Introduction

Carbohydrate sulfotransferase 15 (CHST15) is an enzyme biosynthesizing sulfated matrix glycosaminoglycan that modulates tissue remodeling.

Aims & Methods

We evaluated the efficacy of add-on submucosal injections of GUT-1, the RNA oligonucleotide inhibitor of CHST15, to ongoing tumor necrosis factor (TNF) antagonist treatment in patients with moderate-to-severe ulcerative colitis (UC) and insufficient response to TNF antagonists.
This was an open-label study of 250 nM of GUT-1, which was applied by endoscopic submucosal injections at weeks 0, 2 and 4 in five UC patients who lost response during maintenance treatment to TNF antagonists. The primary endpoint was the rate of endoscopic improvement at week 6 and secondary endpoints included the rates of clinical remission. All patients received follow-up observation with continuous maintenance treatment by the same TNF antagonists till the time of clinical recurrence, defined by rectal bleeding and endoscopic examination, or for overall 48 weeks (Clinical trial Registration Number: UMIN000020900).

Results

At baseline, all included patients showed insufficient clinical and endoscopic response to ongoing TNF antagonist treatment (3 for infliximab and 2 for adalimumab), as measured by modified Mayo Score (mMS) of 7.8 (95%CI: 6.2 to 9.4), Endoscopic Subscore of 2.4 (95%CI: 1.7 to 3.1), Stool Frequency Subscore of 2.8 (95%CI: 2.2 to 3.4) and Rectal Bleeding Subscore of 2.6 (95%CI: 1.9 to 3.3). At week 6, Endoscopic Subscore reduced to 1.0 (95%CI: 0.1 to 1.9) and rate of endoscopic improvement was 80% (n=4/5). mMS reduced to 1.3 (95%CI: 0.4 to 3.2) and rate of clinical remission was 60% (n=3/5). Exploratory, Nancy histological index reduced to 1.8 (95%CI: 0.2 to 3.4) at week 6 from 3.6 (95%CI: 2.9 to 4.3) at baseline. Three patients did not show any signals of clinical recurrence for 48 weeks. All three corticosteroid-dependent patients showed no corticosteroid exposure for at least 20 weeks after achieving clinical remission. During the follow-up period, clinical recurrence was observed in one patient at week 36 and another at week 44.

Conclusion

Add-on multiple injections of GUT-1 to ongoing TNF antagonist treatment was able to induce rapid and durable clinical responses in patients with TNF antagonist-refractory UC. GUT-1 was well tolerated by the patients.

Introduction

Inflammatory bowel diseases are chronic disabling conditions with a complex and multifactorial aetiology, which is still not completely understood. OCTN1, an organic cation transporter could have a role in modulating the inflammatory response, whose genetic polymorphisms were associated to increased risk of inflammatory bowel diseases. Up to now, limited information exists on its role in predicting/modulating response to therapies.

Aims & Methods

The aim of this study was to evaluate the role of OCTN1 in modifying gut microbiota and immune composition to Infliximab therapy in murine colitis. Dextran sodium sulphate model of colitis on C57BL/6 mice and ocnt1 gene knockout mice was used to assess clinical efficacy of infliximab administered intravenously. Stool, colon and mesenteric lymph node samples were collected to assess differences in gut microbiota composition, histology for Rachmilewitz score and T cell populations respectively.

Results

Octn1^-/-influences microbiota profile and is associated with a worse dysbiosis in colitis mice. Infliximab treatment attenuates colitis-associated dysbiosis with increase of bacterial richness and evenness in both strains. In comparison with wild type, octn1^-/- mice have a higher baseline percentage of Treg, Tmemory, Th2 and Th17.

Conclusion

Our data support murine model to study OCTN1 genetic asset in inflammatory bowel diseases. This could be the first step to consider this membrane transporter as a biomarker in inflammatory conditions and as a predictor of response to therapies.

Introduction

Inflammatory bowel disease (IBD) is characterized by chronic inflammation due to an uncontrolled immune response orchestrated through, i.e. neutrophils. The basement membrane acts as a front-line defense promoting tissue integrity, where the α-3 chain of type IV collagen is solely expressed on the outermost layer of the mucosa. Detection of subclinical ulceration is crucial since early-stage IBD presents a unique window of opportunity for intervention, as the disease might become a self-sustaining process once deep inflammation becomes established. We therefore, wanted to develop a biomarker reflecting early tissue injury, aiding in the implementation of prompt treatment.

Aims & Methods

A competitive enzyme-linked immunosorbent assay quantifying a human neutrophil elastase (HNE) degraded fragment of type IV collagen α-3 chain was developed (C4A3-HNE). Dilution- and spiking recovery, inter- and intra-variability, and interference were evaluated. Acceptance criteria for technical validation were a recovery of 100% ±25 and an inter-intra variability of <15%. Commercial serum samples were purchased from ProteoGenex. Biological relevance was validated in an observational study from Odense University Hospital (OUH) and healthy controls. Groups were compared using Kruskal Wallis (Dunn‘s corrected).

Results

The technical validation of the C4A3-HNE assay demonstrated acceptable results for recovery, variation, and interference. Biological relevance was assessed in commercial IBD samples and healthy donors. C4A3-HNE was elevated in both CD and UC compared to healthy (p=0.001 and <0.0001)(AUC [95% CI]: 0.820 [0.669-0.971]; 0.875 [0.775-1.000]). The results were validated in an independent cohort of IBD patients (both p<0.0001). For UC, analysis showed that compared to patients in endoscopic remission, C4A3-HNE is elevated in patients with mild endoscopic activity, decreasing dose-dependently for moderate and severe disease (T1). Fecal calprotectin and CRP levels were also lower in IBD patients with high levels of C4A3-HNE (T1). With a cut-off value of 54.1 ng/ml, C4A3-HNE could significantly discriminate between mild and severe endoscopic disease (T1).

Conclusion

Our study demonstrates the biological and possible clinical relevance of the novel C4A3-HNE biomarker. The biomarker is elevated in patients with IBD compared with healthy, and high levels may reflect early mucosal damage in patients with UC. Furthermore, inflammatory markers were lower in IBD patients with high levels of C4A3-HNE, pointing towards high levels being indicative of early disease. C4A3-HNE may provide early detection of mucosal damage or prediction of relapse; however, further studies are required to assess the clinical validity of this biomarker.

Disclosure

MA, MP, MK, and JM are employees of Nordic Bioscience A/S. MK owns stocks in Nordic Bioscience A/S.

Introduction

Ulcerative colitis (UC) is a refractory inflammatory bowel disease of the colon with repeated relapses and remissions that requires lifelong treatment. Previous studies indicated that proinflammatory cytokines involved the onsets and developments of UC. New treatments for targeting these cytokines, such as TNF-α, IL-12 and IL-23 have been developed in a recent decade, underlying that immune abnormalities are the core for the etiology of UC.
Platelets play a role not only in hemostatic coagulation but in inflammatory mediator by interacting with various cells in the innate and adaptive immunity. Chronic inflammatory response confers platelets activation leading to elevated platelet count and hypercoagulability. Moreover, platelets aggregates with leukocyte in active inflammatory milieu. In fact, thrombocytosis, thromboembolism and upregulation of platelet-monocyte complex (PMC) in UC patients have been reported, implying that platelets could be novel biomarker, therapeutic target and clues for elucidating the pathology of UC. However, the clinical significance of platelet activation and PMC formation in UC is not fully elucidated and few studies were conducted to assess how platelet activation contributes to disease aggravations of UC. Therefore, we comprehensively analyzed platelet activation and platelet-monocyte complex by focusing on a correlation with clinical severity of UC.

Aims & Methods

Patients with UC (n=70) including MES0-2 group (n=34) and MES3 group (n=27), diagnosed according to a combination of symptoms, endoscopic findings, histologic findings, and the absence of alternative diagnoses, and age and sex-matched healthy controls (HCs) (n =19) were enrolled for this study. We analyzed the surface markers such as CD62P, CD40L, CD63, PAC-1 and Annexin V on CD61+ platelets by flowcytometry (FCM) in patients with UC in comparison with those in healthy adults. We also analyzed the proportion of CD61+CD14+ platelet-monocyte complexes and quantified the activation of PMCs by FCM. Moreover, we also investigated the correlation among surface markers, proportion of platelet-monocyte aggregates and Mayo endoscopic score (MES) in UC patients.

Results

The expression of CD62P but not other surface markers on platelets was significantly upregulated in UC when compared to HCs (p<0.01), and was significantly upregulated in in MES3 group when compared to the MES0-2 group (P<0.001). The proportion of PMC was also higher in MES3 groups when compared to MES0-2 group (P<0.05), and was markedly reduced by treatment (P<0.05). In addition, CD16+ monocytes, phenotypically mature and pro-inflammatory cell population, were increased in patients with UC when compared to HCs (P<0.01). The expression of CD16 on monocytes aggregated with platelets was significantly higher when compered to that without platelet (P<0.001).

Conclusion

Our study suggests that platelet activation accelerates mucosal inflammation via adhesion with monocytes in UC and contributes to the aggravation of disease.

References

Semple JW, et al. Platelets and the immune continuum.
Nat Rev Immunol. 2011 Apr;11(4):264-74.
Collins CE, et al. Platelets circulate in an activated state in inflammatory bowel disease.
Gastroenterology. 1994 Apr;106(4):840-5.

Introduction

Inflammatory bowel disease (IBD) is an idiopathic and chronic disorder that includes ulcerative colitis (UC) and Crohn’s disease (CD). Both diseases are different but show an uncontrolled intestinal immune response that generates tissue inflammation. Dendritic cells (DC) are phagocytic professional antigen presenting cells that link the innate and adaptive immune systems. Indeed, they are the only cell type able to stimulate naïve T cells generating an antigen-specific immune response. In humans, DC can be divided into plasmacytoid (pDC) and c conventional type 1 and 2 (cDC1, cDC2). Although cDC migration towards the GI mucosa is enhanced in IBD, the mechanisms underlying these migrations and whether biological drugs can modulate them are currently unknown.

Aims & Methods

This study aimed to analyze DC migratory capacity towards the GI mucosa, and whether biological drugs with different mechanisms of action can modulate this process in health and IBD.This is a cross-sectional observational postmarketing study where the modulatory effect of different biological treatments on samples from patients with an endoscopic diagnosis of IBD and healthy controls was studied ex vivo. Peripheral blood mononuclear cells (PBMC) were obtained from 15 patients per group and were cultured in presence of golimumab or ustekinumab. Following culture, surface markers expression was determined, assessing the differential effect of biological drugs (if any) over the DC subsets in the different groups. After that, the migratory capacity of circulating DC towards CCL2, CCL25, and MadCam1 from the different study groups was determined. Finally, we evaluated the DC migratory capacities in presence of biological drugs or with culture media alone.

Results

The cDC2 subset showed higher expression levels of β7 and CCR5 compared to cDC1. Golimumab and ustekinumab did not modify the expression of the homing markers in any studied subset in pDC and cDC2.On the contrary, in cDC1 both golimumab and ustekinumab increased CCR6 expression in qCD patients and CCR9 in aUC patients. Regarding to the migratory capacities of the different DC subsets toward intestinal chemoattractants ustekinumab decreased the migratory capacity of cDC2 from CD patients towards a medium supplemented with MadCam1 and increases toward CCL2 in case of cDC1 from CU. In the case of migratory capacities of cDC2 from HC were increased by ustekinumab and golimumab toward CCL2 and CCL25 just in case of golimumab.

Conclusion

cDC2 showed more migratory profile markers than other DC populations. Golimumab and ustekinumab modify the expression of the homing markers just in cDC1 subset. Nevertheless, ustekinumab and golimumab modify the migratory capacities of cDC in IBD patients and HC, but do not exert any effect on pDC. These effects occur in a different manner in CD and UC indicates that the behavior of cDC is different in CD and UC, and that the migration capacity of this subset is not dependent exclusively on homing markers.

Introduction

Therapeutic progress in inflammatory bowel disease (IBD) is limited by the lack of understanding of the pathophysiology and the mechanisms involved in response or lack/loss of response to treatments. IBD patients are treated with anti-inflammatory drugs, including biologics such as anti-tumor necrosis factor (TNF) agents, which have been crucial in achieving steroid-free remission and prevention of long-term complications. However, a significant subgroup of patients becomes refractory to these biologicals due to the development of immunogenicity, characterized by the presence of anti-drug antibodies (ADAs). The antibody production and peripheral tolerance are initiated and maintained within lymphoid organs, such as the peripheral lymph nodes, but the exact role of immune cells in these lymphoid structures and whether they are involved in anti-drug antibody (ADA) formation is unknown.

Aims & Methods

We aimed to unravel the pathophysiology behind the development of anti-drug antibodies. Therefore, we performed ultrasound-guided inguinal lymph node needle biopsies from which we isolated leukocytes along with PBMCs from the same patients. Leukocyte populations were analyzed at single cell level via high dimensional phenotyping through mass cytometry (CyTOF).

Results

Using this unique approach, we have so far results from 4 Crohn’s Disease (CD) patients with ADAs (75% females, 50% active disease) and 4 without ADAs (50% females, 75% active disease). Active disease was defined, as an observation of an elevated CRP (c-reactive protein) (>5 mg/L) and/or calprotectin >250 (mg/kg), including symptoms (Harvey-Bradshaw index score > 4 or disease activity index score-CDAI >150).
The proportion of CD4⁺ TEMRA (terminally differentiated effector memory T-cells), CD4⁺ effector and central memory T-cells were increased in the peripheral lymph nodes of patients that developed immunogenicity. Mature NK cells, classical and non-classical monocytes were also increased. Furthermore, the levels of the alpha-4 integrin expression were higher in the lymph node T-lymphocytes, as well as, in the lymph node naïve and memory B-cell subsets in the patient group with ADAs.

Table: Cytometry and Biochemical Characteristics.

Conclusion

Lymph node T-helper cells, monocytes and NK cells potentially play a role in the development ADAs in IBD patients treated with biologics. Although, there was no significant difference in the proportion of naïve and memory B-cells, our findings concerning the alpha-4 integrin expression levels also indicate that both lymph node T and B-lymphocytes, are possibly characterized by a higher migratory potential during immunogenicity conditions.

References

1. Stein RE, Lee DY, Leonard MB, et al. The association between drug levels, anti-drug antibodies, and therapeutic response during infliximab therapy in pediatric Crohn’s disease. J Crohns Colitis 2014; 8: S434.
2. Bodini G, Savarino V, Dulbecco P, et al. The influence of anti-adalimumab antibodies on adalimumab trough levels, TNF-alpha levels and clinical outcome. J Crohns Colitis 2014; 8: S42
3. Stefan S, Sandborn WJ, Choi J, et al. Anti-drug antibodies separate responses of markers of inflammation (c-reactive protein, fecal calprotectin) in Crohn’s disease patients treated with certolizumab pegol. Inflamm Bowel Dis 2014; 20: S68.
4. Strand V, Balsa A, Al-Saleh J, et al. Immunogenicity of Biologics in Chronic Inflammatory Diseases: A Systematic Review. BioDrugs. 2017;31(4):299-316. doi:10.1007/s40259-017-0231-8.
5. Brun MK, Goll GL, Jørgensen KK, et al. Risk factors for anti-drug antibody formation to infliximab: Secondary analyses of a randomised controlled trial. J Intern Med. 2022;292(3):477-491. doi:10.1111/joim.13495.

Disclosure

The authors state no conflict of interest.

Introduction

Tofacitinib is an oral small molecule Janus kinase inhibitor for the treatment of ulcerative colitis (UC). Histological outcomes and the immune landscape were assessed in an UC patient cohort at baseline and after 8 weeks tofacitinib.

Aims & Methods

In this prospective study, 40 patients with moderate to severely active UC received tofacitinib 10 mg twice daily for 8 weeks. Clinical, endoscopic and histological outcomes were assessed at baseline and week 8 and colon biopsies were stained for JAK1-3, Tyrosine kinase 2 (TYK2) and Signal transducer and activator of transcription (STAT) 1-6 total protein expression using immunohistochemistry (IHC). Histological remission was defined as a Robarts Histopathology Index (RHI) ≤3 points without mucosal neutrophils and histological response as 50% decrease in RHI compared to baseline. Response was defined as histological remission and endoscopic Mayo score (EMS) ≤1 (histo-endoscopic mucosal improvement). Biopsies were scored by a blinded pathologist. Whole slide images with multiple biopsies per patients were stained using IHC, analyzed using automated cell detection (QuPath) and quantified in percentages by dividing the number of positive stained cells by the total number of cells on the slide. Outcomes were compared between responders and non-responders (NR).

Results

Out of 40 patients, 26 (65%) had severe endoscopic disease (EMS 3) with a median RHI of 14. Thirty-one patients (78%) had failed prior anti-Tumor Necrosis Factor (anti-TNF) agents and 18 (55%) failed vedolizumab. At week 8, 23 patients (58%) achieved histological remission, 34 (85%) histological response and 15 (38%) histo-endoscopic mucosal improvement. A significant decline in RHI compared to baseline was observed after 8 weeks both in responders (14 vs 0, p<0.001) and NR (15 vs 6, p=0.002). In the entire cohort, total STAT1 (p<0.001), STAT3 (p=0.002) and STAT5 (p=0.026) expression significantly decreased after 8 weeks treatment compared to baseline, which was not different between responders and NR (Table). However, responders to tofacitinib expressed significantly lower total STAT1 levels compared to NR at 8 weeks (p<0.001). Likewise, JAK2 (p=0.008) and total STAT2 expression (p=0.004) were significantly lower in responders compared to NR at 8 weeks, although no significant decrease compared to baseline was observed. A trend towards lower baseline JAK1, JAK2 and total STAT4 expression and higher total STAT6 expression was seen in responders compared to NR.

Conclusion

Tofacitinib resulted in histological response in the majority of UC patients and led to a substantial decline of total STAT1, STAT3 and STAT5 expression both in responders and NR. Yet, after 8 weeks significantly lower total STAT1 levels were observed in responders compared to NR. Responders tended to express lower JAK1, JAK2 and total STAT4 and higher total STAT6 levels at baseline.

Disclosure

This study was funded and supported by Pfizer.