Immunodominant Semen Proteins III: IgG1 and IgG4 Linkage in Female Immune Infertility

Active immune mechanism in the female reproductive tract may produce high levels of anti-seminal/sperm antibodies. Generated antibodies in the process of isoimmunization seem to be associated with female immune infertility. The aim of our study consists in the profiling of specific serum immunoglobulin classes and subclasses in infertile women. We focus on the distribution of serum seminal/sperm-specific antibodies in order to find those apparently related to female isoimmunization. Immunoglobulins G1-4, A1,2, M and E were measured by ELISA in serum from 30 infertile and 10 fertile females. Anti-seminal/sperm IgG1 and IgG4 fractions were predominantly detected. Anti-seminal IgG1 and IgG4 were observed approximately in the 2:1 ratio, anti-sperm fraction in the 1:2 ratio. Strikingly, the approximate ratio between IgG1 and IgG2 was 3:1 in seminal specific and 2:1 in sperm specific antibodies. Surprisingly, IgG3 antibodies were nearly negative for both antigen fractions, seminal and sperm. Concerning our results, the proportionality does exist between seminal and sperm antibody fractions. Based on the poorly detectable levels of semen specific IgE, M, A1,2, G3, the markers of pathologic female isoimmunization appear to be the serum IgG1 and IgG4. These preliminary findings may contribute to a detailed patient diagnosis and an improved therapy.