HELICOBACTER PYLORI

In 1983, Warren and Marshall (1) identified Helicobacter pylori, a new gram-negative bacterial pathogen, in patients suffering from gastritis, and this finding led to studies on the relationship between bacterial infection and chronic gastric disease (2). The pathogen has been shown to be It has been demonstrated that in patients with gastritis, eradication of the bacteria led to healing of the anatomical lesion (4). Diagnostic procedures for the detection of the organism generally involve invasive (gastroscopic) techniques for sample collection. However, a specific immune response is seen in infected patients. The serological test thus represents a useful alternative to the invasive bioptic technique. IgG levels rise with infection and remain constantly high until the infection is eliminated. The efficacy of antimicrobial therapy can therefore be monitored via changes in specific IgG antibody. The determination of the IgA antibody levels is complementary to that of the IgG. As the IgA levels decrease more rapidly than the IgG in some patients undergoing treatment, this parameter can be useful in the follow-up of patients. For the same reason, a low IgA level in IgG-positive patients may indicate a past infection. For unknown reasons, about 2% of serum samples are positive only for IgA.