Spondyloarthritis and inflammatory bowel disease. Comorbidity and treatment implications

Intestinal epithelial expression of human TNF is sufficient to induce small bowel inflammation and sacroiliitis, mimicking human spondyloarthritis

OBJECTIVES

Gut and joint disease commonly co-occur in SpA. Up to 50% of patients with SpA show signs of subclinical gut inflammation, of which 10% develops IBD. However, the mechanisms underlying this gut-joint axis are still unclear. Here we investigated the hypothesis that restricted expression of a pro-inflammatory cytokine in the intestine may trigger the onset of combined gut and joint inflammation.

METHODS

Intestinal expression of human TNF (hTNF) was achieved by driving hTNF gene expression using the rat FAPB2 promoter, creating a new animal model, TNFgut mice, that expresses hTNF in the proximal intestinal tract. Intestinal-specific TNFgut mice were examined for pathological changes in the intestine and extra-intestinal tissues by means of histology, reverse transcription PCR (RT-PCR) and flow cytometry, along with 16S sequencing on stools.

RESULTS

Local expression of hTNF in the epithelium of the small intestine induces a pro-inflammatory state of the proximal intestinal tract, with epithelial alterations and induction of members of the S100 family, as well as local upregulation of Th17 and Treg, but no obvious signs of dysbiosis. Curiously, TNFgut mice develop sacroiliitis (P <0.05) in addition to small bowel inflammation (P <0.05). However, no signs of peripheral arthritis or enthesitis could be documented.

CONCLUSION

Intestinal expression of hTNF is sufficient to initiate a pro-inflammatory cascade culminating in small bowel inflammation and sacroiliitis. Thus, gut-derived cytokines are sufficient to induce SpA.

Oral immune therapy: targeting the systemic immune system via the gut immune system for the treatment of inflammatory bowel disease

Inflammatory bowel diseases (IBD) are associated with an altered systemic immune response leading to inflammation-mediated damage to the gut and other organs. Oral immune therapy is a method of systemic immune modulation via alteration of the gut immune system. It uses the inherit ability of the innate system of the gut to redirect the systemic innate and adaptive immune responses. Oral immune therapy is an attractive clinical approach to treat autoimmune and inflammatory disorders. It can induce immune modulation without immune suppression, has minimal toxicity and is easily administered. Targeting the systemic immune system via the gut immune system can serve as an attractive novel therapeutic method for IBD. This review summarizes the current data and discusses several examples of oral immune therapeutic methods for using the gut immune system to generate signals to reset systemic immunity as a treatment for IBD.

Effect of therapeutic plasma exchange on plasma levels and total removal of adipokines and inflammatory markers

Background

Aside from well-established inflammatory mediators adipokines have recently been found to play an important role in a variety of immunologic diseases. Therapeutic plasma exchange (TPE) is an established treatment modality for the acute removal of pathophysiological relevant disease mediators. The aim of this study was to determine adipokine removal during TPE therapy.

Methods

21 Caucasian patients (10 females, 11 males) with an indication for TPE using albumin as exchange fluid received two consecutive TPE sessions. Blood samples for measurement of resistin, leptin, sICAM-1, sCD40L, MCP-1, and sTNF-R were drawn before and at the end of each TPE session. Samples from the total removed plasma were collected at the end of every treatment.

Results

We found a significant reduction in pre- vs. post-TPE plasma concentrations for sICAM-1 (517 ± 246 vs. 260 ± 159 ng/ml, p < 0.0001), sTNF-R (8.1 ± 6.4 vs. 5.7 ± 3.9 ng/ml, p < 0.05), and resistin plasma levels (14.3 ± 6.9 vs. 9.5 ± 4.7 ng/ml, p < 0.001). Solely sICAM-1 reduction persisted for 25 ± 5 h between the first and second TPE treatment, while the other investigated mediators increased to baseline levels. Substantial amounts of all measured mediators could be recovered from the removed plasma.

Conclusions

TPE provides a persistent reduction in sICAM-1 levels and temporarily affects several adipokine and cytokine plasma levels. Our findings are of importance not only for the interpretation of blood levels of cytokines in patients undergoing TPE but provide solid evidence that TPE markedly decreases sICAM-1.

[Two-year incidence of new immune-mediated inflammatory diseases in patients with inflammatory bowel disease: A study in the AQUILES cohort]

OBJECTIVE

To describe the 2-year incidence of new immune-mediated inflammatory diseases (spondylarthritis, uveitis, psoriasis) in the cohort of patients with inflammatory bowel disease (IBD) included in the AQUILES study.

MATERIALS AND METHODS

Over a 2-year period, 341 patients with IBD (53% women, mean age 40 years) diagnosed with Crohn's disease (60.5%), ulcerative colitis (38.1%) and indeterminate colitis (1.4%) were followed up. New diagnoses made during follow-up were based on reports of the corresponding specialists (rheumatologists, ophthalmologists, and dermatologists).

RESULTS

A total of 22 new diagnoses of immune-mediated inflammatory diseases were established in 21 patients (cumulative incidence of 6.5%, 95% confidence interval [CI] 3.7-9.2, incidence rate of 26 cases per 10,000 patient-years). Most diagnoses were new cases of spondylarthritis (n=15). The cumulative incidence of new diagnoses of immune-mediated inflammatory diseases was similar in patients with Crohn's disease (5.8%, 95% CI 3.4-9.9) and in patients with ulcerative colitis (7.7%, 95% CI 4.2-13.6). On multivariate analysis, the incidence of new immune-mediated inflammatory diseases was significantly associated with a family history of IBD (odds ratio=3.6, 95% CI 1.4-9.4) and the presence of extraintestinal manifestations of IBD (odds ratio=1.8, 95% CI .7-5.2).

CONCLUSIONS

In patients with IBD, the incidence of new immune-mediated inflammatory diseases at 2 years of follow-up was 6.5%. These diseases were more frequent in patients with extraintestinal manifestations of IBD and a family history of IBD.