Geographic Diversity in Atypical Hemolytic Uremic Syndrome (aHUS): The Genetic Background of aHUS Cohort in Japan

Abstract

Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by the dysfunction of the alternative pathway of the complement system, which leads to the spontaneous activation of the complement system in the circulating plasma or cell surface. Recently our group published the cohort analysis of aHUS in Japan (n=118). Through the study, we revealed the followings; 1) the genetic background of aHUS in Japan was different from that in Western countries, 2) the most frequent genetic mutation detected in this study was I1157T in C3 (n=24), which was associated with superior renal outcome in spite of frequent replases, 3) Anti-CFH antibody positive aHUS had an excellent renal outcome, 4) 44% cases presented nephrotic syndrome, 5) only 12 % developed end stage renal disease (ESRD) and 6) there were 13 cases that discontinued eculizumab treatment and were followed up. These findings might help establishing the robust evidence for the optimal treatment of aHUS.