Utilization of two protein markers has the potential to replace most testicular biopsies in men with fertility issues. The two germ cell–specific proteins are effective at differentiating men with infertility and identifying subtypes of azoospermia (nonmeasurable levels of sperm in semen), according to a study published Nov. 20 in Science Translational Medicine. Currently a testicular biopsy is a necessary, but imperfect technique to determine if a man has viable sperm that can be utilized in assisted reproduction. But a new test incorporating these two germ-cell protein markers may spare men unnecessary biopsies and surgeries and can provide more accurate assessment of histopathological subtypes of nonobstructiveazoospermia (NOA) and predict the success of testicular sperm extraction (TESE). The two markers (epididymis-expressed ECM1 and testis-expressed TEX101) differentiated obstructive azoospermia (OA) and NOA with high specificities and sensitivities. Using a cutoff level of 2.3 mg/ml OA was distinguished from normal spermatogenesis with 100 percent specificity, while OA was distinguished from NOA with 73 percent specificity and 100 percent sensitivity. TEX101 semen concentrations differentiated the Sertoli cell–only (SCO) syndrome subtypes of NOA using a cutoff of less than 5 ng/ml and hypospermatogenesis (HS) or maturation arrest (MA) subtypes (at 5 to 120 ng/ml in this […]