The use of GDA-J/F3 monoclonal antibody for the detection of dead spermatozoa (necrosperm) during semen analysis.

The distinction between immotile necrosperm (dead spermatozoa) and those with immotility due to other causes is of the utmost clinical importance. The supravital dyes currently used for the identification of necrosperm are not highly reliable or accurate. In this study, GDA-J/F3 monoclonal antibody (MoAb) which reacts with the fibrous sheath (FS) was used as a specific probe for the detection of necrosperm using indirect immunofluorescence (IIF). Previously, several lines of evidence indicated the reaction of the antibody with necrosperm. This was confirmed in the current study where GDA-J/F3 MoAb failed to react with viable swim-up separated spermatozoa; such cells were only stained following sperm demembranation with 1% Triton X-100. Furthermore, by using immunogold electron microscopy of a normozoospermic sperm sample, all the spermatozoa which reacted with GDA-J/F3 MoAb showed damaged cytoplasmic membranes. Following these initial studies, sperm samples were obtained from 42 men attending infertility clinics and assessed by conventional semen analysis and GDA-J/F3 MoAb screening using IIF. The results showed a wide variation in sperm immotility and GDA-J/F3 reactivity; the ranges were 19-99 and 0-50% respectively. This novel immunological approach provides a simple and specific method of necrosperm enumeration for the investigation of male infertility.