Correlation between Yersinia enterocolitica and type I collagen reactivity in patients with arthropathies.

We investigated the association with Yersinia infection in patients with arthropathies in our region. To assess the reactivity to articular antigens, the correlation of anti-Yersinia with anti-type I and type II collagen antibodies was studied. Sera from 124 patients with musculoskeletal symptoms, and 47 synovial fluids (SF) from patients with rheumatoid arthritis (RA), spondyloarthopathies (SpA) or osteoarthritis (OA) were examined. Immunoglobulins against Yersinia enterocolitica, type I and type II collagens were determined by enzyme-linked immunosorbent assay. Immunoglobulin (Ig) A to Yersinia lipopolysaccharide (LPS) was present in 13/124 sera (10%) and 3/47 SF (6%). By Western blot, IgA to Yersinia outer proteins (Yops) was found in 14/124 sera (11%) and 2/47 SF (4%). Yersinia DNA from SF was not amplified by polymerase chain reaction. We found a significant correlation with anti-collagen type I but not type II antibodies. These results suggest different reactivity to articular collagen in patients with Yersinia antibodies.

Yersinia enterocolitica: a cause of chronic polyarthritis.

To investigate the role of Yersinia persistence in chronic undifferentiated arthritis, two patients who had chronic undifferentiated polyarthritis and circulating IgA and IgG antibodies to Yersinia outer proteins were studied. Immunofluorescence using antibodies directed against Yersinia adhesin A was performed on colonic and synovial tissue. Synovial tissue T cells were cloned aspecifically and screened for their proliferative responses to Yersinia enterocolitica. Furthermore, a Yersinia-specific polymerase chain reaction (PCR) was performed on synovial tissue. Both patients were found to have Yersinia antigens in colonic and synovial tissue. Y. enterocolitica-positive T-cell clones were grown from the synovial tissue: 4 CD4+ clones of 37 clones from patient 1 and 6 CD4+ clones of 53 clones from patient 2. Yersinia-specific PCR products were not detected in the synovial tissue specimens. The results support the hypothesis that an immune-mediated response to Yersinia antigens may play an important role in the pathogenesis of chronic undifferentiated arthritis.

Experimental Yersinia-triggered reactive arthritis: effect of a 3-week course of ciprofloxacin.

Lewis rats were injected i.v. with live Yersinia enterocolitica, resulting in 1-2 weeks in an arthritis greatly resembling human reactive arthritis. Starting on day 3, 5, 10 or 13 after the bacterial inoculation, the rats were treated for 3 weeks with 20 mg/kg/day of ciprofloxacin. The development of arthritis was completely prevented if the antibiotic treatment was started on day 3. In a group of rats treated with ciprofloxacin from day 5 onwards, 2/14 rats already showed mild arthritis at the time when the treatment was started. Antibiotic treatment cured the arthritis of these rats as well as that of one additional individual in this group which developed arthritis. No later exacerbations occurred. If the antibiotic treatment was started on day 10 or 13, i.e. at the time of well-developed arthritis, no effect on arthritis was observed; rather, increased faecal excretion of Yersinia occurred following the antibiotic treatment. We conclude that experimental Yersinia reactive arthritis can be cured by antibiotics introduced at an early phase of arthritic development. Regarding acute human enterogenic arthritis, the decision on antibiotic treatment is not a straightforward matter. Our experimental results indicate that the earlier the treatment is started, the better the result, whereas late treatments seem to favour bacterial persistence.

Influence of blood transfusion on bactericidal activity of human leukocytes and sera against Yersinia enterocolitica and Salmonella typhimurium.

Patients undergoing joint surgery and blood transfusion were studied. Serum and leukocyte bactericidal tests in vitro against Salmonella typhimurium and Yersinia enterocolitica were carried out preoperatively as well as on the 1st, 3rd and 7th days after the operation. The serum complement (C3 and C4) concentrations were determined at the same intervals. It was found that after blood transfusion the bactericidic activity of sera and the serum C3 complement concentrations were increased. In contrast the killing ability of leukocytes was suppressed.

Role of YadA-mediated collagen binding in arthritogenicity of Yersinia enterocolitica serotype O:8: experimental studies with rats.

Outer membrane protein YadA, Yersinia adhesin, is one of the plasmid-encoded virulence factors of yersiniae. YadA protects bacteria against host defense through several different mechanisms. One important role of YadA is to mediate binding to several collagen types. Our recent study revealed that a yadA null mutant of Yersinia enterocolitica serotype O:8 has a drastically reduced arthritogenic capacity when injected intravenously into Lewis rats. To further characterize the arthritogenic role of YadA, we repeated the rat experiments with strain Y. enterocolitica O:8/pYV082; this strain expresses a YadA deletion derivative lacking 22 amino acids from the amino-terminal hydrophobic region and does not bind to collagen. Y. enterocolitica O:8/pYV082 induced arthritis in 5 to 14% of rats inoculated with arthritogenic doses, whereas the arthritis incidence with the wild-type parent strain was 65%. The parent strain was slightly more virulent than Y. enterocolitica O:8/pYV082, as determined by rat mortality. It also frequently induced skin abscesses, whereas Y. enterocolitica O:8/pYV082 did not. Infection kinetics in spleen and mesenteric lymph nodes were about the same with both of the bacterial strains used, and the same was true of the Yersinia-specific antibody response. Altogether, these results suggest that YadA-mediated collagen binding contributes to the arthritogenicity of Y. enterocolitica O:8.

Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.

The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to induce ReA. This indicates that the arthritogenicity of the 19-kDa antigen is not a property of the 19-kDa protein alone but is dependent on its expression in bacteria able to induce ReA.

Pathogenetic role of Chlamydia, Yersinia and Borrelia in undifferentiated oligoarthritis.

We studied the cellular and humoral immune response to Chlamydia trachomatis, Yersinia enterocolitica and Borrelia burgdorferi in paired samples of peripheral blood and synovial fluid (SF) in undifferentiated oligoarthritis, reactive arthritis (ReA) and rheumatoid arthritis. Antigen specific lymphocyte proliferation was found in SF of 43% of patients with ReA and 34% of patients with undifferentiated oligoarthritis. C. trachomatis was the most frequent single agent. HLA-B27 was positive in 83% of patients with ReA and in 62% of patients with undifferentiated oligoarthritis with antigen specific lymphocyte proliferation. Antigen specific lymphocyte proliferation correlated poorly with the specific antibody response. Only chlamydial antigen was detected in SF cells using monoclonal antibodies. We conclude that some patients with undifferentiated oligoarthritis may have a forme fruste of ReA. This finding is important in view of recent evidence supporting the efficacy of antibiotic therapy in ReA.

Influence of antibiotics on IgA and IgG response and persistence of Yersinia enterocolitica in patients with Yersinia-associated spondylarthropathy.

The IgA and IgG antibody response to plasmid-encoded outer membrane proteins was studied in 59 patients with yersinia-associated spondylarthropathy during 15 months of follow-up. Initially, all patients had specific IgA and IgG antibodies to the 36 and 46 kDa and 30% also to the 26 and 58 kDa released proteins, which correlated with the finding of virulent Yersinia bacilli in intestinal biopsies. IgA disappeared in 69% of untreated patients after nine months and persisted in 31% after one year. IgA disappeared within three to six months in 81% of the patients treated with antibiotics for four to six weeks and persisted in 6% after one year (p less than 0.002). IgG antibodies to the 36 and 46 kDa outer membrane proteins persisted in 80% of all patients. Disappearance of IgA was coupled with disappearance of yersinia from intestinal biopsies.

Proliferative response of synovial fluid and peripheral blood mononuclear cells to arthritogenic and non-arthritogenic microbial antigens and to the 65-kDa mycobacterial heat-shock protein.

Cellular immune responses to microbial antigens have been implicated in the pathogenesis of some forms of arthritis including reactive arthritis, Reiter's syndrome, ankylosing spondylitis and rheumatoid arthritis. We investigated the proliferative T cell responses of paired peripheral blood (PB) and synovial fluid (SF) mononuclear cells (MC) to so-called arthritogenic bacteria (Yersinia enterocolitica and Salmonella typhimurium), to control antigens, such as Candida albicans, mumps virus and purified protein derivative, to the recombinant mycobacterial 65-kDa heat-shock protein (hsp 65) and the mitogen phytohemagglutinin (PHA) in 16 patients with different inflammatory rheumatic diseases. The [3H]thymidine uptake of unstimulated cells (medium control) as well as the proliferative response to the different antigens tested was markedly increased in SFMC irrespective of the underlying rheumatic disease. In contrast, mitogenic stimulation was decreased in SFMC. The proliferative response to the hsp 65 correlated significantly with the responses to Yersinia, Salmonella and Candida. These results may reflect an enhanced function of SF antigen-presenting cells, different functional properties and subset distributions of PB and SF T cells with a preferential accumulation of helper-inducer/memory T cells or a maintenance of an ongoing immune response by T cells cross-recognizing self epitopes such as epitopes located on the hsp 65. Thus, care should be taken in the interpretation of SF T cell responses to microbial antigens as diagnostic tools in arthritis.

The pathogenicity of Yersinia enterocolitica for piglets.

The pathogenicity of Yersinia enterocolitica, a bacterium that has been isolated frequently from healthy swine, was studied in piglets by oral challenge of two litters, one derived by cesarean section and deprived of colostrum, and the other delivered at full-term. Eight cesarean-derived piglets were divided into groups of two and challenged with four serotypes of Y. enterocolitica (O:8, O:21, O:3, O:13). Two deaths occurred and two piglets were killed because of severe illness before termination of the experiment eight days after challenge. Surviving piglets showed no clinical signs of illness. Rectal cultures were consistently positive and all cesarean-derived piglets were colonized in the small intestine and throat at necropsy. Full-term piglets were allowed access for 36 hours to sow colostrum containing low levels of antibody against the challenge strains. Six full-term piglets challenged with three serotypes of Y. enterocolitica (O:8, O:21, O:13) survived for 15 days without any signs of illness. These piglets had fewer positive rectal cultures and showed less extensive colonization of internal organs at necropsy than did cesarean-derived piglets. It is uncertain whether this increased resistance to infection with Y. enterocolitica resulted from colostrum-derived antibody, intestinal colonization with other bacteria, or an improved physical condition which accompanied full-term development. Nevertheless, the results of this challenge experiment suggest that piglets are capable of restricting colonization by Y. enterocolitica to the throat and intestinal tract without development of serious illness.

Pathogenesis of Yersinia-triggered reactive arthritis: immunological, microbiological and clinical aspects.

When a patient develops reactive arthritis after Yersinia enteritis, the following conditions are often fulfilled: the patient is HLA-B27-positive; however, some B27-negative individuals develop severe arthritis and some positives do not, in the initial phase, the diarrhea is milder, the anti-Yersinia antibody response of IgG class is more vigorous and persists longer, the anti-Yersinia antibody response of IgA class is more vigorous and persists much longer, the anti-Yersinia antibodies of IgA1 and IgA2 subclass, those with J-chain and, especially, those with secretory piece are produced more vigorously, indicating local immunostimulation close to the intestinal epithelium, in the early phase, Yersinia-IgM immune complexes are found in the circulation, and the lymphocyte transformation response against not only Yersinia but also against other gram-negative enteric bacteria is weaker. When all these aspects are considered together a strong suspicion arises that the patients who are destined to develop reactive arthritis fail in their first line of defense against the invading organism when contracting a Yersinia enteritis. This may lead to persistence of the microorganism within the body, e.g., in the intestinal epithelium or in the mesenteric lymphoid tissues, maintaining a stimulus for a prolonged--apparently futile and perhaps harmful--antibody production. Finally, the initiating and decisive factor should not be forgotten: the Yersinia. Why and how it triggers the process is at present one of the enigmas of the pathogenesis of reactive arthritis.