Clinical features of children with anti-CFH autoantibody-associated hemolytic uremic syndrome: a report of 8 cases

Objective To explore the clinical characteristics, treatment protocol and prognosis of children with anti-complement factor H (CFH) autoantibody (Ab)-associated hemolytic uremic syndrome (HUS).Methods Clinical data of 8 patients with anti-CFH Ab-associated HUS who were admitted to Shandong Provincial Hospital from January 2011 to December 2020 were collected retrospectively.Results The age at disease onset ranged between 5.83 and 13.5 years, with a male: female ratio of 1.67:1. The time of onset was distributed from May to June and November to December. Digestive and upper respiratory tract infections were common prodromal infections. Positivity for anti-CFH Ab and reduced C3 levels were observed among all patients. Heterozygous mutation of the CHFR5 gene (c.669del A) and homozygous loss of the CFHR1 gene [loss2(EXON:2-6)] were found in two patients. All patients received early treatment with plasma exchange and corticosteroid therapy. Six patients were given immunosuppressive agents (cyclophosphamide and/or mycophenolate mofetil) for persistent proteinuria. The follow-up period was 12–114 months. Four of 8 patients achieved complete remission, 3 achieved partial remission, and 1 died. Relapse occurred in two patients.Conclusion Children with anti-CFH Ab-associated HUS were mainly school-aged and predominantly male, with onset times of summer and winter. Digestive and upper respiratory tract infections were common prodromal infections. Plasma exchange combined with methylprednisolone pulse therapy in the acute phase and cyclophosphamide or mycophenolate mofetil treatment for maintenance can be utilized in children with anti-CFH Ab-associated HUS if eculizumab is not available.