The occurrence of autoantibodies to matrilin 1 reflects a tissue-specific response to cartilage of the respiratory tract in patients with relapsing polychondritis

Autoimmunity and Autoinflammation: Relapsing Polychondritis and VEXAS Syndrome Challenge

Relapsing polychondritis is a chronic autoimmune inflammatory condition characterized by recurrent episodes of inflammation at the level of cartilaginous structures and tissues rich in proteoglycans. The pathogenesis of the disease is complex and still incompletely elucidated. The data support the important role of a particular genetic predisposition, with HLA-DR4 being considered an allele that confers a major risk of disease occurrence. Environmental factors, mechanical, chemical or infectious, act as triggers in the development of clinical manifestations, causing the degradation of proteins and the release of cryptic cartilage antigens. Both humoral and cellular immunity play essential roles in the occurrence and perpetuation of autoimmunity and inflammation. Autoantibodies anti-type II, IX and XI collagens, anti-matrilin-1 and anti-COMPs (cartilage oligomeric matrix proteins) have been highlighted in increased titers, being correlated with disease activity and considered prognostic factors. Innate immunity cells, neutrophils, monocytes, macrophages, natural killer lymphocytes and eosinophils have been found in the perichondrium and cartilage, together with activated antigen-presenting cells, C3 deposits and immunoglobulins. Also, T cells play a decisive role in the pathogenesis of the disease, with relapsing polychondritis being considered a TH1-mediated condition. Thus, increased secretions of interferon γ, interleukin (IL)-12 and IL-2 have been highlighted. The "inflammatory storm" formed by a complex network of pro-inflammatory cytokines and chemokines actively modulates the recruitment and infiltration of various cells, with cartilage being a source of antigens. Along with RP, VEXAS syndrome, another systemic autoimmune disease with genetic determinism, has an etiopathogenesis that is still incompletely known, and it involves the activation of the innate immune system through different pathways and the appearance of the cytokine storm. The clinical manifestations of VEXAS syndrome include an inflammatory phenotype often similar to that of RP, which raises diagnostic problems. The management of RP and VEXAS syndrome includes common immunosuppressive therapies whose main goal is to control systemic inflammatory manifestations. The objective of this paper is to detail the main etiopathogenetic mechanisms of a rare disease, summarizing the latest data and presenting the distinct features of these mechanisms.

Relapsing Polychondritis with Tracheobronchial Involvement: A Detailed Description of Two Pediatric Cases and Review of the Literature

Relapsing polychondritis (RP) is a rare immune-mediated disease that primarily affects the cartilaginous structures of the ears, nose and airways. The clinical spectrum ranges from mild to severe disease characterized by progressive destruction of cartilage in the tracheobronchial tree leading to airway obstruction and acute respiratory failure. Early diagnosis is crucial to prevent irreversible airway damage and life-threatening complications. Due to its rarity and variability of symptoms, the diagnosis of RP is often delayed particularly in childhood. To address this and increase awareness of this rare disease, we present a detailed case report of two adolescent females affected by RP. We aim to describe the clinical findings, consequences of a delayed diagnosis and provide a review of the current literature.

[Relapsing polychondritis]

Relapsing polychondritis (RP) is a rare multisystemic disease predominantly involving the extracellular matrix. Typical manifestations are chondritis of the ears, nose and trachea as well as an asymmetrical oligoarthritis or polyarthritis of small and also larger joints. Various other involvements have also been described. The treatment of RP is individually dependent on a variety of factors, e.g., organ manifestations. Glucocorticoids, immunosuppressants and targeted treatment are implemented. In the case of seronegative rheumatoid arthritis or vasculitis with an atypical course the symptoms of RP should be taken into consideration.

Development and validation of diagnostic and activity-assessing models for relapsing polychondritis based on laboratory parameters

Background

Relapsing polychondritis (RP) as a rare autoimmune disease is characterized by recurrent inflammation of the organs containing cartilage. Currently, no biomarkers have been integrated into clinical practice. This study aimed to construct and evaluate models based on laboratory parameters to aid in RP diagnosis, assess activity assessment, and explore associations with the pathological process.

Methods

RP patients and healthy controls (HCs) were recruited at the Peking Union Medical College Hospital from July 2017 to July 2023. Clinical data including Relapsing Polychondritis Disease Activity Index (RPDAI) score and laboratory tests were collected. Differences in laboratory data between RP patients and HCs and active and inactive patients were analyzed.

Results

The discovery cohort (cohort 1) consisted of 78 RP patients and 94 HCs. A model based on monocyte counts and neutrophil to lymphocyte ratio (NLR) could effectively distinguish RP patients from HCs with an AUC of 0.845. Active RP patients exhibited increased erythrocyte sedimentation rate, complement 3, platelet to lymphocyte ratio (PLR), NLR, and C-reactive protein to albumin ratio (CAR) compared with stable patients, which were also positively correlated with RPDAI. Notably, CAR emerged as an independent risk factor of disease activity (OR = 4.422) and could identify active patients with an AUC of 0.758. To confirm the reliability and stability of the aforementioned models, a replication cohort (cohort 2) was enrolled, including 79 RP patients and 94 HCs. The monocyte-combined NLR and CAR showed a sensitivity of 0.886 and 0.577 and a specificity of 0.830 and 0.833 in RP diagnosis and activity prediction, respectively. Furthermore, lower natural killer cell levels in RP patients and higher B-cell levels in active patients may contribute to elucidating the pathological mechanisms of disease occurrence and exacerbation.

Conclusions

The utilization of laboratory parameters provides cost-effective and valuable markers that can assist in RP diagnosis, identify disease activity, and elucidate pathogenic mechanisms.

Innate immune responses in Behçet disease and relapsing polychondritis

Behçet disease (BD) and relapsing polychondritis (RP) are chronic multisystem disorders characterized by recurrent flare-ups of tissue inflammation. Major clinical manifestations of BD are oral aphthae, genital aphthous ulcers, skin lesions, arthritis, and uveitis. Patients with BD may develop rare but serious neural, intestinal, and vascular complications, with high relapse rates. Meanwhile, RP is characterized by the inflammation of the cartilaginous tissues of the ears, nose, peripheral joints, and tracheobronchial tree. Additionally, it affects the proteoglycan-rich structures in the eyes, inner ear, heart, blood vessels, and kidneys. The mouth and genital ulcers with inflamed cartilage (MAGIC) syndrome is a common characteristic of BD and RP. The immunopathology of these two diseases may be closely related. It is established that the genetic predisposition to BD is related to the human leukocyte antigen (HLA)-B51 gene. Skin histopathology demonstrates the overactivation of innate immunity, such as neutrophilic dermatitis/panniculitis, in patients with BD. Monocytes and neutrophils frequently infiltrate cartilaginous tissues of patients with RP. Somatic mutations in UBA1, which encodes a ubiquitylation-related enzyme, cause vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome (VEXAS) with severe systemic inflammation and activation of myeloid cells. VEXAS prompts auricular and/or nasal chondritis, with neutrophilic infiltration around the cartilage in 52-60% of patients. Thus, innate immune cells may play an important role in the initiation of inflammatory processes underlying both diseases. This review summarizes the recent advances in our understanding of the innate cell-mediated immunopathology of BD and RP, with a focus on the common and distinct features of these mechanisms.

Progress and challenges in the use of blood biomarkers in relapsing polychondritis

Relapsing polychondritis (RP) is a rare inflammatory disease with significant individual heterogeneity that involves systemic organs. The diagnosis of RP mainly depends on the clinical manifestations; currently, there are no molecular biomarkers routinely evaluated in clinical practice. Biomarkers have diagnostic or monitoring values and can predict response to treatment or the disease course. Over the years, many biomarkers have been proposed to facilitate diagnosis and prognosis. Unfortunately, ideal biomarkers to diagnose RP have not yet been discovered. Most of the molecular biomarkers in RP are immunological biomarkers, with autoantibodies and proteins related to cartilage damage in the blood being the most common. Alterations in some genes (HLA typing and UBA1 somatic mutation) were detected in patients with RP, which could serve as a potential biomarker for the diagnosis of RP. Moreover, proinflammatory cytokines and lymphocyte levels, and certain laboratory tests, have certain values of RP diagnosis and disease activity assessment but lack specificity and sensitivity. This review describes the different types of biomarkers and their clinical correlation with respect to the diagnosis of RP and disease activity. Research on biomarkers and disease pathology is ongoing to identify the ideal biomarkers that are sensitive and specific for RP.

Relapsing Polychondritis: A Rare Case Report

Relapsing polychondritis is an uncommon disorder of unknown cause characterized by inflammation of cartilage, predominantly affecting the ear, nose, and laryngotracheobronchial tree. The case under discussion is a 50-year-old female with a classical presentation of relapsing polychondritis with saddle nose deformity, bilateral auriculitis, and laryngotracheobronchomalacia with joint involvement.

Relapsing polychondritis: Best Practice & Clinical Rheumatology

Relapsing polychondritis (RP) is an uncommon inflammatory disorder that predominantly targets cartilaginous structures. The disease frequently affects the nose, ears, airways, and joints, but it can also impact organs that aren't primarily cartilage-based, such as blood vessels, skin, inner ear, and eyes. Given its infrequent occurrence and recurrent symptoms, patients often experience delays in proper diagnosis. Lately, based on the organs involved, the disease's diverse manifestations have been categorized into specific clinical groups, based on the most likely organ involvement including auricular, nasal, pulmonary, and musculoskeletal. More recently the discovery of a new disease, called (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) VEXAS syndrome, due to mutations in UBA1 gene, identified the cause of 8 % of the patients with a clinical diagnosis of RP. VEXAS is likely the cause of a previously described "hematologic subgroup" in RP. This discovery is proof of concept that RP is likely more than one disease (Beck et al., Dec 31 2020; Ferrada et al., 2021). People diagnosed with RP face numerous hurdles, with the quality of their lives and overall prognosis being affected. Diagnosing the condition is particularly challenging due to its fluctuating symptoms, the absence of specific markers, and the lack of universally recognized classification criteria. For a correct diagnosis, it's imperative for healthcare professionals to identify its unique clinical patterns. Moreover, there are no approved metrics to gauge the disease's severity, complicating patient management. This review seeks to equip clinicians with pertinent insights to better diagnose and attend to these complex patients.

Comparison between idiopathic and VEXAS-relapsing polychondritis: analysis of a French case series of 95 patients

Objective

A new adult-onset autoinflammatory syndrome has been described, named VEXAS (Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic). We aimed to compare the clinical characteristics, the laboratory features and the outcomes between idiopathic-relapsing polychondritis (I-RP) and VEXAS-relapsing polychondritis (VEXAS-RP).

Methods

Patients from French retrospective multicentre cohort of RP were separated into two groups: a VEXAS-RP and an I-RP.

Results

Compared with patients with I-RP (n=40), patients with VEXAS-RP (n=55) were men (96% vs 30%, p<0.001) and were older at diagnosis (66 vs 44 years, p<0.001). They had a greater prevalence of fever (60% vs 10%, p<0.001), of skin lesions (82% vs 20%, p<0.001), of ocular involvement (57% vs 28%, p=0.01), of pulmonary infiltrates (46% vs 0%, p<0.001), of heart involvement (11% vs 0%, p=0.0336) and with higher median C-reactive protein levels (64 mg/L vs 10 mg/L, p<0.001). Seventy-five per cent of the patients with VEXAS-RP had myelodysplastic syndrome (MDS) versus none in I-RP group. The glucocorticoids use, and the number of steroid sparing agents were similar in both groups, but patients with VEXAS-RP had more frequent refractory disease (remission obtained in 27% vs 90%, p<0001). VEXAS-RP was associated with higher risk of death: six patients (11%) died in the VEXAS-RP group after a median follow-up of 37 months and none in the I-RP group after a median follow-up of 92 months (p<0.05).

Conclusion

We report the largest cohort of VEXAS-RP, characterised by high prevalence of male sex, fever, skin lesion, ocular involvement, pulmonary infiltration, heart involvement, older age and MDS association.

Comparison of relapsing polychondritis patients with and without respiratory involvement based on chest computed tomography: a retrospective cohort study

BACKGROUND

Relapsing polychondritis (RP) patients with tracheal cartilage involvement are different from other patients. The objective of this study was to compare the clinical features and disease patterns between a respiratory involvement subgroup and a non-respiratory involvement subgroup according to chest computed tomography.

METHOD

We performed a retrospective cohort study collecting RP patients hospitalized at the Beijing Chao-Yang Hospital between January 2012 and August 2021.

RESULTS

Respiratory involvement affected 59.7% of patients in our cohort. The incidence of costochondritis was more common in RP patients with respiratory involvement (p = 0.03); the incidence of inflammatory eye disease (p = 0.001) and auricular chondritis (p = 0.001) was less frequent in RP respiratory involvement patients.. Compared with the non-respiratory involvement subgroup the incidence of pulmonary infection marginally increased in the respiratory involvement subgroup (p = 0.06). Inflammatory indexes except for C-reactive protein to albumin ratio (CAR) were significantly higher in the respiratory involvement subgroup; analysis revealed no significant relationship between inflammatory indexes and pulmonary infection.

CONCLUSION

RP patients with respiratory involvement had a greater incidence of costochondritis and pulmonary infectionand lesser incidence of inflammatory eye diseases and auricular chondritis compared to non-respiratory involvement. Increasing inflammatory indexes suggests that patients with respiratory involvement had a higher disease activity index of RP. The difference in probability of survival was insignificant between subgroups.

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.

Mechanical model of steady-state and inflammatory conditions in patients with relapsing polychondritis: A review

Relapsing polychondritis (RP) is a multisystem inflammatory disorder, considered to associate with immune aberration.Increased T helper type-1 cell-related cytokines were reported in RP patients. mRNA expressions of a regulatory T cell cytokine interleukin (IL)-10 increased, whereas pro-inflammatory cytokines IL1β and IL6 mRNA expressions decreased in freshly isolated peripheral blood mononuclear cells of RP patients compared with those in healthy individuals. Upon in vitro stimulation with mitogen, IL10 mRNA expressions decreased, and IL1β and IL6 mRNA expressions increased in RP patients.This short-time dynamic change of gene expressions from anti-inflammatory to pro-inflammatory features of immune cells may be associated with the "relapsing" disease course of patients with RP. IL1β mRNA expressions of peripheral blood mononuclear cells exhibited positive correlations with serum matrix metalloproteinase (MMP)-3 concentrations in patients with respiratory involvement. Such positive correlation was not found in those without respiratory involvement.In a metagenomic analysis, an altered composition of gut microbes was found, suggesting that microbe metabolites such as short-chain fatty acids may affect T cell responses of the patients.In this review, the relationships among RP-related inflammatory molecules were summarized. The data support a hypothesis that the immune conditions are different between steady-state and inflammation in RP patients.

Ocular Involvement in Relapsing Polychondritis

Relapsing polychondritis (RPC) is a rare systemic immune-mediated disease characterized by recurrent inflammation of cartilaginous and proteoglycan-rich tissues throughout the body. Auricular, nasal, tracheal, and articular chondritis and arthritis are common systemic symptoms in patients with RPC. Ocular tissues are also targets of inflammation in RPC, and a variety of ocular symptoms are observed in approximately half of the patients with RPC. Scleritis/episcleritis, uveitis, and conjunctivitis are common symptoms associated with RPC. Less frequently, keratitis, retinopathy, optic neuropathy, muscle palsy, and orbital inflammation are also observed. Ocular inflammation could also be the first manifestation of RPC. Although RPC is a potentially fatal and sight-threatening disease, the rarity of the disease and its protean clinical presentation may lead to delayed diagnosis or misdiagnosis. Given the high prevalence of ocular involvement in RPC, to avoid misdiagnosis, physicians should be suspicious of RPC when they see patients with recurrent ocular inflammatory conditions and various systemic symptoms. In this article, we provide a comprehensive review of ocular manifestations associated with RPC.

Relapsing polychondritis: state-of-the-art review with three case presentations

BACKGROUND

Relapsing polychondritis (RPC) is a complex immune-mediated systemic disease affecting cartilaginous tissue and proteoglycan-rich organs. The most common and earliest clinical features are intermittent inflammation involving the auricular and nasal regions, although all cartilage types can be potentially affected. The life-threatening effects of rpc involve the tracheobronchial tree and cardiac connective components. Rpc is difficult to identify among other autoimmune comorbidities; diagnosis is usually delayed and based on nonspecific clinical symptoms with limited laboratory aid and investigations. Medications can vary, from steroids, immunosuppressants, and biologics, including anti-tnf alpha antagonist drugs.

METHOD

Information on updated etiology, clinical symptoms, diagnosis, and treatment of rpc has been obtained via extensive research of electronic literature published between 1976 and 2019 using PubMed and medline databases. English was the language of use. Search inputs included 'relapsing polychondritis,' 'polychondritis,' 'relapsing polychondritis symptoms,' and 'treatment of relapsing polychondritis.' Published articles in English that outlined and reported rpc's clinical manifestations and treatment ultimately met the inclusion criteria. Articles that failed to report the above and reported on other cartilaginous diseases met the exclusion criteria.

RESULT

Utilizing an extensive overview of work undertaken in critical areas of RPC research, this review intends to further explore and educate the approach to this disease in all dimensions from pathophysiology, diagnosis, and management.

CONCLUSION

RPC is a rare multi-systemic autoimmune disease and possibly fatal. The management remains empiric and is identified based on the severity of the disease per case. The optimal way to advance is to continue sharing data on RPC from reference centers; furthermore, clinical trials in randomized control groups must provide evidence-based treatment and management. Acquiring such information will refine the current knowledge of RPC, which will improve not only treatment but also diagnostic methods, including imaging and biological markers.

Rare Diseases of Larynx, Trachea and Thyroid

This review article covers data on rare diseases of the larynx, the trachea and the thyroid. In particular, congenital malformations, rare manifestations of inflammatory laryngeal disorders, benign and malignant epithelial as well as non-epithelial tumors, laryngeal and tracheal manifestations of general diseases and, finally, thyroid disorders are discussed. The individual chapters contain an overview of the data situation in the literature, the clinical appearance of each disorder, important key points for diagnosis and therapy and a statement on the prognosis of the disease. Finally, the authors indicate on study registers and self-help groups.

Role of matrilin-1 (MATN1) polymorphism in class III skeletal malocclusion with mandibular prognathism in Deutero-Malay race: a case-control study

Background

Several studies have identified different genes that control the final dimension and structure of the mandible. Prognathism of the mandible is thought to correlate with these genes; however, no specific gene has been assigned as a risk factor due to various genome-wide scan results in different races. Previous studies that involved the Han ethnic group in China and Korea suggested matrilin-1 (MATN1) polymorphism as the contributor for mandibular prognathism. To date, no study has been conducted to understand the role of MATN1 in Deutero-Malay population. This study aimed to detect MATN1 gene polymorphism in the promoter and exon 5 regions, which is a proposed risk factor in class III skeletal malocclusion with mandibular prognathism in Deutero-Malay population. This was a case-control study with purposive sampling method that involved 47 class III skeletal malocclusion subjects with mandibular prognathism (case group) and 47 class I skeletal relation subjects (control group) performed in the Molecular Genetics Laboratory of Faculty of Medicine, Universitas Padjadjaran, Indonesia. DNA isolated from buccal mucous epithelia and MATN1 gene was amplified using the polymerase chain reaction (PCR) and sequencing technique. Data were then analyzed statistically to observe the frequency of allele/genotype MATN1 in class III skeletal malocclusion and mandibular prognathism patients in comparison with the normal mandibular as well as to identify the risk factor of mandibular prognathism.

Result

The frequency of the 354 T > C(rs20566) CC genotype gene polymorphism in the case group was significantly higher than in the control group. The odd ratio (OR) value of the case group was also higher than in the control group (χ2 = 4.89; p = 0.027; OR = 6.27).

Conclusions

Our results show that the polymorphism of 354 T > C in the exon 5 region of the CC genotype MATN1 gene is a risk factor for class III skeletal malocclusion with mandible prognathism in Deutero-Malay population.

A case of localized tracheobronchial relapsing polychondritis with positive matrilin-1 staining

Background

Relapsing polychondritis (RPC) is a rare progressive autoimmune disease characterized by inflammation in the cartilage of multiple organs. Tracheobronchial involvement appears in nearly half of RPC patients during the course of their disease and represents the main cause of death. Localized tracheobronchial RPC is much rarer, and the pathogenesis remains unclear. Matrilin-1 is a non-collagenous cartilage matrix protein and has been suggested to be a potent autoantigen that induces the airway disease of RPC in animal models. However, the expression of matrilin-1 in tracheobronchial tissue in human remains unclear. Therefore, we examined the expression of matrilin-1 in the tracheal and auricular tissues in a localized tracheobronchial RPC patient.

Case presentation

A 62-year-old man with systemic sclerosis presented with cough and dyspnea on exertion. The lung function test showed an expiratory flow limitation and chest computed tomography showed diffuse thickness from the trachea to the bronchiole. No other tests showed abnormal findings. To evaluate further, bronchoscopy was performed and endobronchial ultrasonography showed thickness in the fourth-marginal echo layer suggesting inflammation of the cartilage. However, the tracheal biopsy showed no specific findings. The subsequent surgical tracheal biopsies showed inflammatory cell infiltration with destruction of the cartilage. Neither auricular nor nasal deformity, except for a tracheobronchial lesion, was detected. Biopsy from the left auricular cartilage also did not show any inflammatory changes. Finally, we diagnosed the patient with localized tracheobronchial RPC. To address the hypothesis that autoimmunity against matrilin-1 is involved in the pathogenesis of localized tracheobronchial RPC, we evaluated the expression level of matrilin-1 in a tracheal and auricular specimen from this patient. Immunohistochemical staining with anti-matrilin-1 antibody showed matrilin-1 in the tracheal but not in the auricular cartilage.

Conclusions

We first demonstrated the expression of matrilin-1 in tracheal but not in auricular cartilage in a localized tracheobronchial RPC patient. This result supports the possibility that matrilin-1 is involved in the pathogenesis of localized tracheobronchial RPC. However, this is only one case report and further observations will be needed to confirm this result.

Case report of mixed-type autoimmune hemolytic anemia in a patient with relapsing polychondritis

RATIONALE

Relapsing polychondritis (RP) is a rare autoimmune-related disease and may be associated with other autoimmune diseases.

PATIENT CONCERNS

Here we reported a case of RP patients with mixed-type AIHA. The patient was diagnosed with RP in March 2008 which was treated and the patient was in stable condition. Laboratory data revealed progressive decrease in hemoglobin during her hospitalization due to pulmonary infection in 2016. Positive Coombs' test and moderate titer of anti-cold agglutinin was detected.

DIAGNOSIS

Mixed-type AIHA was diagnosed as a comorbidity in this case given the circumstance that her RP was stable and low-dose oral corticosteroids was enough to maintain remission.

INTERVENTIONS

The patient was treated with intravenous immunoglobulin and steroids.

OUTCOMES

The patient's body temperature dropped and hemoglobin levels rose in 2 weeks.

LESSONS

Reports of RP patients with autoimmune hemolytic anemia (AIHA) are extremely rare and cases with the mixed-type AIHA has not been reported. Here we describe a case of RP with mixed-type AIHA which was considered as a comorbidity rather than a complication.

Propionate-producing bacteria in the intestine may associate with skewed responses of IL10-producing regulatory T cells in patients with relapsing polychondritis

Relapsing polychondritis (RP) is an inflammatory disease of unknown causes, characterized by recurrent inflammation in cartilaginous tissues of the whole body. Recently, researchers have reported that, in mouse experiments, altered gut microbe-dependent T cell differentiation occurred in gut associated lymphoid tissues. Here, we investigated whether gut microbe alteration existed, and if so, the alteration affected peripheral T cell differentiation in patients with RP. In an analysis of gut microbiota, we found increased annotated species numbers in RP patients compared with normal individuals. In the RP gut microbiota, we observed several predominant species, namely Veillonella parvula, Bacteroides eggerthii, Bacteroides fragilis, Ruminococcus bromii, and Eubacterium dolichum, all species of which were reported to associate with propionate production in human intestine. Propionate is a short-chain fatty acid and is suggested to associate with interleukin (IL)10-producing regulatory T (Treg) cell differentiation in gut associated lymphoid tissues. IL10 gene expressions were moderately higher in freshly isolated peripheral blood mononuclear cells (PBMC) of RP patients than those of normal individuals. Six hours after the initiation of the cell culture, regardless of the presence and absence of mitogen stimulation, IL10 gene expressions were significantly lower in RP patients than those in normal individuals. It is well known that PBMC of patients with autoimmune and inflammatory diseases show hyporesponsiveness to mitogen stimulation. We suggest that, in RP patients, continuous stimulation of intestinal T cells by excessive propionate leads to the spontaneous IL10 production and a subsequent refractory period of T cells in patients with RP. The hyporesponsiveness of Treg cells upon activation may associate with inflammatory cytokine production of PBMC and subsequently relate to chondritis in RP patients.

Relapsing Polychondritis: An Updated Review

Relapsing polychondritis is an immune-mediated systemic disease characterized by recurrent episodes of inflammation of cartilaginous and proteoglycan-rich tissues, resulting in progressive anatomical deformation and functional impairment of the involved structures. Auricular and nasal chondritis and/or polyarthritis represent the most common clinical features, but potentially all types of cartilage may be involved. Because of the pleomorphic nature of the disease, with non-specific symptoms at the onset, the diagnosis of relapsing polychondritis is often delayed. In this review article we provide a comprehensive look into clinical presentation, laboratory and instrumental investigations, diagnostic criteria, and therapeutic options.

Refractory relapsing polychondritis: challenges and solutions

Relapsing polychondritis is a severe systemic immune-mediated disease characterized by an episodic and progressive inflammatory condition with progressive destruction of cartilaginous structures. This disease has for nearly a century kept secrets not yet explained. The real incidence and prevalence of this rare disease are unknown. The multiple clinical presentations and episodic nature of relapsing polychondritis cause a significant diagnosis delay. No guidelines for the management of patients with relapsing polychondritis have been validated to date. The challenges remain, both in the understanding of its pathophysiology and diagnosis, evaluation of its activity and prognosis, and its treatment. Possible solutions involve the sharing of data for relapsing polychondritis from worldwide reference centers. Thus, we would be able to evolve toward a better knowledge of its pathophysiology, the publication of new diagnosis criteria, which will include biological markers and imaging findings, the prediction of life-threatening or organ-threatening situations, and the publication of therapeutic evidence-based guidelines after performing at randomized controlled trials.

Relapsing polychondritis, an underestimated dermatological urgency: case report and literature review

BACKGROUND

Relapsing polychondritis is an autoimmune multisystemic disease with primary chondral involvement. Its high mortality and morbidity make it a real clinical challenge.

CASE DESCRIPTION

A 32-year-old woman with a history of relapsing polychondritis, refractory to multiple treatments, with multisystem compromise, imminent risk of death due to severe tracheobronchial damage and difficult ventilatory support, and successful treatment with infliximab.

DISCUSSION AND EVALUATION

Several treatments have been described in the literature, such as nonsteroidal anti-inflammatory drugs, corticosteroids, dapsone, azathioprine, cyclosporine, cyclophosphamide, and methotrexate. However, the cases refractory to conventional therapy may lead to chronicity, irreversibility, and death. As a result, a third-line therapy could improve the prognosis of these patients.

CONCLUSIONS

Biological therapy is a good option for disease control and quality of life improvement. In addition, the physician should consider these treatments to avoid the chronicity and risk of death of these patients.

Relapsing Polychondritis Can Be Characterized by Three Different Clinical Phenotypes: Analysis of a Recent Series of 142 Patients

OBJECTIVE

Relapsing polychondritis (RP) is a rare condition characterized by recurrent inflammation of cartilaginous tissue and systemic manifestations. Data on this disease remain scarce. This study was undertaken to describe patient characteristics and disease evolution, identify prognostic factors, and define different clinical phenotypes of RP.

METHODS

We performed a retrospective study of 142 patients with RP who were seen between 2000 and 2012 in a single center.

RESULTS

Of the 142 patients, 86 (61%) were women. The mean ± SD age at first symptoms was 43.5 ± 15 years. Patients had the following chondritis types: auricular (89%; n = 127), nasal (63%; n = 89), laryngeal (43%; n = 61), tracheobronchial (22%; n = 32), and/orcostochondritis (40%; n = 57). The main other manifestations were articular (69%; n = 98), ophthalmologic (56%; n = 80), audiovestibular (34%; n = 48), cardiac (27%; n = 38), and cutaneous (28%; n = 40). At a mean ± SD followup of 13 ± 9 years, the 5- and 10-year survival rates were 95 ± 2% and 91 ± 3%, respectively. Factors associated with death on multivariable analysis were male sex (P = 0.01), cardiac abnormalities (P = 0.03), and concomitant myelodysplastic syndrome (MDS) (P = 0.004) or another hematologic malignancy (P = 0.01). Cluster analysis revealed that separating patients into 3 groups was clinically relevant, thereby separating patients with associated MDS, those with tracheobronchial involvement, and those without the 2 features in terms of clinical characteristics, therapeutic management, and prognosis.

CONCLUSION

This large series of patients with definite RP revealed an improvement in survival as compared with previous studies. Factors associated with death were male sex, cardiac involvement, and concomitant hematologic malignancy. We identified 3 distinct phenotypes.

Relapsing polychondritis associated with psoriasis vulgaris successfully treated with adalimumab: A case report with published work review

Relapsing polychondritis (RP) is a rare autoimmune-mediated disease characterized by inflammation involving cartilaginous tissues. We report here a case of RP in a 38-year-old Japanese man with 13-year duration of psoriasis vulgaris treated with topical steroids and vitamin D₃ . The patient presented with tender swelling and erythema of both auricles, and the antibody to type II collagen was detected. The biopsy specimen revealed a dense mixed cell infiltration over the auricular cartilage. We reviewed eight cases with the association of RP and psoriasis, and in all cases the clinical course of psoriasis did not correlate with that of RP. The severity of RP was mild in the majority of cases, and our case was unique in that the patient had no joint symptoms. Adalimumab treatment was effective for both RP and psoriasis. Fat-suppressed contrast-enhanced magnetic resonance imaging was beneficial, not only to demonstrate subclinical inflammation in the nasal septum, but also to subjectively assess the improvement of RP.

Relapsing Polychondritis: A Review and Guide for the Dermatologist

Relapsing polychondritis, or RP, is a rare connective tissue disease characterized by relapsing-remitting destructive inflammation of the cartilaginous and other proteoglycan-rich structures in the body. Given the relatively low incidence of RP, a concise clinically relevant guide, focusing on the cutaneous manifestations of this serious disease, is lacking. In this review, we provide the dermatologist with an approach to diagnosing RP and a guide to its initial work-up, and management. We close with an overview of the currently available treatment modalities for RP.

Zebrafish Developmental Models of Skeletal Diseases

The zebrafish skeleton shares many similarities with human and other vertebrate skeletons. Over the past years, work in zebrafish has provided an extensive understanding of the basic developmental mechanisms and cellular pathways directing skeletal development and homeostasis. This review will focus on the cell biology of cartilage and bone and how the basic cellular processes within chondrocytes and osteocytes function to assemble the structural frame of a vertebrate body. We will discuss fundamental functions of skeletal cells in production and secretion of extracellular matrix and cellular activities leading to differentiation of progenitors to mature cells that make up the skeleton. We highlight important examples where findings in zebrafish provided direction for the search for genes causing human skeletal defects and also how zebrafish research has proven important for validating candidate human disease genes. The work we cover here illustrates utility of zebrafish in unraveling molecular mechanisms of cellular functions necessary to form and maintain a healthy skeleton.

Relapsing polychondritis: A 2016 update on clinical features, diagnostic tools, treatment and biological drug use

Relapsing polychondritis (RP) is a very rare autoimmune disease characterised by a relapsing inflammation of the cartilaginous tissues (joints, ears, nose, intervertebral discs, larynx, trachea and cartilaginous bronchi), which may progress to long-lasting atrophy and/or deformity of the cartilages. Non-cartilaginous tissues may also be affected, such as the eyes, heart, aorta, inner ear and skin. RP has a long and unpredictable course. Because no randomised therapeutic trials are available, the treatment of RP remains mainly empirical. Minor forms of the disease can be treated with non-steroidal anti-inflammatory drugs, whereas more severe forms are treated with systemic corticosteroids. Life-threatening diseases and corticosteroid-dependent or resistant diseases are an indication for immunosuppressant therapy such as methotrexate, azathioprine, mycophenolate mofetil and cyclophosphamide. Biologics could be given as second-line treatment in patients with an active disease despite the use of steroids and immunosuppressive drugs. Although the biologics represent new potential treatment for RP, very scarce information is available to draw any firm conclusion on their use in RP.

Relapsing polychondritis

Relapsing polychondritis (RP) is a rare disease in which recurrent bouts of inflammation, in some cases followed by destruction, affect the cartilage of the ears, nose, larynx, and tracheobronchial tree. At presentation, however, arthritis is the most common manifestation and more than half the patients have no evidence of chondritis. The subsequent development of chondritis provides the correct diagnosis in patients who present with polyarthritis, ocular inflammation, or skin or audiovestibular manifestations of unknown origin. A concomitant autoimmune disease is present in one-third of patients with RP. The pathogenesis of RP involves an autoimmune response to as yet unidentified cartilage antigens followed by cartilage matrix destruction by proteolytic enzymes. The diagnosis rests on clinical grounds and can benefit from use of Michet's criteria. Anti-collagen type II and anti-matrilin-1 antibodies are neither sensitive nor specific and consequently cannot be used for diagnostic purposes. In addition to the physical evaluation and laboratory tests, useful investigations include dynamic expiratory computed tomography, magnetic resonance imaging, Doppler echocardiography, and lung function tests. Bronchoscopy has been suggested as a helpful investigation but can worsen the respiratory dysfunction. The treatment of RP is not standardized. The drug regimen should be tailored to each individual patient based on disease activity and severity. Glucocorticoid therapy is the cornerstone of the treatment of RP and is used chronically in most patients. Immunosuppressive agents are given to patients with severe respiratory or vascular involvement and to those with steroid-resistant or steroid-dependent disease. Methotrexate is often effective. Cyclophosphamide is used in severe forms.

Proteomic Surveillance of Autoantigens in Relapsing Polychondritis

Relapsing polychondritis (RP) is a systemic inflammatory disease, in which autoimmunity to cartilage-related components is thought to be involved in its pathogenesis. However, the autoimmune profile in RP has not been studied fully. We therefore investigated autoantibodies/autoantigens in RP comprehensively, by 2-dimensional electrophoresis (2DE), subsequent western blotting (WB) and mass spectrometry, using cell-extracted proteins as the antigen source. As a result, we detected 15 autoantigens on 2DE-WB, and further identified five of them. On average, one RP serum recognized approximately 8 out of the 15 autoantigens. Frequencies of the autoantibodies to the 5 identified antigens of tubulin alpha ubiquitous/6, vimentin, alpha enolase, calreticulin, and colligin-1/-2 were 91%, 46%, 36%, 82%, and 36%, respectively. ELISA using recombinant proteins for them revealed that frequencies of the autoantibodies to tubulin alpha ubiquitous, vimentin, alpha enolase, calreticulin, and colligin-1 were 36%, 64%, 46%, 27%, and 18%, respectively. Our data demonstrated that the autoimmune reaction was not restricted to cartilagerelated components, rather a variety of autoimmune responses occurred in patients with RP, which may be involved in the pathophysiology of RP. In addition, the proteomic approach using cell-extracted proteins would be a powerful way to investigate autoantigens.

Pathogenesis of relapsing polychondritis: a 2013 update

Relapsing polychondritis (RP) is a systemic inflammatory disease primarily affecting not only the cartilaginous structures of the ears, nose and tracheobronchial tree but also the joints, the inner ear, the eyes, and the cardiovascular system. RP is an immune-mediated disease during which target antigens are still unknown, but data from human studies and murine models strongly support a role of both Collagen Type II (CII) and matrilin-1 as potential candidates. RP is likely a Th1-mediated disease as serum levels of interferon (IFN)-γ, interleukin [IL]-12, and IL-2 parallel changes in disease activity, while the levels of Th2 cytokines do not. Serum levels of sTREM-1, interferon-γ, CCL4, vascular endothelial growth factor, and matrix metalloproteinases-3 are significantly higher in RP patients than in healthy donors, with sTREM-1 correlating with disease activity. Patients with active RP also have significantly higher levels of MCP-1, MIP-1β, MIF, and IL-8 than controls. These pro-inflammatory chemokines are involved in the modulation and recruitment of monocytes and neutrophils. Altogether, these data suggest that a complex cytokine network orchestrates the recruitment of infiltrating cells in RP lesions. Cytokine modulation using TNFα blockers, rituximab, anakinra, tocilizumab, and abatacept has recently been shown effective in some RP cases but further data are needed. Better understanding of the repertoire of infiltrating cells may provide interesting clues to further define the putative RP auto-antigens. Study of circulating mononuclear cells during RP flares may also provide crucial information about the ongoing cellular trafficking and recruitment processes involved in this rare disease.

Analysis of new Matrilin-1 gene variants in a case-control study related to dental malocclusions in Equus asinus

Prognathism and brachygnathism are craniofacial deformities that severely affect the health of human and vertebrates, such as donkeys. The multifactorial etiology of this disease makes the genetic analysis a powerful tool for its understanding and prevention of spreading these deformities. This study aims to contribute to the characterization of the genetic basis of prognathism and brachygnathism in donkeys, using the Zamorano-Leonés donkey, an endangered Spanish breed, as a model. Matrilin-1 (MATN1) polymorphisms have been previously described as markers for mandibular prognathism in Korean and Japanese human populations. Genetic variations in MATN1 gene were sought, in order to verify its association in a case-control study, including 30 donkeys presenting brachygnathism, 30 donkeys presenting prognathism and 30 donkeys with normal occlusion phenotypes. One genetic variation (g503G > A) located in an intronic region of MATN1 gene was identified and characterized. Statistically significant differences were detected between the control group and prognathism cases, but no statistical significant results were found between the control group and the brachygnathism cases. These results support evidence for an important role of MATN1 on prognathism in the analyzed population with MATN1 genetic variation - 503G>A - having a protective effect. Further studies should be developed in order to understand the whole role of MATN1 and the mechanisms affected by its genetic variations.

Relapsing polychondritis complicated by giant cell myocarditis and myositis

An 83-year-old man presented with a three-week history of dyspnea. The clinical features suggested a diagnosis of relapsing polychondritis (RP); however, the patient died of heart failure. An autopsy revealed active chondritis of the tracheal and bronchial cartilage. Furthermore, giant cell myocarditis (GCM) and myositis were detected. To the best of our knowledge, this represents the first report of RP complicated by GCM and myositis. In patients with RP, GCM and myositis, CD163-positive macrophages and T-cells are most common, and the T-cell subset exhibits CD8 predominance. Common mechanisms of tissue damage caused by cytotoxic T-cells are likely to contribute to RP, GCM and myositis.

Patients with relapsing polychondritis and previous cartilage trauma present more autoimmunity phenomena

Relapsing polychondritis (RP) is an autoimmune disease characterized by inflammation and destruction of all type of body cartilage, and the cartilage trauma may be a trigger of the disease in a susceptible person. We describe the clinical and laboratory findings in a group of 18 patients with RP with (7 cases) or without (11 cases) anteceding cartilage trauma. The mean age was 41 years in the group with cartilage trauma and 55 years in the group without cartilage trauma. For both groups, female gender was predominant. All patients presented with auricular chondritis. Systemic manifestations and autoimmunity were more common in patients with anteceding trauma.

Relapsing polychondritis: a description of a case and review article

Relapsing polychondritis (RPC) is a rare autoimmune disease in which the cartilaginous tissues are the target for inflammation and destruction, the associated immune reaction causes inflammation in non-cartilaginous tissues like kidney and blood vessels. This article provides a description of a case of RPC and a review article about the disease.

Polymorphisms in the Matrilin-1 gene and risk of mandibular prognathism in Koreans

Previous linkage analysis of an Asian population proposed possible candidate genes for mandibular prognathism, such as Matrilin-1 (cartilage matrix protein). To investigate the association between the single-nucleotide polymorphisms (SNPs) in Matrilin-1 and mandibular prognathism, we investigated three sequence variants (-158 T>C, 7987 G>A, 8572 C>T) in 164 mandibular prognathism patients and 132 control individuals with a normal occlusion. The results showed that the 8572 TT genotypes in Matrilin-1 showed increased risk of mandibular prognathism (OR = 9.28, 95% Cl = 1.19~197.57, P < 0.05), whereas the 7987 AA genotype showed a protective effect for mandibular prognathism (OR = 0.16, 95% Cl = 0.05~0.47, P < 0.05). Genotyping results showed that the Matrilin-1 polymorphism haplotype TGC (ht4; 158T, 7987G, and 8572C alleles) had a pronounced risk effect for mandibular prognathism compared with controls (OR = 5.16, 95% Cl = 2.03~13.93, P < 0.01). The results suggest that polymorphisms in Matrilin-1 could be used as a marker for genetic susceptibility to mandibular prognathism.

Treatment of relapsing polychondritis with the TNF-alpha antagonist adalimumab

Relapsing polychondritis (RP) is a rare immune-mediated disease which is associated with inflammation in cartilaginous tissue throughout the body. Especially, the cartilaginous structures of ear, respiratory tract, nose, and joints are affected. Around 30% of the cases are associated with other diseases especially systemic vasculitis. Onset of RP is most likely between the ages of 40-60 years. This case reports the often disguised and similar symptoms of RP to Wegner's granulomatosis and the challenge of diagnosis. The relative rarity of RP has not permitted clinical trials to determine the efficacy and safety of different therapies. Current treatment is largely empiric and based on case reports. In this case, we successfully used a treatment with the TNF-alpha antagonist adalimumab.