Immunology: The indirect immunobead test for seminal antisperm antibodies and fertilization rates at in-vitro fertifization

Abstract

A series of 183 patients with positive indirect immunobead tests on semen was studied to determine the correlation in semen between specific antibody types, binding sites, antibody concentration, and fertilizing ability. IgM was present in only 44 ejaculates and was present in sufficient quantity to cause significant binding to immunobeads (i.e. >20% of motile donor spermatozoa) in only three of them. There was no correlation between the percentages of motile donor spermatozoa that bound IgA and IgG immunobeads but the two classes of beads generally bound to the same region of the spermatozoa. A total of 63 couples went on to attempt in-vitro fertilization (IVF) treatment, all with mature eggs recovered. Of these mature eggs, 44% were fertilized and cleaved normally in comparison to 68% in a group of patients with tubal disease. Fertilization rates in individuals followed a bimodal distribution with a substantial number of couples experiencing zero or very poor rates (0-20%), the mode for the remainder lying between 60 and 80%. The fertilization rate tended to decrease as the amount of antibody increased. The percentage of donor spermatozoa that bound to immunobeads, taken as the greater of IgA and IgG, was selected by logistic regression as a significant predictor of poor fertilization (rate <=25%). The predictive power of the equation was improved by including the motile normal sperm concentration but the equation could only account for a small proportion of the total variation in fertilization rate. The presence of antibodies to the sperm head was highly correlated with the antibody concentration but was not selected as a predictor of fertilization. We conclude that the nature of the antigen against which the seminal antisperm antibody is directed may be as important as the antibody concentration in affecting sperm function. There seems to be little practical value in measuring IgM in seminal plasma.

Semen Analysis and Antisperm Antibody

“…In fact, Witkin et al [42] reported on the examination by the IBT of 67 couples after an unsuccessfid IVF cycle that sperm-bound antibodies were detected in 35.7% (5/14) of men with poor fertilization rate (9-19%) and in none (0/19) of the patients with greater than 40% fertilization rate 0) < .02). Recently, Ford et al [43] demonstrated a significantly lower fertilization rate (up to cleaving, 38%, 209/544) of mature oocytes in cases of positive IBT in the seminal plasma than that (68%, 380/555; p < .001) of the control group.…”

Immunobiology of Spermatozoa: A Review

“…73,93,94 Although the presence of antisperm antibodies to the sperm head is highly correlated with the antibody concentration, it is not a predictor of the fertilization rate. 95 While these antibodies can bind to the spermatozoon head, middle piece, or tail, their binding is most prominent to the middle piece.…”

Naturally-occurring antisperm antibodies in men: interference with fertility and implications for treatment

“…Altogether, these observations suggest that both humoral and local sperm autoimmunizzation exhibit the same behaviour in impairing or not the ZP-binding. The fact that ZP-binding is not unavoidably inhibited by ASA, could explain the high fertilization rate in IVF programs, which was reported in some cases even in the presence of a high degree of sperm-autoimmunization (121,123,124,128). However, the ZP-binding is only the first step of the more complex interaction between spermatozoa and zona.…”

“…Table 2 shows the fertilization rates reported in series including couples with sperm autoimmunization in the male partner. In most reports the fertilization rate was significantly lower in the presence of sperm-bound antibodies than in the case of other indications for IVF (119)(120)(121)(122)(123)(124). However, in some other reports no significant difference was found (125-127).…”