Indirect mixed antiglobulin reaction (MAR) as a screening procedure for antisperm antibodies. I. Methodological studies.

Direct mixed antiglobulin reaction (MAR) cannot always be carried out because it requires motile spermatozoa in the patient's ejaculate. Therefore, the indirect MAR for IgG and IgA using donor spermatozoa sensitized with serum or seminal plasma from patients was investigated with the aim of developing a practical screening procedure for antisperm antibodies involving a characterization of the Ig-class of the antibodies. Samples from 23 men, 13 men with and 10 men without agglutinating antisperm antibodies, were used for the methodological experiments with the indirect MAR. Among three procedures to diminish the amount of nonbound immunoglobulin after sensitizing the donor spermatozoa with serial dilutions of serum or seminal plasma, a swim-up method was found to be optimal. The indirect MAR was carried out with glutaraldehyde-fixed sheep erythrocytes coated with IgG or IgA and various dilutions of anti-IgG and anti-IgA, respectively. These experiments led to a standardization of the indirect MAR, making it sensitive, easy to read, and allowing the reactions for IgG and IgA to be compared on an approximately equimolecular basis.