Department of Andrology, University Hospital, D-35033 Marburg e-mail: krause{at}mailer.uni-marburg.de
Dear Sir,
We would like to thank Dr Check for his kind comments and his excellent and valuable additions to our article.
On the basis of previous results of his group, Dr Check quotes the advantages of inrauterine insemination (IUI) in immune infertility due to antisperm antibodies (ASA). He suggests that those ASA that inhibit the penetration of sperm through the cervix mucus also inhibit fertilization by interfering with the process of spermoocyte interaction. In these cases, the treatment of sperm bearing ASA with chymotrypsin might improve not only the mucus penetration, but also the fertilization outcome.
This is a valuable suggestion. However, unfortunately also in these studies the cognate antigens of the ASA concerned remain unknown. The results may also be explained by the suggestion quoted already in our article that there are ASA binding to antigens involved in the process of fertilization and to others which are not involved. In order to test the hypothesis, it would be of great interest to repeat the studies quoted, if at least some of the cognate antigens of the patients ASA are characterized.
After this, Dr Check poses two questions:
(i) Are components of the complement system present in other parts of the female genital tract beyond the cervical mucus? We are not aware of studies dealing with components of the complement system in the female genital tract except the cervix mucus. However, since these components are proteins circulating in the blood, it is possible that they also diffuse into other genital fluids. The concentrations in these fluids are expected to be much lower than in the blood serum, as is also observed in the cervical mucus. Bronson et al. (1987) suggested that the low concentration of the complement system in cervical mucus is the reason for a delayed effect of ASA on sperm motility. Thus it seems to be unlikely that low concentrations of complement components in the other parts of the female genital tract would be able to exert any effect on sperm.
(ii) Is corticosteroid treatment of ASA safe and effective? First, our statement concerning immunosuppression by cytotoxic drugs in the treatment of ASA did not include corticosteroids. In general, we did not intend to discuss the treatment options for ASA in our article. Although corticosteroids were often suggested to suppress ASA, the evidence from controlled studies is scarce. A meta-analysis published by Kamischke and Nieschlag (1999) came to the conclusion that there is no evidence for the value of corticosteroid treatment of ASA in terms of fertilization rate. This is a great pity, for taking the side-effects into consideration, a corticosteroid treatment would be preferable to ICSI.
References
Bronson, R.A., Cooper, G.W., Rosenfeld, D.L., Gilbert, J.V. and Plaut, A.G. (1987) The effect of an IgA1 protease on immunoglobulins bound to the sperm surface and sperm cervical mucus penetrating ability. Fertil. Steril., 47, 985991.[ISI][Medline]
Kamischke, A. and Nieschlag, E. (1999) Analysis of medical treatment of male infertility. Hum. Reprod., 14 (Suppl. 1), 123.