Clinical characteristics of patients with AIHA
In patients with AIHA, the median age at time of transplant was 7.4 years (range: 0.1-23.2) and median time to development of AIHA after the day of transplant was 4.7 months (range: 1.0-29.7). At the time of AIHA diagnosis, all patients had a positive direct antiglobulin test, including IgG and C3 (n=16), IgG only (n=11), C3 only (n=4), and two patients in which neither IgG nor C3 was identified. IgM, IgA, and Donath-Landsteiner antibodies were not tested. Fifteen patients (15/33, 45.5%) converted their blood type from recipient to donor prior to the time of AIHA diagnosis, 6 converted after AIHA diagnosis, 8 recipient/donor pairs had identical blood types, and, in 4 patients, time to conversion was unable to be determined. Sixty-nine percent of patients (20/29, unknown = 4) had >28 days between their last packed red blood cell transfusion (pRBC) and onset of AIHA. The median number of days between last pRBC transfusion and development of AIHA was 73.5 days (range: 1-889).
CMV and EBV infections occurred either prior to or concurrently with AIHA diagnosis in a portion of patients with AIHA. CMV infection occurred in 24.2% (8/33) of patients with AIHA; of those with an infection, 62.5% (5/8) had positive blood CMV PCR testing at the time of diagnosis of AIHA. EBV infection occurred in 21.2% (7/33) with AIHA, and, of those with an infection, 100% (7/7) had positive blood EBV PCR testing at the time of AIHA. GVHD was diagnosed in a minority of patients with AIHA; 7 patients (21.2%) had acute GVHD in the first 100 days after transplant (grade range 1-3). Two patients required GVHD treatment with systemic steroid monotherapy and 4 patients required combination therapy with systemic corticosteroids and additional agents. Eight patients (24.2%) had chronic GVHD in the first-year after transplant with 1 patient (12.5%) having limited disease and 7 patients (87.5%) having extensive disease. Seven of these patients required treatment with systemic corticosteroids and additional agents.