High prevalence of endocrine dysfunction in long-term survivors after allogeneic bone marrow transplantation for hematologic diseases

BACKGROUND. The progressively increasing number of long-term survivors after allogeneic bone marrow transplantation (allo-BMT) led researchers to focus on the early and late complications of this procedure. Endocrine dysfunction occurred mostly in patients who had undergone total body irradiation (TBI) as part of pretransplantation treatment. The extent to which chemotherapy and immune system derangement affect endocrine function in allo-BMT recipients is still unclear. METHODS. Forty consecutive patients (21 women, 19 men) with hematologic diseases surviving 12 or more months after allo-BMT from HLA-identical siblings were studied. Patients' age at transplantation ranged from 13 to 45 years and their post-BMT follow-up lasted 12-62 months. The conditioning regimen BUCY2 was employed. Graft versus host disease (GVHD) was observed in the acute form in 13 patients and in the chronic form in 26. The function of hypothalamic-pituitary-gonad, thyroid, somatotrophic, and adrenal axes was assessed. RESULTS. The most common endocrine dysfunction was ovarian insufficiency (95% of women), followed by an increase in follicle-stimulating hormone in 47% of men, indicating spermatogenesis damage. Hormone replacement therapy was contraindicated in three women because of chronic liver GVHD and it was ineffective partially in four others because of reduced intestinal or cutaneous absorption. Thyroid dysfunction occurred in 47.5% of patients and included low T3 syndrome, chronic thyroiditis, and transient subclinical hyperthyroidism and subclinical hypothyroidism. Adrenal function was abnormal in 10%, mostly related to the prolonged corticosteroid treatment. IGF-I was lower than age-reference values in 27% of all patients and in 38% of those with chronic GVHD. Thyroid, adrenal, and IGF-I impairments were more frequent in patients with chronic GVHD than in patients without this disease (P = 0.048). CONCLUSIONS. A high prevalence of endocrine dysfunction was detected in a cohort of allo-BMT recipients not treated by TBI. Although gonadal failure was likely related to intensive myeloablative treatments, thyroid, adrenal, and IGF-I impairments were late events, suggesting that immunosuppressive treatment and immune system derangement may play a role in the development of endocrine dysfunction after allografting.