[Modified sperm stress test. Immune response and functionality of the human spermatozoid membrane]

Our purpose was to study, in semen samples of infertile patients, the relationship between the Modified Sperm Stress Test (MOST) and the presence of antisperm antibodies (ASA), macrophages concentration and the Hypoosmotic Swelling Test (HOST).

Semen samples from 42 men undergoing evaluation for infertility were examined according to WHO criteria. Twenty-five of them, whithout clumping non hyperviscosity, were selected. The MOST test was applied according to the author's original technique. ASA were determined with a direct mixed agglutination test, TAC II, developed and validate by our group. Macrophage concentration was evaluated with Neutral Red stain, and functional integrity of the sperm membrane with the Hypoosmotic Swelling Test using an hypoosmotic solution of 150 mOm/ml composed of equal parts of fructose and sodium citrate.

The Chi square test was applied to the observational data obtaining the following results: There was a statistically significant association between the presence of ASA and altered MOST (p<0.001). In all samples with ASA, abnormal MOST values were obtained (MOST<0.39). Besides, there is a statistically significant association exists between the increased concentration of macrophages and abnormal MOST (p<0.01); and altered HOST was positively correlated with abnormal MOST (p<0.02).

Results clearly demonstrate the high predictive power of MOST like a test of sperm resistance to the forced lipoperoxidation, offering conditions to become a good predictor of sperm performance. Understanding the sperm resistance to the ROS and their harmfull effects on the sperm functions, a proportion of infertile men can be succesfully treated.