Anti CFH-associated HUS: do we still need Plasma Exchange?

Abstract Background Five to 50% of atypical hemolytic and uremic syndrome (aHUS) in children are caused by autoantibodies against complement Factor H (CFH). Given the acquired autoimmune nature of the disease, plasma exchange and various immunosuppressive treatments have been used. More recently, eculizumab has been proposed. Methods In this multicenter, retrospective study, we report the outcome of 12 children with anti-CFH antibody-associated HUS treated with eculizumab associated with various immunosuppressive regimens. Results Patients were treated with eculizumab for 15.5 [9.5;23.0] months and 3 received plasma exchange (PE) or IgG adsorption. Three patients received MMF alone, 1 patient received an association of MMF and steroids, 1 patient received an association of MMF and rituximab, 3 patients received MMF/steroids and rituximab and 4 patients did not receive any immunosuppression. Anti-CFH ab levels significantly decreased but no difference was observed based on the immunosuppressive regimen. ECZ was discontinued in 7/10 patients after 11 [7.5–15.5] months and MMF in 6/8 patients after 36 [35;40] months. Anti-CFH titers at MMF discontinuation ranged from 257 to 3425 UI/L. None of these patients relapsed and eGFR at last follow-up was above 70mL/min/1.73m 2 in all patients. Conclusion Eculizumab is effective and safe in inducing and maintaining remission in aHUS secondary to anti-CFH antibodies and renders anti-CFH titers reduction less urgent. Anti-CFH antibody titers decreased in most patients irrespective of the immunosuppressive treatment chosen, so that a strategy consisting of associating eculizumab with MMF monotherapy seems sufficient at least in non-Indian or less severe forms of anti-CFH antibody-associated HUS.