ESPE Abstracts

Introduction: Hormonal deficits are well known complications after allogeneic human stem cell transplantation (alloHSCT) in childhood and treated according to existing guidelines. It is assumed that bone mass and strength accrual during puberty is also often impaired, due to toxic therapy and prolonged inactivity, but data on bone geometry and strength are scare in this particular group.

Objective/Patients and Methods: Cross-sectional study of bone health in boys and girls (aged 15-25 years) who received HSCT in childhood, as compared to healthy controls. All cases received alloHSCT for a hematological malignancy. Bone mass, size and density (BMD) were determined by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Statistical analysis was performed using SPSS (version 25): Mann-Whitney U-Test and unpaired student-t Test, as appropriate.

Results: Twenty-two cases (11 males) and 22 healthy controls (11 males) participated. Mean age at time of alloHSCT was 9,2 ± 4,91 years and mean interval since alloHSCT was 10,9 ± 4,57 years. DXA results revealed no significant difference in whole body BMD (wbBMD) and lumbar spine BMD in female patients as compared to controls (P=0,916 and 0,475, respectively). pQCT scans in females revealed comparable results with no difference in trabecular vBMD, cortical vBMD, periostal and endosteal circumferences and polar strength strain index (SSIp) between patients and controls (NS). In male patients, wbBMD was significantly lower in patients as compared to controls (P=0,003). Lumbar spine BMD was also lower but did not reach significance (P =0.058). Male patients had a lower tibia and radius cortical thickness (P=0.035 and 0.026 respectively), mainly due to a smaller periostal circumference (P=0,032) and a lower tibia and radius SSIp (P=0.003 and 0.015, respectively).

Conclusion: Young adults, several years after HSCT in childhood, are at risk for suboptimal bone mass in comparison with a control group. Our data highlight the need for life style interventions post alloHSCT aimed at optimizing bone health.