RESUMO
Objective of study: To investigate the re l a t i o n s h i p between seminal levels of zinc and cadmium and spermatozoal quality, and their effects on the immune response. Study Design and Methodology: Forty-five infertile and 16 fertile males were included in this study. Investigations included semen analysis, a hypo-osmotic swelling test, antisperm antibodies by immunobeads, trace elements with atomic absorption spectroscopy and TNF- and interleukin-4 with ELISA. A high zinc/cadmium [Zn/Cd] ratio of more than 200 was associated with a normal sperm count and motility. There was an inverse relationship between the Zn/Cd ratio and impairment of spermatozoa motility. A high Zn/Cd ratio was associated with a low incidence of antisperm antibodies, especially IgA and IgM, a positive correlation with seminal IL-4 but inverse relationship with TNF-. The Zn/Cd ratio may be a better index of sperm quality than seminal zinc and cadmium, independently, through a differential reduction of the humoral immunity and enhancement of the T helper-2 cytokine Interleukin-4 as well as a down regulation of the T helper-1 cellular immune response