We got a question from a patient on anti-sperm antibodies last week: the patient wanted to know the level of anti-sperm antibodies in his blood because he is concerned that they will influence the success rate of a vasectomy reversal. This blog post will specifically address this issue.
What is an Antibody?
An antibody is a blood protein produced by your body’s immune system in response to the stimulation of a specific antigen. Common antigens include multiple antigens in bacteria, viruses, cancer cells and foreign substances in the blood. The antibodies combine chemically with antigens and serve to help the body target and fight-off theses “dangerous” or “unwanted” cells or substances.
What are Anti–sperm Antibodies?
Normally, sperm antigens in sperm are not exposed to the immune system because of the blood-testis barrier and other epithelial barriers along the reproductive tract. When the blood-testis barrier is compromised under certain circumstances, such as trauma/surgery, infection, cancer and congenital defect, sperm could be exposed to blood and trigger the immune responses, which leads to antibody development. Development of anti-sperm antibodies after vasectomy is thought to be related to the breakdown of the blood-testis barrier and leakage of sperm antigens from the epididymis.
Antisperm antibodies are found in between 8% and 21% of men in the general population, 9% and 36% of infertile patients, and 70-100% of men after vasectomy.
What is the Relationship of Anti-sperm Antibodies with Vasectomy and Vasectomy Reversal Procedures?
How Anti-sperm antibodies affect fertility following vasectomy reversal is not clear. The practice guidelines of the American Society for Reproductive Medicine and the Society for Male Reproduction and Urology stated:
“Overall postoperative conception rate (following vasectomy reversal) is relatively high (50% to 70%) and the presence of antisperm antibodies does not correlate closely with postoperative fecundability. Consequently, the value of preoperative antisperm antibody testing remains controversial and unproven.”
Here is a summary of research evidence:
1) Despite almost all men having detectable antibodies following a vasectomy, two thirds of vasectomy reversals are successful in achieving a pregnancy.
2) The presence and levels of antibodies following vasectomy reversal inconsistently predicts what couples will be successful in achieving a pregnancy.
3) The subjects of most research were infertile men. Research data from fertile men is lacking.
4) Testing for sperm antibodies is not well standardized. There are different types of antibodies and different locations in the sperm. The influences from each antibody are unclear.
What is the Long Term Medical Consequence of Existing Anti-sperm Antibodies?
Studies have provided convincing evidence that a vasectomy does not lead to development of autoantibodies in men other than anti-sperm antibodies, and there is no evidence of any immunologic or other diseases related to development of anti-sperm antibodies following vasectomy.