Fertility status in male cystinosis patients treated with cysteamine

Objective: To analyze the fertility status in adult, male cystinosis patients treated with cysteamine. Cystinosis is an autosomal recessive disease leading to intralysosomal cystine accumulation. Worldwide, a few female cystinosis patients have given birth. However, no male cystinosis patients are known to have induced pregnancy. Adequate cysteamine treatment might improve male fertility. Patient(s): Seven male cystinosis patients (19-43 years) were submitted. Intervention(s): Glomerular filtration rate was estimated using the Cockcroft formula. Serum LH, FSH, testosterone, and inhibin B were determined. Semen analysis was performed in five patients. Testicular biopsy was performed in one patient. Results: Glomerular filtration rate ranged between 10 and 110 (normal >90) mL/min/1.73 m², LH and FSH levels ranged between 7.4 and 235.0 (normal 1.4-8.5) E/L and 6.8-298.0 (normal 1.5-11) E/L, respectively. Plasma testosterone level ranged between 8.7 and 31.3 (normal 11-45) nmol/L; plasma inhibin B level ranged between 10 and 210 (normal 150-400) ng/L. All of the collected sperm samples showed azoospermia. The testicular biopsy showed a Johnson score of 8 to 9. Conclusion(s): We demonstrate azoospermia in male cystinosis patients, even if adequately treated with cysteamine starting from an early age. The finding of spermatogenesis in the testis biopsy of one patient may provide opportunities to male cystinosis patients to produce their own offspring by in vitro fertilization after testicular sperm extraction.