Effect of iron overload on impaired fertility in male patients with transfusion-dependent beta-thalassemia

BACKGROUND: To investigate the fertility of male patients with transfusion-dependent beta-thalassemia, and to use magnetic resonance imaging (MRI) as a novel method to assess the iron overload status of testis in such patients. METHODS: Twenty-one male patients with transfusion-dependent beta-thalassemia and five normal male controls enrolled in this study. Hormonal profiles, iron levels, MRI testicular dimension, MRI T2 values, parameters for sperm quality, and sperm DNA fragmentation (SDF) of participants were measured. RESULTS: The MRI T2 values of the testis were significantly lower in transfusion-dependent beta-thalassemia patients than in normal controls (P = 0.027), and they correlated to serum ferritin levels in all enrolled subjects (R-2 = 0.258, P = 0.008). There were significantly lower sperm concentrations (P = 0.037), a lower percentage of sperm with normal morphology (P = 0.001), and a higher percentage of SDF (P = 0.009) in transfusion-dependent beta-thalassemia patients without hypogonadotropic hypogonadism and with spontaneous spermatogenesis compared with normal controls. The percentage of SDF was significantly correlated with serum ferritin levels in transfusion-dependent beta-thalassemia male patients with spontaneous spermatogenesis (R-2 = 0.48, P = 0.009). CONCLUSION: Our study is the first demonstration of iron deposition in the testis of patients with transfusion-dependent beta-thalassemia based on imaging, and such findings might explain the high prevalence of impaired fertility in above patients with normal pituitary function.