RNA sequencing of intestinal mucosa reveals novel pathways functionally linked to celiac disease pathogenesis

BACKGROUND & AIMS

The early steps in the pathophysiology of celiac disease (CD) leading to loss of tolerance to gluten are poorly described. Our aim was to use RNA sequencing of duodenal biopsies in patients with active CD, CD in remission, and non-CD controls to gain insight into CD pathophysiology, identify additional genetic signatures linked to CD, and possibly uncover targets for future therapeutic agents.

METHODS

We performed whole transcriptome shotgun sequencing of intestinal biopsies in subjects with active and remission CD and non-CD controls. We also performed functional pathway analysis of differentially expressed genes to identify statistically significant pathways that are up or down regulated in subjects with active CD compared to remission CD.

RESULTS

We identified the upregulation of novel genes including IL12R, ITGAM and IGSF4 involved in the immune response machinery and cell adhesion process in the mucosa of subjects with active CD compared to those in remission. We identified a unique signature of genes, related to innate immunity, perturbed exclusively in CD irrespective of disease status. Finally, we highlight novel pathways of interest that may contribute to the early steps of CD pathogenesis and its comorbidities such as the spliceosome, pathways related to the innate immune response, and pathways related to autoimmunity.

CONCLUSIONS

Our study confirmed previous findings based on GWAS and immunological studies pertinent to CD pathogenesis and describes novel genes and pathways that with further validation may be found to contribute to the early steps in the pathogenesis of CD, ongoing inflammation, and comorbidities associated with CD.

Treatment Persistence and Healthcare Costs Among Patients with Rheumatoid Arthritis Changing Biologics in the USA

Introduction

After a patient with rheumatoid arthritis (RA) fails tumor necrosis factor inhibitor (TNFi) treatment, clinical guidelines support either cycling to another TNFi or switching to a different mechanism of action (MOA), but payers often require TNFi cycling before they reimburse switching MOA. This study examined treatment persistence, cost, and cost per persistent patient among MOA switchers versus TNFi cyclers.

Methods

This study of Commercial and Medicare Advantage claims data from the Optum Research Database included patients with RA and at least one claim for a TNFi (adalimumab, certolizumab pegol, etanercept, golimumab, or infliximab) between January 2012 and September 2015 who changed to another TNFi or a different MOA therapy (abatacept, tocilizumab, or tofacitinib) within 1 year. The index date was the date of the change in therapy. Treatment persistence was defined as no subsequent switch or 60-day gap in therapy for 1 year post-index. RA-related costs included plan-paid and patient-paid amounts for inpatient, outpatient, and pharmacy claims. Medication costs included index and post-index costs of TNFi and different MOA therapies.

Results

There were 581 (38.3%) MOA switchers and 935 (61.7%) TNFi cyclers. The treatment persistence rate was significantly higher for MOA switchers versus TNFi cyclers (47.7% versus 40.2%, P = 0.004). Mean 1-year healthcare costs were significantly lower among MOA switchers versus TNFi cyclers for total RA-related costs ($37,804 versus $42,116; P < 0.001) and medication costs ($29,001 versus $34,917; P < 0.001). When costs were divided by treatment persistence, costs per persistent patient were lower among MOA switchers versus TNFi cyclers: $25,436 lower total RA-related cost and $25,999 lower medication costs.

Conclusion

MOA switching is associated with higher treatment persistence and lower healthcare costs than TNFi cycling. Reimbursement policies that require patients to cycle TNFi before switching MOA may result in suboptimal outcomes for both patients and payers.

Funding

Sanofi and Regeneron Pharmaceuticals.