title: Antibodies to ubiquitin in relation to Yersinia infection status in patients with ankylosing spondylitis.
abstract: The aim of this study was to investigate IgG and IgM antibodies to ubiquitin in relation to Yersinia enterocolitica infection status in patients with AS. Twenty-eight AS patients (M:F 24:4, mean age 43.9 yrs, range 22-70 yrs, mean disease duration 15.9 yrs) and 35 healthy controls (M:F 31:4, mean age 52.1 yrs, range 22-80 yrs) were included. The levels of antibodies to ubiquitin and Yersinia O:3 and O:9 antigens were measured using specific ELISA. The results were expressed as optical density (OD) ratio. Antibody levels were assumed increased when the OD ratio was higher than mean OD ratio + 3SD in the control group. IgM antibodies to ubiquitin were found in five patients and one control ( P < 0.05, Fisher's exact test). Anti-ubiquitin antibodies of IgG class were found in two cases, one AS patient and one control (NS). IgG antibodies to Yersinia serotypes O:3 and O:9 were present in eight and five AS patients, respectively ( P < 0.001 and P < 0.05 vs. controls, Fisher's exact test). No IgM antibodies to Yersinia were found. High levels of IgG antibodies to Y. enterocolitica serotype O:3 were found in three out of five patients with high levels of IgM antibodies to ubiquitin, compared with five out of 23 patients with low levels of anti-ubiquitin antibodies ( P=0.1231, NS). Antibodies to Yersinia serotype O:9 were found in three out of five patients with IgM antibodies to ubiquitin, compared to two out of 23 patients with low serum levels of IgM antibodies to ubiquitin ( P < 0.05). The results suggest that Y. enterocolitica infection may induce antibodies to ubiquitin in a subset of patients with AS. This may be explained by the involvement of a newly discovered ubiquitin-dependent mechanism related to Y. enterocolitica virulence.
authors.affiliation: Department of Rheumatology and Clinical Immunology, Karol Marcinkowski University of Medical Sciences, Winogrady 144, 61-626 Poznań, Poland. phrycaj@icpnet.pl
authors.forename: P
authors.initials: P
authors.lastname: Hrycaj
authors.forename: J K
authors.initials: JK
authors.lastname: Łacki
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000032:analysis*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008297:Male; D008875:Middle Aged; D013167:Spondylitis, Ankylosing / Q000276:immunology* / Q000382:microbiology*; D025801:Ubiquitin / Q000276:immunology*; D015009:Yersinia Infections; D015008:Yersinia enterocolitica / Q000276:immunology
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D025801:Ubiquitin