Persistence of Yersinia antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3 infection with or without reactive arthritis

OBJECTIVE

To assess the persistence of bacterial antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3-triggered reactive arthritis (ReA).

METHODS

Peripheral blood samples were obtained from 20 patients with Y. enterocolitica O:3 infection (11 with ReA and 9 without). These samples were studied by immunochemical techniques for the presence of Yersinia antigens at the beginning of infection and up to 4 years thereafter. Synovial fluid samples from 6 of the 11 ReA patients were also studied.

RESULTS

The Yersinia antigens lipopolysaccharide and heat-shock protein (HSP) were detected in peripheral blood mononuclear cells and polymorphonuclear phagocytes from all patients studied at the early phase of the disease. They were also found in the synovial fluid cells of patients with Yersinia-triggered ReA. At 4 years after the onset of infection, these bacterial antigens were still detected in the peripheral blood cells of most of the ReA patients studied.

CONCLUSION

This study has, for the first time, directly demonstrated that bacterial antigens persist for a long time in patients who develop ReA after Y. enterocolitica O:3 infection. The finding of bacterial HSP in synovial fluid cells could provide a link to the pathogenesis of ReA, since T cell responses of synovial cells have been shown to be directed against that structure. A close similarity between the bacterial and host HSP might contribute to the development of the relatively common, chronic form of this complication.

Oncoprotein expression in human synovial tissue: an immunohistochemical study of different types of arthritis

Based on the fact that synovial lining cells have some properties of transformed-appearing cells, we have examined the expression of Myc, Myb, Fos, Jun and Ras oncoproteins in synovial tissues from patients with different types of arthritis. Formalin-fixed and paraffin-embedded sections of synovial tissue from 12 patients with rheumatoid arthritis (RA), 14 with reactive arthritis (ReA), nine with other seronegative arthritis (OSA), seven with bacterial arthritis (BA), eight with probable bacterial arthritis (PBA) and eight with osteoarthritis (OA) were studied using the immunoperoxidase staining technique. The oncoproteins studied were expressed both in the synovial lining layer and in the sublining layer, consisting of lymphocytes, other inflammatory cells and blood vessels. Among the six disease entities, RA and OA appeared to be the most distinct, whereas the results obtained for ReA and OSA, and on the other hand for BA and PBA, closely resembled each other. The expression of Myc, Myb, Fos and Jun was significantly correlated both to the degree of synovial hypercellularity and the synovial lymphocytic infiltration. For Ras, such a correlation could not be seen. We conclude that we find no evidence of a cell lineage-specific or a disease-specific abnormality of proto-oncogene products in RA, and the expression of these oncoproteins is consistent with inflammation rather than with any primary abnormality of cell growth.

Propionibacterium acnes isolated from sternal osteitis in a patient with SAPHO syndrome

A woman presented with palmar pustulosis and deep chest pain in association with osteitic lesions in the lower part of the sternum. Propionibacterium acnes was isolated and grew in pure culture from 6 surgically obtained bone specimens. The patient received clindamycin treatment for 6 months. Synovitis in both her wrists persisted and, based on a clinical suspicion of seronegative rheumatoid arthritis, she was treated with intramuscular gold and methotrexate with no apparent benefit. Subsequently, she was diagnosed with SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteomyelitis). Our patient provides further data on the potential association between P. acnes and SAPHO syndrome.

Expression of bcl-2 in rheumatoid arthritis

Since defective apoptosis has been suggested to play a role in the development of autoimmune diseases, we have investigated the expression of the proto-oncogene bcl-2 in patients with rheumatoid arthritis (RA). The expression of bcl-2 was studied in peripheral blood (PB) and synovial fluid (SF) lymphocytes and synovial tissues (ST) from patients with RA using immunohistochemistry, flow cytometry and nucleic acid hybridization. Patients with reactive arthritis (ReA) or osteoarthritis (OA) and healthy individuals were used as controls. The expression of bcl-2 protein in PB lymphocytes and the expression of bcl-2 mRNA in PB mononuclear cells (PBMC) was similar in healthy controls and patients with RA. However, bcl-2 protein expression was significantly reduced in SF lymphocytes when compared to PB lymphocytes. Similar results were observed with lymphocytes from patients with ReA, and irrespective of whether total lymphocytes, T cells or different T-cell subsets were studied. In the synovial sections, the expression of bcl-2 was restricted to lymphocytes, and bcl-2+ cells were observed in the majority of samples from patients with RA, OA and ReA. These data indicate that the expression of bcl-2 is not increased in the lymphocytes or ST derived from patients with RA. Instead, decreased expression of bcl-2 protein in SF lymphocytes compared to PB lymphocytes was demonstrated. We suggest that bcl-2 does not play a significant role in the pathogenesis of RA.

Yersinia-specific antibodies in serum and synovial fluid in patients with Yersinia triggered reactive arthritis

OBJECTIVES

To further evaluate the role of bacterial antigens in triggering inflammation in the joint in patients with reactive arthritis by studying local antibody synthesis in the joint.

METHODS

Yersinia-specific antibodies in paired serum and synovial fluid samples from 29 patients with yersinia triggered reactive arthritis were studied using an enzyme linked immunosorbent assay (ELISA), an inhibition ELISA with six monoclonal antibodies against lipopolysaccharide or released proteins of yersinia and immunoblotting. Antibodies of IgM, IgG and IgA classes, as well as antibodies of IgA subclasses and those containing secretory component were measured against the lipopolysaccharide and the sodium dodecyl sulphate extract of whole Yersinia enterocolitica O:3 bacteria.

RESULTS

It was shown that yersinia-specific antibodies, as well as antibodies against other microbial antigens (rubella, measles, Bordetella pertussis, tetanus toxoid and Candida albicans) in synovial fluid mirror those in serum by concentration, by specificity and by distribution in classes and subclasses.

CONCLUSION

These results do not suggest any strong local antibody production, but indicate that the majority of yersinia antibodies in the synovial fluid are derived from the circulation.

Electron microscopy and immunolabeling of Yersinia antigens in human synovial fluid cells

Recent findings have emphasized the involvement of bacterial antigens in synovitis in reactive arthritis. It is still unclear, however, in what form the microbial material exists in the joint. Both antigen-containing cells and intact bacteria have been proposed as candidates on the basis of immunohistochemical studies of the synovial membrane. This study addresses that question by electron microscopy and peroxidase immunolabeling of synovial fluid cells from three patients with reactive arthritis triggered by Yersinia enterocolitica O:3. For all three patients a diffuse reaction in the cytoplasm of phagocytes was interpreted as bacterial material in a degraded form. These results are consistent with our proposal that intact bacteria rarely, if ever, enter the joints of Yersinia-triggered reactive arthritis patients.

Effect of antimicrobial treatment on chronic reactive arthritis

In a double-blind study comprising 36 patients the effect of a three-month course of ciprofloxacin on chronic reactive arthritis was evaluated. At the end of the follow-up period 6 months after stopping the therapy, arthralgia, pain at movement and morning stiffness had decreased significantly compared to the values before the treatment in the ciprofloxacin group, whereas the Ritchie index and ESR showed a significant decrease in the control group. We conclude that further studies are necessary before the value of prolonged ciprofloxacin treatment of chronic reactive arthritis can be established.

Yersinia-triggered reactive arthritis. Use of polymerase chain reaction and immunocytochemical staining in the detection of bacterial components from synovial specimens

OBJECTIVE

To investigate whether microbial DNA is present in synovial specimens from patients with Yersinia-triggered reactive arthritis.

METHODS

Synovial specimens from 13 patients with Yersinia enterocolitica O:3-triggered reactive arthritis and from 16 control patients were studied using polymerase chain reaction and immunocytochemical staining techniques.

RESULTS

Yersinia chromosomal DNA was not found in any of the synovial specimens from Yersinia-triggered arthritis patients or controls, whereas with immunocytochemical techniques, Yersinia antigens were observed in synovial specimens from all of the patients with Yersinia-triggered reactive arthritis.

CONCLUSION

Only stable bacterial degradation products, not whole bacteria, are present at the site of inflammation in Yersinia-triggered reactive arthritis.

Long term follow up of SHR rats with experimental yersinia associated arthritis

One hundred and one SHR rats were injected intravenously with live Yersinia enterocolitica O:8. The rats were randomly divided into two groups consisting of 48 and 53 rats. The group of 48 rats was monitored for 245 days to establish the incidence and the clinical features of the arthritis. The remaining 53 rats were killed in groups of three to five rats at intervals from four to 245 days after inoculation to examine the clearance of bacteria and the development of histological changes in the synovial membrane. Arthritis developed in 23/48 (48%) rats at seven to 27 days after inoculation. The arthritis subsided in most rats within four weeks, without leading to ankylosis of the affected joints. The arthritis was prolonged in three rats and recurrent in two. In the group of 53 rats Yersinia enterocolitica O:8 was cleared from most of the internal organs by day 77, but persisted in the inguinal lymph nodes in many of the rats up to day 245. All macroscopically arthritic joints showed clear histological signs of non-suppurative synovitis. No histological synovitis was detected in those joints observed macroscopically to be non-arthritic. Yersinia associated arthritis in SHR rats provides a potential model for reactive arthritis. There are strong similarities in the course of the arthritis and histopathological changes in the synovium between this animal model and reactive arthritis in humans. This study supports the association between poor elimination of the causative agent and the development of arthritis.

Bacterial antigens in synovial biopsy specimens in yersinia triggered reactive arthritis

Non-viable structures of Yersinia enterocolitica O:3 were shown at the site of inflammation within mononuclear cells in the synovial membrane of eight out of 10 patients with yersinia triggered reactive arthritis. An avidin-biotin-peroxidase complex method, with a rabbit antiserum specific for Y enterocolitica O:3, was used to visualise yersinia structures. All 13 control samples were negative except for one with non-specific mast cell staining. The findings emphasise the significance of foreign material in the initiation of synovitis in reactive arthritis.

Risk of Yersinia infection among butchers

The purpose of this study was to evaluate the risk of yersinia infection among butchers. Serum samples were collected from 146 abattoir workers, stratified into 3 groups according to exposure to swine throats and intestines. 100 healthy blood donors were used as controls. Antibodies against Yersinia enterocolitica O:3 and O:9 and Y. pseudotuberculosis I and III were measured using ELISA. Symptoms associated with yersiniosis were recorded in a questionnaire. Antibodies against Y. enterocolitica O:3 were observed more often in the sera of abattoir workers (19%), especially in butchers handling swine throats and intestines (27%), than in the sera of healthy blood donors (10%). During the 6 months preceding this study, 30-40% of the workers reported symptoms of abdominal pains and diarrhoea. However, the symptoms did not correlate with the occurrence of antibodies. One butcher had developed a yersinia-triggered prolonged reactive arthritis. Tonsil samples were collected from 120 pigs to determine the extent of yersinia contamination. Positive isolates were obtained from 54 pigs (45%). Y. enterocolitica O:3 was isolated from 31 pigs and Y. pseudotuberculosis III from 11 pigs. All of these strains shared characteristics typical for virulent strains. We conclude that yersinia infections are an occupational health risk to workers slaughtering swine in the abattoirs.

Synovial fluid acid phosphatase in seropositive and seronegative arthritides

Synovial fluid acid phosphatase was investigated in 82 arthritic patients with hydropsy in a knee joint. 39 of the patients were seropositive and 43 seronegative. 36 of the seropositive group had erosive rheumatoid arthritis. The mean synovial fluid acid phosphatase in the seropositive group, 11.6 U/l (SD +/- 8.4), was significantly higher (p less than 0.001) than in the seronegative group, 6.5 U/l (SD +/- 4.8).

Prognostic significance of synovial fluid analysis in rheumatoid arthritis

Thirty patients with definite rheumatoid arthritis and hydropsy in a knee joint were followed for 42 months in a prospective study. The knee joints were initially aspirated and 15 synovial fluid variables investigated. The patients were split into two groups, those with and those without progress of radiologically detected destruction in the knee joints during the follow-up. Of the synovial fluid variables at the start synovial fluid proteins (P = 0.002) and acid phosphatase (P = 0.03) differed statistically significantly between the groups, both being higher in patients with worsening of knee joint. The results suggest that high synovial fluid proteins and acid phosphatase are predictors of poor prognosis in a joint affected by rheumatoid arthritis.

Synovial T lymphocyte recognition of organisms that trigger reactive arthritis

Reactive arthritis (ReA) is believed to be "triggered' by infection with certain bacteria. When the proliferative responses of mononuclear cells (MC) obtained from the synovial fluid (SF) of ReA patients were examined, it was found that they responded maximally to the specific organism responsible for the preceding infection. The response was shown to be due to Class II MHC-restricted T cells by inhibition experiments using cyclosporin A and monoclonal antibodies. Significant SFMC responses to additional organisms associated with ReA were also recorded; since there was no serological evidence of preceding infection by these organisms, this finding suggests that these bacteria share common T cell-recognized antigenic epitopes. The corresponding responses by peripheral blood mononuclear cells (PBMC) were much lower and often barely detectable, whereas their responses to PHA were consistently higher than those of SFMC. These results, combined with evidence that bacterial antigens localize in the joint, indicate that a bacteria-specific, T-cell-mediated response may play a central role in the pathogenesis of ReA.

Yersinia antigens in synovial-fluid cells from patients with reactive arthritis

We examined synovial-fluid cells from 15 patients with reactive arthritis after yersinia infection for the presence of yersinia antigens. Extensive bacterial cultures of the synovial fluid were negative. All the samples were studied by immunofluorescence with use of a rabbit antiserum to Yersinia enterocolitica O:3 and a monoclonal antibody to Y. enterocolitica O:3 lipopolysaccharide. Synovial-fluid cells from 41 patients with other rheumatic diseases served as controls. Synovial-fluid cells from 10 patients with reactive arthritis after yersinia infection stained positively on immunofluorescence; rabbit antiserum and the monoclonal antibody yielded similar results. In most patients the percentage of positive cells ranged from 1 to 10 percent, but in one patient nearly all the cells in the sample stained strongly. Most of the positively stained cells were polymorphonuclear leukocytes, but yersinia antigens were also found in mononuclear phagocytes. All the control samples were negative. Synovial-fluid cell deposits from nine patients were also studied by Western blotting with use of the same antibodies. The results were positive in six of the nine cell deposits from patients with reactive arthritis and in none of the 10 cell deposits from control patients with rheumatoid arthritis. We conclude that in patients with reactive arthritis after yersinia infection, microbial antigens can be found in synovial-fluid cells from the affected joints.

Experimental Yersinia-associated arthritis in the spontaneously hypertensive rat

Sterile arthritis resembling human reactive arthritis was induced in spontaneously hypertensive SHR rats by intravenous injection of live Yersinia enterocolitica 0:8. Histologically the synovitis appears as proliferation of the lining cell layer, with inflammatory cells present in the subsynovium. The inflammatory cells are mostly lymphocytes. Infection with Yersinia enterocolitica 0:3 or Yersinia pseudotuberculosis did not induce arthritis. Susceptibility to Yersinia-associated arthritis is not determined by the major histocompatibility complex (MHC), since rats of the normotensive control strain (WKY) with the same MHC do not develop arthritis.

Yersinia-associated arthritis in the rat: experimental model for human reactive arthritis?

Rats of five different strains were injected intravenously with live Yersinia enterocolitica O:8 or Yersinia pseudotuberculosis III. Twelve to 18 days after inoculation of Y. enterocolitica O:8, arthritic symptoms appeared in the hindpaws of SHR rats. They started with erythema, followed by swelling and painful movement, closely resembling findings in adjuvant arthritis. Histologically, the inflammation was dominated by neutrophils in two cases, whereas in two others the inflammatory cells were predominantly lymphocytes. Two of five rats yielded positive bacterial cultures from the joints. Altogether, arthritis was observed in five of nine SHR surviving beyond day 14 after the bacterial inoculation. Rats of Lewis, Wistar, WKY and Zucker strains did not develop any signs of arthritis after intravenous injection of Y. enterocolitica or pseudotuberculosis. Also in the SHR rats, Y. pseudotuberculosis failed to induce arthritis.