Relationship between semen quality and the seminal plasma components carnitine, alpha-glucosidase, fructose, citrate and granulocyte elastase in infertile men compared with a normal population.

The seminal plasma components neutral alpha-glucosidase, carnitine, fructose, citrate, and polymorphonuclear granulocyte (PMN) elastase in 253 men were determined. The seminal plasma of 221 infertile men, a control group with proved fertility and 13 patients after vasectomy were investigated. The concentrations of free carnitine (212 versus 521 micromol/l, n = 219, P < 0.001), total carnitine (437 versus 743 micromol/l, n = 219, P < 0.001), and the activity of neutral alpha-glucosidase (15.1 versus 23.4 IU/l, n = 236, P < 0.05) were significantly reduced in the infertile patient group as compared to the fertile control group, the concentration of PMN elastase (102 versus 48 microg/l, n = 234, P < 0.05) being significantly increased in the infertile patients. In the patients after vasectomy the activity of neutral alpha-glucosidase was the only epididymal marker that was significantly reduced (4.3 versus 9. 8 IU/l, n = 35, P = 0.002) in comparison with the patients with testicular azoospermia. At a limit of 6 IU/l the sensitivity of the method was 92% and the specificity was 72%. Altogether, the epididymal markers were reduced in subfertile patients compared with the control group. For the differential diagnosis of azoospermia only the determination of the neutral alpha-glucosidase activity is useful.