ANTIBODY-RESPONSE TO THE LIPOPOLYSACCHARIDE AND PROTEIN ANTIGENS OF SALMONELLA-TYPHI DURING TYPHOID INFECTION .1. MEASUREMENT OF SERUM ANTIBODIES BY RADIOIMMUNOASSAY

  • 1 January 1981
    • journal article
    • research article
    • Vol. 46  (3) , 508-514
Abstract
Serum antibody responses to the lipopolysaccharide and protein antigens of S. typhi in typhoid patients were studied using a solid-phase radioimmunoassay technique. Sera from 24 adult typhoid patients and 20 non-typhoid adult controls were compared. As a group, sera from typhoid patients showed increased IgA, IgG and IgM levels and gave significantly higher anti-LPS and anti-protein antibody titers in all 3 major Ig classes than did non-typhoid controls. Levels of antibodies against LPS or protein in sera of typhoid patients were highly variable with a skew distribution. A good correlation was found between antibody titers to the LPS antigen and those to a protein antigen. No correlation, however, was found between the anti-LPS antibody titers measured by radioimmunoassay and the anti-O antibody titers measured by the Widal agglutination test. Titration of anti-LPS or anti-protein antibodies by radioimmunoassay was found to be more sensitive and specific than Widal test for the serological diagnosis of typhoid fever. The advantages of measuring antibody response by radioimmunoassay over conventional Widal test are discussed.