Unveiling the clinical spectrum of relapsing polychondritis: insights into its pathogenesis, novel monogenic causes, and therapeutic strategies.

Relapsing polychondritis is a rare multisystem disease involving cartilaginous and proteoglycan-rich structures. The diagnosis of this disease is mainly suggested by the presence of flares of inflammation of the cartilage, particularly in the ears, nose or respiratory tract, and more rarely, in the presence of other manifestations. The spectrum of clinical presentations may vary from intermittent episodes of painful and often disfiguring auricular and nasal chondritis to an occasional organ or even life-threatening manifestations such as lower airway collapse. There is a lack of awareness about this disease is mainly due to its rarity. In 2020, VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, a novel autoinflammatory syndrome, was described. VEXAS syndrome is attributed to somatic mutations in methionine-41 of UBA1, the major E1 enzyme that initiates ubiquitylation. This new disease entity connects seemingly unrelated conditions: systemic inflammatory syndromes (relapsing chondritis, Sweet's syndrome, and neutrophilic dermatosis) and hematologic disorders (myelodysplastic syndrome or multiple myeloma). Therefore, this article reviews the current literature on both disease entities.

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.

Risk factors associated with severe adverse events in patients with relapsing polychondritis undergoing flexible bronchoscopy.

BACKGROUND: Patients with relapsing polychondritis (RP) sometimes experience upper airway collapse or lower airway stenosis, and bronchoscopy may provide a valuable typical image to confirm the diagnosis. This study aimed to identify potential risk factors associated with severe adverse effects during bronchoscopy. METHODS: We performed a retrospective cohort study of 82 consecutive patients with RP hospitalized at Peking Union Medical College Hospital between January 1, 2012 and December 31, 2022. Clinical features and disease patterns were compared among patients with RP undergoing bronchoscopy with or without severe adverse effects. Binary logistic regression analysis was performed to identify the associated risk factors. RESULTS: For patients with RP undergoing bronchoscopy with severe adverse effects, the forced vital capacity (FVC), forced vital capacity percent predicted values (FVC%), and peak expiratory flow were significantly lower (P = 0.001, P = 0.001, and P = 0.021, respectively) than those in the non-severe adverse effect subgroup. Binary logistic regression analysis revealed that low FVC% (odds ratio, 0.930; 95% confidence interval, 0.880-0.982; P = 0.009) was an independent risk factor for severe adverse events in patients undergoing bronchoscopy. CONCLUSIONS: Low FVC or FVC% suggests a high risk of severe adverse effects in patients with RP undergoing bronchoscopy. Patients with such risk factors should be carefully evaluated before bronchoscopy and adequately prepared for emergency tracheal intubation or tracheostomy.

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.

Síndrome de VEXAS: manifestaciones clínicas, diagnóstico y tratamiento / VEXAS syndrome: Clinical manifestations, diagnosis, and treatment

El síndrome de VEXAS (Vacuolas, enzima E1, ligado al X, Autoinflamatorio, Somático) es un síndrome autoinflamatorio de inicio en la edad adulta que se caracteriza por mutaciones somáticas en el gen UBA1 y se considera el prototipo de enfermedad hematoinflamatoria. Los pacientes con síndrome de VEXAS exhiben manifestaciones inflamatorias y hematológicas que pueden conducir a diagnósticos clínicos como policondritis recidivante, poliarteritis nodosa, síndrome de Sweet y síndrome mielodisplásico. El diagnóstico requiere la evaluación de la médula ósea en búsqueda de vacuolas citoplásmicas en precursores mieloides y eritroides. Sin embargo, la confirmación genética de las mutaciones en UBA1 es necesaria. El tratamiento es un desafío y a menudo incluye glucocorticoides e inmunosupresores, con respuestas variables. Las terapias hipometilantes y el trasplante alogénico de células progenitoras hematopoyéticas se consideran terapias prometedoras. El pronóstico es influido por factores genéticos y clínicos. El objetivo de esta revisión es proporcionar una visión general sobre la patogénesis, la presentación clínica, el tratamiento y el pronóstico del síndrome de VEXAS para la comunidad médica latinoamericana.(AU)

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is an adult-onset autoinflammatory syndrome characterized by somatic mutations in the UBA1 gene and is considered the prototype of hematoinflammatory diseases. Patients with VEXAS syndrome exhibit inflammatory and hematological manifestations that can lead to clinical diagnoses such as relapsing polychondritis, polyarteritis nodosa, Sweet syndrome, and myelodysplastic syndrome. Diagnosis requires bone marrow evaluation to identify cytoplasmic vacuoles in myeloid and erythroid precursors. However, genetic confirmation of mutations in UBA1 is necessary. Treatment is challenging and often involves glucocorticoids and immunosuppressants with variable responses. Hypomethylating agents and allogenic haemopoietic stem cell transplant are considered promising therapies. Prognosis is influenced by genetic and clinical factors. The aim of this review is to provide an overview of the pathogenesis, clinical presentation, treatment, and prognosis of VEXAS syndrome for the Latin American medical community.(AU)

Dynamic monitoring of UBA1 somatic mutations in patients with relapsing polychondritis.

BACKGROUND: Commonly clinically diagnosed with relapsing polychondritis (RP), vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome (VEXAS) is a recently identified autoinflammatory disease caused by UBA1 somatic mutations. The low frequency and dynamic changes challenge the accurate detection of somatic mutations. The present study monitored these mutations in Chinese patients with RP. We included 44 patients with RP. Sanger sequencing of UBA1 was performed using genomic DNA from peripheral blood. Droplet digital polymerase chain reaction (ddPCR) was performed to screen low-prevalence somatic variants. RESULTS: Multiple ddPCR detections were performed using available blood samples collected at different follow-up time points. Three male patients were UBA1 somatic mutation carriers. Sanger sequencing detected the somatic UBA1 variant c.122T > C (p.Met41Thr) in two male patients. Initial ddPCR confirmed the variant in the two patients, with allele fractions of 73.75% and 88.46%, respectively, while yielding negative results in other patients. Subsequent ddPCR detected the somatic variant (c.122T > C) with low prevalence (1.02%) in another male patient from blood samples collected at a different time point, and confirmed dynamically fractional abundance in one patient with VEXAS, with allele fractions of 73.75%, 61.28%, 65.01%, and 73.75%. Nine patients assessed by ddPCR at different time points remained negative. CONCLUSION: We report UBA1 variants in patients with RP in the Chinese population for the first time. Multiple ddPCR detections from samples collected at different time points can enhance sensitivity and should be considered for patients with initial negative ddPCR results.

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.

Ocular Inflammation as the First Sign of Relapsing Polychondritis in Hispanic Patients: Report of Three Cases.

BACKGROUND: Relapsing polychondritis (RP) is a rare inflammatory systemic disease characterized by recurrent inflammatory episodes of cartilaginous and proteoglycan-rich tissues, particularly ears, nose, respiratory tract, eyes, and joints. PURPOSE: To present the clinical features, management, and prognosis of three Hispanic patients presenting with RP and ocular involvement as the first manifestation of the disease. CONCLUSION: This study extends the knowledge regarding ocular disease characteristics in patients with RP. Furthermore, it increases ophthalmologists' awareness of the findings, leading to earlier diagnoses and adequate treatment for improved patients' prognoses.

Relapsing polychondritis presenting with sero-negative limbic encephalitis.

The presented case highlights a rare instance of relapsing polychondritis (RP) manifesting as seronegative limbic encephalitis, an uncommon neurological complication. A 70-year-old female patient with a history of RP-related inflammation, along with neuropsychiatric symptoms, was diagnosed through multidisciplinary collaboration. Swift administration of steroid therapy, followed by azathioprine, led to remarkable physical and cognitive recovery. This case emphasises the importance of a multidisciplinary approach in diagnosing and treating complex autoimmune disorders with neurological manifestations.

[Relapsing polychondritis]. / 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.

Imaging features and clinical value of 18F-FDG PET/CT for predicting airway involvement in patients with relapsing polychondritis.

BACKGROUND: The clinical value of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in assessing relapsing polychondritis (RP) with airway involvement remains controversial. This study aimed to investigate PET/CT features of RP with airway involvement and explore its clinical value in predicting disease pattern, severity and prognosis. METHODS: RP patients with airway involvement who underwent PET/CT from January 2010 to July 2022 were retrospectively reviewed. PET/CT features were analyzed both visually and semiquantitatively with the maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG). Patterns of airway involvement on PET were summarized. Correlations of SUVmax and TLG of the airway were made with spirometric indicators and serological inflammatory markers (CRP and ESR). In addition, long-term follow-up was conducted through questionnaires in regard to symptom control, subjective feeling, pulmonary function, and quality of life. RESULTS: Fifty-two cases were finally included. 18F-FDG PET showed FDG-avid lesions with increased FDG uptake in the airway among 94.2% of the patients. Three patterns (focal, multifocal and diffuse patterns) were identified. TLG of the whole airway was lower in patients with previous therapy (p = 0.046). Bronchoscopy was more sensitive in detecting tracheal abnormalities (90.7% vs.53.5%, p = 0.039) but less sensitive for peripheral airway lesions (65.1% vs. 79.1%, p = 0.046) compared with PET. SUVmax and TLG of the airway positively correlated with spirometry indicators (FEV1%pred, FEV1/FVC, MEF 50%pred, etc.) and serological inflammatory markers. Five patients died during the follow-up, with two deaths related to airway problems. Higher FDG uptake predicted worse subjective feeling, but not with symptom control or pulmonary function. CONCLUSION: PET/CT is a valuable tool for RP with airway involvement, particularly in assessing peripheral airway lesions, and PET/CT related parameters are significantly associated with disease patterns, severity, and long-term outcomes.

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.