In our previous paper, the differences in specific antiboty levels in the sera of dysentery patients and carriers in terms of three immunoglobulin classes were studied by using the indirect radioimmunoassay.
In the present paper, a simple method for demonstration of specific IgM and IgA antibodies to sonne bacilli by absorption of most IgG antibodies with Protein A-Sepharose CL-4B column is described.
Furthermore, adsorption of three immunoglobulin classes onto Protein A containing Staphylococci, Protein A itself or Protein A-Sepharose CL-4B is elucidated by employing single radial immunodiffusion.
This paper reported the results of serological investigations performed on 118 serum samples from 36 cases who were treated at Osaka Municipal Momoyama Hospital in 1972. These cases included 29 sonne dysentery patients and 7 sonne carriers. Serological methods used were bacterial agglutination test, indirect radioimmunoassay and absorption of IgG antibody with Protein A-Sepharose CL-4B.
The results are as follows:
1) The best and the most simple procedure to remove most of IgG without losing IgM and IgA was the affinity absorption technique using Protein A-Sepharose CL-4B column. The amounts absorbed by this procedure were 90, <10 and 10-20% of the total, respectively for IgG, IgM and IgA.
2) In combination with the results of radioimmunoassay, it became evident that most of IgG and a part of IgA antibodies combined to protein A from serum with this procedure, and the agglutinability which remained in absorbed sera was demonstrated to be caused by IgM and IgA antibodies.
3) Sera containing IgG antibodies showed decreased agglutinin titer of 1/4 or less after processing by this procedure.
4) Sera from patients with recent infection showed unchanged or somewhat decreased agglutinin titers after processing, but still had significantly higher titer than negative control sera.
5) In contrast, Protein A-Sepharose column completly removed agglutinin from most of sera of carriers with anamnestically remote infection.
6) These findings were in accordance with the results obtained by indirect radioimmunoassay which could determine whether the sera tested were from patients or from carriers.