OBJECTIVE: To determine the lactate dehydrogenase C4 (LDH-C4) isoenzyme activity in seminal fluid with the purpose of studying its clinical use as marker of seminiferous epithelium activity. DESIGN: A total of 224 semen samples were classified into the following four groups: [1] men with proven fertility (n = 27); [2] oligozoospermic patients (n = 34); [3] normozoospermic subjects with infertile couple (n = 120); and [4] vasectomized patients (n = 22). RESULTS: It was found that LDH-C4 activity discriminates well between the infertile groups (groups 2 and 3) with the fertile group (group 1). We correlated LDH-C4 activity with the different parameters of the seminogram, the best correlation being obtained with the sperm count. Lactate dehydrogenase-C4 activity:sperm count ratio showed a high correlation with the "vital" variables of spermatozoon. The logistic regression analysis gave a mathematical model that only includes viability and percent C4. This model accurately classifies 88.4% of the cases. In vasectomized individuals, we proved an earlier disappearance of the LDH-C4 activity, than that of the sperm count. CONCLUSION: Our results confirm the clinical utility of this parameter as a good marker for both germinal activity and spermatozoid quality.
OBJECTIVE: To determine the lactate dehydrogenase C4 (LDH-C4) isoenzyme activity in seminal fluid with the purpose of studying its clinical use as marker of seminiferous epithelium activity. DESIGN: A total of 224 semen samples were classified into the following four groups: [1] men with proven fertility (n = 27); [2] oligozoospermic patients (n = 34); [3] normozoospermic subjects with infertile couple (n = 120); and [4] vasectomized patients (n = 22). RESULTS: It was found that LDH-C4 activity discriminates well between the infertile groups (groups 2 and 3) with the fertile group (group 1). We correlated LDH-C4 activity with the different parameters of the seminogram, the best correlation being obtained with the sperm count. Lactate dehydrogenase-C4 activity:sperm count ratio showed a high correlation with the "vital" variables of spermatozoon. The logistic regression analysis gave a mathematical model that only includes viability and percent C4. This model accurately classifies 88.4% of the cases. In vasectomized individuals, we proved an earlier disappearance of the LDH-C4 activity, than that of the sperm count. CONCLUSION: Our results confirm the clinical utility of this parameter as a good marker for both germinal activity and spermatozoid quality.