A novel unconventional T cell population enriched in Crohn's disease

OBJECTIVE

One of the current hypotheses to explain the proinflammatory immune response in IBD is a dysregulated T cell reaction to yet unknown intestinal antigens. As such, it may be possible to identify disease-associated T cell clonotypes by analysing the peripheral and intestinal T-cell receptor (TCR) repertoire of patients with IBD and controls.

DESIGN

We performed bulk TCR repertoire profiling of both the TCR alpha and beta chains using high-throughput sequencing in peripheral blood samples of a total of 244 patients with IBD and healthy controls as well as from matched blood and intestinal tissue of 59 patients with IBD and disease controls. We further characterised specific T cell clonotypes via single-cell RNAseq.

RESULTS

We identified a group of clonotypes, characterised by semi-invariant TCR alpha chains, to be significantly enriched in the blood of patients with Crohn's disease (CD) and particularly expanded in the CD8⁺ T cell population. Single-cell RNAseq data showed an innate-like phenotype of these cells, with a comparable gene expression to unconventional T cells such as mucosal associated invariant T and natural killer T (NKT) cells, but with distinct TCRs.

CONCLUSIONS

We identified and characterised a subpopulation of unconventional Crohn-associated invariant T (CAIT) cells. Multiple evidence suggests these cells to be part of the NKT type II population. The potential implications of this population for CD or a subset thereof remain to be elucidated, and the immunophenotype and antigen reactivity of CAIT cells need further investigations in future studies.

Longitudinal monitoring of STAT3 phosphorylation and histologic outcome of tofacitinib therapy in patients with ulcerative colitis

BACKGROUND

Tofacitinib is the first in class, pan-JAK inhibitor approved for ulcerative colitis (UC). Clinical efficacy has been shown, but long-term real-life endoscopic and histologic data are lacking.

AIM

To investigate the effects of tofacitinib in patients with refractory UC focussing on endoscopic, histologic and molecular outcomes, including STAT3 phosphorylation (pSTAT3) detection in the spatial context of mucosal inflammation METHODS: We prospectively monitored 59 highly refractory patients (96.7% anti-TNF exposure, 91.7% vedolizumab exposure) initiating tofacitinib at two IBD referral centres and assessed outcome at the end of induction and after 48 weeks of therapy. Endoscopic improvement was defined as a Mayo endoscopic subscore ≤1, endoscopic and histologic remission as Mayo endoscopic subscore 0 and Nancy histologic score 0. Multiplex immunohistochemistry with multispectral imaging was used to assess pSTAT3.

RESULTS

Endoscopic improvement was achieved by 24.4% and 30.5% of patients at weeks 8 and 48, respectively. Endoscopic and histologic remission rates were 11.1%, 23.7 and 16.7%, 21.4%, respectively. Endoscopic improvement at week 8 was significantly associated with treatment continuation in the long-term (72.7% vs 20.6%, p = 0.003). Although we observed a gradual decrease of mucosal pSTAT3 levels in both remitters and non-remitters (p < 0.05), no association with treatment outcome could be demonstrated. However, lamina propria pSTAT3 was significantly associated with the Nancy Histologic index (p = 0.004).

CONCLUSION

Tofacitinib can induce and maintain endoscopic and histologic remission in up to one-quarter of highly refractory UC patients. Longitudinal monitoring of nuclear pSTAT3 in mucosal tissue compartments reflects distinctive on-target effects, independently of long-term treatment outcomes.

Patient Reported Outcomes in Chronic Inflammatory Diseases: Current State, Limitations and Perspectives

Chronic inflammatory diseases (CID) are emerging disorders which do not only affect specific organs with respective clinical symptoms but can also affect various aspects of life, such as emotional distress, anxiety, fatigue and quality of life. These facets of chronic disease are often not recognized in the therapy of CID patients. Furthermore, the symptoms and patient-reported outcomes often do not correlate well with the actual inflammatory burden. The discrepancy between patient-reported symptoms and objectively assessed disease activity can indeed be instructive for the treating physician to draw an integrative picture of an individual's disease course. This poses a challenge for the design of novel, more comprehensive disease assessments. In this mini-review, we report on the currently available patient-reported outcomes, the unmet needs in the field of chronic inflammatory diseases and the challenges of addressing these.

Effekt von Suramin auf Proliferation und Migration von Linsenepithelzellen in vitro

BACKGROUND

New approaches for the treatment of secondary cataract focus on a pharmacological therapy to prevent posterior capsule opacification. In this study we investigated the effect of the naphthylurea suramin in vitro in a cell culture model.

MATERIAL AND METHODS

Cell proliferation was measured using a proliferation assay and cell migration with a migration assay. Analyses of suramin toxicity were carried out using trypan blue staining.

RESULTS

A significant dose-dependent effect of suramin on the inhibition of LEC proliferation and migration was found even after short (1 or 2 h) incubation times ( p<0.01). Cell lysis reflecting a cytotoxic effect of suramin was not found even with high concentrations. However, preincubation of lens capsules with suramin did not prevent LECs from migrating compared to control cultures.

CONCLUSION

These results demonstrate the efficiency of suramin in vitro to inhibit migration of HLEC which can be explained by blocking growth factor-mediated effects on the cells. However, further investigations on the pharmacokinetic properties of suramin and possible side-effects on other intraocular tissues must follow.

[Analysis of the aqueous humor in keratoplasty patients with keratitis. Initial results]

OBJECTIVE

Herpetic keratitis is a common indication for corneal transplantation. In this patient group especially, there is a relatively high risk of graft failure, partly because of viral recurrence. It can be difficult to clinically distinguish stromal herpetic recurrence from early endothelial allograft rejection. Also a perioperative observation of viral activity seems advisable because of therapeutic consequences. For these reasons we use aqueous humor analysis in certain corneal transplant patients to determine intraocular antibody production. The aim of this study was to evaluate the diagnostic value of such an analysis of aqueous humor.

MATERIAL AND METHODS

A total of 28 samples of aqueous humor were obtained from 24 eyes and all samples were tested for antibodies against herpes simplex virus (HSV), most samples (26/28) were tested for antibodies against varizella zoster virus (VZV) and some samples (6/28) for antibodies against cytomegalovirus. We used a modified micro-ELISA technique to detect intraocular IgG production.

RESULTS

In 14 samples (50%) we found antibodies against HSV, in 7 samples (25%) against HSV and VZV, in 1 sample (3.6%) against VZV and 6 samples (21.4%) were negative for all antibodies tested.

CONCLUSION

The results of aqueous humor analysis led to a specific local or systemic antiviral therapy perioperatively or in the case of postoperative recurrence of herpetic keratitis in most patients. Some patients could be spared long-term treatment with antiviral agents because of negative results in the aqueous humor analysis.

Intraocular antibody production in intraocular inflammation

BACKGROUND

The production of intraocular antibodies is considered a specific marker for active infectious uveitis. The aim of our study was to evaluate the diagnostic value of aqueous humor analysis in consecutive patients referred to a tertiary clinical center.

METHODS

We analyzed 91 paired aqueous humor/serum samples from 89 patients with intraocular inflammation. In 71 patients aqueous humor analysis was used as a positive or negative confirmation of the suspected cause, whereas in 18 patients the clinical diagnosis was completely uncertain. A modified micro-ELISA technique was used to detect intraocular IgG production against Toxoplasma gondii, varicella zoster virus, herpes simplex virus and cytomegalovirus. Statistical analysis was performed using the "Cohen's kappa" test.

RESULTS

Specific intra-ocular antibody production could be detected in 12 (66.7%) of 18 patients with uncertain diagnosis. Subsequently initiated therapy led to clinical improvement in 10 patients, whereas 2 patients remained unchanged. In 2 (2.8%) of 71 patients aqueous humor analysis led to revision of the initially suspected etiology and to a change of therapy. Statistical analysis showed a significant accordance of diagnosis and aqueous humor analysis (P<0.01).

CONCLUSION

In patients with infectious uveitis, analysis of intraocular synthesis of specific antibodies is a valuable tool to establish the etiology rapidly and allows initiation of targeted antimicrobial treatment.