Characterization of circulating Yersinia-specific immune complexes in patients with yersiniosis

Spondylarthropathy and selective IgA deficiency

No serum IgA was detected in a young male patient suffering from spondylarthropathy (SpA) with bilateral sacroiliitis arthritis, enthesopathy and inflammatory low back pain, whose symptoms occurred in reaction to a sexually induced urethritis. After a period of several months in which the spondylarthropathy was active, disease activity came to a rest. Three years later no progression of the SpA was observed. This finding might be an indication that IgA is not involved in the pathogenesis of spondylarthropathy.

Chemotaxis and chemiluminescence responses of synovial fluid polymorphonuclear leucocytes during acute reactive arthritis

The chemotaxis and chemiluminescence responses of polymorphonuclear leucocytes (PMN) of synovial fluid and peripheral blood from patients with acute reactive arthritis were studied. Rates of chemotactic and chemokinetic migration of synovial fluid PMN were significantly decreased. In addition, chemiluminescence responses tended to be depressed, suggesting that the cells were deactivated for both chemotaxis and production of oxygen derived free radicals. Such deactivation has been described previously as a characteristic of synovial fluid PMN in rheumatoid arthritis. Compared with those with a mild disease, patients with severe acute reactive arthritis had higher chemiluminescence responses of synovial fluid PMN to phorbol myristate acetate during acute disease and developed increased migration of peripheral blood PMN towards zymosan treated serum after recovery from the disease. This supports the view that hyperreactive PMN contribute to the development of severe inflammatory symptoms in acute reactive arthritis.

Mechanisms involved in the pathogenesis of Yersinia infections

Yersinia enterocolitica and Yersinia pseudotuberculosis are food-borne enterobacterial pathogens which may initiate rheumatoid diseases. By molecular genetic analysis of the pathogenicity of these species virulence gene loci could be identified on the chromosome and on a plasmid. Plasmid-encoded proteins mediate cell adherence, phagocytosis resistance, survival in serum, cytotoxicity, and collagen binding. Y. enterocolitica of serotype 0:8 is mouse-lethal and arthritogenic for Lewis rats. Mouse lethality is closely associated with the expression of a chromosome-encoded high-affinity iron transport system which enables the pathogen to acquire iron for growth in iron-deficient environments. The antibody response to virulence-associated antigens of arthritis-susceptible Lewis rats differed from that of arthritis-resistant Fisher rats: Lewis rats respond strongly to the collagen-binding protein Yop1 and weakly to the iron-transport receptor protein FyuA, whereas the reverse is found with Fisher rats. This specific antibody response of Lewis rats is suggested to be important for induction of arthritis.

Avidity of anti-Yersinia antibodies in yersiniosis patients with and without Yersinia-triggered reactive arthritis

Avidity of IgM, IgG, and IgA class anti-Yersinia antibodies was compared in sera of 22 patients with yersiniosis and subsequent reactive arthritis versus sera of 22 patients without postinfection complications. An enzyme-linked immunosorbent assay was used for antibody determination. Less than 2 months after onset of the infection, the patients with arthritis had fewer high-avidity IgM antibodies against the bacterial lipopolysaccharide (P = 0.035) and more high-avidity IgA antibodies against bacterial cell extract (P = 0.039) than did the patients without arthritis. This difference increased with time.

Yersinia specific immune complexes in the synovial fluid of patients with yersinia triggered reactive arthritis

Yersinia specific immune complexes were demonstrated in the synovial fluid of three patients out of 12 with yersinia triggered reactive arthritis. They were not detectable in the synovial fluid of any of the 16 control patients, including nine with reactive arthritis triggered by factors other than yersiniae. Platelet reactive IgG was detectable in the synovial fluid of eight out of the 12 patients with yersinia triggered reactive arthritis and in three of the 16 control patients, all three having rheumatoid arthritis. An enzyme linked immunosorbent assay and a platelet 125I labelled staphylococcal protein A test were used to measure yersinia specific immune complexes and platelet reactive IgG respectively. The results obtained show for the first time the occurrence of bacterial antigens, derived from the causative strain, in the synovial fluid in yersinia triggered reactive arthritis.