Intermediate filaments of human Sertoli cells in germinal alterations

Immunohistochemical techniques were used to examine testis biopsy specimens in subjects of different ages, in whom histological examination of the seminiferous tubules revealed a reduction in number, immaturity or absence of germinal elements. Our aim was to detect changes in the expression of the vimentin and cytokeratin (8-18-19) intermediate filaments in Sertoli cells. The use of anti-vimentin antibodies demonstrated intense Sertoli cell positivity in all the cases studied, confirming that germinal alterations do not interfere with the expression of these filaments. The Sertoli cells of the subjects affected by pathological conditions also reacted positively to anti-cytokeratin antibodies. This finding was constant in all the testes, showing evident signs of germinal immaturity. In contrast, anti-cytokeratin positivity was not observed in the control specimens after the pre-pubertal stage. Our findings show that persisting co-expression of vimentin and cytokeratin filaments in the Sertoli cells of productive subjects may be a marker of germinal cell degeneration.