Immunoglobulin analysis of anti-streptolysin-O antibody.

The immunoglobulin characteristics of human serum ASLO antibody were examined using Sephadex gel filtration column chromatography. IgM associated ASLO antibody was found in certain sera. IgM ASLO antibody appeared in sera from individuals suspected of having had their initial streptococcal infection, and was detected only in sera from children having ASLO titres below 2 Todd unit (T.u.) at first, and having acquired titres of around 333 T.u. after 3 months. IgM ASLO antibody was never found in sera from children who were not at the initial streptococcal infection stage. In addition IgM ASLO antibody was not detected in the sera of children having ASLO titres of over 500 units, even if they were at the initial streptococcal infection stage. No adult sera were shown to have IgM ASLO antibody regardless of their ASLO titres.