Low prevalence of monoclonal B cells in Helicobacter pylori gastritis patients with duodenal ulcer.
We have studied the prevalence of B-cell clonality among a large group of 320 patients with Helicobacter pylori gastritis and duodenal ulcer. These patients underwent endoscopic examination with multiple gastric biopsies at diagnosis and were followed 2 and 12 months after therapy. Histopathologic examination of 809 sets of biopsy specimens showed lymphoid gastritis with lymphoid aggregates or follicles, but without lymphoepithelial lesion, in 302 samples corresponding to initial biopsy specimens (n=130) or to posttreatment biopsy specimens (n=172). DNA extracted from fresh antral specimens allowed the amplification of Helicobacter pylori DNA in all cases before therapy. The arrangement of the immunoglobulin heavy chain gene was studied by polymerase chain reaction (PCR) in the 302 selected lymphoid gastritis samples. Single or dominant bands were seen only in four specimens from three patients (1.3%), whereas a polyclonal pattern was seen in the other 298 samples. The detection threshold of our PCR technique was approximately 3% of clonal B cells diluted in a polyclonal population. This threshold appeared to be a reliable cutoff between polyclonal gastritis and clonal MALT lymphoma. In our experience, Helicobacter pylori lymphoid gastritis appeared mainly as a benign polyclonal condition.
Equipe Histologie et Pathologie du Système Immunitaire, CHU de Bordeaux et Université de Bordeaux 2, Pessac, France.
A
A
de Mascarel
P
P
Dubus
G
G
Belleannée
F
F
Megraud
J P
JP
Merlio
D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology*; D001706:Biopsy; D017931:DNA Primers / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis; D004381:Duodenal Ulcer / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D005756:Gastritis / Q000175:diagnosis* / Q000382:microbiology; D015321:Gene Rearrangement / Q000235:genetics; D005803:Genes, Immunoglobulin / Q000235:genetics; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis* / Q000382:microbiology; D008297:Male; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000382:microbiology
D017931:DNA Primers; D004269:DNA, Bacterial; D007143:Immunoglobulin Heavy Chains