Antisperm Antibodies

A semen analysis sample can also be used to perform an antisperm antibody test.

The semen sample that is provided by the male partner for the purpose of performing a semen analysis can also be used to perform a test known as an anti-sperm antibody test. This reveals the presence or absence of anti-bodies in a man’s semen to his own sperm. The presence of anti-bodies in seminal fluid can compromise the ability of sperm to swim to the egg or may prevent the sperm from binding to or penetrating the egg.

Sperm are composed of proteins and are manufactured in the testes. They are located in tubules within the testes and epididymis. The normal anatomy of a man keeps the sperm isolated from the blood located in blood vessels. However, if this barrier between the sperm and the blood is broken by injury, surgery or infection the sperm will come into contact with the blood. This abnormal condition causes the sperm to be considered as a foreign protein and the body forms anti-bodies against that protein. The anti-bodies are present in all of the body fluids.

So, at ejaculation, when the sperm are combined with the fluids of the prostate and the seminal vesicles, the anti-bodies within these fluids attach to the surface of the sperm and cause the sperm to clump together.

The presence of anti-bodies can be overcome. They only present a problem if they are not detected and nothing is done to prevent the clumping from happening. If sperm are collected in a cup containing medium with a high percent of protein, the sperm clumping will be greatly reduced. This motile sperm can then be used in intrauterine insemination or in vitro fertilization.

The significance of anti-sperm antibodies is that they can be a contributing factor to infertility. While the presence of a low percentage of positive sperm might not be enough to prevent pregnancy from occurring, the coupling of antibodies with a low sperm count or low motility or morphology could be enough to significantly reduce a couple’s chances for success.