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Background Light chain proximal tubulopathy (LCPT) is a rare form of paraprotein-related disease, occurring in two main histopathological forms; crystalline and non-crystalline. The clinicopathological features, treatment strategies and outcomes, especially of the non-crystalline form, are not well described. Methods Single-centre retrospective case series of 12 LCPT patients, 5 crystalline and 7 non-crystalline, between 2005-2021. Observations Median age was 69.5 years (range, 47-80). 10 patients presented with CKD and significant proteinuria (median eGFR of 43.5 ml/min/1.73m2; uPCR 328 mg/mmol). Only 6 patients had known haematological disease at the time of renal biopsy. Multiple myeloma (MM) was diagnosed in 7 cases and MGRS in 5. A clone was detected in all cases combining serum/urine electrophoresis and free LC assays. Crystalline and non-crystalline variants had similar clinical presentations. For the non-crystalline variant, a diagnosis was reached based on combination of CKD without other cause, haematological work-up, LC restriction on IF and abnormalities on EM. Nine of 12 patients received clone-directed treatment. Patients who achieved haematological response (including all non-crystalline LCPT) had improved renal outcomes over a median follow-up of 79 months. Conclusions The non-crystalline variant may go unrecognised because of its subtle histopathological features and requires EM to distinguish it from “excessive LC resorption without tubular injury”. Clone-directed treatment with good haematological response improves renal outcomes in both variants but limited data exist in MGRS. Multi-centre prospective studies are needed to better define the clinico-pathological characteristics associated with poor outcomes and optimize treatment strategies in patients with MGRS.

Aim Alport syndrome (AS) is the second most common hereditary kidney disease caused by mutations in collagen IV genes. Patients present with microhaematuria that progressively leads to proteinuria and end stage renal disease. Currently, no specific treatment exists for AS. Using mass spectrometry based proteomics, we aimed to detect early alterations in molecular pathways implicated in AS before the stage of overt proteinuria, which could be amenable to therapeutic intervention. Methods Kidneys were harvested from male Col4a3 −/− knock out and sex and age‐matched Col4a3 +/+ wild‐type mice at 4 weeks of age. Purified peptides were separated by liquid chromatography and analysed by high resolution mass spectrometry. The Cytoscape bioinformatics tool was used for function enrichment and pathway analysis. PPARα expression levels were evaluated by immunofluorescence and immunoblotting. Results Proteomic analysis identified 415 significantly differentially expressed proteins, which were mainly involved in metabolic and cellular processes, the extracellular matrix, binding and catalytic activity. Pathway enrichment analysis revealed among others, downregulation of the proteasome and PPAR pathways. PPARα protein expression levels were observed to be downregulated in Alport mice, supporting further the results of the discovery proteomics. Conclusion This study provides additional evidence that alterations in proteins which participate in cellular metabolism and mitochondrial homeostasis in kidney cells are early events in the development of chronic kidney disease in AS. Of note is the dysregulation of the PPAR pathway, which is amenable to therapeutic intervention and provides a new potential target for therapy in AS., SUMMARY AT A GLANCE Alterations in proteins which participate in cellular metabolism and mitochondrial homeostasis in kidney cells, are early events in the development of CKD in Alport syndrome. In addition, pathway enrichment analysis revealed among others, dysregulation of the proteasome, protein digestion and absorption pathways as well as PPAR pathway in AS compared to control mice. Targeting the PPAR pathway could be a potential therapeutic approach in AS.

Aim: Fibrates have proven efficacy in cardiovascular risk reduction and are commonly used, in addition to statins, to control hypertriglyceridaemia. Their use is often limited due to reduction in glomerular filtration rate at treatment initiation. However, recent studies suggest benign changes in kidney function and improvement of proteinuria, an established early marker of microvascular disease and kidney disease progression. We summarize the evidence from existing trials and provide a summary of effects of fibrates, alone or in combination, on kidney disease progression and proteinuria. Methods and Results: Systematic review and meta-analysis of randomized, controlled trials (PROSPERO CRD42020187764). Out of 12,243 potentially eligible studies, 29 were included in qualitative and quantitative analysis, with a total of 20,176 patients. Mean creatinine increased by 1.05 (95% CI (0.63 to 1.46)) units in patients receiving fibrates vs. comparator, and this was similar in all other subgroups. eGFR showed a bigger decrease in the fibrates arm (SMD −1.99; 95% CI (−3.49 to −0.48)) when all studies were pooled together. Notably, short-term serum creatinine and eGFR changes remained constant in the long-term. Pooled estimates show that fibrates improve albuminuria progression, RR 0.86; 95% CI (0.76 to 0.98); albuminuria regression, RR 1.19; 95% CI (1.08 to 1.310). Conclusions: Fibrates improve albuminuria in patients with and without diabetes when used to treat hyperlipidaemia. The modest creatinine increase should not be a limiting factor for fibrate initiation in people with preserved renal function or mild CKD. The long-term effects on kidney disease progression warrant further study.

Cryoglobulins (CGs) are immunoglobulins that precipitate at temperatures below 37 °C and dissolve again after rewarming. Cryoglobulinemia may be asymptomatic or cause end-organ damage by CG precipitation in small- to medium-sized blood vessels.1 In their seminal work, Brouet et al.2 classify cryoglobulinemias into 3 subgroups according to CG composition and clonality. In type II cryoglobulinemia there is a mixture of monoclonal IgM with rheumatoid factor activity and polyclonal IgG. In type III, CGs consist of polyclonal IgM and IgG.1 Type II and III cryoglobulinemias are also referred to as mixed cryoglobulinemias and are often caused by chronic hepatitis C infection and less frequently by autoimmune diseases or other viral infections (hepatitis B infection, HIV).3 CGs in type I cryoglobulinemia are monoclonal Igs (MIg), also known as paraproteins, commonly IgG, IgM subtypes, or free light chains. The underlying pathological process is a plasma cell or B-cell lymphoproliferative disease, such as multiple myeloma (MM), Waldenstrom macroglobulinemia, chronic lymphocytic leukemia, or other B-cell non-Hodgkin lymphoma. However, in approximately 40% of symptomatic cases, the plasma cell or B-cell clone is too small to fulfill the diagnostic criteria of MM or overt lymphoma. The term monoclonal gammopathy of undetermined significance (MGUS) used for these cases is a misnomer, as the MIg causes disease regardless of the size and tumor burden.4 For cases with renal involvement, the International Kidney and Monoclonal Gammopathy Research Group introduced the term monoclonal gammopathies of renal significance (MGRS).5 The updated MGRS definition includes monoclonal gammopathies that cause renal disease but have low tumor burden and thus treatment from the hematological standpoint is not imminently indicated.6 These patients may have fewer than 10% plasma cells in bone marrow biopsy, smoldering myeloma, or low-grade lymphomas.7 MGRSs are not of undetermined significance, and their relevance to renal pathology has opened the use of clone-directed therapies targeting the nephrotoxic MIg-producing clone, with an aim to preserve renal function.8 Retrospective studies to date suggest that clone-directed therapy improves renal outcomes.9 MGRS encompasses a wide spectrum of renal histopathological entities caused by a nephrotoxic MIg, including ever rarer subtypes such as type I cryoglobulinemic glomerulonephritis.S1,S2 Historically, MGRS may have gone underdiagnosed and patients not offered optimal treatment, unlike their counterparts fulfilling consensus myeloma or lymphoma diagnostic criteria.S3 Here, we report a case of severe type I crystal cryoglobulinemic glomerulonephritis caused by MGRS, for which treatment with myeloma induction therapy and autologous stem cell transplantation (ASCT) induced long-lasting complete hematological response and renal function preservation.

Background Non-invasive cardiovascular disease (CVD) risk prediction, in subclinical stages, aiming to stratify patients and tailor interventions remains an unmet need in chronic kidney disease (CKD). In this meta-analysis, we summarize the association of carotid intima–media thickness (cIMT), coronary artery calcium score (CACS) and pulse wave velocity (PWV) with all-cause mortality, cardiovascular (CV) mortality and CV events in non-dialysis CKD and patients on haemodialysis. Methods Systematic review and meta-analysis of prospective cohort studies. Results Out of 27 984 records, a total of 45 studies were eligible for quantitative synthesis; 11 for cIMT, 18 for CACS and 16 for PWV involving 2235, 4904 and 5717 patients, respectively. Meta-analysis was possible from pooled data of five cIMT studies (708 subjects), eight CACS studies (862 subjects) and nine PWV studies (1508 subjects). In dialysis patients, cIMT was associated with all-cause mortality [relative risk (RR) per unit increase: 1.08, 95% confidence interval (CI) 1.00–1.17, I2: 68%] and CV mortality (RR: 1.29, 95% CI 1.14–1.47, I2: 0%). High versus low CACS was associated with all-cause mortality (RR: 2.51, 95% CI 1.66–3.79, I2: 5.7%) and CV events (RR: 3.77 95% CI 2.16–6.58, I2: 20.2%). High versus low PWV was associated with all-cause (RR: 5.34, 95% CI 3.01–9.47, I2: 0%) and CV mortality (RR: 8.55, 95% CI 4.37–16.73, I2: 0%). The combined estimated for all-cause mortality per 1 m/s increment unit in PWV was 1.25 (95% CI 1.17–1.34, I2: 0%) and for CV mortality was 1.24 (95% CI 1.16–1.34, I2: 15.5%). In non-dialysis patients, CACS was associated with CV events (RR: 4.02, 95% CI 1.57–10.29, I2: 63.4%). High versus low PWV was associated with all-cause mortality (RR: 2.52, 95% CI 1.40–4.55, I2: 62.6%). Conclusions Non-invasive measures of atherosclerosis and arterial stiffening are associated with all-cause and CV mortality as well as CV events among patients with all stages of CKD. These markers could be considered for the evaluation of CV morbidity and mortality risks. Moreover, the results of this meta-analysis support the study of interventions, with effect on these markers of vascular disease, on long-term CVD outcomes.

Monoclonal Gammopathy of Renal Significance (MGRS) encompasses a wide spectrum of histopathology. Characterizing rare forms of MGRS-related renal pathology remains work in progress. Light chain crystalline podocytopathy in the context of MGRS, either in isolation or combined with proximal tubulopathy (LCPT) has rarely been described. Unravelling MGRS pathologies is critical for patient management and often requires ancillary techniques for antigen retrieval to demonstrate light chain (LC) restriction on immunofluorescence (IF).

Introduction There are limited data pertaining to comparative outcomes of remaining on dialysis versus kidney transplantation as the threat of coronavirus disease 2019 (COVID-19) remains. In this study we delineate the differential risks involved using serologic methods to help define exposure rates. Methods From a cohort of 1433 patients with end-stage kidney disease (ESKD), we analyzed COVID-19 infection rates and outcomes in 299 waitlist patients compared with 237 transplant recipients within their first year post-transplant. Patients were followed over a 68-day period from the time our transplant program closed due to COVID-19. Results The overall mortality rates in waitlist and transplant populations were equivalent (P = 0.69). However, COVID-19 infection was more commonly diagnosed in the waitlist patients (P = 0.001), who were more likely to be tested by reverse transcriptase polymerase chain reaction (P = 0.0004). Once infection was confirmed, mortality risk was higher in the transplant patients (P = 0.015). The seroprevalence in dialysis and transplant patients with undetected infection was 18.3% and 4.6%, respectively (P = 0.0001). After adjusting for potential screening bias, the relative risk of death after a diagnosis of COVID-19 remained higher in transplant recipients (hazard ratio = 3.36 [95% confidence interval = 1.19–9.50], P = 0.022). Conclusions Although COVID-19 infection was more common in the waitlist patients, a higher COVID-19‒associated mortality rate was seen in the transplant recipients, resulting in comparable overall mortality rates.

Background/Objectives: Fibrates reduce cardiovascular risk in the general population and in patients with chronic kidney disease (CKD). Although, they are commonly used as second-line agents in addition to statins for hypertriglyceridemia, their use in CKD is limited due to a decrease of glomerular filtration rate (GFR) at treatment initiation. This change in GFR is reversible with fibrate discontinuation. Importantly, randomised control trials with fibrate treatment have demonstrated reduction in proteinuria and benefit for microvascular diabetic complications. In addition, a number of experimental studies have shown nephroprotective effects with fibrates through attenuation of renal fibrosis and inflammation. Thus, the effect of fibrates on renal outcomes remains undetermined. The objective of this systematic review is to summarize the evidence from randomised controlled studies and provide pooled estimates on the effect of fibrates on short- and long-term renal outcomes. Methods/Design: The study will be contacted according to the Cochrane Collaboration principles for Systematic reviews. We will include randomised trials comparing fibrate to placebo or studies comparing the addition of fibrate on statin versus statin alone and reporting on the short- and long-term effects on renal function, CKD progression and proteinuria. We will examine studies including patients with established CKD and those studies including patients at risk of developing CKD, separately. A comprehensive summary of the evidence will be reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Data from included studies suitable for metanalysis will be analyses accordingly to provide quantitative estimates using a random effects model. The Cochrane Collaboration tool for assessing the risk of bias in randomized clinical trials will be utilised. The quality of the evidence from included studies will be addressed descriptively using GRADE (Grading of Recommendations, Assessment, Development and Evaluations).Discussion: The results of this systematic review will be informative for clinicians. A summary of high-level evidence with robust estimates of the effect of fibrates on safety and renal outcomes may be used to inform clinical practice guideline development for dyslipidaemias and primary and secondary prevention of CVD. Systematic review registration: PROSPERO CRD42020187764

Validated tools to improve cardiovascular disease (CVD) risk assessment and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) are lacking. Noninvasive measures of arteriosclerosis and subclinical atherosclerosis such as pulse wave velocity (PWV) and carotid intima-media thickness (cIMT), respectively, have emerged as promising risk stratification tools and potential modifiable biomarkers. Their wide use as surrogate markers in clinical research studies is based on the strong pathophysiological links with CVD. However, whether their effect as risk stratification or intervention targets is superior to established clinical approaches is uncertain. In this review, we examine the evidence on the utility of PWV, cIMT, and plaque assessment in routine practice and highlight unanswered questions from the clinician's perspective.Electronic databases PubMed and Google Scholar were searched until February 2020.This narrative review is based on peer-reviewed meta-analyses, national and international societies' guidelines, and on focused critical review of recent original studies and landmark studies in the field.Although patients with CKD are considered in the high-risk CVD groups, there is still need for tools to improve risk stratification and individualized management strategies within this group of patients. Carotid intima-media thickness is associated with all-cause mortality, CVD mortality, and events in CKD and hemodialysis cohorts. However, the evidence that measurement of cIMT has a clinically meaningful role over and above existing risk scores and management strategies is limited. Plaque assessment is a better predictor than cIMT in non-CKD populations and it has been incorporated in recent nonrenal-specific guidelines. In the CKD population, one large observational study provided evidence for a potential role of plaque assessment in CKD similar to the non-CKD studies; however, whether it improves prediction and outcomes in CKD is largely understudied. Pulse wave velocity as a marker of arterial stiffness has a strong pathophysiological link with CVD in CKD and numerous observational studies demonstrated associations with increased cardiovascular risk. However, PWV did not improve CVD reclassification of dialysis patients when added to common risk factors in a reanalysis of ESRD cohorts with available PWV data. Therapeutic strategies to regress PWV, independently from blood pressure reduction, have not been studied in well-conducted randomized trials.This study provides a comprehensive review based on extensive literature search and critical appraisal of included studies. Nevertheless, formal systematic literature review and quality assessment were not performed and the possibility of selection bias cannot be excluded.Larger, prospective, randomized studies with homogeneous approach, designed to answer specific clinical questions and taking into consideration special characteristics of CKD and dialysis, are needed to study the potentially beneficial role of cIMT/plaque assessment and PWV in routine practice.Les outils validés pour faciliter l’évaluation des risques de maladies cardiovasculaires (MCV) et de mortalité chez les patients atteints d’insuffisance rénale terminale (IRT) sont insuffisants. Les mesures non invasives de l’artériosclérose et de l’artériosclérose infraclinique, respectivement la vitesse de l’onde de pouls (VOP) et la mesure de l’épaisseur intima-média de la carotide (EIMc), sont apparues comme des outils prometteurs de stratification des risques et des biomarqueurs potentiellement modifiables. L’usage répandu de la VOP et de l’EIMc comme marqueurs de substitution dans les études cliniques est fondé sur leurs liens physiopathologiques étroits avec les MCV. On ignore toutefois si leur effet pour la stratification des risques ou comme cibles d’intervention est supérieur aux approches cliniques établies. Cette revue examine les données probantes sur la pertinence des mesures de VOP et d’EIMc et de l’analyse plaquettaire dans les pratiques courantes et met en lumière les questions sans réponses du point de vue du clinicien.Les bases de données PubMed et Google Scholar ont été consultées jusqu’en février 2020.Cette revue narrative est fondée sur des méta-analyses révisées par les pairs, sur les lignes directrices de sociétés nationales et internationales et sur un examen critique et ciblé des études originales récentes et d’études phares dans le domaine.Bien que les patients atteints d’IRT fassent déjà partie des groupes présentant un risque élevé de MCV, l’ajout d’outils pour améliorer la stratification des risques et de stratégies de gestion individualisées est toujours nécessaire pour ce groupe de patients. L’EIMc est associée à la mortalité toutes causes, ainsi qu’aux risques d’événements cardiovasculaires et de mortalité liée aux MCV dans les cohortes de patients atteints d’IRT et hémodialysés. Les preuves soutenant un rôle cliniquement significatif de la mesure de l’EMIc au-delà des scores de risque et des stratégies de gestion existantes sont toutefois limitées. L’analyse plaquettaire s’avère un meilleur prédicteur que l’EIMc dans les populations non atteintes d’IRT et a récemment été intégrée aux lignes directrices non liées aux maladies rénales. Dans les populations atteintes d’IRT, une vaste étude observationnelle a fourni des preuves quant à un possible rôle de l’analyse plaquettaire similaire à celui rapporté dans les études ne portant pas sur des patients atteints d’IRT. Cependant, la question de savoir si cette mesure améliore la prédiction et les résultats des patients atteints d’IRT demeure largement sous-étudiée. La VOP, à titre de marqueur de la rigidité artérielle, a un lien physiopathologique fort avec les MCV en contexte d’IRT, plusieurs études observationnelles ayant démontré des associations avec un risque accru d’événements cardiovasculaires. Par contre, la VOP n’a pas amélioré le reclassement cardiovasculaire des patients dialysés lorsqu’on l’a ajoutée aux facteurs de risques communs dans une nouvelle analyse des cohortes de patients atteints d’IRT disposant de données de VOP. Les stratégies thérapeutiques pour réduire la VOP, indépendamment de la pression artérielle, n’ont pas été étudiées dans le cadre d’essais à répartition aléatoire bien menés.Cette étude fournit une revue complète fondée sur une recherche documentaire approfondie et une évaluation critique des études incluses. Cependant, aucune analyse documentaire systématique formelle ou d’évaluation de la qualité n’ont été effectuées et un biais de sélection ne peut être exclu.L’étude d’un rôle potentiellement bénéfique des mesures de VOP et d’EIMc et de l’analyse plaquettaire dans la pratique courante en contexte d’IRT requiert des essais prospectifs de grande envergure avec répartition aléatoire. Ces essais devraient s’articuler autour d’une approche homogène, être conçus pour répondre à des questions cliniques spécifiques et tenir compte des caractéristiques propres aux patients atteints d’IRT et dialysés.

Background Approximately 50% of systemic lupus erythematosus (SLE) patients develop nephritis, which is among the most severe and frequent complications of the disease and a leading cause of morbidity and mortality. Despite intensive research, there are still no reliable lupus nephritis (LN) markers in clinical use that can assess renal damage and activity with a high sensitivity and specificity. To this end, the aim of this study was to identify new clinically relevant tissue-specific protein biomarkers and possible underlying molecular mechanisms associated with renal involvement in SLE, using mass spectrometry (MS)-based proteomics. Methods Kidneys were harvested from female triple congenic B6.NZMsle1/sle2/sle3 lupus mice model, and the respective sex- and age-matched C57BL/6 control mice at 12, 24 and 36 weeks of age, representing pre-symptomatic, established and end-stage LN, respectively. Proteins were extracted from kidneys, purified, reduced, alkylated and digested by trypsin. Purified peptides were separated by liquid chromatography and analysed by high-resolution MS. Data were processed by the Progenesis QIp software, and functional annotation analysis was performed using DAVID bioinformatics resources. Immunofluorescence and multiple reaction monitoring (MRM) MS methods were used to confirm prospective biomarkers in SLE mouse strains as well as human serum samples. Results Proteomic profiling of kidney tissues from SLE and control mice resulted in the identification of more than 3800 unique proteins. Pathway analysis revealed a number of dysregulated molecular pathways that may be mechanistically involved in renal pathology, including phagosome and proximal tubule bicarbonate reclamation pathways. Proteomic analysis supported by human transcriptomic data and pathway analysis revealed Coronin-1A, Ubiquitin-like protein ISG15, and Rho GDP-dissociation inhibitor 2, as potential LN biomarkers. These results were further validated in other SLE mouse strains using MRM-MS. Most importantly, experiments in humans showed that measurement of Coronin-1A in human sera using MRM-MS can segregate LN patients from SLE patients without nephritis with a high sensitivity (100%) and specificity (100%). Conclusions These preliminary findings suggest that serum Coronin-1A may serve as a promising non-invasive biomarker for LN and, upon validation in larger cohorts, may be employed in the future as a screening test for renal disease in SLE patients.

Paraproteins are intact monoclonal immunoglobulins (MIg) or isolated MIg heavy or light chains, detected in the blood or urine and caused by a clonal proliferation of B cells or plasma cells. Paraproteins often cause renal injury, referred to here as paraprotein-related renal disease (PPRD), whether the underlying clonal disorder is characterized by high tumour burden requiring treatment or low tumour burden and thus not requiring immediate treatment from the haematological standpoint. For the latter, an important recent update is the introduction of the concept of Monoclonal Gammopathy of Renal Significance (MGRS), in which the renal pathology in itself may justify the use of clone-directed therapies targeting the nephrotoxic clone, in order to preserve renal function. A bewildering array of renal pathology can be caused by paraproteins, affecting all compartments of the kidney – glomeruli, tubules, interstitium and blood vessels. This review aims to provide an overview of the different renal lesions that can be seen, organized by predominant compartment affected, with guidance on how to spot them and classify them.

Background. Cardiovascular disease (CVD) remains a significant problem in Chronic Kidney Disease (CKD). Subclinical atherosclerosis identified by noninvasive methods could improve CVD risk prediction in CKD but these methods are often unavailable. We therefore systematically reviewed whether circulating levels of Matrix Metalloproteinases (MMPs) and tissue inhibitors (TIMPs) are associated with subclinical atherosclerosis in CKD, as this would support their use as biomarkers or pharmacologic targets. Methods. All major electronic databases were systematically searched from inception until May 2015 using appropriate terms. Studies involving CKD patients with data on circulating MMPs levels and atherosclerosis were considered and subjected to quality assessment. Results. Overall, 16 studies were identified for qualitative synthesis and 9 studies were included in quantitative synthesis. MMP-2 and TIMP-1 were most frequently studied while most studies assessed carotid Intima-Media Thickness (cIMT) as a measure of subclinical atherosclerosis. Only MMP-2 demonstrated a consistent positive association with cIMT. Considerable variability in cIMT measurement methodology and poor plaque assessment was found. Conclusions. Although MMPs demonstrate great potential as biomarkers of subclinical atherosclerosis, they are understudied in CKD and not enough data existed for meta-analysis. Larger studies involving several MMPs, with more homogenized approaches in determining the atherosclerotic burden in CKD, are needed.

Advances in mass spectrometry technologies have created new opportunities for discovering novel protein biomarkers in systemic lupus erythematosus (SLE). We performed a systematic review of published reports on proteomic biomarkers identified in SLE patients using mass spectrometry‐based proteomics and highlight their potential disease association and clinical utility. Two electronic databases, MEDLINE and EMBASE, were systematically searched up to July 2015. The methodological quality of studies included in the review was performed according to Preferred Reporting Items for Systematic Reviews and Meta‐analyses guidelines. Twenty‐five studies were included in the review, identifying 241 SLE candidate proteomic biomarkers related to various aspects of the disease including disease diagnosis and activity or pinpointing specific organ involvement. Furthermore, 13 of the 25 studies validated their results for a selected number of biomarkers in an independent cohort, resulting in the validation of 28 candidate biomarkers. It is noteworthy that 11 candidate biomarkers were identified in more than one study. A significant number of potential proteomic biomarkers that are related to a number of aspects of SLE have been identified using mass spectrometry proteomic approaches. However, further studies are required to assess the utility of these biomarkers in routine clinical practice.

Complement Factor H-Related protein 5 Nephropathy (CFHR5N) is an endemic hereditary renal disease in the island of Cyprus. Although only very recently recognized, it has provided insight into previously unknown genetic aspects of complement-mediated renal diseases and in fact it has contributed to the introduction of the new disease classification, 'C3 Glomerulopathy'. Herein, based on evidence from epidemiological, genetic, clinical and basic research studies, the hypothesis that CFHR5N could be protective from rickettsial infections is proposed. Confirming this hypothesis, could have significant implications for the study of Complement Factor- H Related Proteins (CFHRs) in renal diseases and rickettsial molecular microbiology.

Background: The anti-CD52 monoclonal antibody alemtuzumab (Alem) induces a rapid-onset, profound and long-lasting depletion of lymphocytes: B cells recover within 12 months, while T cell recovery is still incomplete after 30 months. Alem is used as induction therapy for solid organ transplantations, including renal. Autoimmune complications following Alem include thyroid disorders (20-30%), immune thrombocytopenia (ITP) (2-3%), and autoimmune hemolytic anemia (AIHA) and autoimmune nephropathies (< 1%). Methods: we retrospectively analyzed 41 patients (pts) attending the Haematology Clinic at Hammersmith Hospital (HH), who developed autoimmune cytopenias (ITP or AIHA) after an Alem-induced renal transplant. The autoimmune cytopenia was defined as a rapid onset of isolated thrombocytopenia and/or anemia without other explanation. For ITP, complete response (CR) and response (R) were defined according to IWG standard criteria (Rodeghiero,Blood,2009). For AIHA, CR was defined as a stable Hb level >120 g/L, no transfusion requirement and no signs of hemolysis; partial response (PR) as a rise in Hb levels >20 g/L, without transfusion requirement. The study aim is to report clinical features and treatment outcomes of these 41 pts. Results: Between 1/11/05 and 14/12/16, 1431 pts received an Alem-induced renal transplant at HH. 34 (2.3%) developed ITP and 7 (0.48%) AIHA; 28 (68%) pts were males. Median age at renal transplant was 48 (range 20-69) years. The cytopenia developed a median of 35 months (range 6-161) after Alem administration. Median lowest platelet count was 5.5x109/L (range 0-41) and median nadir of hemoglobin (Hb) was 58 g/L (range 35-65). ITP pts: 2 pts achieved spontaneous CR. Of the remaining 32, 91% received steroids, IVIG or both as first line therapy, with an overall response rate (ORR) of 62%. 10 pts (31%) maintained the response without any further treatment. 22 pts required second line therapy, 11 required ≥ 3 lines of treatment. Treatments included: thrombopoietin receptor agonists (TPO-RA), rituximab (RTX), MMF and/or a combination. TPO-RA were used 15 times, with an ORR of 80%, a relapse rate of 33% and a median duration of response (DOR) of 22 months (range 3-48); 10/12 pts (83%) who responded to TPO-RA, discontinued treatment after a median of 64 days (range 7 - 528): 6 maintained the response after discontinuation. RTX was used 10 times, with an ORR of 90%, a relapse rate of 22% and a median DOR of 27 months (range 3 - 83). A combination of RTX and TPO-RA was used 7 times, with an ORR of 71%, a relapse rate of 40% and a median duration of response (DOR) of 5 months (range 2-44); the 5 responders discontinued treatment after a median of 49 days (range 14-462): 3/5 maintained their response. After a median follow-up of 38 months (range 3-96), all ITP pts maintained a response (91% CR and 9% R); 4 were still on treatment (2 TPO-RA and 2 MMF). AIHA pts: 6 of 7 (86%) pts with AIHA received first line steroids +/- IVIG with an ORR of 67%. 4 pts needed second line therapy: all received RTX with an ORR of 50%. 2 pts needed ≥ 3 lines of therapy. After a median follow-up of 68 months (range 27-102) all AIHA pts maintained a response (57% CR and 43% PR), without any ongoing treatment. Adverse events: 33 pts (80%) experienced 1 or more adverse events (AEs): 25 cardiovascular (including 14 thrombosis), 21 infections (16 grade ≥3), 5 steroid-induced diabetes, 3 graft failures, 10 malignancies (6 solid tumors and 4 PTLD). 6 of the ITP pts also developed AIHA (Evans syndrome). 3 ITP pts died. Conclusions: ITP and AIHA represent important complications of Alem-induced renal transplant. Response rates after first-line therapy for ITP were comparable to primary ITP (30%). However, long-term response rate, sustained response to RTX and the proportion of pts able to continue in remission after discontinuing TPO-RA are higher than seen with primary ITP. Recovery from cytopenias may occur in conjunction with T cell reconstitution post Alem (this is under investigation). The large majority of AEs were related to multifactorial heavy immunosuppression and increased thrombotic risk distinguishing this group of pts. Hence for ITP and AIHA, steroids should be limited, as they are curative in only a few pts and burdened by many side effects. Both RTX and a short course of TPO-RA appear valid options, but the choice should be driven by the individual balance between thrombotic and infectious risks versus persistence of cytopenias. Disclosures Cooper: Amgen, Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Background.Cardiovascular disease (CVD) remains a significant problem in Chronic Kidney Disease (CKD). Subclinical atherosclerosis identified by noninvasive methods could improve CVD risk prediction in CKD but these methods are often unavailable. We therefore systematically reviewed whether circulating levels of Matrix Metalloproteinases (MMPs) and tissue inhibitors (TIMPs) are associated with subclinical atherosclerosis in CKD, as this would support their use as biomarkers or pharmacologic targets.Methods.All major electronic databases were systematically searched from inception until May 2015 using appropriate terms. Studies involving CKD patients with data on circulating MMPs levels and atherosclerosis were considered and subjected to quality assessment.Results.Overall, 16 studies were identified for qualitative synthesis and 9 studies were included in quantitative synthesis. MMP-2 and TIMP-1 were most frequently studied while most studies assessed carotid Intima-Media Thickness (cIMT) as a measure of subclinical atherosclerosis. Only MMP-2 demonstrated a consistent positive association with cIMT. Considerable variability in cIMT measurement methodology and poor plaque assessment was found.Conclusions.Although MMPs demonstrate great potential as biomarkers of subclinical atherosclerosis, they are understudied in CKD and not enough data existed for meta-analysis. Larger studies involving several MMPs, with more homogenized approaches in determining the atherosclerotic burden in CKD, are needed.

A case of severe calciphylaxis in a patient with End Stage Renal Disease on peritoneal dialysis is presented. Diagnosis was based on medical history and clinical findings and was confirmed by skin biopsy. A multidisciplinary medical team was involved in the patient’s management who was treated with intravenous sodium thiosulfate, intensified hemodialysis sessions, parathyroidectomy and surgical debridement. Calciphylaxis is a rare manifestation of chronic kidney disease, although non uremic causes have also been identified. The prognosis is generally poor. When confronting the disease, the physician does not stand on solid ground due to the lack of well designed treatment studies.