Human Sera Containing Immunoglobulin and Nonimmunoglobulin Spermagglutinins

Human spermagglutinating sera showed three patterns in their reactions in a microagglutination (Franklin and Dukes, F and D) and a macroagglutination in gelatin (Kibrick) test. Some sera were active in the F and D test only; some were active in the Kibrick test only; and some were active in both. Eight sera of the first type, two of the second type, and three of the third type have been fractionated by zone electrophoresis, gel filtration in Sephadex G-200, and by ion exchange chromatography on DEAE-cellulose. Sera which were positive in only the F and D test were shown to have spermagglutinins which are nonimmunoglobulins. The agglutinins have a high mol wt and the electrophoretic mobility of β-globulins. Their activity appears to be directed towards seminal plasma, since they agglutinated fresh sheep red blood cells coated with human seminal plasma coupled by glutaraldehyde. Sera which acted in the Kibrick test were shown to possess spermagglutinins which were immunoglobulins. The sera which reacted by the Kibrick test only had IgG spermagglutinins. Other sera had IgG which reacted in both the Kibrick and F and D tests. One serum had only IgM agglutinins that agglutinated by both the Kibrick and F and D techniques. The reason for some sera agglutinating by only the Kibrick technique, whereas others agglutinated by both techniques, is uncertain, but possibly indicates different specificities of the sera. None of the human sera possessing spermagglutinating immunoglobulins agglutinated glutaraldehyde-treated fresh sheep red blood cells coated with seminal plasma. However, rabbit antisera directed against seminal plasma did. This suggests that the human antibodies are not directed at those components of seminal plasma which readily adhere to sheep red cells under the conditions used.