Antispermatozoal antibodies in three men with infertility due to congenital aplasia of the vasa deferentia

Cystic fibrosis and congenital agenesis of the vas deferens, antisperm antibodies and CF-genotype

Antisperm antibodies are formed as a result of vasal and epididymal obstruction. Fourteen males of different ages (pre-, peri- and post-pubertal) with bilateral congenital vasal agenesis and epididymal obstruction secondary to cystic fibrosis (CF), and seven men with congenital bilateral aplasia of the vas deferens (CBAVD) were evaluated with regard to both the presence and levels of serum antisperm antibodies, and the CF-genotype. While IgA and IgG were not detected among pre- and peri-pubertal CF patients, 4 out of 10 (40%) exhibited IgM binding to sperm tail-tip. Post-pubertal CF patients showed high antisperm antibody (ASA) levels in 3 of the 4 males (75%) evaluated for the three isotypes assayed. ASA were found in 5 of 7 CBAVD patients (71%); IgG (n = 3) and IgM (n = 4) were found to be the predominant isotypes bound to sperm tail-tip. CF-genotype analysis revealed two pre-pubertal patients with the DeltaF508/DeltaF508 CF-genotype and a positive ASA response, thus suggesting an earlier or more severe blockage. In addition, the two CBAVD patients found to have a ?/? CF-genotype on the initial screening did not have ASA. The altered antigenicity of sperm associated with initiation of spermatogenesis appears to modify the antisperm antibody isotypes. Further studies on a larger number of patients may allow for a better understanding of the ASA response, as well as a better understanding of a possible phenotype/genotype association between the CF-genotype and the immunologic response.

Sperm antibodies in a patient with obstructive azoospermia

An artificial spermatocoele was constructed at the level of the caput epididymis in a patient with obstructive azoospermia. Morphologically normal spermatozoa were harvested but motility and progression were inadequate for intra-uterine insemination or in vitro fertilisation. In addition, there was an antispermatozoal antibody response which transuded back into the reproductive tract and coated spermatozoa with antibody. It is recommended that if harvesting of epididymal spermatozoa is contemplated, the serum should initially be assessed for spermatozoal antibody.

Relationship of epididymal sperm antibodies to their in vitro fertilization capacity in men with congenital absence of the vas deferens

OBJECTIVES

To test, using the immunobead binding technique, for the presence of antisperm antibodies on epididymal sperm, in epididymal fluid, and in serum of men with congenital absence of the vas deferens. To evaluate the in vitro fertilization (IVF) capacity of human epididymal sperm in the presence of antisperm antibodies.

DESIGN

Prospective. At the time of oocyte insemination, sperm from the proximal caput epididymis or vasa efferentia were tested by direct immunobinding technique. The epididymal fluid and serum were tested by indirect immunobinding technique.

SETTING

Center for Reproductive Health, University of California-Irvine.

PATIENTS

Forty-five patients with congenital absence of the vas deferens participating in the microsurgical epididymal sperm aspiration and IVF program.

MAIN OUTCOME MEASURE

Incidence of antisperm antibodies to epididymal sperm and their relationship with IVF results.

RESULTS

Sixteen men (35%) tested positively to the direct immunobead test on epididymal sperm; 7 (16%) were positive in epididymal fluid and 13 (29%) were positive in serum. Five pregnancies (31%) occurred in the positive group of which two were from patients who had sperm binding of 100% for immunoglobulin (Ig)G (all over sperm surface) and 90% (midpiece, tail) and 50% (tail, tiptail), respectively, for IgA. Five pregnancies (18%) were obtained in the negative group. No statistical difference was observed in the overall fertilization rate between the two groups.

CONCLUSION

Human epididymal sperm and epididymal fluid retrieved from men with congenital absence of the vas deferens can react positively to immunobead test. However, the presence of antisperm antibodies do not seem to impair the IVF capacity of epididymal sperm.

Auto-antibodies to human sperm basic nuclear proteins in infertile and vasectomized men: characterization of antigens and epitopes recognized by antibodies

The sera of vasectomized men and of patients with immune infertility were used to study the antigens and epitopes of sperm nuclear proteins that bind antibodies in these sera. No reaction with sperm histones was observed except for one serum. P1, P2 protamines and pro-P2 protamines were recognized by auto-antibodies. Studies with peptides derived from P1 and P2 protamines and with mammalian protamines related to HP1 showed that antibodies are mainly specific for a folded protamine molecule, more especially antibodies from vasectomized men. These results disagree with the random coil model proposed for protamines by several previous works. A cross-reactivity between P1 and P2 protamines was observed only for the whole molecules and not for peptides derived from them. This observation suggests that the two classes of protamines, different in sequence, may have a similar folding and thereby may be functionally equivalent.

Sperm antibodies

Anti-sperm antibodies (ASA) occur in 1% to 30% of infertile couples. Mechanisms by which ASA impair fertility include prevention of fertilization by decreasing acrosome reaction and/or zona pellucida binding, and postfertilization effects. Treatment for ASA involves assisted reproductive technologies.