New non-invasive biomarker for diagnosis and prognosis in male sterility

Researchers from the Human Molecular Genetics group of the Bellvitge Biomedical Research Institute (IDIBELL), led by Dr. Sara Larriba, have identified a new non-invasive biomarker of the presence of sperm in the testis of azoospermic men, who represent 10% of the cases of male sterility. The work, published in the prestigious international journal Human Reproduction, has been carried out in collaboration with the team of Dr. Bassas, of the Andrology Service of the Fundació Puigvert.

Azoospermia, the total absence of sperm in the ejaculate, causes sterility, but does not always rule out assisted reproduction techniques such as ICSI (intracytoplasmic sperm injection) with sperm or spermatids recovered from the testicle itself. "Although hormonal determinations and other clinical data can guide us, there is still a lack of non-invasive diagnostic methods that accurately determine if there are spermatozoa in the testis in azoospermic males, a must-have for assisted reproduction treatment. Therefore, the diagnosis always requires a biopsy”, says Dr. Bassas.

The research team proved that the quantification of certain ribonucleic acid molecules called miRNAs, contained in vesicles of seminal plasma, can be used as non-invasive biomarkers of the presence of sperm in the testicle, so they represent an alternative to identify a priori those individuals with real possibilities of positive recovery of sperm, avoiding unnecessary biopsies. "The seminal plasma shows a high concentration of ribonucleic acid (RNA), both messenger RNA (mRNA) and other RNAs (miRNAs), which can be identified and quantified, which makes them excellent candidates as non-invasive biomarkers for diagnostic purposes and prognosis" explains Dr. Larriba, responsible for the line of Molecular Genetics of Male Fertility in IDIBELL.

The finding has been protected by a patent and was presented as an invited lecture at the 32nd Congress of the Spanish Fertility Society (SEF), held this month of May, and accepted as an oral communication at the Congress of the European Society of Human Reproduction and Embryology (ESHRE), which will be held in Barcelona in July 2018.