title: Chlamydia trachomatis serology in ankylosing spondylitis.
abstract: Demonstration of chlamydial antibodies in patients with ankylosing spondylitis (AS) could show an etiological role of Chlamydia trachomatis in this condition. We studied serum specimens from 50 HLA-B27 positive patients with AS (Group I), 34 HLA-B27 positive patients with other rheumatic diseases (Group II), 67 HLA-B27 positive healthy blood donors (Group III) and 37 healthy untyped blood donors. (Group IV). Measured by an immunoperoxidase assay (IPA) chlamydial IgA (titre greater than or equal to 1:20) was more prevalent in the HLA-B27 positive persons than in the healthy controls not selected for HLA-group (Groups I + II + III vs IV : p less than 0.02). Chlamydia trachomatis IgA-IPA containing sera also had specific IgG-IPA antibodies (greater than or equal to 1:80) in 29 (96%) out of 30 sera from HLA-B27 positive individuals and controls. Conversely, 45% of specific IgG-positive (greater than or equal to 1:80) AS sera, 27.7% sera in Group II, 39.4% Group III sera vs. 11.1% of sera in Group IV had concomitant chlamydial IgA (greater than or equal to 1:20). The differences in the prevalence of specific IgA were statistically significant: Group I vs. IV : p less than 0.01; Group III vs. IV :p less than 0.05 and Gr. I + II + III vs. IV: p less than 0.05. Our data suggest an enhanced antibody production against Chlamydia trachomatis among the HLA-B27 positive individuals whether they have AS or are healthy.
authors.affiliation: Department of Microbiology, Vest-Agder Central Hospital, Kristiansand, Norway.
authors.forename: P A
authors.initials: PA
authors.lastname: Csángó
authors.forename: M T
authors.initials: MT
authors.lastname: Upsahl
authors.forename: O
authors.initials: O
authors.lastname: Romberg
authors.forename: L
authors.initials: L
authors.lastname: Kornstad
authors.forename: I
authors.initials: I
authors.lastname: Sarov
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis*; D002690:Chlamydia Infections / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006680:HLA Antigens / Q000032:analysis; D015796:HLA-B27 Antigen; D006650:Histocompatibility Testing; D006801:Humans; D007124:Immunoenzyme Techniques; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D013167:Spondylitis, Ankylosing / Q000209:etiology*
chemical_list: D000907:Antibodies, Bacterial; D006680:HLA Antigens; D015796:HLA-B27 Antigen; D007070:Immunoglobulin A; D007074:Immunoglobulin G