Age-related prevalence of human serum IgG and IgM antibody to the core glycolipid of Escherichia coli strain J5, as measured by ELISA.

Administration of antibody to Escherichia coli strain J5 reduces mortality in patients with gram-negative septic shock. Limited evidence suggests that this antibody is present in the serum of healthy individuals and deficient in persons with malignancy; however, the age-related prevalence of serum antibody to strain J5 in normal subjects is unknown. We developed an ELISA method to measure IgG and IgM antibody to purified J5 lipopolysaccharide (LPS) in sera from 33 maternal-newborn cord pairs, 40 neonates, and 253 individuals aged from one day to twenty years. Reciprocal geometric mean titers for serum antibody to strain J5 LPS were as follows: maternal-IgG, 12.3; IgM, 174; one month old or less-IgG, 8.3; IgM, 5.6; one to 24 months old-IgG, 10.5; IgM, 44.7; greater than 24 months old -IgG, 16.2; IgM, 200. We conclude that human serum antibody to J5 LPS is predominantly IgM and that it is usually present by two years of age. The ELISA method should provide a valuable tool in studying the relation of core glycolipid antibody to immunity and therapy of gram-negative bacterial infections.