Why Do We Need New Markers for Male Hypogonadism and How Seminal Proteomics Might Solve the Problem?

Male hypogonadism is "a clinical syndrome that results from failure of the testis to produce physiological concentrations of testosterone and/or a normal number of spermatozoa due to pathology at one or more levels of the hypothalamic- pituitary-testicular axis". The diagnostic protocol of male hypogonadism includes accurate medical history, physical exam, as well as hormone assays and instrumental evaluation. Basal hormonal evaluation of serum testosterone, LH, and FSH is important in the evaluation of diseases of the hypothalamus-pituitary-testis axis. Total testosterone levels < 8 nmol/l profoundly suggest the diagnosis of hypogonadism. An inadequate androgen status is moreover possible if the total testosterone levels are 8-12 nmol/L. In this "grey zone" the diagnosis of hypogonadism is debated and the appropriateness for treating these patients with testosterone should be fostered by symptoms, although often non-specific. Up to now, no markers of androgen tissue action can be used in clinical practice. The identification of markers of androgens action might be useful in supporting diagnosis, Testosterone Replacement Treatment (TRT) and clinical follow-up. The aim of this review is to analyze the main findings of recent studies in the field of discovering putative diagnostic markers of male hypogonadism in seminal plasma by proteomic techniques. The identified proteins might represent a "molecular androtest" useful as a seminal fingerprint of male hypogonadism, for the diagnosis of patients with moderate grades of testosterone reduction and in the follow-up of testosterone replacement treatment.