Characterization of patients with aHUS and associated triggers or clinical conditions: A Global aHUS Registry analysis

Abstract

AbstractIntroductionAtypical haemolytic uremic syndrome (aHUS) is a rare form of thrombotic microangiopathy (TMA) associated with complement dysregulation; aHUS may be associated with other ‘triggers’ or ‘clinical conditions’. This study aimed to characterize this patient population using data from the Global aHUS Registry, the largest collection of real‐world data on patients with aHUS.MethodsPatients enrolled in the Global aHUS Registry between April 2012 and June 2021 and with recorded aHUS‐associated triggers or clinical conditions prior/up to aHUS onset were analysed. aHUS was diagnosed by the treating physician. Data were classified by age at onset of aHUS (< or ≥18 years) and additionally by the presence/absence of identified pathogenic complement genetic variant(s) and/or anti‐complement factor H (CFH) antibodies. Genetically/immunologically untested patients were excluded.Results1947 patients were enrolled in the Global aHUS Registry by June 2021, and 349 (17.9%) met inclusion criteria. 307/349 patients (88.0%) had a single associated trigger or clinical condition and were included in the primary analysis. Malignancy was most common (58/307, 18.9%), followed by pregnancy and acute infections (both 53/307, 17.3%). Patients with an associated trigger or clinical condition were generally more likely to be adults at aHUS onset.ConclusionOur analysis suggests that aHUS‐associated triggers or clinical conditions may be organized into clinically relevant categories, and their presence does not exclude the concurrent presence of pathogenic complement genetic variants and/or anti‐CFH antibodies. Considering a diagnosis of aHUS with associated triggers or clinical conditions in patients presenting with TMA may allow faster and more appropriate treatment.image