[Biochemical study of testicular biopsy in infertility]

Basic semen tests nowadays contain no variables that may allow to certify that a man is fertile. Starting from this premise it could be clinically very useful, for the diagnosis of male infertility, to evaluate a parameter that may be related to sexual maturity and be specific of the germinal tissue, such as the C4-lactate dehydrogenase isoenzyme (C4-LDH), which could indicate the activity of the germinal epithelium and the quality of the spermatozoa. In our experience, C4-LDH activity in seminal plasma discriminates between fertile and non-fertile males; also, their testicular study has a good correlation both with histologically diagnosed disease and the seminal plasma levels. All of which suggest the diagnostic validity of plasma C4-LDH in male infertility, as a routine test which thus precludes the use of invasive techniques in the patient.