Alpha-1,4-glucosidase activity and the presence of germinal epithelium cells in the semen for differential diagnosis of obstructive and nonobstructive azoospermia

Andrology laboratory technique for analysis of semen in men with azoospermia

ABSTRACT

Discovery of spermatozoa during the 17th century led to developing technologies for semen analysis in the early 1900s, and then, standard techniques were implemented during the 20th century. Semen analysis has a pivotal role in the male infertility evaluation, and azoospermia is an important finding. Azoospermia is identified in 15% of infertile men. However, the accurate laboratory assessment of azoospermia poses certain technical challenges. Laboratories currently perform semen assessment with great variability; thus, a standard method should be used. Planning suitable management and determining the cause of infertility require a precise evaluation of azoospermia. This review aims to address the definition of azoospermia and highlight laboratory methods in the assessments of azoospermia. Basic methods such as centrifugation, repeat pellet analysis, and staining and advanced methods such as genetic testing and biomarkers have been discussed. These methods have helped in standardizing the protocol for accurate azoospermia assessments with less variability.

The Effect of Neutral Alpha-Glucosidase on Semen Parameters

INTRODUCTION

The objective of this study was to investigate the relationship between the activity of neutral α-glucosidase in seminal plasma and semen quality and to explore the effect of secretory capability of the epididymis on male fertility.

METHODS

A retrospective analysis of 542 men treated in the Center for Reproductive Medicine and Infertility from February to December 2022, the semen parameters and neutral α-glucosidase were tested and compared among different groups. These 542 men included normozoospermia, oligospermia, asthenospermia, and teratozoospermia.

RESULTS

There was statistical difference in neutral alpha-glucosidase (NAG) level among different groups with different sperm concentration, motility, and morphology (p < 0.001). The NAG activity in seminal plasma was positively correlated with ejaculate volume and sperm concentration; meanwhile, a very weak positive correlation was found between NAG level and sperm motility, sperm morphology, respectively.

CONCLUSIONS

Our results indicated that the secretion of NAG affected the volume, concentration, motility, and morphology of sperm to a certain extent. Given that NAG is a specific and marker enzyme in epididymis, where is the site of sperm maturation, we can conclude that there is a close relationship between NAG and sperm quality. Therefore, seminal plasma NAG has a definite clinical value in helping diagnosis of male infertility.

A novel laboratory procedure to validate American Urological Association guideline on vasectomy success and to diagnose obstructive azoospermia

The objective was to develop a laboratory procedure to validate American Urological Association (AUA) Guideline on vasectomy success when nonmotile spermatozoa are found in the post-vasectomy ejaculate. The neutral α-glucosidase (NAG) an epididymal protein assay modified to determine the activity at 30 and 90 min of incubation from 24 pre- and 47 post-vasectomy ejaculates. The difference between the two points in the relative activity was calculated and if the difference was nonsignificant will confirm vasectomy success. The mean differences in the relative NAG activity were significantly different in pre- and post-vasectomy ejaculates, respectively. The mean differences in the relative NAG activity were similar in post-vasectomy ejaculates with and without nonmotile spermatozoa. No difference in relative NAG activity in post-vasectomy ejaculates between two time points of incubation may be a reliable method to confirm occlusion of the vas deferens. It also validates the recommendation by AUA Guideline on vasectomy success in the presence of few nonmotile spermatozoa.

Why do we determine alpha-glucosidase activity in human semen during infertility work-up?

alpha-Glucosidase is a normal constituent of human semen, produced mainly in the epididymis. It is significantly correlated to sperm count. Its activity is low in cases of epididymal obstruction. We evaluated alpha-glucosidase activity in 653 semen samples of patients, who attended our department for marital infertility, with respect to associations to clinical and other seminal parameters. The normal range (mean +/- 2 SD) in samples with normal parameter values was 7.2-46.4 mU ml-1. The determination in patients with azoospermia revealed mean values of 7.7 +/- 9.5 mU ml-1 in obstructive azoospermia, and 15.8 +/- 11.5 mU ml-1 in nonobstructive azoospermia. The difference was not statistically significant in that the sensitivity of determination with respect to the presence of obstruction was only 0.66, and the specificity 0.83. A significant correlation (r = 0.34) of alpha-glucosidase activity with log sperm count was observed. The mean alpha-glucosidase activity was not significantly different in groups formed according to sperm motility, according to leucocyte count or according to semen volume. A difference between smokers and nonsmokers with comparable sperm count, as reported in the literature, did not occur. We conclude from our results that the determination of alpha-glucosidase activity does not give additional information of the fertility status exceeding that of other clinical investigations or parameters of semen analysis.