SEROPREVALENCE OF IMMUNOGLOBULIN-G, IMMUNOGLOBULIN-M, AND IMMUNOGLOBULIN-A ANTIBODIES TO HELICOBACTER-PYLORI IN AN UNSELECTED DANISH POPULATION

The seroprevalences of increased levels of immunoglobulin G (IgG), M ( IgM), and A (IgA) antibodies to Helicobacter pylori were assessed by e nzyme-linked immunosorbent assay techniques in 3,589 Danes who partici pated in a population study in Copenhagen County in 1982. A total of 3 3.9% of the study population had one or more classes of increased anti bodies to H. pylori. Increased levels of IgG, IgM, and IgA antibodies to H. pylori were seen in 25.9% (95% confidence interval (CI) 24.5-27. 3), 4.5% (95% CI 2.2-7.0), and 12.0% (95% CI 10.9-13.1) of the partici pants, respectively. Women were significantly more likely than men to be seropositive for IgM antibodies (Mantel-Haenszel summary odds ratio = 1.85, 95% CI 1.34-2.57). Seropositivity for IgM antibodies to H. py lori was found less often with increasing age, An IgG antibody respons e was not seen in 23.7% of cases with overall increased antibodies to H. pylori. Increased levels of IgG or IgA antibodies were more frequen t in people with a history of peptic ulcer disease. Seroprevalences of increased H. pylori antibodies are high in unselected populations. Pr imary H. pylori infections are contracted at all ages, but infection r ates decline with age. Inclusion of measurements of IgA and IgM antibo dy levels in future screening for H. pylori may improve the diagnostic sensitivity of serologic analyses.