The role of antisperm antibodies in causation of male infertility is controversial. The immunological tests done on seminal fluid include mixed antiglobulin reaction (MAR test) and immunobead test.
The antibodies against sperms immobilize or kill them, thus preventing their passage through the cervix to the ovum. The antibodies can be tested in the serum, seminal fluid, or cervical mucus. If the antibodies are present bound to the head of the sperm, they will prevent the penetration of the egg by the sperm. If antibodies are bound to the tail of the sperm, they will retard motility.
This test can detect IgG and IgA antibodies against sperm surface in semen sample. In direct SpermMAR™ IgG test, a drop each of semen (fresh and unwashed), IgG-coated latex particles, and anti-human immunoglobulin are mixed together on a glass slide. At least 200 motile spermatozoa are examined. If the spermatozoa have antibodies on their surface, antihuman immunoglobulin will bind IgG-coated latex particles to IgG on the surface of the spermatozoa; this will cause attachment of latex particles to spermatozoa, and motile, swimming sperms with attached particles will be seen. If the spermatozoa do not have antibodies on their surface, they will be seen swimming without attached particles; the latex particles will show clumping due to binding of their IgG to antihuman immunoglobulin.
In direct SpermMAR™ IgA test, a drop each of fresh unwashed semen and of IgA-coated latex particles, are mixed on a glass slide. The latex particles will bind to spermatozoa if spermatozoa are coated with IgA antibodies.
In indirect SpermMAR™ tests, fluid without spermatozoa (e.g. serum) is tested for the presence of antisperm antibodies. First, antibodies are bound to donor spermatozoa which are then mixed with the fluid to be analyzed. These antibodies are then detected as described above for direct tests.
Atleast 200 motile spermatozoa should be counted. If >50% of spermatozoa show attached latex particles, immunological problem is likely.
Antibodies bound to the surface of the spermatozoa can be detected by antibodies attached to immunobeads (plastic particles with attached anti-human immunoglobulin that may be either IgG, IgA, or IgM). Percentage of motile spermatozoa with attached two or more immunobeads are counted amongst 200 motile spermatozoa. Finding of >50% spermatozoa with attached beads is abnormal.