Clinical features of atypical hemolytic uremic syndrome with CFHR1,CFHR3 genetic abnormalities in children

Abstract

Objective To analyze the clinical features of atypical hemolytic uremic syndrome(aHUS) with CFHR1, CFHR3 genetic abnormalities in children. Methods The clinical, pathological data and CFHR1, CFHR3 genetic test results of 13 patients with aHUS were collected.A retrospective analysis of the clinical characteristics, pathological features, treatment and prognosis, and an analysis of the clinical manifestations according to the result of genetic testing were conducted. Results Thirteen aHUS patients were included in the study, including 9 male and 4 female, ranging in age from 1 year and a half to 13 years.All the patients had the typical clinical manifestations, and all patients had gastrointestinal symptoms such as nausea, vomiting, abdominal pain or bloating, and so on, but no diarrhea.All the patients showed massive proteinuria, complement C3 decrease; 12 cases with hypertension.Three patients underwent renal biopsy.All the patients were treated by plasmapheresis.After treatment, 1 patient was chronic kidney disease, others had normal renal function, and proteinuria either disappeared or was significantly reduced, but complement C3 was normal.CFH gene of the 13 patients was normal.CFHR1/CFHR3 gene had deletion in 6 cases; CFHR1 gene had homozygous deletion in 1 case; CFHR1 gene homozygous mutation in 2 cases; CFHR1 gene heterozygous mutation in 1 case; CFHR1 gene loss of heterozygosity in 2 cases; CFHR1 and CFHR3 increased gene copy number in 1 case. Conclusions aHUS with CFHR1, CFHR3 genetic abnormalities in children had severe renal injury, and decrease of complement was prominent.Plasmapheresis therapy was recommended as key treatment, which should be earlier and intensive.And this kind of aHUS is easy to relapse. Key words: Atypical hemolytic uremic syndrome; Plasmapheresis; CFHR1 gene; CFHR3 gene