Increased Mucosal Production of Monomeric IgA1 but No IgA1 Protease Activity in Helicobacter pylori Gastritis

• Published in: The American journal of pathology Vol. 155; no. 4; pp. 1097 - 1104
• Main Authors: Berstad, Audun E., Kilian, Mogens, Valnes, Kølbjørn N., Brandtzaeg, Per
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.10.1999; ASIP; American Society for Investigative Pathology
• Subjects: Adult; Aged; Aged, 80 and over; Bacterial diseases; Bacterial diseases of the digestive system and abdomen; Biological and medical sciences; Cell Count; Female; Gastric Mucosa - cytology; Gastric Mucosa - enzymology; Gastric Mucosa - immunology; Gastric Mucosa - microbiology; Gastritis - enzymology; Gastritis - immunology; Gastritis - microbiology; Gastritis - pathology; Gastroenterology. Liver. Pancreas. Abdomen; Helicobacter Infections - enzymology; Helicobacter pylori - enzymology; Helicobacter pylori - isolation & purification; Human bacterial diseases; Humans; Immunoglobulin A - biosynthesis; Immunoglobulin A - metabolism; Immunoglobulin A, Secretory - metabolism; Immunoglobulin J-Chains - biosynthesis; Infectious diseases; Leukocytes - cytology; Leukocytes - metabolism; Male; Medical sciences; Microscopy, Fluorescence; Middle Aged; Other diseases. Semiology; Regular; Serine Endopeptidases - metabolism; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Urease - metabolism; Human; Immunohistochemistry; Immunoglobulins; Spirillales; Enzyme; Pathogenesis; Mucosa; Spirillaceae; IgA1; J-Peptide chain; Gastritis; Infection; Pathology; Peptidases; Helicobacter pylori; Bacteriosis; Immunoblotting assay; Digestive diseases; Bacteria; Hydrolases; Immunocyte; Monomer; Gastric disease
• ISSN: 0002-9440; 1525-2191
• DOI: 10.1016/S0002-9440(10)65212-1

Immunoglobulin A and IgM are subjected to epithelial transport only when they are produced as polymers with incorporated J chain. Immunocytes containing various Ig isotypes and associated J chain in gastric mucosa, as well as IgA-degrading protease activity in Helicobacter pylori cultures, were examined. Gastric body specimens from 15 H. pylori -positive and 14 H. pylori -negative patients were studied by paired immunofluorescence for IgA, IgA1, IgA2, IgG, or IgM and concurrent cellular J chain. H. pylori isolates were incubated with IgA1 or secretory IgA and examined by immunoelectrophoresis for cleavage products. A substantial increase of Ig-producing cells occurred in chronic gastritis, particularly in the IgA1 isotype, but H. pylori was shown to possess neither IgA1-specific nor nonspecific IgA-degrading protease activity. Regardless of infection status, reduced J chain expression was observed for all immunocyte isotypes (except for IgM) in inflamed compared with normal gastric body mucosa, the median positivity for IgA1 cells being reduced to 58.7% versus 87.9% ( P = 0.0002), and for IgA2 cells to 48.9% versus 87.8% ( P = 0.0002). This down-regulation of the J chain suggested that a large fraction of IgA monomers is produced in gastritis.