[Clinical significance of direct immunobead test to detect anti-sperm antibody]

Direct immunobead test (IBT) (IgG.IgA) was carried out for 290 infertile men to detect antisperm antibodies. The results, compared with semen data analyzed by traditional methods and a computer assisted semen analyzer and with hormone levels, were as follows. 1) In 21(7.2%) out of the 290 men, IgG-immunobead (IB) binding was observed in more than 50% of their motile spermatozoa; in 10(3.4%) of the 290, IgA-IB binding. 2) In all of the cases with proven fertility, the IB binding rate was less than 60% for IgG-IB, and less than 40% for IgA-IB. This suggested that antibodies attached to sperm could be among the factors in male infertility. 3) Antibodies attached to the sperm head with binding rate of less than 40% were not considered to be a causative factor in male infertility. 4) The incidence of positive IgG-IB was higher, and also in each case the IgG-IB binding rate was higher than the IgA-IB. 5) IgG-IB binding parts of each spermatozoon included IgA-IB binding parts. 6) No significant relationship was observed between the results of traditional semen analysis, LH.FSH.PRL levels or PENETRAK and the rates of IB binding.