Gonadal Function In Patients with Beta-Thalassemia Major Following Bone Marrow Transplantation,

Conditioning chemotherapy prior to allogeneic bone marrow transplantation (BMT) can induce impairment in gonadal function. Patients with beta-thalassemia major generally undergo BMT at a young age and long-term data on its effects on gonadal function in this patient population are limited.

To address the effect of BMT on gonadal function in long term survivors with beta-thalassemia major following successful BMT.

The hormonal profiles of gonadotrophins (LH and FSH), sex hormones (total and free testosterone in males, and 17 beta-estradiol in females) and inhibin B were assayed yearly after BMT. We analyzed data on patients who underwent BMT between January 1996 and June 2009 in whom the pubertal process should have started.

A total of 84 patients received BMT for thalassemia major; 51 (20 females and 31 males) have reached the age of puberty at the time of this analysis. Median age at transplant was 10 years (range: 3 – 17). With a median follow-up of 8 years (range: 2–15), the median age at last follow-up was 18 years (range: 13 – 26). All transplants were from matched sibling donors. Conditioning was myeloablative and consisted of: Busulfan, total dose of 600mg/m² and Cyclophosphamide, total dose 200mg/kg (BuCy) before January 2005 and Busulfan, total dose 520mg/m², Fludarabine, total dose 180mg/m² and ATG, total dose 40mg/kg (BuFluATG) from January 2005 onwards. The impact of BMT appears to be different in the two sexes. 18 of 20 (80%) female patients had evidence of primary ovarian failure. Leydig cell failure was seen in only two male patients. However, injury to the germinal epithelium (as shown by low inhibin B levels which is predictive of oligo- or azoospermia) was seen in 22 of 31 (70%) male patients. A correlation was not found between the low inhibin B levels and age at BMT or type of conditioning regimen.

Our data confirm that gonads in male and female thalassemic patients are affected by the cytotoxic effects of the preparative regimens of BMT, albeit at different levels. These findings emphasize the need for vigilant long term follow up of thalassemic patients post-BMT so that those requiring hormone replacement therapy can be identified and treated early. These findings are also important for pre- and post-BMT counseling.

No relevant conflicts of interest to declare.