OBJECTIVETo investigate and analyze the results of the determination of sperm concentration, fructose concentration, alpha-glucosidase and acid phosphatase (ACP) activities in the seminal plasma from different hospitals in the city of Nanjing, so as to provide a basis for the external quality control (EQC) of semen analysis within Jiangsu Province or even the whole country.

METHODSEight samples of quality control products for low and high concentrations sperm count, fructose, alpha-glucosidase and ACP determination were prepared and divided, each detected for the sperm concentration, fructose, alpha-glucosidase and ACP activity, and the coefficient variances (CVs) were calculated. The products were then distributed to 11 hospitals in the city, and the results were collected and analyzed. In addition, the total relative errors (REs) for each product was calculated based on the results after dividing as reference values.

RESULTSThe CVs from the 8 samples after dividing were 3.83% - 11.16%. Collected from the 11 hospitals attending EQC were 11 reports of the results of sperm concentration, and 5 the results of fructose, alpha-glucosidase and ACP in seminal plasma. Among the results from different laboratories, those of fructose determination showed the minimal difference (CVs: 8.99% and 3.95% for low and high concentrations, respectively) , next came alpha-glucosidase (CVs: 16.66% and 18.41% for low and high activities, respectively), and ACP determination showed the maximal difference (CVs: 54.12% and 65.58% for low and high activities, respectively). Moreover, the same trend was observed in RE values, as shown in the total REs, which were 11.99% (low concentration) and 20.31% (high concentration) for the determination of fructose in seminal plasma, 22.92% and 27.26% for alpha-glucosidase, 7.34% and 318.35% for ACP in different laboratories, and the maximal RE value was detected in the result of the high-activity ACP sample. Of the 11 hospitals, 6 determined sperm concentration with the computer-assisted semen analysis (CASA) system, and the other 5 with the modified hemocytometer. RE values (148.47% and 187.59% for low and high concentration samples, respectively) and sperm concentrations ([62.74 +/- 16.63] x 10(6)/ml and [163.32 +/- 36.24] x 10(6)/ml) counted with the hemocytometer were significantly higher than those with the CASA system (REs 13.97% and 10.48%; sperm concentrations [24.88 +/- 4.16] x 10(6)/ml and [54.24 +/-23.06] x 10(6)/ml ).

CONCLUSIONThe methods of seminal alpha-glucosidase and fructose determination were relatively stable in current andrology laboratories, and the variance range could be accepted. However, the method of seminal ACP determination might be unadaptable to clinical application, and needs to be further improved. Hemocytometer, which significantly overestimated sperm concentration, could not be applied to the assay of sperm concentration.