There are three types of sperm autoimmunity: that associated with genital tract obstruction, that accompanied by tesricular inflammation, and a spontaneously occurring type that does not present with either of the preceding associated features.
Sperm Autoimmunity Associated with Genital Tract Obstruction
About 50% of men seen with positive sperm antibody tests also have genital tract obstruction — most commonly the result of vasectomies, post-inflammatory epididymal obstructions, or reconstructive surgery. More than 70% of men develop sperm antibodies in their serum within twelve months of vasectomy. The antibodies are more frequent in men who also have sperm granulomas associated with the vasectomy. The presence of these antibodies is an adverse factor for the future success of vasovasostomy, as well as surgery for other genital tract obstructions. Sperm autoimmunity is common in men with persisting infertility after vasectomy reversal.
The other types of genital tract obstruction associated with sperm autoimmunity appears to be that which occurs after puberty, such as post-gonococcal epididymitis or obstruction due to trauma, including iatrogenic vasal damage inflicted at the time of inguinal hernia surgery. Unilateral genital tract obstruction may also cause sperm antibody production. Sperm antibodies are less common with congenital epididymal obstructions, Young syndrome, and congenital absence of the vasa. The presence of antibodies in this group may be related to the length of unobstructed epididymis.
Sperm Autoimmunity Associated with Orchitis
Occasionally, inflammatory cell infiltrates are found in testicular biopsies of men with sperm antibodies. This “autoimmune orchitis” may follow an episode of epididymo-orchiris or it may occur spontaneously. Whether the infiltrates are related to the sperm antibodies is unknown, as they may exist in the absence of sperm antibodies. Sympathetic orchitis following testicular injury may occur, but it is very rare.
Spontaneous Sperm Autoimmunity
About half the men with sperm antibodies have no obvious genital tract obstruction or orchitis. Some may have a genetic or familial predisposition to autoimmunity. Wall et al. found thyroid antibodies to be more common in infertile men, some of whom had sperm antibodies. The authors of this post have previously reported 101 non-azoospermic men with positive sperm antibody tests who were found to have a higher frequency of family histories of other autoimmune diseases such as pernicious anemia and thyroid disorders (32% compared with 11% in 725 control infertile men). In a study of 102 men with spontaneously occurring sperm autoimmunity and 277 control infertile men without azoospermia and negative sperm immobilization test, a significantly higher frequency of positive thyroid microsomal antibodies was also found: 11.8% compared with 4.3% in controls. Positivity for any thyroid or gastric antibody was also higher than in controls (18.6% compared with 8.7%). The results for another 57 patients with sperm autoimmunity associated with genital tract obstruction were similar to the sperm immobilization test negative control patients. Previously, several researchers had shown that vasectomy itself does not predispose to the development of any auto-antibodies other than antisperm antibodies. The existence of patients with sperm autoimmunity and other concomitant autoimmune diseases, such as Hashimoto thyroidiris, however, has since been demonstrated. It is possible that there are HLA subtypes that predispose a patient to the development of sperm antibodies. Notably, the frequency of positive sperm antibody positive results tends to increase with age in men. These features suggest that this form of sperm autoimmunity has a similar pathogenesis to other organ-specific autoimmune diseases. It is interesting that neonatal thymectomy in some strains of mice and rats produces autoimmune endocrine gland disorders, orchitis, and infertility associated with sperm antibodies.
Other Associations of Sperm Antibodies
Associations between sperm antibodies and other conditions such as mumps orchitis, varicocele, sexually transmissible and non-specific male accessory gland inflammation, leprosy, chronic alcoholism, hyperprolacrinemia, immotile cilia and failure of ejaculation of various causes including chronic spinal cord injury have been suggested but not confirmed. Testicular biopsy, orchiopexy for undescended testes, other scrotal surgery, testicular torsion and other injuries do not appear to cause or aggravate sperm autoimmunity. During the evaluation of a method for fine needle tissue aspiration biopsy of the testis, the authors attempted to observe a change in tirre of sperm antibodies in men previously known to be positive. Serum was collected two weeks after the biopsy, when an anamnestic response would be expected to peak. There was, however, no change detected by the indirect immunobead test in any IgG, IgA, or IgM antibody class. Apart from the association with genital tract obstruction of post-pubertal onset, minor damage to the scrotal contents is unlikely to be relevant to the production of sperm antibodies. Histories of testicular trauma, inflammation and surgery appear to be no more frequent in men with sperm antibodies than in other infertile men.