Anti-Factor H Autoantibody-Associated Hemolytic Uremic Syndrome in an Argentinean pediatric cohort

CÉLIA DOS SANTOS; NATALIA MOGOLLÓN MOLINA; MARÍA F ALBERTO; MARÍA L ROMERO; ANALÍA SÁNCHEZ-LUCEROS

Dublin

Congreso; 64th Annual Meeting of the Scientific Standardization Committee of the International Society on Thrombosis and Haemostasis; 2018

The International Society on Thrombosis and Haemostasis

The presence of autoantibodies directed against Factor H, a regulator of the complement alternative pathway, can be associated with atypical Hemolytic Uremic Syndrome (aHUS) manifesting microangiopathic hemolytic anemia, thrombocytopenia and kidney injury. Affecting mainly children, this autoimmune form of the disease was detected in 5 to 25% of aHUS pediatric cases in Europe, 30% in Korea and 56% in India.To describe for the first time in Argentina the incidence of anti-Factor H autoantibody-associated aHUS.Our retrospective study, realized with patients? informed consent, was approved by the institutional ethical committee. Anti-FH autoantibodies were detected by ELISA assay.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 which results from 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 parameter appeared to be increased in patients presenting anti-FH antibodies (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.The first study detecting anti-FH autoantibodies-associated aHUS in Argentina showed a frequency of 14.8% cases in pediatric cohort. The number of studied population needs to be increased to analyze if, in the country, aHUS patients with anti-FH antibodies have poorer prognosis than patients with other aHUS forms.