Serum IgG response to differentiated antigens of Helicobacter pylori.

AIM:To detect antibodies against Helicobacter pylori spiral and coccoid antigens in human sera.METHODS:Blood samples were collected from 278 patients with gastric diseases. A 3-day-old culture of H. pylori on chocolate blood agar was used to providespiral form. Synchronous coccoids were cultured in (BHY) (brain heart infusion supplemented with 10% horse serum and 0.4% yeast extract) medium in a chemostat.Antigens from spiral and coccoid form were prepared using acid glycine extraction.Enzyme-linked immunosorbent assay (ELISA) was performed to detect serum IgG anti-bodies against spiral and coccoid forms of H. pylori.RESULTS:Seroprevalence of H. pylori infection was higher in patients with gastric ulcer (79%) and gastric cancer (83%) than those with non-ulcer dyspepsia (NUD)(44%) and other diseases (45%) (P <0.05). IgG antibodies against spiral and coccoid antigens were detected in 50.7% (141/278) and 49.6% (138/278), respectively.CONCLUSION:The spiral and coccoid forms of H.pylori coexist in patients infected with the bacterium.