p = 0.007)., Conclusions: The coexistence of AAV with different autoimmune diseases is not common, but it might affect the clinical course of the disease. Polyautoimmunity prolonged the time to diagnosis, but the AAV course seemed to be milder. Particular attention should be paid to the increased risk of cancer in these patients. It also seems reasonable that AAV patients should receive a serological screening to exclude the development of overlapping diseases., (© 2024. The Author(s).)

While the incidence and prevalence of non-tuberculous mycobacterial-pulmonary disease (NTM-PD) are increasing and microscopic polyangiitis (MPA) is common in East Asian countries, case reports of MPA associated with NTM-PD are limited. A 72-year-old male receiving treatment for NTM-PD with antibiotics was referred to our hospital with fever and arthralgia that developed a few months previously. A blood test revealed the presence of the myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) and renal impairment. Based on a pathological examination of renal tissue, which showed crescentic glomerulonephritis, the patient was diagnosed with MPA. Due to acute kidney injury and strongly positive MPO-ANCA, pulse steroid therapy was initiated followed by intravenous rituximab (RTX). The patient also received plasmapheresis (14 sessions). Renal dysfunction was reversed. MPA associated with NTM-PD is extremely rare and, thus, there is currently no established treatment. Our patient was diagnosed with MPA based on the findings of renal biopsy while receiving treatment for NTM-PD. RTX and plasmapheresis combined with systemic glucocorticoid therapy were initiated before these clinical conditions had fully recovered. Although MPA secondary to NTM-PD may be more refractory to treatment than primary MPA in the presence of a very low interferon-gamma (IFN-γ) level, this case was successfully treated with steroids, RTX, and plasmapheresis., (© 2023. The Author(s), under exclusive licence to Japanese Society of Nephrology.)

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a systemic autoimmune disease characterized by necrotizing inflammation of small blood vessels. Glucocorticoids (GC) in combination with rituximab or cyclophosphamide can reduce AAV-related mortality and rescue renal function. However, several side effects associated with these agents, including GC toxicity, are concerning. Avacopan, an inhibitor of the C5a receptor, is now available for AAV treatment and is expected to mitigate GC toxicity. We present a case of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-positive microscopic polyangiitis (MPA) with rapidly progressive glomerulonephritis treated with an early switch from GC to avacopan in combination with rituximab during induction therapy. Over a 6-month treatment period, clinical remission was achieved and maintained without infection or elevated liver enzyme levels. Efficacy and safety data regarding avacopan for AAV induction therapy remain limited. Therefore, more case reports are required to clarify the role of avacopan in AAV induction and maintenance therapy. Since the MPO-ANCA titer remained elevated despite the clinical remission of AAV in this case, the ANCA titer may not necessarily be a reliable biomarker for predicting AAV relapse when avacopan is applied as an induction therapy for AAV., (© 2023. The Author(s), under exclusive licence to Japanese Society of Nephrology.)

Avacopan, an orally administered C5a receptor antagonist, is effective in microscopic polyangiitis via the inhibition of neutrophil priming induced by C5a. However, the exact effect of avacopan on the production of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) is yet to be clearly established. This report presents a microscopic polyangiitis patient without major organ damage where high levels of MPO-ANCA persisted with high-dose steroid therapy and azathioprine, but the addition of avacopan led to a reduction in MPO-ANCA titres. The present case implies that avacopan-mediated inhibition of C5a may lead to a reduction in MPO-ANCA levels, thereby potentially ameliorating the pathophysiology of ANCA-associated vasculitis. Nevertheless, the impact of avacopan on MPO-ANCA production cannot be asserted solely based on this report; therefore, further examination is necessary through subgroup analysis using data from larger-scale studies., (© Japan College of Rheumatology 2024. Published by Oxford University Press.)

We herein report a case of immune-mediated necrotizing myopathy (IMNM) in a patient with microscopic polyangiitis (MPA). A 77-year-old Japanese woman presented with a 2-day history of proximal muscle weakness and myalgia, with elevated serum creatinine kinase (CK) levels. Findings of a muscle biopsy were compatible with IMNM; however, anti-signal recognition particle (SRP) and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies were negative. She also had peripheral neuropathy with elevated serum myeloperoxidase anti-neutrophil cytoplasmic antibody titers, leading to a diagnosis of MPA. IMNM can be a pathological result of MPA muscle involvement.

Pulmonary manifestations of vasculitis are associated with significant morbidity and mortality in affected individuals. They result from a complex interplay between immune dysregulation, which leads to vascular inflammation and tissue damage. This review explored the underlying pathogenesis of pulmonary involvement in vasculitis, encompassing various forms such as granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), and anti-GBM disease. Mechanisms involving ANCA and anti-GBM autoantibodies, neutrophil activation, and neutrophil extracellular trap (NETs) formation are discussed, along with the role of the complement system in inducing pulmonary injury. Furthermore, the impact of genetic predisposition and environmental factors on disease susceptibility and severity was considered, and the current treatment options were presented. Understanding the mechanisms involved in the pathogenesis of pulmonary vasculitis is crucial for developing targeted therapies and improving clinical outcomes in affected individuals.

Objective: This study aimed to establish prediction models for respiratory-related mortality in microscopic polyangiitis (MPA) complicated by interstitial lung disease (ILD) using clinical characteristics., Methods: We enrolled patients with MPA with ILD between May 2005 and June 2021 in a multicentre cohort of Japanese patients with MPA (REVEAL cohort). We evaluated the demographic, clinical, laboratory, radiological findings, treatments and the presence of honeycombing 1 cm above the diaphragm using chest high-resolution CT (HRCT) on admission. We explored the risk factors predictive of respiratory-related mortality., Results: Of 115 patients, 26 cases died of respiratory-related diseases during a median follow-up of 3.8 years. Eighteen patients (69%) died due to respiratory infection, three (12%) had diffuse alveolar haemorrhage, and five (19%) had exacerbation of ILD. In univariate analysis, older age, lower percent forced vital capacity (%FVC), lower percent diffusing capacity of carbon monoxide (%DLCO), and the presence of honeycombing in the right lower lobe were identified as risk factors. Additionally, in multivariate analysis adjusted for age and treatment, %FVC, %DLCO and the presence of honeycombing in the right lower lobe were independently associated with respiratory-related mortality. We created prediction models based on the values of %FVC, %DLCO and presence of honeycombing on chest HRCT (termed "MPF model"). The 5-year respiratory-related death-free rate was significantly different between patients with MPA with ILD stratified by the number of risk factors based on the MPF model., Conclusions: Our study indicates that the MPF model may help predict respiratory-related death in patients with MPA with ILD., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: To examine whether patients with ANCA-associated vasculitis (AAV) have an increased risk of cardiovascular disease in the months prior to diagnosis of AAV., Methods: Using a nested case-control framework, patients with granulomatosis with polyangiitis and microscopic polyangiitis were identified through the Danish Nationwide Registries from 1996 to 2021 and matched 1:3 with age- and sex-matched controls without AAV. Each control was assigned the same index date (date of AAV diagnosis) as their corresponding case. Conditional logistic regression was used to compute adjusted hazard ratios (HRs) for major adverse cardiovascular events (MACE), ischaemic heart disease, coronary angiogram, heart failure, venous thromboembolism, atrial fibrillation, ischaemic stroke, pericarditis and ventricular arrhythmias/implantable cardioverter defibrillator implantation/cardiac arrest (VA/ICD/CA) within 12 months, 6 months, 3 months, 2 months and 1 month before index date., Results: A total of 2371 patients with AAV (median age 63 years, 53.7% male) were matched with 7113 controls. The prevalence of any cardiovascular outcome and MACE within 12 months preceding index date were 10.3% and 2.4% for AAV, compared with 3.8% [HR 3.05 (95% CI 2.48-3.75)] and 1.3% [HR 1.98 (95% CI 1.39-2.82)] of controls. The risk of cardiovascular outcomes was similarly increased in temporal proximity to the diagnosis, with the highest HR at 1 month prior to index date: any cardiovascular outcome [HR 10.73 (95% CI 7.05-16.32)] and MACE [HR 5.78 (95% CI 2.67-12.52)]. In individual analysis, a significantly higher rate was observed for all outcomes (excluding VA/ICD/CA)., Conclusions: AAV disease is associated with an increased risk of cardiovascular disease in the months preceding diagnosis, which underlines the importance of early clinical vigilance towards cardiovascular disease., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Patients with microscopic polyangiitis (MPA) and positive myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) may present with various abnormalities in chest computed tomography (CT). This study aimed to identify subphenotypes using latent class analysis (LCA) and to explore the relationship between the subphenotypes and clinical patterns, as well as compare the clinical characteristics of these subphenotypes in patients with MPO-ANCA-positive MPA (MPO-MPA)., Methods: The study identified subphenotypes using LCA based on chest CT findings in 178 patients with MPO-MPA and pulmonary involvement from June 2014 to August 2022., Results: LCA identified 27 participants (15.2%) in class 1, 43 (24.1%) in class 2, 35 (19.7%) in class 3, and 73 (41.0%) in class 4. Class 1 was characterized by prominent inflammatory exudation, class 2 by fibrosis and architectural distortion, class 3 by predominantly bronchiectasis, and class 4 by lesions mixed with inflammation and fibrosis. Class 1 had the highest level of extrapulmonary disease activity, with 77.8% of patients experiencing diffuse alveolar hemorrhage. Class 2 had the lowest level of extrapulmonary disease activity, with 41.9% of patients showing usual interstitial pneumonia. Class 3 patients were more likely to have complications involving the ear, nose, and throat, as well as pulmonary infections before treatment, and they exhibited the best outcomes. The characteristics and outcomes of class 4 were intermediate among the four classes., Conclusions: These findings suggest that bronchiectasis may represent a unique pattern of pulmonary involvement in MPO-MPA, highlighting the importance of screening for bronchiectasis in MPO-MPA and identifying optimal management strategies., Competing Interests: Declaration of competing interest The authors declared they had no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are the two major antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)., Objectives: To characterize a homogenous AAV cohort and to assess the impact of clinicopathological profiles and ANCA serotypes on clinical presentation and prognosis. Clinical differences in GPA patients according to ANCA serotype and the diagnostic yield for vasculitis of biopsies in different territories were also investigated., Results: This retrospective study (2000-2021) included 152 patients with AAV (77 MPA/75 GPA). MPA patients (96.1% myeloperoxidase [MPO]-ANCA and 2.6% proteinase 3 [PR3]-ANCA) presented more often with weight loss, myalgia, renal involvement, interstitial lung disease (ILD), cutaneous purpura, and peripheral nerve involvement. Patients with GPA (44% PR3-ANCA, 33.3% MPO, and 22.7% negative/atypical ANCA) presented more commonly with ear, nose, and throat and eye/orbital manifestations, more relapses, and higher survival than patients with MPA. GPA was the only independent risk factor for relapse. Poor survival predictors were older age at diagnosis and peripheral nerve involvement. ANCA serotypes differentiated clinical features in a lesser degree than clinical phenotypes. A mean of 1.5 biopsies were performed in 93.4% of patients in different territories. Overall, vasculitis was identified in 80.3% (97.3% in MPA and 61.8% in GPA) of patients., Conclusions: The identification of GPA presentations associated with MPO-ANCA and awareness of risk factors for relapse and mortality are important to guide proper therapeutic strategies in AAV patients. Biopsies of different affected territories should be pursued in difficult-to-diagnose patients based on their significant diagnostic yield., (© 2024 The Association for the Publication of the Journal of Internal Medicine.)

Objective: To investigate the clinical and electrophysiological characteristics of ANCA-associated vasculitic neuropathy (VN) and analyze the predictors of treatment outcomes. Methods: Retrospective case series. In all, 652 consecutive patients with ANCA-associated vasculitis were admitted to the First Medical Center of the Chinese PLA General Hospital between January 2006 and December 2022. Peripheral neuropathy occurred in 91 patients. Patients were excluded if other known causes of neuropathy were present. Sixty-one patients were eventually enrolled, including 17 with eosinophilic granulomatosis with polyangiitis (EGPA), 11 with granulomatosis polyangiitis (GPA), and 33 with microscopic polyangiitis (MPA). Their clinical data were collected and clinical characteristics, VN manifestations, electrophysiological findings (including interside amplitude ratio [IAR]), and treatment outcomes were compared among the three subsets of AAV. Then, factors influencing the treatment outcomes were analyzed using multivariable logistic regression analysis. Results: Peripheral neuropathy occurred in 62.1%(18/29) of EGPA, 8.3%(15/180) of GPA, and 13.1%(58/443) of MPA patients. The age at onset and examination was higher in patients with MPA than those with EGPA or GPA ( P <0.01). The occurrence of VN was later in patients with GPA than those with EGPA ( P <0.01), and the GPA group had fewer affected nerves than the other two groups ( P <0.016). The abnormal IARs of motor nerves in lower limbs were more detected in the EGPA than the MPA group ( P <0.01). Logistic regression analysis suggested that higher Birmingham vasculitis activity score-version 3 (BVAS-V3) ( OR =6.85, 95% CI 1.33-35.30) was associated with better treatment outcomes of VN. However, central nervous system involvement was a risk factor for poor treatment outcomes ( OR =0.13, 95% CI 0.02-0.89). Conclusions: The clinical and electrophysiological characteristics of VN were slightly different among subsets of AAV. Patients with GPA often presented with polyneuropathy and had fewer nerves affected; mononeuritis multiplex was more common in EGPA than GPA and MPA. Higher BVAS-V3 and central nervous system involvement might predict the treatment outcome of VN.

Objective: This study aimed to evaluate the Ministry of Health, Labour and Welfare (MHLW) diagnostic criteria for antineutrophil cytoplasmic antibody-associated vasculitis compared to the new American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria., Methods: Two nationwide cohort studies were used, and participants were categorised as having eosinophilic granulomatosis with polyangiitis, granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) according to the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 and MHLW criteria., Results: Of the entire patient population, only 10 (2.1%) were unclassifiable according to the MHLW probable criteria, while a significant number of patients (71.3%) met at least two criteria. The MHLW probable criteria for MPA had some challenges in differentiating between MPA and eosinophilic granulomatosis with polyangiitis, and the same was true for MHLW probable criteria for GPA in differentiating MPA from GPA. Nevertheless, improved classification results were obtained when the MHLW probable criteria were applied in the order of eosinophilic granulomatosis with polyangiitis, MPA, and GPA., Conclusions: The application of MHLW criteria could categorise a substantial number of patients with antineutrophil cytoplasmic antibody-associated vasculitis into one of the three antineutrophil cytoplasmic antibody-associated vasculitis diseases. The classification was in accordance with the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria when considering the order of application., (© Japan College of Rheumatology 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare type of idiopathic interstitial pneumonia, which is characterised by pleural fibrosis and subjacent parenchymal fibroelastosis of the upper lobes. Herein, we present a case of microscopic polyangiitis (MPA) following PPFE. The patient had abnormal shadows on chest radiographs 15 years before the onset of MPA, and the patient was diagnosed with PPFE. Four years after the PPFE diagnosis, the patient was diagnosed with MPA based on persistent fever, purpura, mononeuritis multiplex, myeloperoxidase-antineutrophil cytoplasmic antibody positivity, and pathological findings of peritubular capillaritis on kidney biopsy. The patient was treated with glucocorticoids, including methylprednisolone pulse therapy and rituximab, followed by maintenance therapy with rituximab. One year after treatment, the PPFE had not worsened. PPFE occasionally occurs secondary to connective tissue disease, including MPA; however, to the best of our knowledge, this is the first report of PPFE preceding MPA. Our case suggests that PPFE, as other interstitial lung diseases, may be associated with MPA and precede the onset of MPA. The accumulation of more cases is needed to clarify the characteristics of MPA-associated PPFE., (© Japan College of Rheumatology 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Rationale: Immune system deregulation, including AAV, is a key event that may potentially evolve into ESRD. Abnormal activation of the cAP is also a cardinal feature of TMA, particularly aHUS. The kidney is the most frequently involved organ, and renal-limited forms of TMA are often encountered in clinical practice. Isolated case reports described the occurrence of renal TMA in AAV patients. Some cases of both de novo and relapses of AAV and/or TMAs after anti-SARS-CoV2 vaccination have been reported. We reported, for the 1st time, a case of patients with new-onset MPA and aHUS occurring 3 weeks after the third dose of mRNA-1273 vaccine anti-SARS-CoV2., Patient Concerns: We present a 67-year-old man, affected by arterial hypertension, reported, after mRNA-1273 vaccine anti-SARS-CoV2, anuria, fatigue, anorexia and nausea. Laboratory data revealed acute renal failure., Diagnosis: Positivity of MPO-ANCA was observed. 7 days after admission, we observed a worsening of anemia and thrombocytopenia with haptoglobin reduction, LDH increase and presence of schistocytes. Plasma levels of ADAMTS-13 were normal. A renal biopsy was performed, and findings were consistent with microscopic polyangiitis, with features of micro-thrombotic glomerulopathy. Genetic tests revealed absence of hybrid genes associated with the increased risk of aHUS., Interventions and Outcomes: We started renal replacement treatment, including hemodialysis, and pulsed methylprednisolone, with no improvement of laboratory parameters. Then, plasma exchange was performed leading to partial haematological response. Only with Eculizumab, a human C5 inhibitor, we observed a normalization of haptoglobin levels and platelets' count. However, three months after discharge, the patient still required hemodialysis., Lessons: To our knowledge we observed the first case aHUS, without genetic predisposition, associated with MPA occurring after the third dose of anti-SARS-CoV2 vaccine. This case report highlights the potential link between anti-SARS-CoV2 vaccine as a trigger of MPA and aHUS. This systematic review offers additional perspectives. It is plausible to hypothesize that the vaccine was the trigger for the development of these 2 diseases.Solid evidence on the mechanisms of interaction between vaccine and immune system, the role of genetic predisposition, and other variables, will shed additional light on the controversial link between anti-SARS-CoV2 vaccine and autoimmunity., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The association between pulmonary involvement and microscopic polyangiitis (MPA) has been increasingly recognized in recent years. Whether interstitial lung disease (ILD) and bronchiectasis (BE) are disease manifestations of MPA, preexisting comorbidities or important complications remains unclear. The purpose of this study was to determine the clinical characteristics and prognosis of MPA with pulmonary involvement to further guide clinical management., Methods: The data for 97 patients with a definitive diagnosis of MPA were retrospectively reviewed. The MPA diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria. The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis., Results: Forty-seven out of the 97 (48.5%) patients who were diagnosed with MPA presented with pulmonary involvement, including 37 patients with ILD, 12 patients with BE and two patients with diffuse alveolar haemorrhage (DAH). ILD and BE antedated MPA in 56.76% and 75.00% of the patients, respectively. Compared with that in the MPA-BE group, the serum LDH level (222.86 ± 68.19 vs. 171.58 ± 31.43, p  = .016) in the MPA-ILD group was significantly higher. In the multivariate Cox analysis, elevated serum creatinine (HR 4.08, confidence interval (CI) 1.38-12.05, p  = .011) was an independent risk factor for shorter survival in MPA patients with pulmonary involvement, and treatment with glucocorticoid pulse cyclophosphamide therapy (HR 0.095, 95% CI 0.019-0.47, p  = .004) was independently associated with prolonged survival. Among the patients in the MPA-ILD group, acute exacerbations of ILD (HR 4.55 CI 1.16-17.86, p  = .029) and elevated serum creatinine (HR 4.95, CI 1.39-17.54, p  = .014) were independently associated with a poor prognosis, and treatment with glucocorticoids (HR 0.057, 95% CI 0.012-0.28, p  < .001) was independently associated with significant prolongation of survival., Conclusions: Patients with MPA have a high prevalence of pulmonary involvement, and ILD is the most common subtype of MPA. ILD and BE can be considered preexisting comorbidities of MPA. Elevated serum creatinine was associated with shorter survival. However, remission induction regimens with glucocorticoids and/or immunosuppressants may improve this outcome.

Background: The pulmonary involvement in patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) is well known at disease onset but data during follow-up (after the induction regimen and when the first relapse occurs) are limited. Our goal was to analyze chest high-resolution computed tomography (HRCT) findings of (ANCA)-associated vasculitis patients., Method: All consecutive unselected AAV patients over eighteen with positive ANCA status and with HRCT chest performed at the diagnosis were retrospectively enrolled between 2004 and 2019 at the Toulouse University Hospital (France). Two experienced pulmonologists and one expert respiratory radiologist reviewed independently HRCT chest scans., Results: A total of 157 AAV patients were included in the study. Two-thirds of AAV patients had pulmonary involvement at diagnosis. Diffuse alveolar hemorrhage (DAH) was observed in 31.2 % of cases, nodules and masses in 18.5 %, bronchial airway involvement in 13.4 %, and interstitial involvement in 12.7 %. Following the induction regimen, chest HRCT scans over a two-year period demonstrated significant improvement in DAH and nodular manifestations, whereas bronchial airway involvement exhibited variability and half of cases of interstitial lung disease (ILD) had progressive course. Outcomes and survival rates are better for nodular and bronchial involvement. DAH was the most frequent cause of deaths. Progressive fibrotic changes in ILD over time could impact prognosis despite AAV remission., Conclusion: Employing a pattern-based approach with HRCT chest scans to assess lung involvement could be valuable in predicting treatment response, relapse, mortality, and could improved the management of AAV patients., Competing Interests: Declaration of Competing Interest TV has received consulting fees from Boeringer Ingelheim. SF has received consulting fees for Abionyx, Pharma, CSL-Vifor, Sanofi-Genzyme, Novartis SA, Alexion, Baxter. GPr, GPu and SC have nothing to disclose., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: This study examined the relationship between age at diagnosis and disease characteristics and damage in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)., Methods: Analysis of a prospective longitudinal cohort of patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic GPA (EGPA) in the Vasculitis Clinical Research Consortium (2013-2021). Disease cohorts were divided by age at diagnosis (years): children (<18), young adults (18-40), middle-aged adults (41-65), and older adults (>65). Data included demographics, ANCA type, clinical characteristics, Vasculitis Damage Index (VDI) scores, ANCA Vasculitis Index of Damage (AVID) scores, and novel disease-specific and non-disease-specific damage scores built from VDI and AVID items., Results: Analysis included data from 1020 patients with GPA/MPA and 357 with EGPA. Female predominance in GPA/MPA decreased with age at diagnosis. AAV in childhood was more often GPA and proteinase 3-ANCA positive. Children with GPA/MPA experienced more subglottic stenosis and alveolar hemorrhage; children and young adults with EGPA experienced more alveolar hemorrhage, need for intubation, and gastrointestinal involvement. Older adults (GPA/MPA) had more neurologic manifestations. After adjusting for disease duration, medications, tobacco, and ANCA, all damage scores increased with age at diagnosis for GPA/MPA (P < 0.001) except the disease-specific damage score, which did not differ (P = 0.44). For EGPA, VDI scores increased with age at diagnosis (P < 0.009), whereas all other scores were not significantly different., Conclusion: Age at diagnosis is associated with clinical characteristics in AAV. Although VDI and AVID scores increase with age at diagnosis, this is driven by non-disease-specific damage items., (© 2023 American College of Rheumatology.)

This study aimed to evaluate the risk factors for end-stage renal disease (ESRD) in microscopic polyangiitis (MPA). In total, 74 patients with MPA were enrolled, and we compared the baseline clinical characteristics and disease activity between MPA patients who have progressed to ESRD and those without ESRD to select predictive factors for ESRD. Out of 74 patients, 12 patients (16.2%) had ESRD during follow-up. Serum C4 levels were significantly higher in MPA patients who have progressed to ESRD than in those without ESRD ( p = 0.009). Multivariate analyses revealed that high serum creatinine levels (odds ratio (OR) 4.4, 95% confidence interval (CI) 1.25-15.5) and high serum C4 levels (OR 1.24, 95% CI 1.03-1.49) were risk factors for ESRD. Using receiver operating characteristic analysis, the cut-off value for initial serum C4 levels and serum creatinine levels were 29.6 mg/dL and 3.54 mg/dL, respectively. Patients with MPA with a greater number of risk factors (serum C4 levels > 29.6 mg/dL and serum creatinine levels > 3.54 mg/dL) had a higher ESRD progression rate. Serum C4 levels were significantly positively correlated with serum creatinine levels and kidney Birmingham vasculitis activity score ( p = 0.02 and 0.04, respectively). These results suggest that serum C4 levels are useful tools for assessing renal disease activity and prognosis in MPA.

Objective: To clarify seasonal and other environmental effects on the onset of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)., Methods: We enrolled patients with new-onset eosinophilic granulomatosis with polyangiitis (EGPA), microscopic polyangiitis (MPA), and granulomatosis with polyangiitis (GPA) registered in the database of a Japanese multicenter cohort study. We investigated the relationship between environmental factors and clinical characteristics. Seasons were divided into 4 (spring, summer, autumn, and winter), and the seasonal differences in AAV onset were analyzed using Pearson chi-square test, with an expected probability of 25% for each season., Results: A total of 454 patients were enrolled, with a mean age of 70.9 years and a female proportion of 55.5%. Overall, 74, 291, and 89 patients were classified as having EGPA, MPA, and GPA, respectively. Positivity for myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA was observed in 355 and 46 patients, respectively. Overall, the seasonality of AAV onset significantly deviated from the expected 25% for each season ( P = 0.001), and its onset was less frequently observed in autumn. In ANCA serotypes, seasonality was significant in patients with MPO-ANCA ( P < 0.001), but not in those with PR3-ANCA ( P = 0.97). Additionally, rural residency of patients with AAV was associated with PR3-ANCA positivity and biopsy-proven pulmonary vasculitis., Conclusion: The onset of AAV was influenced by seasonal variations and was less frequently observed in autumn. In contrast, the occurrence of PR3-ANCA was triggered, not by season, but by rural residency., (Copyright © 2023 by the Journal of Rheumatology.)

Competing Interests: Competing interests: None declared.

Objectives: ANCA-associated vasculitis (AAV) is a group of multisystem diseases that can have several ocular manifestations. There are published data on ocular manifestations of granulomatosis with polyangiitis (GPA), but few for eosinophilic granulomatosis with polyangiitis (EGPA) or microscopic polyangiitis (MPA). There is little information concerning chronicity, complications, and association with other cranial manifestations of AAV., Methods: This study retrospectively analysed longitudinal multicentre cohorts of individuals with AAV followed between 2006 and 2022. Data included diagnosis, demographics, cranial manifestations of disease, presence of manifestations at onset of disease and/or follow-up, and ocular complications of disease. Univariate and multivariable logistic regression analysis assessed associations across disease manifestations., Results: Data from 1441 patients were analysed, including 395 with EGPA, 876 with GPA, and 170 with MPA. Ocular manifestations were seen within 23.1% of patients: 39 (9.9%) with EGPA, 287 (32.7%) with GPA, and 12 (7.1%) with MPA at any time in the disease course. There were more ocular manifestations at onset (n = 224) than during follow-up (n = 120). The most common disease-related manifestations were conjunctivitis/episcleritis and scleritis. In multivariable analysis, dacryocystitis, lacrimal duct obstruction, and retro-orbital disease were associated with sinonasal manifestations of GPA; ocular manifestations were associated with hearing loss in MPA. The most common ocular complications and/or damage seen were cataracts (n = 168) and visual impairment (n = 195)., Conclusion: Ocular manifestations occur in all forms of AAV, especially in GPA. Clinicians should be mindful of the wide spectrum of ocular disease in AAV, caused by active vasculitis, disease-associated damage, and toxicities of therapy., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Despite newer treatments with immunosuppressive agents, there still exists a considerable morbidity and mortality risk among patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Since 1994 the European Vasculitis Society (EUVAS) has aimed for an improved outcome for patients with AAV, conducting several prospective randomized controlled trials (RCTs). The aim for the present study was to further evaluate the long-term survival of patients with AAV included in seven RCTs conducted by the EUVAS as well as to identify potential prognostic factors., Methods: Long-term follow-up data were collected from questionnaires sent to the principal investigators of the original RCTs (1995-2012): MEPEX, NORAM, CYCAZAREM, CYCLOPS, IMPROVE, RITUXVAS and MYCYC, comprising 848 patients, all newly diagnosed with AAV. Relative survival estimates are presented for the study cohorts. Demographic, clinical and laboratory characteristics at trial entry were studied as potential prognostic factors in multivariable models., Results: A total of 478 (56%) patients had granulomatosis with polyangiitis (GPA) and 370 (44%) had microscopic polyangiitis (MPA) with a mean age at diagnosis of 58 ± 14 years. The median follow-up time was 8 years (interquartile range 2.9-13.6). During the observation period there were 305 deaths and the main causes were infections (26%), cardiovascular disease (14%) and malignancies (13%). When compared with a matched cohort (regarding country, age group and sex) from the background population there were 14.2% more deaths among our cohort of AAV patients at 5 years, 19.9% at 10 years, 28.8% at 15 years and 36.3% at 20 years. The excess mortality occurred in all age groups. The estimated median survival time (from diagnosis) was 17.8 years (95% confidence interval 15.7-20). Among variables measured at baseline, advanced age, male sex, low estimated glomerular filtration rate and low platelet count were identified as predictors of death in a multivariate Cox model., Conclusions: Patients with AAV still have an increased risk of mortality compared with the general population despite newer therapeutic regimens. Treatment complications and organ damage are the main causes of limited survival and infections remain the leading cause of mortality among patients with AAV., (© The Author(s) 2023. Published by Oxford University Press on behalf of the ERA.)

To the best of our knowledge, systemic sclerosis with overlapping characteristics of both microscopic polyangiitis and giant cell arteritis (i.e. microscopic polyangiitis involving the superficial temporal artery or giant cell arteritis with myeloperoxidase anti-neutrophil cytoplasmic antibody seropositivity) has not been reported previously. An 82-year-old woman with diffuse cutaneous systemic sclerosis experienced dyspnoea on exertion and fever. No signs of infection were observed on computed tomography. Her fever persisted despite antibiotic treatment for occult bacterial infection and secondary Clostridioides difficile-associated diarrhoea. Microscopic polyangiitis was suspected because of myeloperoxidase anti-neutrophil cytoplasmic antibody seropositivity, and giant cell arteritis was suspected as a differential diagnosis due to swelling of the superficial temporal artery. Arterial biopsy revealed inflammatory cell infiltration with granuloma formation. Based on the presence of granulomatous inflammation in the superficial temporal artery, we concluded that giant cell arteritis with myeloperoxidase anti-neutrophil cytoplasmic antibody seropositivity occurred as a complication. After glucocorticoid therapy, her fever and dyspnoea on exertion improved with a gradual decline in the serum myeloperoxidase anti-neutrophil cytoplasmic antibody levels. It is possible that vasculitis occurs as a complication in patients with systemic sclerosis in cases where the fever persists and cannot be explained by systemic sclerosis itself, infectious disease, or malignancy. Clinicians must be careful not to prematurely diagnose microscopic polyangiitis based on myeloperoxidase anti-neutrophil cytoplasmic antibody seropositivity or giant cell arteritis based on the swelling of the superficial temporal artery. Careful evaluation of the presence of granulomatous inflammation in an arterial biopsy specimen is essential to differentiate between microscopic polyangiitis and giant cell arteritis., (© Japan College of Rheumatology 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Because of some similarities in organ involvement, clinical manifestations, and histopathological features, IgG4-related disease (IgG4-RD) may occur concurrently with some clinicopathologic variants of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). An overlap syndrome of IgG4-RD and AAV has recently been proposed in clinical and/or histopathological studies, indicating that there may be some potential pathophysiological associations between the two disease entities; however, the mechanisms underlying these are incompletely understood. Here, we describe a rare case of a 63-year-old man with IgG4-related tubulointerstitial nephritis (IgG4-TIN) and microscopic polyangiitis-associated glomerulonephritis (MPA-GN) overlap syndrome. The clinical diagnosis of MPA was based on the 2022 American College of Rheumatology (ACR)/European League Against Rheumatology (EULAR) classification criteria. Remission induction therapy with intravenous methylprednisolone was initiated, followed by oral prednisone maintenance therapy with gradual tapering. The patient remained asymptomatic and his renal function was essentially normalized within 3.5 months of follow-up. The serum IgG4 levels decreased to 5 g/L. We also conducted a literature review to identify clinical findings, treatment options, and outcomes of patients with concurrent IgG4-RD and MPA and briefly discussed the potential pathophysiological association between IgG4-RD and MPA. Our findings enrich the database of this rare overlap syndrome and provide a basis for the diagnosis and early intervention in both diseases. These results provide some insights for clinicians to recognize and treat this overlap syndrome., (© 2022. The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR).)

Objectives: Interstitial lung disease (ILD) has been described as a possible pulmonary involvement in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV), mainly granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). Aim of this cross-sectional Italian national study was to describe demographic, clinical and serological profile of ILD related to MPA and GPA and investigate possible correlations between radiologic patterns of ILD and vasculitis features., Methods: We enrolled 95 consecutive patients with AAV-ILD, 56 affected by MPA (58.9%) and 39 by GPA (41.1%)., Results: NSIP was the most frequently detected ILD pattern, observed in c-ANCA patients in 60.9% of cases, followed by UIP pattern mainly observed in p-ANCA patients (47.7%, p=0.03). ILD represented the first clinical manifestation, preceding vasculitis diagnosis in 22.1% of cases and, globally, ILD was already detectable at AAV diagnosis in 66.3% of patients. The diagnosis of ILD preceded that of AAV in 85.7% of p-ANCA positive-patients, while only one patient with c-ANCA developed ILD before AAV (p= 0.039). Multivariate analysis confirmed the correlation of UIP pattern with p-ANCA-positivity and a diagnosis of ILD before AAV, also when adjusted for age and sex., Conclusions: Our study confirms that UIP is a frequent pattern of lung disease in AAVILD patients. Our results also suggest that ILD can represent an early complication of AAV but also occur in the course of the disease, suggesting the need of a careful evaluation by both pulmonologist and rheumatologist to achieve an early diagnosis. Further prospective studies are needed to define ILD prevalence and evolution in AAV patients.

Background: Microscopic polyangiitis (MPA), a kind of antineutrophil cytoplasmic autoantibody associated vasculitis (AAV), predominantly affects small-sized vessels. MPA is a significant cause of the pulmonary-renal syndrome. Pauci-immune necrotizing and crescentic glomerulonephritis is the typical renal histological feature of AAV. Tubulointerstitial lesions may occur and mostly form with inflammatory cell infiltration in the interstitium. However, a few cases reported only tubulointerstitial involvement without glomerular lesions in patients with MPA., Case Presentation: We present an MPA case, a 70-year-old male patient diagnosed with acute kidney injury accompanying the dialysis requirement. Only acute tubulointerstitial nephritis was revealed in kidney biopsy without evidence of glomerular injury. Also, interstitial pulmonary fibrosis was determined on computerized tomography, and myeloperoxidase antineutrophil cytoplasmic autoantibody was positive. Consequently, we have considered the main diagnosis as MPA. We did not prefer a standard tubulointerstitial nephritis treatment regimen due to the presence of life-threatening systemic vasculitis. Treatment was established like crescentic glomerulonephritis. Induction therapy consisted of pulse steroid, cyclophosphamide, and plasmapheresis. Unfortunately, severe SARS-CoV-2 infection caused death during induction therapy in this case., Conclusions: The lack of glomerular injury and solely interstitial inflammation is atypical regarding AAV involvement in the kidney. This diversity might be initially considered as only a simple histological elaboration. However, it is a significant entity for guiding the treatment of AAV., (© 2023. The Author(s).)