Testing for serum IgG antibodies to Helicobacter pylori cytotoxin-associated protein detects children with higher grades of gastric inflammation.
BACKGROUND
Little information is available about the relationships between Helicobacter pylori cytotoxin-associated protein (CagA) and clinicopathologic features in children. The purpose of this study was to test whether determining serum IgG antibodies to CagA is a useful tool for detecting more severe disease.


METHODS
One hundred twenty-seven consecutive children (age range, 0.75-17.8 years; median, 9.4 years) referred for gastroscopy were included in the study. Antral and corpus biopsies were taken for gastric histology and H. pylori detection. Major symptoms and endoscopic findings were recorded. A serum sample was drawn from each child and assayed for IgG antibodies CagA by a commercial enzyme-linked immunosorbent assay.


RESULTS
Sixty-three (50%) children had no evidence of H. pylori infection, 28 (22%) were H. pylori positive/CagA positive, and 36 (28%) were H. pylori positive/CagA negative. There were no differences in clinical diagnosis and occurrence of any predominant symptom according to H. pylori and CagA status. Findings of antral nodularity were more frequent (p = 0.003) in H. pylori-positive/CagA-positive children than in H. pylori-positive/CagA-negative children. The gastritis score was significantly higher in H. pylori-positive/CagA-positive children than in H. pylori-positive/CagA-negative children (5.7 +/- 1.9 vs. 3.8 +/- 1.6, respectively; p = 0.0003), either in the antral (p = 0.0002) or in the corpus (p = 0.001) mucosa. Inflammation (p = 0.0001) and activity (p = 0.0001) scores were both higher in H. pylori-positive/CagA-positive children than in H. pylori-positive/CagA-negative children, but the H. pylori density score was not significantly different (p = NS). In no case was normal gastric mucosa found in H. pylori-positive/ CagA-positive children. Lymphocytic gastritis (p = 0.0008) and lymphoid follicles (p = 0.000003) were a more frequent finding in H. pylori-positive children than in H. pylori negative children, irrespective of CagA status.


CONCLUSIONS
Testing for serum IgG to CagA detects higher grades of gastric inflammation among children with H. pylori infection. It may be useful in targeting H. pylori-positive/ CagA-positive children for antimicrobial therapy while reducing the need for endoscopy and gastric biopsy.
Luzza
F
F
Dipartimento di Medicina Sperimentale e Clinica, Università di Catanzaro Magna Graecia, Italy.
Contaldo
A
A
Imeneo
M
M
Mancuso
M
M
Pensabene
L
L
Giancotti
L
L
La Vecchia
A M
AM
Costa
M C
MC
Strisciuglio
P
P
Docimo
C
C
Pallone
F
F
Guandalini
S
S
D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000276:immunology*; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D005756:Gastritis / Q000382:microbiology* / Q000473:pathology; D016481:Helicobacter Infections / Q000382:microbiology / Q000473:pathology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D008297:Male
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C080866:cagA protein, Helicobacter pylori