Anti-seminal plasma antibodies associated with infertility: II. Comparative investigation of human antibody binding to normo-, astheno-, and azoospermic seminal plasma antigens.

Problem: Sera from infertile patients with elevated reactivity against normozoospermic seminal plasma (NSP) have been selected to investigate human antibody binding to seminal fluid antigens present in abnormal ejaculates.

Method: Sera from 32 idiopathically infertile patients and 44 control sera from fertile individuals were examined by ELISA against: 1) pooled seminal plasma from asthenozoospermic ejaculates (AsthSP), 2) pooled seminal plasma from patients with aspermatogenic azoospermia (AzooSP), and 3) chromatographic fractions from NSP, AsthSP and AzooSP.

Results: Of 32 patients positive for anti-NSP antibodies, only four exhibited increased reactivity to whole AsthSP and/or AzooSP, while 14 recognized antigens of different Mr and various distributions in the corresponding chromatographic fractions.

Conclusion: Targets of human anti-NSP antibodies might be lacking, less concentrated, and/or modified in AsthSP and AzooSP. These findings suggest their physiological importance and the possible relevance of the observed auto- and iso-immune responses to infertility.