Performance characteristics of an enzyme-linked immunosorbent assay for the determination of immunoglobulin M anti-Salmonella typhi lipopolysaccharide antibodies.

Some characteristics of an enzyme-linked immunosorbent assay for the determination of immunoglobulin M anti-Salmonella lipopolysaccharide antibodies have been assessed. Immunoglobulin M anti-lipopolysaccharide antibodies in serum samples from most patients with typhoid fever cross-reacted with S. typhimurium lipopolysaccharide. However, absorbance values with S. typhi lipopolysaccharide were always higher than with the heterologous antigens. Serum samples from two patients with S. paratyphi B infection failed to show significant immunoglobulin M binding to S. typhi lipopolysaccharide. Serum samples from six rheumatoid arthritis patients were negative in this immunoenzymatic assay with S. typhi or S. typhimurium lipopolysaccharide as coating antigen. Finally, interference by specific immunoglobulin G in the immunoglobulin M anti-S. typhi lipopolysaccharide antibodies determination was excluded.