Assessment of TNF-α inhibitors in airway involvement of relapsing polychondritis: A systematic review

Ultra-rare genetic variation in relapsing polychondritis: a whole-exome sequencing study

OBJECTIVE

Relapsing polychondritis (RP) is a systemic inflammatory disease of unknown aetiology. The objective of this study was to examine the contribution of rare genetic variations to RP.

METHODS

We performed a case-control exome-wide rare variant association analysis that included 66 unrelated European American cases with RP and 2923 healthy controls (HC). Gene-level collapsing analysis was performed using Firth's logistics regression. Exploratory pathway analysis was performed using three different methods: Gene Set Enrichment Analysis, sequence kernel association test and higher criticism test. Plasma DCBLD2 levels were measured in patients with RP and HC using ELISA.

RESULTS

In the collapsing analysis, RP was associated with a significantly higher burden of ultra-rare damaging variants in the DCBLD2 gene (7.6% vs 0.1%, unadjusted OR=79.8, p=2.93×10-7). Plasma DCBLD2 protein levels were significantly higher in RP than in HC (median 4.06 ng/µL vs 0.05 ng/µL, p<0.001). The pathway analysis revealed a statistically significant enrichment of genes in the tumour necrosis factor signalling pathway driven by rare damaging variants in RELB, RELA and REL using higher criticism test weighted by eigenvector centrality.

CONCLUSIONS

This study identified specific rare variants in the DCBLD2 gene as a putative genetic risk factor for RP. These findings should be validated in additional patients with RP and supported by future functional experiments.

Relapsing Polychondritis: A Case of Marked Improvement After Steroid Administration for Airway Obstruction

Relapsing polychondritis is a rare disease that causes progressive and recurrent destruction of cartilage in the auricles, eyes, nose, and airways. A 90-year-old man was brought to the emergency department with fever, low SpO2, and effortful breathing. Arterial blood gas analysis showed that PaCO2 levels had accumulated to 120 mmHg. Although CT showed marked thickening of the bronchial wall from the central to the peripheral region, the cause was unknown. At the family's request, the patient was not placed on a ventilator, and treatment was started with steroids alone. After admission, the patient's condition improved with only intravenous steroids, and he was discharged to the facility with continued oral steroid medication. After a short treatment period, the possibility of relapsing polychondritis was considered and confirmed. The patient met Levine's diagnostic criteria, with findings of destruction of the bilateral auricular cartilage and the airway and a response to steroid administration. Although it is very difficult to diagnose relapsing polychondritis at the initial emergency department visit, early administration of steroids is worth trying in patients with asphyxia with extensive thickening of the airway on CT findings, as relapsing polychondritis may be considered, and early steroid administration may improve patient symptoms.

Ultra-Rare Genetic Variation in Relapsing Polychondritis: A Whole-Exome Sequencing Study

Objective

Relapsing polychondritis (RP) is a systemic inflammatory disease of unknown etiology. The study objective was to examine the contribution of rare genetic variations in RP.

Methods

We performed a case-control exome-wide rare variant association analysis including 66 unrelated European American RP cases and 2923 healthy controls. Gene-level collapsing analysis was performed using Firth's logistics regression. Pathway analysis was performed on an exploratory basis with three different methods: Gene Set Enrichment Analysis (GSEA), sequence kernel association test (SKAT) and higher criticism test. Plasma DCBLD2 levels were measured in patients with RP and healthy controls using enzyme-linked immunosorbent assay (ELISA).

Results

In the collapsing analysis, RP was associated with higher burden of ultra-rare damaging variants in the DCBLD2 gene (7.6% vs 0.1%, unadjusted odds ratio = 79.8, p = 2.93 × 10-7). Patients with RP and ultra-rare damaging variants in DCBLD2 had a higher prevalence of cardiovascular manifestations. Plasma DCBLD2 protein levels were significantly higher in RP than healthy controls (5.9 vs 2.3, p < 0.001). Pathway analysis showed statistically significant enrichment of genes in the tumor necrosis factor (TNF) signaling pathway driven by rare damaging variants in RELB, RELA and REL using higher criticism test weighted by degree and eigenvector centrality.

Conclusions

This study identified specific rare variants in DCBLD2 as putative genetic risk factors for RP. Genetic variation within the TNF pathway is also potentially associated with development of RP. These findings should be validated in additional patients with RP and supported by future functional experiments.

Biologic therapy in relapsing polychondritis: navigating between options

INTRODUCTION

Relapsing polychondritis (RP) is a rare systemic inflammatory disease of unknown etiology, primarily affecting cartilaginous tissue and proteoglycan-rich structures. Clinical manifestations vary from mild symptoms to occasional organ or life-threatening complications. Treatment can be challenging and is mostly based on experience or case reports/series.

AREAS COVERED

There is growing literature investigating the role of biologics in the management of RP. TNFα antagonists, abatacept, tocilizumab, rituximab, anakinra and tofacitinib have been prescribed in several RP patients, mainly as second-line treatment, after conventional immunosuppressive agents' failure.

EXPERT OPINION

: Glucocorticoids represent the gold standard treatment of RP. Conventional immunosuppressants should be administered in refractory patients or when a glucocorticoid-sparing effect is needed. Biologic therapy should be used after failure of conventional treatments or in severe manifestations. TNFα inhibitors are the most prescribed biologic agent, with partial or complete response in several cases; but loss of efficacy may occur over time. Infliximab and adalimumab should be preferred among TNFα antagonists. Abatacept and tocilizumab proved to be effective as second-line biologic agents, but frequent infections are reported with the former. Data on anakinra and rituximab are controversial, therefore they are not recommended as first-line biologic drugs. The use of JAK inhibitors is still anecdotal.

Nationwide cross-sectional survey of patients with relapsing polychondritis in 2019 demonstrates reduction of airway involvement compared with that in 2009

We conducted retrospective cohort studies of patients with relapsing polychondritis (RP) twice in 2009 and 2019, using a physician questionnaire. We compared the patients’ clinical statuses between the years. Age and gender were comparable between the two surveys. Mean disease duration was longer in 2019 survey (8.3 years) than that in 2009 survey (4.8 years, P < 0.001). The mortality rate declined in 2019 survey compared with those in 2009 survey (from 9.2 to 1.6%, P < 0.001). Incidence of airway involvement decreased in 2019 survey compared with that in 2009 survey (from 49 to 37%, P = 0.012). In 2019 survey, we found more frequent use of biological agents and immunosuppressants in patients with airway involvement. When we focused on RP patients with airway involvement, physicians in 2019 chose methotrexate and calcineurin inhibitors preferentially, compared with azathioprine and cyclophosphamide. Of note is that increased use of infliximab was observed in RP patients with airway involvement, but not in those without. Reduction of airway involvement and mortality in patients with RP was observed in 2019 survey. The reduction may associate with the frequent use of biologics including infliximab in RP patients with airway involvement.

Case of paediatric relapsing polychondritis with severe airway involvement: the challenges of long-term airway and respiratory management

We describe a case of a 15-year-old girl diagnosed with relapsing polychondritis (RP) with involvement of the tracheobronchial tree, resulting in an increased difficulty in breathing, hoarseness of voice and stridor.Her case required the input of multiple specialities including ear, nose and throat, rheumatology, respiratory team and intensive care. Airway assessment and imaging showed glottic and subglottic stenosis and left bronchomalacia. Despite the use of steroids, cyclophosphamide and rituximab, her symptoms progressed and she was started on overnight non-invasive ventilation.She had further relapses of her airway RP-she was started on adalimumab and methotrexate and underwent monthly balloon dilatations which helped with her symptoms and facilitated a safe discharge home. However, she had further relapses and intensive care admissions and following further discussions, a tracheostomy was inserted. She is now stable on her tracheostomy and is off any respiratory support.

A Glance at the Use of Glucocorticoids in Rare Inflammatory and Autoimmune Diseases: Still an Indispensable Pharmacological Tool?

Since their discovery, glucocorticoids (GCs) have been used to treat almost all autoimmune and chronic inflammatory diseases, as well as allergies and some forms of malignancies, because of their immunosuppressive and anti-inflammatory effects. Although GCs provide only symptomatic relief and do not eliminate the cause of the pathology, in the majority of treatments, GCs frequently cannot be replaced by other classes of drugs. Consequently, long-term treatments cause adverse effects that may, in turn, lead to new pathologies that sometimes require the withdrawal of GC therapy. Therefore, thus far, researchers have focused their efforts on molecules that have the same efficacy as that of GCs but cause fewer adverse effects. To this end, some GC-induced proteins, such as glucocorticoid-induced leucine zipper (GILZ), have been used as drugs in mouse models of inflammatory pathologies. In this review, we focus on some important but rare autoimmune and chronic inflammatory diseases for which the biomedical research investment in new therapies is less likely. Additionally, we critically evaluate the possibility of treating such diseases with other drugs, either GC-related or unrelated.