1. Functional and Genetic Landscape of Complement Dysregulation Along the Spectrum of Thrombotic Microangiopathy and its Potential Implications on Clinical Outcomes
- Author
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Chris P. M. Reutelingsperger, Johann Morelle, Alexis Werion, Pieter van Paassen, Sjoerd A.M.E.G. Timmermans, Jan Damoiseaux, UCL - SSS/IREC/NEFR - Pôle de Néphrologie, UCL - (SLuc) Service de néphrologie, Interne Geneeskunde, MUMC+: MA Med Staf Artsass Interne Geneeskunde (9), RS: Carim - B02 Vascular aspects thrombosis and Haemostasis, RS: MHeNs - R1 - Cognitive Neuropsychiatry and Clinical Neuroscience, Faculteit FHML Centraal, MUMC+: DA CDL Algemeen (9), RS: NUTRIM - R3 - Respiratory & Age-related Health, Biochemie, MUMC+: MA Nefrologie (9), and MUMC+: MA Klinische Immunologie (9)
- Subjects
medicine.medical_specialty ,Thrombotic microangiopathy ,FACTOR-I ,030232 urology & nephrology ,kidney transplantation ,Disease ,Complement factor I ,030204 cardiovascular system & hematology ,VARIANTS ,lcsh:RC870-923 ,Gastroenterology ,DISEASE ,ACTIVATION ,03 medical and health sciences ,0302 clinical medicine ,Clinical Research ,Internal medicine ,Atypical hemolytic uremic syndrome ,medicine ,complement ,INHIBITOR ECULIZUMAB ,Kidney transplantation ,business.industry ,MUTATIONS ,atypical hemolytic uremic syndrome ,Odds ratio ,DEFECTS ,Eculizumab ,medicine.disease ,lcsh:Diseases of the genitourinary system. Urology ,Complement system ,thrombotic microangiopathy ,hypertensive emergency ,Nephrology ,HEMOLYTIC-UREMIC SYNDROME ,eculizumab ,pregnancy ,business ,AHUS ,medicine.drug - Abstract
Introduction The syndromes of thrombotic microangiopathy (TMA) are diverse and represent severe endothelial damage caused by various mechanisms. The complement system plays a major role in a subset of patients with TMA, and its recognition is of clinical importance because it guides choice and duration of treatment. Methods We studied a well-defined cohort of patients with TMA and hypothesized that assessment of serum-induced ex vivo C5b9 formation on the endothelium and screening for rare variants in complement genes can better categorize TMA. Results Massive ex vivo C5b9 formation was found in all patients with primary atypical hemolytic uremic syndrome (n/N = 11/11) and in 59% of patients with TMA and coexisting conditions (n/N = 30/51). Massive ex vivo C5b9 formation was associated with rare genetic variants (45% [n/N = 20/44] vs. 0% [n/N = 0/21] patients with normal ex vivo C5b9 formation; P < 0.001). Massive ex vivo C5b9 formation was associated with favorable renal response to therapeutic complement inhibition in patients with TMA and coexisting conditions (86% [n/N = 12/14] vs. 31% [n/N = 5/16] of untreated patients; P < 0.001), indicating complement-mediated TMA rather than secondary disease. Among treated patients, the odds ratio for 1-year kidney survival was 12.0 (95% confidence interval 1.2-115.4). TMA recurrence was linked to rare genetic variants in all cases. Patients with normal ex vivo C5b9 formation had an acute, nonrelapsing form of TMA. Conclusions Ex vivo C5b9 formation and genetic testing appears to categorize TMAs into different groups because it identifies complement as a driving factor of disease, with potential therapeutic and prognostic implications., Graphical abstract
- Published
- 2021