# Incidence, Risk Factors, and Treatment of Autoimmune Cytopenia Following Pediatric Allogeneic Hematopoietic Stem Cell Transplantation

## TL;DR

This study examines autoimmune cytopenia in children after stem cell transplants, identifying risk factors and treatment outcomes.

## Contribution

The study identifies chronic graft-versus-host disease as an independent risk factor for autoimmune cytopenia in pediatric stem cell transplant patients.

## Key findings

- 37 out of 436 pediatric patients developed autoimmune cytopenia after allogeneic stem cell transplantation.
- Chronic graft-versus-host disease was identified as an independent risk factor for autoimmune cytopenia.
- Steroids and intravenous immunoglobulin achieved complete remission in nearly half of the patients with autoimmune cytopenia.

## Abstract

Autoimmune cytopenia (AIC) following pediatric allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is relatively rare but it is a challenging complication, and standardized treatment guidelines are lacking. We retrospectively analyzed 436 pediatric patients undergoing allo‐HSCT; 37 (8.5%) developed AIC, characterized by autoimmune hemolytic anemia (n = 13), immune thrombocytopenia (n = 11), and Evans syndrome (n = 13). Risk factor analysis revealed that younger age at HSCT, nonmalignant diseases, unrelated donor transplantation, and chronic graft‐versus‐host disease (cGVHD) were significantly associated with the development of AIC. Through multivariate analysis, cGVHD was identified as an independent risk factor for AIC. In our study, the first‐line treatment for AIC involved steroids and/or intravenous immunoglobulin, with a complete remission rate of 48.6%. Additional therapeutic strategies included rituximab, which led to complete remission in 5 of 12 patients we treated, and sirolimus, with 3 of 7 patients achieving complete remission. Three patients achieved partial remission, while 9 patients died due to complications, such as severe infections, extensive GVHD, and multiorgan bleeding. Our findings suggest that cGVHD is an independent risk factor for post‐transplant AIC and is typically associated with adverse outcomes, highlighting the critical importance of timely and effective interventions.