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BACKGROUND: Thrombotic microangiopathy (TMA) is a rare, life-threatening disorder characterized by microangiopathic hemolytic anemia, thrombocytopenia, and end-organ damage. Atypical hemolytic uremic syndrome (aHUS) is even less common, comprising less than 10% of hemolytic uremic syndrome (HUS) cases. aHUS in postpartum is associated with poor maternal outcomes, with the majority of cases resulting in end-stage renal disease. aHUS, unlike other types of TMA, is related to complement dysregulation. Thus, the current treatment of choice for aHUS is complement blockade, which limits unregulated activation of complement and complement-mediated end organ damage. CASE PRESENTATION: We present a rare case of a previously healthy, postpartum, 20-year-old Hispanic female patient who underwent a laparoscopic cholecystectomy and subsequently developed complement-mediated TMA, successfully treated with eculizumab. Unique to our case was renal failure owing to multiple insults and partial resolution of hematologic TMA findings prior to initiation of eculizumab. CONCLUSION: Our case emphasizes the importance of clinicians possessing a high degree of clinical awareness and judgement surrounding complement-mediated TMA, aHUS and its subsets, and surgery as a precipitator, regardless of safety, particularly during the postpartum period.

ABSTRACT Introduction Methods Results Conclusion The TECHNOSCREEN ADAMTS‐13 assay (ADSC) is a new lateral flow test which is simple and quick to perform, with a high negative predictive value (NPV); it may improve the diagnostic workflow for TTP. LabPlus in Auckland, New Zealand, performs all ADAMTS13 tests in the Auckland and Northland regions. The ADSC was used at LabPlus between 2022 and 2023 as part of a protocol where results of 0 IU/mL and 0.1 IU/mL were confirmed with the TECHNOZYM ADAMTS‐13 Activity chromogenic ELISA assay (ADATS). The aim was to improve cost efficiency by reducing the need for the labour‐intensive ADATS, particularly in low probability requests. This retrospective audit analyses the efficacy and efficiency of the testing protocol.All ADAMTS‐13 tests performed in the year before the ADSC (March 2021–March 2022) and after the ADSC protocol was introduced (March 2022–March 2023) were collected from the LabPlus laboratory information system (LIS), and correlated with clinical information from the electronic health record. Statistical analysis was performed.Ninety‐four test requests were audited. ADSC had an NPV of 100% on diagnostic samples. The protocol increased the median turn‐around time (TAT) by 18 h (p = 0.01). If an ADSC of 0.1 IU/mL was taken as a negative, the median TAT was decreased by 17 h (p = 0.0003) in diagnostic samples from LabPlus adjacent hospitals.ADSC has a high NPV but did not improve TAT when used as part of a testing protocol for our central laboratory receiving samples from a large area. [ABSTRACT FROM AUTHOR]

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Summary: The immunosuppressive treatment of immune‐mediated thrombotic thrombocytopenic purpura (iTTP) in patients with intolerance or refractoriness to the B‐cell depleting monoclonal antibody rituximab remains debated. Daratumumab, a plasma cell‐directed monoclonal antibody targeting CD38, represents a therapeutic option, but data are scarce. The French Thrombotic Microangiopathies Reference Center conducted a nationwide survey on iTTP patients treated with daratumumab. Nine episodes from seven patients were identified. Treatment was administered for A Disintegrin And Metalloproteinase with ThromboSpondin‐1 motifs, 13th member (ADAMTS13) relapses while patients were otherwise in clinical response (N = 8), or during the acute phase of the disease following rituximab intolerance (N = 1). Patients have received a median of three previous therapeutic lines. ADAMTS13 activity improved in eight cases following daratumumab administration, including three cases where ADAMTS13 normalized. ADAMTS13 relapses occurred in three patients; in two cases, retreatment with daratumumab was successful. Median ADAMTS13 relapse‐free survival was not reached; 12‐month ADAMTS13 relapse‐free survival was 56%. Daratumumab‐related adverse events occurred in five cases and were non‐severe infusion‐related reactions in all cases. These results suggest that daratumumab may be an effective treatment option for iTTP patients with intolerance or refractoriness to rituximab. [ABSTRACT FROM AUTHOR]

Discovered in late 2019, the SARS-CoV-2 coronavirus has caused the largest pandemic of the 21st century, claiming more than seven million lives. In most cases, the COVID-19 disease caused by the SARS-CoV-2 virus is relatively mild and affects only the upper respiratory tract; it most often manifests itself with fever, chills, cough, and sore throat, but also has less-common mild symptoms. In most cases, patients do not require hospitalization, and fully recover. However, in some cases, infection with the SARS-CoV-2 virus leads to the development of a severe form of COVID-19, which is characterized by the development of life-threatening complications affecting not only the lungs, but also other organs and systems. In particular, various forms of thrombotic complications are common among patients with a severe form of COVID-19. The mechanisms for the development of thrombotic complications in COVID-19 remain unclear. Accumulated data indicate that the pathogenesis of severe COVID-19 is based on disruptions in the functioning of various innate immune systems. The key role in the primary response to a viral infection is assigned to two systems. These are the pattern recognition receptors, primarily members of the toll-like receptor (TLR) family, and the complement system. Both systems are the first to engage in the fight against the virus and launch a whole range of mechanisms aimed at its rapid elimination. Normally, their joint activity leads to the destruction of the pathogen and recovery. However, disruptions in the functioning of these innate immune systems in COVID-19 can cause the development of an excessive inflammatory response that is dangerous for the body. In turn, excessive inflammation entails activation of and damage to the vascular endothelium, as well as the development of the hypercoagulable state observed in patients seriously ill with COVID-19. Activation of the endothelium and hypercoagulation lead to the development of thrombosis and, as a result, damage to organs and tissues. Immune-mediated thrombotic complications are termed "immunothrombosis". In this review, we discuss in detail the features of immunothrombosis associated with SARS-CoV-2 infection and its potential underlying mechanisms. [ABSTRACT FROM AUTHOR]

Thrombotic microangiopathy (TMA), characterized by microangiopathic hemolytic anemia, thrombocytopenia, and multisystem organ dysfunction, is a life‐threatening disease. Patients with TMA who do not exhibit a severe ADAMTS‐13 deficiency (defined as a disintegrin‐like and metalloprotease with thrombospondin type 1 motif no. 13 activity ≥10%: TMA‐13n) continue to experience elevated mortality rates. This study explores the prognostic indicators for augmented mortality risk or necessitating chronic renal replacement therapy (composite outcome: CO) in TMA‐13n patients. We included 42 TMA‐13n patients from January 2008 to May 2018. Median age of 41 years and 60% were female. At presentation, 62% required dialysis, and 57% warranted intensive care unit admission. CO was observed in 45% of patients, including a 9‐patient mortality subset. Multivariate logistic regression revealed three independent prognostic factors for CO: early administration of eculizumab (median time from hospitalization to eculizumab initiation: 5 days, range 0–19 days; odds ratio [OR], 0.14; 95% confidence interval [CI], 0.02–0.94), presence of neuroradiological lesions (OR, 6.67; 95% CI, 1.12–39.80), and a PLASMIC score ≤4 (OR, 7.39; 95% CI, 1.18–46.11). In conclusion, TMA‐13n patients exhibit a heightened risk of CO in the presence of low PLASMIC scores and neuroradiological lesions, while early eculizumab therapy was the only protective factor. [ABSTRACT FROM AUTHOR]

Copyright of Magyar Nőorvosok Lapja is the property of Hungarian Society of Obsterics & Gynaecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening, often immune-mediated disease that affects 2–13 persons per million per year. Hemolytic anemia, thrombocytopenia, and end-organ damage due to the formation of microthrombi are characteristic of TTP. ADAMTS13 is a disintegrin, metalloproteinase, cleaving protein of von Willebrand factor (VWF) that processes the VWF multimers to prevent them from interacting with platelets and, in turn, to microvascular thrombosis. Prompt diagnosis of TTP is critical yet challenging. Thrombotic microangiopathies have similar clinical presentation. Measurement of ADAMTS13 activity helps in the differential diagnosis. Less than 10% ADAMTS13 activity is indicative of TTP. Laboratory ADAMTS13 activity assays include incubating the test plasma with the substrate (full-length VWM multimers) and detection with direct or indirect measurement of the cleavage product. The purpose of this study is to examine the diagnostic potential, advantages, and weaknesses of the ADAMTS13 potency in TTP. [ABSTRACT FROM AUTHOR]

Background: Thrombotic microangiopathies (TMA) are a group of disorders with overlapping clinical features that require urgent intervention. Treatment is based on the recognition of the TMA type, which is often challenging. The aim of this study was to identify specific HLA associations with different TMA types to aid rapid diagnosis and appropriate treatment, since the HLA assay can be completed within five hours. Methods: All 86 consecutive patients who presented to the University of Arkansas for Medical Sciences between May 2013 and January 2021 with a presumptive diagnosis of TMA were included in this study. HLA typing was performed and correlated with other clinical and laboratory studies. Results: In comparison with other types of TMA, patients with acquired thrombotic thrombocytopenic purpura (aTTP) showed increased frequencies of HLA-DRB1*11, HLA-DQB1*03:01/19, HLA-DRB1*08 and HLA-DRB3. Combining the presence of these HLA associations with a PLASMIC score of 6 or more achieved a higher positive predictive value (90%) for identifying aTTP than the PLASMIC score alone (69%). In comparison with other TMA types, patients with aTTP showed decreased frequencies of HLA-DRB4, HLA-DRB1*07, HLA-DQB1*02. The HLA-DRB1*07/DQB1*02 was not observed in any aTTP patients (negative predictive value: 100%), and thus the presence of this haplotype essentially rules out aTTP. Further, HLA-DRB1*11/DQB1*03:01/19 was absent in atypical hemolytic uremic syndrome patients. Conclusion: HLA alleles can be used as an adjunct for the rapid assessment of TMA and can help to differentiate it from other primary and secondary forms of TMA, allowing for earlier definitive therapy.

Copyright of Osmangazi Journal of Medicine / Osmangazi Tip Dergisi is the property of Eskisehir Osmangazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The complement system, an important part of the innate system, is known to play a central role in many immune mediated kidney diseases. All parts of the complement system including the classical, alternative, and mannose-binding lectin pathways have been implicated in complement-mediated kidney injury. Although complement components are thought to be mainly synthesized in the liver and activated in the circulation, emerging data suggest that complement is synthesized and activated inside the kidney leading to direct injury. Urinary complement biomarkers are likely a better reflection of inflammation within the kidneys as compared to traditional serum complement biomarkers which may be influenced by systemic inflammation. In addition, urinary complement biomarkers have the advantage of being non-invasive and easily accessible. With the rise of therapies targeting the complement pathways, there is a critical need to better understand the role of complement in kidney diseases and to develop reliable and non-invasive biomarkers to assess disease activity, predict treatment response and guide therapeutic interventions. In this review, we summarized the current knowledge on urinary complement biomarkers of kidney diseases due to immune complex deposition (lupus nephritis, primary membranous nephropathy, IgA nephropathy) and due to activation of the alternative pathway (C3 glomerulopathy, thrombotic microangiography, ANCA-associated vasculitis). We also address the limitations of current research and propose future directions for the discovery of urinary complement biomarkers. [ABSTRACT FROM AUTHOR]

Copyright of Notfall & Rettungsmedizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Intensive care physicians may assume the primary care of patients with transplant-associated thrombotic microangiopathy (TA-TMA), an uncommon but potentially critical complication of hematopoietic stem cell transplants (HSCTs) and solid organ transplants. TA-TMA can have a dramatic presentation with multiple organ dysfunction syndrome (MODS) associated with high morbidity and mortality. The typical presenting clinical features are hemolytic anemia, thrombocytopenia, refractory hypertension, proteinuria and worsening renal failure. Intestinal involvement, with abdominal pain, nausea and vomiting, gastrointestinal bleeding, and ascites are also common. Cardiopulmonary involvement may develop from various causes including pulmonary arteriolar hypertension, pleural and pericardial effusions, and diffuse alveolar hemorrhage. Due to other often concurrent complications after HSCT, early diagnosis and effective management of TA-TMA may be challenging. Close collaboration between ICU and transplant physicians, along with other relevant specialists, is needed to best manage these patients. There are currently no approved therapies for the treatment of TA-TMA. Plasma exchange and rituximab are not recommended unless circulating factor H (CFH) antibodies or thrombotic thrombocytopenic purpura (TTP; ADAMTS activity < 10%) are diagnosed or highly suspected. The role of the complement pathway activation in the pathophysiology of TA-TMA has led to the successful use of targeted complement inhibitors, such as eculizumab. However, the relatively larger studies using eculizumab have been mostly conducted in the pediatric population with limited data on the adult population. This review is focused on the role of intensive care physicians to emphasize the clinical approach to patients with suspected TA-TMA and to discuss diagnosis and treatment strategies. [ABSTRACT FROM AUTHOR]

Catastrophic antiphospholipid syndrome (CAPS) is a rare clinical form of antiphospholipid syndrome (APS) associated with life-threatening complications due to simultaneous thrombosis that may affect small and large vessels. It may be localized to the venous and/or arteries at the same time, and there are not available guidelines based on randomized clinical trials or large series. We here report a clinical case of CAPS with onset after resolution of oligo-symptomatic infection SARS-CoV-2, that had transient improvement with warfarin after recurrent thromboses occurred despite treatment off-label with low doses of low molecular weight heparin. Furthermore, we tried to trace a line by which a multidisciplinary team may set specific timing to have follow-up because of the high morbidity, mortality, and prolonged time of hospitalization.

This article examines the association between weekend and holiday hospitalizations and mortality risk among patients with hematological malignancies and febrile neutropenia. The study, conducted in Denmark, included all emergency hospitalizations for febrile neutropenia in four out of five administrative regions over a five-year period. The results showed that hospitalizations during weekends and holidays were associated with a 17% to 37% higher 30-day mortality compared to hospitalizations on regular weekdays. However, the cause of this association remains unknown and further research with more detailed data is needed to understand the underlying factors. [Extracted from the article]

Catastrophic antiphospholipid syndrome (CAPS) is a rare clinical form of antiphospholipid syndrome (APS) associated with life-threatening complications due to simultaneous thrombosis that may affect small and large vessels. It may be localized to the venous and/or arteries at the same time, and there are not available guidelines based on randomized clinical trials or large series. We here report a clinical case of CAPS with onset after resolution of oligo-symptomatic infection SARS-CoV-2, that had transient improvement with warfarin after recurrent thromboses occurred despite treatment off-label with low doses of low molecular weight heparin. Furthermore, we tried to trace a line by which a multidisciplinary team may set specific timing to have follow-up because of the high morbidity, mortality, and prolonged time of hospitalization. [ABSTRACT FROM AUTHOR]

Thrombotic microangiopathies (TMAs) comprise a distinct group of diseases with different manifestations that can occur in both pediatric and adult patients. They can be hereditary or acquired, with subtle onset or a rapidly progressive course, and they are particularly known for their morbidity and mortality. Pregnancy is a high-risk time for the development of several types of thrombotic microangiopathies. The three major syndromes are hemolysis, elevated liver function tests, and low platelets (HELLP); hemolytic uremic syndrome (HUS); and thrombotic thrombocytopenic purpura (TTP). Because of their rarity, clinical information and therapeutic results related to these conditions are often obtained from case reports, small series, registries, and reviews. The collection of individual observations, the evolution of diagnostic laboratories that have identified autoimmune and/or genetic abnormalities using von Willebrand factor post-secretion processing or genetic–functional alterations in the regulation of alternative complement pathways in some of these TMAs, and, most importantly, the introduction of advanced treatments, have enabled the preservation of affected organs and improved survival rates. Although TMAs may show different etiopathogenesis routes, they all show the presence of pathological lesions, which are characterized by endothelial damage and the formation of thrombi rich in platelets at the microvascular level, as a common denominator, and thrombotic damage to microcirculation pathways induces "mechanical" (microangiopathic) hemolytic anemia, the consumption of platelets, and ischemic organ damage. In this review, we highlight the current knowledge about the diagnosis and management of these complications during pregnancy. [ABSTRACT FROM AUTHOR]

This article discusses immune-mediated thrombotic thrombocytopenic purpura (iTTP), a rare but serious disorder characterized by microvascular thrombosis and potentially life-threatening complications. iTTP is caused by a deficiency in the von Willebrand factor (VWF)-cleaving protease ADAMTS13, which leads to the accumulation of ultralarge VWF multimers and triggers platelet clumping and microvascular thrombosis. Early diagnosis and comprehensive therapy are crucial for optimal patient outcomes. The article provides guidance for diagnosing iTTP, sorting TMA etiologies, assessing severity, and initiating appropriate treatment. It emphasizes the importance of avoiding platelet transfusions and highlights the need for a personalized approach to diagnosis and treatment. [Extracted from the article]

Thrombotic microangiopathies (TMAs) have in common a terminal phenotype of microangiopathic hemolytic anemia with end-organ dysfunction. Thrombotic thrombocytopenic purpura results from von Willebrand factor multimerization, Shiga toxin-mediated hemolytic uremic syndrome causes toxin-induced endothelial dysfunction, while atypical hemolytic uremic syndrome results from complement system dysregulation. Drug-induced TMA, rheumatological disease-induced TMA, and renal-limited TMA exist in an intermediate space that represents secondary complement activation and may overlap with atypical hemolytic uremic syndrome clinically. The existence of TMA without microangiopathic hemolytic features, renal-limited TMA, represents an undiscovered syndrome that responds incompletely and inconsistently to complement blockade. Hematopoietic stem cell transplant-TMA represents another more resistant form of TMA with different therapeutic needs and clinical course. It has become apparent that TMA syndromes are an emerging field in nephrology, rheumatology, and hematology. Much work remains in genetics, molecular biology, and therapeutics to unravel the puzzle of the relationships and distinctions apparent between the different subclasses of TMA syndromes.

Pregnancy and the postpartum period represent phases of heightened vulnerability to thrombotic microangiopathies (TMAs), as evidenced by distinct patterns of pregnancy-specific TMAs (e.g., preeclampsia, HELLP syndrome), as well as a higher incidence of nonspecific TMAs, such as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome, during pregnancy. Significant strides have been taken in understanding the underlying mechanisms of these disorders in the past 40 years. This progress has involved the identification of pivotal factors contributing to TMAs, such as the complement system, ADAMTS13, and the soluble VEGF receptor Flt1. Regardless of the specific causal factor (which is not generally unique in relation to the usual multifactorial origin of TMAs), the endothelial cell stands as a central player in the pathophysiology of TMAs. Pregnancy has a major impact on the physiology of the endothelium. Besides to the development of placenta and its vascular consequences, pregnancy modifies the characteristics of the women’s microvascular endothelium and tends to render it more prone to thrombosis. This review aims to delineate the distinct features of pregnancy-related TMAs and explore the contributing mechanisms that lead to this increased susceptibility, particularly influenced by the “gravid endothelium.” Furthermore, we will discuss the potential contribution of histopathological studies in facilitating the etiological diagnosis of pregnancy-related TMAs.