Characteristics and outcomes of autoimmune hemolytic anemia after
pediatric allogeneic stem cell transplant
Background: Autoimmune hemolytic anemia (AIHA) after allogeneic
hematopoietic stem cell transplant (HSCT) is a rare but complex and
serious complication. Detailed descriptions of cases and management
strategies are needed due to lack of prospective trials. Objectives:
Describe the incidence, clinical characteristics, and management of AIHA
after HSCT in a pediatric cohort. Methods: This is a retrospective
cohort study of 33 pediatric patients with AIHA after HSCT at an
academic tertiary care center from 2003 to 2019. A case-control analysis
was performed to compare outcomes. Results: The overall incidence of
AIHA after allogeneic HSCT was 3.8% (33/868). AIHA was significantly
more common after transplant for non-malignant versus malignant
diagnoses (7.0% (26/370) vs. 1.4% (7/498), p<0.0001). AIHA
developed at a median of 4.7 months (range: 1.0-29.7) after transplant.
Sixteen of 33 patients (48.5%) required new AIHA-directed pharmacologic
therapy; 17 (51.5%) were managed on their current immunosuppression and
supportive care. Patients managed without additional therapy were
significantly older, more likely to have a malignant diagnosis, and
tended to develop AIHA at an earlier timepoint after transplant.
Patients received a median of 2 red blood cell transfusions within the
first two weeks of diagnosis and a median of one AIHA-directed
medication (range: 1-4), most commonly corticosteroids and rituximab.
Conclusions: AIHA after HSCT is rare but occurs more commonly in
patients transplanted for non-malignant diagnoses. While some patients
can be managed on current immunosuppression and supportive care, many
require AIHA-directed therapy including second-line medications.