Background Previous studies have explored post-hematopoietic cell transplant (HCT) outcomes by race in adults; however, pediatric data addressing this topic are scarce. Procedure This retrospective registry study included 238 White (W) and 57 Black (B) children with hematologic malignancies (HM) receiving first allogeneic HCT between 2010 and 2019 in one of five Florida pediatric HCT centers. Results We found no differences between W and B children by transplant characteristics, other than donor type. There was a significant difference in use of HLA-mismatched donors (HLA-MMD) (53% W, 71% B, p=0.01). When comparing HLA-MMD use to fully HLA-matched donors, B had RR of 1.47 [95% CI 0.7-3] of receiving a mismatched unrelated donor (MMUD), RR of 2.34 [95% CI 1.2-4.4] of receiving a mismatched related donor (MMRD), and a RR of 1.9 [95% CI 0.99-3.6] of receiving a mismatched cord blood donor (MMCBD) HCT, respectively. There was no significant difference in the incidence of aGVHD (48% W, 35% B), p=0.1 or cGVHD (19% W 28% B, p=0.1), or primary cause of death. Overall 24-month survival was 61% [95% CI 54-68%] for W, and 60% [95% CI 38-68] for B children, log-rank p=0.72. While HLA matching improved survival in W children, the number of B children receiving HLA-matched HCT was too small to identify the impact of HLA matching on survival. Conclusions In this contemporary cohort of children with HM we found that B children were more likely to receive HLA-MMD transplants, but this did not adversely affect survival or GVHD rates.

Abstract Background: Graft-versus-host disease (GVHD) is a common and undesirable complication of hematopoietic cell transplant (HCT) for non-malignant disorders (NMD). Understanding the incidence and risk factors for GVHD in children with NMD is an important step in developing strategies for its prevention. Study Design: This is a retrospective, registry, study that included children with NMD receiving HCT in 5 centers in Florida between 2010 and 2019. Results: Among 183 patients evaluable for GVHD, acute GVHD (aGVHD) grades I, II, III, and IV were present in 18%, 12.6%, 3.8% and 5.5% of patients, respectively. Limited and extensive chronic GVHD (cGVHD), were observed in 8.7% and 12.6% of patients. Patients with aGVHD grade III/IV had significantly lower 3-year survival rates than those without aGVHD, or those with aGVHD grade I/II (52.9% [95% confidence interval (CI) 34-83] vs. 90.1% [95% CI 84-96], vs. 98.1% [95%CI 95-100], p<0.001). Patients without cGVHD and those with limited and extensive cGVHD had 3-year survival rates of 88.9% [95%CI 84-94], 91.7% [95%CI 77-100], and 84.8% [95%CI 70-100], respectively, log rank p=0.3. Receiving transplant from an HLA-mismatched unrelated donor (MMUD), as compared to a matched related donor (MRD), increased the risk for aGVHD grade III/IV (Odds ratio 10.4 [95% CI 2.5-47.6]). There were no cases of aGVHD grade III/IV among recipients of mismatched related/haploidentical transplants. Conclusions: Grade III/IV aGVHD, which significantly reduced overall survival, was reported in 9.3% of children with NMD receiving HCT. Risk factors included HCT from a MMUD but not mismatched related donors.