Evaluation for antisperm antibodies after storage of sperm in TEST-yolk buffer *

Objective To determine if TEST-yolk buffer, consisting of TES (N-tris [hydroxymethyl]-methyl-2-aminoethanesufonic acid), Tris (Tris[hydroxymethyl]aninomethane), and chicken egg yolk, affects the presence of antisperm antibodies on the sperm surface as detected by the immunobead test. Design A prospective study of antisperm antibodies on sperm surface before and after incubation in TEST-yolk buffer. Direct immunobead test and indirect immunobead test were done the day of collection of the semen sample to detect the presence of human immunoglobulin class G (IgG) and immunoglobulin class A (IgA); immunobead tests were repeated on the same sperm samples after 24hours of storage in TEST buffer. Setting Academic tertiary institution. Participants Patients undergoing evaluation for infertility. Results There was no significant difference in the outcome of the direct immunobead test after extending semen samples with TEST-yolk buffer for 24hours at 4°C. Eleven samples that were initially negative for IgG and 13 samples that were negative for IgA remained negative after 24-hour storage in TEST-yolk buffer. Eleven samples that were positive for IgG and nine samples that were positive for IgA by the direct immunobead test the first day remained positive the next day. Five extended sperm samples used in the indirect immunobead test with IgG positive serum gave positive results and four of five used with IgA positive serum gave positive results. Conclusions These findings suggest that TEST-yolk buffer can be used to extend semen without affecting the presence of antibodies on the sperm surface as indicated by the direct immunobead test. The higher variability of the indirect immunobead tests indicates there may be some alteration of sperm antigens after storing in TEST-yolk buffer. These findings indicate that TEST-yolk buffer can be used to store semen for batched processing of samples or as a transport medium for delivery to a central laboratory for antibody testing.