Growth velocity in pediatric bone marrow transplantation: significance of donor type and treatment factors.

Children who have undergone bone marrow transplantation (BMT) often have decreased growth. Growth is a multifactorial process, and the factors that influence growth after BMT are not completely understood. The authors hypothesized that donor type may be a factor influencing growth. Sixty-five children and adolescents who underwent BMT (32 related matched, 33 unrelated matched) were evaluated. Growth velocity (height standard deviation) was assessed prior to and 2 years following BMT. The results indicated that children and adolescents who underwent unrelated matched transplants had lower growth velocity (P < .059) than those with related matched transplants. Those who received the standard conditioning regimen that included total body irradiation (TBI) had a significantly lower growth velocity (P < .045) than those with chemotherapy-only regimens. Significant correlates of growth velocity included younger age at BMT and pre-BMT growth velocity. Thus, donor type, age at BMT, prior treatment, and BMT conditioning regimens that include TBI may all affect growth post-BMT. Careful monitoring of growth velocity is required for patients who have received an unrelated donor BMT.