Efficacy of Acrosome Reaction after Ionophore Challenge (ARIC) Test in Evaluation of Fertilization Capacity of Human Spermatozoa

Ryu, B Y; Kim, S H; Park, S Y; Jee, B C; Jung, B J; Kim, H S; Pang, M G; Oh, S K; Suh, C S; Choi, Y M; Kim, J K; Moon, S Y; Lee, J Y; Son, Y S

Abstract

Over recent years, major emphasis has been focused on the management of male factor infertility, and it has become increasingly clear that standard semen analysis has many limits for the prediction of fertilization. As in vitro fertilization and embryo transfer (IVF-ET) is an important therapeutic option in male factor infertility, enormous efforts have been geared towards the development of better tests that might predict the fertilizing potential of a given semen specimen. The present study was designed to evaluate and verify the effectiveness of the acrosome reaction following ionophore challenge (ARIC) test as a prognostic indicator of fertilization capacity of human spermatozoa. Such parameters as the spontaneous reaction rate (control), the induced reaction rate (ionophore challenged), and the difference between the spontaneous and induced rates (ARIC value), and the proportion of spermatozoa capable of reacting in response to calcium influx were measured in 86 men with good fertilization rate (> or =30%) and 39 men with poor fertilization rate (<30%) undergoing IVF-ET. While the spontaneous reaction rate had no relation to the fertilizing capacity, the induced reaction rate and ARIC value were significantly reduced in the poor fertilization group, indicating acrosomal dysfunction is a likely cause of fertilization failure. In evaluating the effectiveness of ARIC test, ROC curve was used. Among the various thresholds for the prediction of fertilizing capacity, ARIC value 8.5 corresponded to the value with higher sensitivity and lower false positive rate, and was determined as a cut-off value. Using this cut-off point, sensitivity, specificity, positive predictive value (PPV), and negtive predictive value (NPV) for ARIC test was 83.7%, 92.3%, 96.0% and 72.0%, respectively. These results suggest that ARIC test can be a valuable tool as a prognostic indicator of fertilization capacity of human spermatozoa.