title: The incidence of sperm-associated immunoglobulin and C3, the third component of complement, in infertile men.
abstract: One hundred four consecutive men who underwent a semen analysis as part of their infertility evaluation were assayed for sperm-associated immunoglobulin (Ig) and the third component of complement (C3). Sixteen (15%) of the 104 men had increased IgG, and 10 (12%) of 86 men tested had increased IgA on their sperm; however, only 4 (5%) of the 87 men tested were positive for plasma IgG antisperm antibody. Only 2 (13%) of the 16 men with increased sperm-associated IgG had detectable IgG antisperm antibodies in their seminal plasma. Five (10%) of 50 men tested had increased sperm-associated C3; none had seminal plasma that deposited C3 on sperm. These data suggest that of the three compartments that can be tested--circulating plasma, seminal plasma, and the sperm surface--the direct measurement of sperm surface Ig may be most important in the evaluation of infertile men. The presence of sperm-associated IgG or IgA was not associated with semen abnormality. In contrast, the presence of sperm-associated IgG was associated with decreased mucus penetration at the time of postcoital testing despite normal-appearing mucus.
mesh_terms: D003176:Complement C3 / Q000032:analysis*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007136:Immunoglobulins / Q000032:analysis*; D007248:Infertility, Male / Q000276:immunology*; D008297:Male; D013094:Spermatozoa / Q000276:immunology*
chemical_list: D003176:Complement C3; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins