Immunohistochemical expression of cyclin A in testicular biopsies of fertile and infertile men: correlation with the morphometry of seminiferous tubules.

Cyclin A is a member of the cyclin family of proteins, which are required for both the mitotic and meiotic divisions that characterise spermatogenesis in human and other mammalian species. The data on cyclin A expression in various human spermatogenic disorders and its relationship to the morphology of seminiferous tubules are not well clarified. This study aimed to evaluate the immunohistochemical expression of cyclin A in testicular biopsies of different spermatogenic disorders correlating with the morphology of seminiferous tubules using morphometry tools. Immunohistochemical evaluation of cyclin A was carried out on testicular biopsies obtained from 48 infertile males (nonobstructive azoospermia) and 15 normal subjects together with using semiautomatic morphometric analysis for evaluation of seminiferous tubules. Cyclin A is expressed in 100% of normal and hypospermatogenesis groups and in 80% of maturation arrest group, with complete absence in Sertoli cell only group. In positive cases, cyclin A stained the nuclei of spermatogonia and primary spermatocytes with a higher intensity of expression in normal cases compared with infertile group. Cyclin A expression was significantly associated with the different examined morphometric parameters. Cyclin A is involved in both mitosis and meiosis of human spermatogenesis as it is expressed in spermatogonia and primary spermatocytes. Morphometry of human testis is intimately correlated with the testicular histopathology.