Use of antisperm antibodies in differential display Western blotting to identify sperm proteins important in fertility.
BACKGROUND
Antisperm antibodies (ASA) may be an important cause of infertility but current tests for the detection of ASA have poor prognostic value. The inadequacy of current tests may reflect the inability of these tests to define the antigenic specificity of the sperm proteins with which the ASA react. Identification of the sperm proteins that ASA bind to is a necessary preliminary step to the development of more useful diagnostic tests for ASA.


METHODS
A sensitive Western blotting technique was used to compare the antigenic specificities of ASA from men who were infertile (n = 6) with those who were fertile following vasectomy reversal (n = 3). Normal fertile men (n = 3) and infertile men with known ASA (n = 4) were also included in the analysis.


RESULTS
All men, including the normal fertile controls, had ASA detectable in our system. Several sperm proteins were identified that react with ASA from infertile but not fertile men. Quantitative differences in the binding of ASA to some proteins were also demonstrated. Additionally, we demonstrated that normal motile sperm are coated with an antibody that appears to be bound to sperm by a non-antigenic mechanism.


CONCLUSIONS
Sera from all men contained ASA, but clearly some of these did not cause infertility. Characterization of the proteins that are antigens for ASA from infertile but not fertile men may allow the development of more accurate tests for infertility-inducing ASA. The significance of immunoglobulin G coated on normal sperm remains to be determined.
Chiu
W W C
WW
Department of Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand. will.chiu@auckland.ac.nz
Chamley
L W C
LW
D000906:Antibodies / Q000032:analysis / Q000276:immunology*; D015153:Blotting, Western / Q000379:methods; D000939:Epitopes; D005298:Fertility / Q000502:physiology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000302:isolation & purification; D007248:Infertility, Male / Q000276:immunology; D008297:Male; D011184:Postoperative Period; D011506:Proteins / Q000502:physiology*; D012016:Reference Values; D013094:Spermatozoa / Q000276:immunology* / Q000378:metabolism*; D014669:Vasovasostomy
D000906:Antibodies; D000939:Epitopes; D007074:Immunoglobulin G; D011506:Proteins