Cyclosporine A 4(CyA)-Induced Decrease of Serum Gonadotropin Levels in a Case of Klinefelter's Syndrome

Abstract

We report a case of Klinefelter's syndrome who developed a decrease of serum gonadotropin levels, particularly LH, after CyA treatment for complicated focal glomerulosclerosis (FGS). A 38-year-old man suffering from general malaise and pretibial edema was diagnosed FGS by renal biopsy in October 1988, and was referred to our hospital for further evaluation and treatment for FGS in December 1988. He was not married, and closer anamnesis revealed that he had had impaired seminal ejaculation from the age of 30. The physical examination showed 37% obesity, scanty body hair, pretibial edema and small bilateral testes (3.0 x 1.5cm). Laboratory findings included marked proteinuria (5.3g/day) and mild renal dysfunction (serum creatinine 1.3mg/dl, glomerular filtration rate 57.2ml/min). Endocrinologically, high basal levels of LH and FSH (133.6mIU/ml and 93.7mIU/ml, respectively) and the hyperresponses of LH and FSH to LH-RH stimulation were found, but the other pituitary hormone levels, thyroid and adrenal status, were in the normal range. In testicular biopsy, nodularly proliferated Leydig cells and no seminal tubules could be seen. The chromosome analysis showed 47,XXY karyotype, which confirmed the diagnosis of Klinefelter's syndrome in this patient. From 9 January 1989, CyA (6mg/Kg.day) was orally administered for 4 weeks in order to treat for FGS. After CyA administration, basal levels of LH and FSH remarkably decreased, particularly LH, and their decrease lasted for at least 6 weeks after cessation of CyA (final levels; LH 28.2mIU/ml, FSH 69.8mIU/ml). On the other hand, serum testosterone level was low normal or slightly under normal, and no apparent changes could be seen during CyA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)