Detection of circulating Yersinia-immunoglobulin complexes by enzyme immunoassay (EIA)

Effect of a three month course of ciprofloxacin on the outcome of reactive arthritis

BACKGROUND

Treatment of reactive arthritis (ReA) with antibiotics has so far remained controversial. Eradication of the causative microbe appears logical, but short term antibiotic treatment has no beneficial effect on the outcome of ReA.

OBJECTIVE

To evaluate the effect of a three month course of ciprofloxacin on ReA.

METHODS

In a randomised, double blind, placebo controlled trial, between December 1992 and February 1996, 71 patients with acute ReA triggered by a gastrointestinal or a urogenital infection were randomly assigned to receive ciprofloxacin 500 mg or placebo twice daily for three months. Patients were assessed at study entry, at 6 weeks, 3 months, 6 months, and 12 months. Sixty two patients were valid for the efficacy analysis. The primary outcome measures were erythrocyte sedimentation rate, number of swollen joints, patients self assessment, and complete recovery.

RESULTS

Adverse events were mostly mild and occurred in both treatment groups. There were no statistically significant differences in any of the primary or secondary efficacy variables between the study groups at baseline or during the 12 month follow up. All primary outcome measures indicated that the condition of the patients improved during the study.

CONCLUSION

Both groups tended to recover. Ciprofloxacin, given as a three month course, had no advantage over placebo treatment.

Characterization of immune complex components by dot blot analysis

A method is described for the characterization of immune complex components by dot blot analysis. After isolation by chromatographic techniques and precipitation with polyethylene glycol, immune complexes were dissociated in 0.1 M phosphate (pH 2) and bound to a nitrocellulose membrane in a dot blot unit. Biotinylated probes were then used to identify the following immune complex components: specific antigens, biologically active antibodies, antibody isotypes, antibody subclasses, antibody idiotypes, and rheumatoid factors. This nonradioactive procedure takes less than 2 h to perform and has been used to analyze immune complexes isolated from sera (rabbit and human) and synovial fluid (human).

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.

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.

Circulating yersinia specific immune complexes after acute yersiniosis: a follow up study of patients with and without reactive arthritis

The occurrence of immune complexes (ICs) containing Yersinia enterocolitica antigen and immunoglobulin was studied in 216 serum samples from 51 patients with recent yersiniosis at an early stage of the disease and during a follow up of two to 12 months. Twenty eight of the patients developed reactive arthritis, 23 recovered from the infection without any complications. An enzyme linked immunosorbent assay (ELISA) recently developed for detection of ICs containing yersinia antigen(s) and IgM, IgG, or IgA was applied. During the first two months after onset of the infection yersinia specific IgM complexes were demonstrated in higher concentrations in patients with arthritis than in those not developing this postinfection complication (p less than 0.02). The difference in the occurrence of IgM complexes between the two groups decreased with time. Yersinia specific IgA complexes were demonstrable in four patients with arthritis and in none of the non-arthritic patients. Yersinia specific IgG complexes were occasionally present in both patient groups. Altogether, more than eight months after onset of the infection yersinia specific ICs were detected in six arthritic and two non-arthritic patients, suggesting that in certain individuals yersiniae may hide after the initial infection for prolonged periods.

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

The size of immune complexes (ICs) containing Yersinia enterocolitica antigens was studied by size exclusion high-pressure liquid chromatography and sucrose density gradient ultracentrifugation in sera of patients with recent yersiniosis. The ICs detected were relatively small, i.e., of equal size to or slightly larger than the corresponding anti-Yersinia antibodies. The size of the ICs was equal in the patients with Yersinia-triggered reactive arthritis and in those recovering without complications. No changes were observed during a follow-up. The equal size of ICs in the patients with and without arthritis also suggests that antigens and antibodies involved are similar in both patient groups. Taken together with our earlier findings indicating occurrence of high concentrations of Yersinia IgM ICs in the arthritic patients, the present results suggest that Yersinia--IgM ICs have a role in the pathogenesis of Yersinia-triggered reactive arthritis.

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.