Anti-factor H Autoantibody-associated Hemolytic Uremic Syndrome in an Argentinean Pediatric Cohort

ALBERTO MF; MOGOLLON N; SÁNCHEZ LUCEROS A; DOS SANTOS C; ROMERO ML

Dublin

Congreso; 64th Annual Scientific and Standardization Committee (SSC) meeting; 2018

International Society on Thrombosis and Haemostasis, Scientific and Standardization Committee (SSC)

Background: The presence of autoantibodies directed against Factor H (FH), regulator of the complement alternative pathway, is associated with atypical Hemolytic Uremic Syndrome (aHUS) manifesting microangiopathic hemolytic anemia, thrombocytopenia and kidney injury. Affecting mainly children, this autoimmune form was detected in 5-25% of aHUS pediatric cases in Europe, 30% in Koreaand 56% in India.Aims: To describe for the first time in Argentina the incidence of anti-Factor H autoantibody-associated aHUS.Methods: Our retrospective study, realized with patients? informed consent, was approved by the institutional ethical committee. Standard and positive control for detection of anti-FH antibodies by ELISA were kind gifts from Dr Dragon-Durey (Hôpital Européen G. Pompidou, France).Results: Anti-FH autoantibodies were screened in 113 patients (59 adults and 54 children) presenting clinical features of aHUS. Renal biopsy oriented the diagnosis of 3 patients towards C3 glomerulonephretis, a chronic kidney disease defined by abnormalities of the complement alternative pathway. Positive titers were found exclusively in 8 pediatric patients with suspicion of aHUS. Laboratory features and clinical manifestations of anti-FH positive aHUS cases were compared to subjects with no autoantibodies detected (Table 1).Patients with uncomplete clinical history or studied outside the acute phase (n=19) were excluded from the analysis. Although our study is sample size limited, LDH appeared to be increased in patients presenting anti-FHantibodies (Mann-Whitney U-test P=0.05).No other laboratory test showed significant difference between aHUS groups. Occurrence of extrarenal manifestations was slightly higher in patients with anti-FH antibodies.Conclusions: The first study detecting anti-FH autoantibodies-associated aHUS in Argentina showed a frequency of 14.8% cases in pediatric cohort. Sample size needs to be increased to compare prognosis between aHUS patients with anti-FHantibodies and patients with other aHUS forms.Reach the World Travel Grant