• Sperm antibodies;
  • immunobead test (IBT);
  • cervical mucus penetration;
  • Kremer test

ABSTRACT: The immunoglobulin class and regional specificity of sperm antibodies was analyzed in relation to in vitro cervical mucus penetration using a capillary test. There was a highly significant (X2, P < 0.001) association of strong (≥ 95% sperm coated) immunobead test (IBT) results for sperm-bound antibodies of IgA immunoglobulin class with poor (< 3.0 cm/2 h) mucus penetration. There was also a significant (P < 0.01) association between poor penetration and the presence of antibodies on the sperm tail mainpiece. In contrast, IgG class antibodies did not show any significant association with poor penetration. These results confirm and extend previous work and imply that development of a male antispermatozoal vaccine that inhibits mucus penetration must involve stimulation of local IgA response rather than systemic antibody levels.