Expression of VASA mRNA in testis as a significant predictor of sperm recovery by microdissection testicular sperm extraction in patient with nonobstructive azoospermia.

It would be of value to evaluate whether expression levels of mRNAs playing important roles in spermatogenesis could be used as predictors of successful testicular sperm recovery by microdissection testicular sperm extraction (TESE) in patients with nonobstructive azoospermia (NOA). This study included 52 patients with NOA who underwent therapeutic sperm retrieval by micro-TESE at our institution. We measured expression levels of VASA, outer dense fiber-1 (ODF1), ODF2, and sperm mitochondria-associated cysteine-rich protein (SMCP) mRNAs in testicular tissue specimens obtained from these patients by quantitative real-time reverse transcription polymerase chain reaction. Expression patterns of these mRNAs were analyzed focusing on the outcomes of sperm retrieval by micro-TESE. There were no significant differences in age, testicular volume, and serum levels of follicle-stimulating hormone, luteinizing hormone, and testosterone between successful and unsuccessful TESE groups; however, the proportion of patients with Sertoli cell only in the successful TESE group was significantly lower than that in the unsuccessful TESE group. Additionally, expression levels of VASA, ODF1, ODF2, and SMCP mRNAs in the successful TESE group were significantly greater than those in the unsuccessful TESE group. Univariate analysis identified histological classification, VASA, ODF1, ODF2, and SMCP expressions as significant predictors of sperm retrieval, of which only VASA mRNA expression appeared to be independently related to micro-TESE outcome on multivariate analysis. These findings suggest that measurement of VASA mRNA in testis could be a useful adjunct to conventional parameters for predicting sperm retrieval by micro-TESE in patients with NOA.