Clinical characteristics and prognosis of anti-factor H antibody associated-atypical hemolytic uremic syndrome in children / 中华实用儿科临床杂志

ABSTRACT

Objective:To summarize the clinical data of anti-factor H antibody-associated atypical hemolytic uremic syndrome (aHUS) in children, and analyze the risk factors for disease recurrence and poor prognosis.Methods:A prospective cohort study was conducted on 52 children with anti-factor H antibody-associated aHUS in Beijing Children′s Hospital, Capital Medical University from November 2011 to November 2021.Patient information about the genetic background, clinical and renal pathological characteristics, treatment, and prognosis were collected.Then, the disease recurrence and prognosis were analyzed using the survival curve and Cox regression model. Results:In 52 children, there were 33 males and 19 females.The average age of onset for aHUS was 2.4-12.8 years, and 92.3%(48/52) of the children developed symptoms at the age of 4-12 years.The copy numbers of complement factor-H-related 1 (CFHR1) and complement factor-H-related 3 (CFHR3) genes were calculated in 42 children.Among the 42 cases, 18 cases (42.9%) had CFHR1 homozygous deletion, and 83.3% (15/18) of them also had CFHR3 homozygous deletion.All the patients were given plasma therapy.Besides, 76.9% (40/52) of the children were treated with immunosuppressive therapy (steroid and/or immunosuppressant) at the first onset of the disease.About 86.5%(45/52 cases) of the patients received immunosuppressive therapy in the course of disease, and the immunosuppressive treatment lasted for 6-20 months in total.The median follow-up time was 58 (28, 91) months.Among 52 patients, only 12 patients (23.1%) suffered disease recurrence.The relapse-free survival rate in children with CFHR1 homozygous deletion was significantly lower than that in children with non-homozygous deletion ( χ2=4.700, P=0.030). The relapse-free survival rate in children with CFHR1 and CFHR3 homozygous deletions was also significantly lower than that in other children ( χ2=4.181, P=0.041). At the end of the follow-up, 73.1%(38/52) of the children had normal renal function and no persistent proteinuria or hypertension.23.1%(12/52 cases) of the children had persistent proteinuria and/or hypertension.One child had Stage 3-4 chronic kidney disease, and 1 child was dialysis dependent. Conclusions:Anti-factor H antibody-associated aHUS is prone to occur in children aged between 4-12 years old, who respond well to plasma therapy and immunosuppressive therapy.Children with anti-factor H antibody-associated aHUS and CFHR1 and CFHR3 homozygous deletions have a high recurrence rate.Treatment with immunosuppressive therapy and assessment of the copy number of CFHR1 and CFHR3 genes in the early stage of the disease are important for preventing disease recurrence and improving prognosis.