[Analysis of the monomeric IgA to polymeric IgA ratio in specific IgA antibodies for Chlamydia trachomatis--clinical studies in chlamydial urogenital infections].
Antibody titers of monomeric and polymeric types of serum specific IgA for Chlamydia trachomatis were measured by indirect immunoperoxidase assay (Savyon kit) in male and female cases with various chlamydial urogenital infections. From these results, the ratio of monomeric to polymeric IgA (m/p ratio) was determined. All cases were positive for specific IgA and IgG antibodies for C. trachomatis, and the antigen was also detected in all of cases except for those with prostatitis. 1. Study in males: The m/p ratio (mean +/- S.E.) was 2.6 +/- 1.0 in acute chlamydial urethritis and 8.0 +/- 2.2 in chronic non-bacterial prostatitis. The result indicated monomeric IgA-predominance in the chronic stage. 2. Study in females: The m/p ratio was 5.0 +/- 1.9 in subacute chlamydial cervicitis, while it was 8.5 +/- 2.9 in pregnant women considered to have chronic chlamydial infection. The rate was 31.5 +/- 16.8 in prostitutes considered to have repeated chlamydial infections. The result suggested that monomeric IgA was predominant in patients with chronic and repeated infections. 3. As for sequential changes of IgA antibody titer, polymeric IgA alone decreased after treatment of acute chlamydial urethritis. However monomeric IgA decreased in chronic infection such as prostatitis, and a similar change was shown in IgG antibody. 4. These results suggest that polymeric IgA is predominant in the acute stage of chlamydial infections, while monomeric IgA predominates in the chronic stage.