Secondary atypical hemolytic uremic syndromes in the era of complement blockade

Le Clech et al. found rare variants in complement genes in only 5% of patients among a large cohort of secondary hemolytic uremic syndrome cases. The absence of genetic abnormalities does not exclude, however, the implication of complement in the pathogenesis of secondary hemolytic uremic syndrome. Prospective studies should be performed to evaluate the efficacy of complement blockers in patients with secondary atypical hemolytic uremic syndrome who do not respond to the treatment of the triggering condition.