ESPE Abstracts

Background: Bone marrow transplantation (BMT) is known to affect endocrine function, most commonly causing primary hypothyroidism and hypogonadism in children. Newer reduced intensity conditioning (RIC) uses less myeloablative chemotherapy and no irradiation. Our study goal was to evaluate endocrine effects at 1 year post BMT in pediatric patients who received RIC.

Methods: Retrospective, IRB-approved chart review was performed on 121 patients (44 females) who underwent a single RIC BMT to treat immune disorders (HLH, SCID, IPEX, and XLP), genetic syndromes (Shwachman, Hurler, Seckel, and ALD), or malignancy (ALL and CML), and survived at least a year. Data recorded included dates, age, gender, diagnosis, height SDS, weight, and endocrine hormone results.

Results: Among the study population, 43 patients, aged 2–17, had height and weight data both prior to and at least 1 year following BMT. The mean interval between first and last values was 20.5 months. Height SDS and BMI z-scores (BMI-Z) were examined separately using linear mixed effects models. There was a significant decrease in post-BMT height SDS compared to pre-BMT values (−1.26±1.42 vs −0.94±1.55, P=0.0471). BMI-Z was also significantly reduced following BMT (0.28±1.45 vs 1.02±1.49, P=0.0028). When grouped by diagnosis, there was no significant difference in height SDS or BMI-Z among immune disorders (n=21) vs all others (n=22). Thyroid function testing was performed on 78 patients following BMT, and 63 (81%) had normal TSH and free T₄. Among the remainder, 11 (14%) had evidence of primary hypothyroidism and 4 (5%) of these received hormone replacement. Four patients (5%) had evidence of primary hyperthyroidism or central hypothyroidism. Of the 67 patients with 25-OH vitamin D levels, 46 (69%) were normal (≥30 ng/ml), while 21 (31%) were low.

Conclusions: Despite RIC, children undergoing BMT still have significant late endocrine effects following transplant. Prospective follow up for early detection of endocrine deficiencies after BMT is needed in these children. Further analysis is required in order to compare the degree of post-transplant endocrine effects with patients undergoing standard chemotherapy protocols.