Pediatric autoimmune hemolytic anemia: A single-center retrospective study.

Background: Autoimmune hemolytic anemia (AIHA) is a rare, life-threatening disease in pediatrics. This article describes the clinical features, diagnostic workup, treatment and outcome in patients with AIHA.

Method: Medical charts of under 18-year-old patients with AIHA treated at a tertiary Brazilian institution from 2006 to 2021 were retrospectively reviewed. Data analysis was primarily descriptive, using medians, interquartile ranges, and categorical variables presented as absolute frequencies.

Main Results: Twenty-four patients (14 female, 10 male) were evaluated in this study. The median age at diagnosis was 5.99 years (range: 0.25-17.1 years) and the median hemoglobin level was 4.85 g/dL (range: 4.17-5.57 g/dL). Most had warm antibodies (83.3 %). Twelve patients (50 %) had known underlining diseases, four (16.6 %) presented with AIHA concomitant with acute infectious diseases and three (12.5 %) had an undetermined post-vaccine association. Steroids and intravenous immunoglobulin were first-line therapy in 23 cases. Seven patients (29.1 %) required second and third-line treatments (rituximab, cyclophosphamide and splenectomy). The median follow-up period was 4.4 years (range: 1.0-6.7 years). Thirteen patients (54.1 %) were discharged, five cases (20.8 %) were lost to follow-up and no patient died. The median age for the six remaining patients was 11.53 years (8.5-14.7) with all of them having complete responses with no further therapies.

Conclusion: Most cases of AIHA are secondary to an underlying systemic disease or have a possible correlation with infections/vaccines and respond to steroids. The second and third-line therapies for refractory and relapse cases remain a dilemma. A prospective, multicenter study is essential to address the best therapeutic combinations.