Pylori-specific IgG Antibodies Research Articles

Serum immune response to Helicobacter pylori in children: Epidemiologic and clinical applications

Antibody responses to Helicobacter pylori were measured by a solid-phase whole-cell enzyme-linked immunosorbent assay in 150 children and adolescents; in 47 consecutive children undergoing upper gastrointestinal endoscopy, including 17 with H. pylori infection before and after antimicrobial treatment; and in 46 family members of the infected children. Abnormal levels of either IgG or IgA were found in 6% of the 150 children. In the latter group the prevalence of H. pylori seropositivity increased with age. Parents and siblings of the infected children had 94% and 71% seropositivity, respectively, suggesting intrafamilial spread. Abnormal levels of IgG or IgA against H. pylori identified infected children with 95% sensitivity and 84% specificity. Eradication of the infection was accompanied by a significant decrease in IgG and IgA titers, with normalization in 10 cured patients in 12 months or less. We conclude that the method described for evaluation of H. pylori-specific IgG and IgA antibodies gives helpful information on the epidemiology of the infection and represents a useful adjunct to diagnosis and management of chronic gastritis in children.

Intrafamilial Clustering ofHelicobacter pyloriInfection

Colonization of the gastric antrum by Helicobacter pylori (formerly Campylobacter pylori) has been associated with primary gastritis. We determined the frequency of colonization by H. pylori in gastric-antrum biopsy specimens from 93 children undergoing gastroscopy for the evaluation of upper gastrointestinal symptoms. We also determined H. pylori IgG antibody levels by enzyme-linked immunosorbent assay in coded serum samples from these children, family members, and control subjects of comparable ages. Among 27 children with primary, or unexplained, gastritis, H. pylori was identified by silver staining in 24 biopsy specimens and by culture in 22; specific antibodies were present in 23 children (96 percent). Three children with unexplained gastritis had no evidence of H. pylori in the antrum, nor did any of 13 children with secondary gastritis or any of 53 children with normal antral histologic features; specific antibodies were present in only 1 of these 69 children. H. pylori antibody was detected in 25 of 34 parents of colonized children, but in only 8 of 33 parents of noncolonized children (P less than 0.001). Of 22 siblings of children colonized by H. pylori, 18 had specific antibodies, as compared with only 5 of 37 controls (P less than 0.001). We conclude that H. pylori-specific IgG antibodies are associated with bacterial colonization of the gastric antrum by this organism. The intrafamilial clustering of H. pylori infection suggests that there may be person-to-person spread of these bacteria.

68 DIAGNOSIS OF CAMPYLOBACTER PYLORI GASTRITIS BY IgG ELISA

11 patients age range 8-15, median 13 years, presenting with abdominal pain were investigated for Campylobacter pylori (C pylori) associated gastritis by upper GI endoscopy and serum IgG antibodies to C pylori. Control sera were obtained from 9 patients aged 9-15, median 12 years, undergoing orthopaedic procedures. Antral biopsies were examined for chronic gastritis and stained for C pylori using a modified Giemsa stain. C pylori specific IgG antibodies were assayed by an indirect ELISA technique, using a soluble bacterial antigen preparation as antigen and the results expressed as optical density measurement. 4 patients with chronic gastritis were colonised with C pylori. Serum IgG mean optical density value was 172±35 for C pylori +ve patients and 30±16 for C pylori -ve patients. Control patients had a mean optical density value of 22.9±4, similar to C pylori -ve patients.