Relapsing polychondritis: clinical updates and new differential diagnoses.

Relapsing polychondritis is a rare inflammatory disease characterized by recurrent inflammation of cartilaginous structures, mainly of the ears, nose and respiratory tract, with a broad spectrum of accompanying systemic features. Despite its rarity, prompt recognition and accurate diagnosis of relapsing polychondritis is crucial for appropriate management and optimal outcomes. Our understanding of relapsing polychondritis has changed markedly in the past couple of years with the identification of three distinct patient clusters that have different clinical manifestations and prognostic outcomes. With the progress of pangenomic sequencing and the discovery of new somatic and monogenic autoinflammatory diseases, new differential diagnoses have emerged, notably the vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome, autoinflammatory diseases and immune checkpoint inhibitor-related adverse events. In this Review, we present a detailed update of the newly identified clusters and highlight red flags that should raise suspicion of these alternative diagnoses. The identification of these different clusters and mimickers has a direct impact on the management, follow-up and prognosis of patients with relapsing polychondritis and autoinflammatory syndromes.

[Tracheobronchial involvement in relapsing polychondritis and differential diagnoses]. / Atteinte trachéo-bronchique de la polychondrite atrophiante et diagnostics différentiels.

Relapsing polychondritis is a systemic auto-immune disease that mainly affects cartilage structures, progressing through inflammatory flare-ups between phases of remission and ultimately leading to deformation of the cartilages involved. In addition to characteristic damage of auricular or nasal cartilage, tracheobronchial and cardiac involvement are particularly severe, and can seriously alter the prognosis. Tracheobronchial lesions are assessed by means of a multimodal approach, including dynamic thoracic imaging, measurement of pulmonary function (with recent emphasis on pulse oscillometry), and mapping of tracheal lesions through flexible bronchoscopy. Diagnosis can be difficult in the absence of specific diagnostic tools, especially as there may exist a large number of differential diagnoses, particularly as regards inflammatory diseases. The prognosis has improved, due largely to upgraded interventional bronchoscopy techniques and the development of immunosuppressant drugs and targeted therapies, offering patients a number of treatment options.

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.

Orbital/ocular inflammatory involvement in VEXAS syndrome: Data from the international AIDA network VEXAS registry.

VEXAS syndrome is a recently described monogenic autoinflammatory disease capable of manifesting itself with a wide array of organs and tissues involvement. Orbital/ocular inflammatory manifestations are frequently described in VEXAS patients. The objective of this study is to further describe orbital/ocular conditions in VEXAS syndrome while investigating potential associations with other disease manifestations. In the present study, twenty-seven out of 59 (45.8 %) VEXAS patients showed an inflammatory orbital/ocular involvement during their clinical history. The most frequent orbital/ocular affections were represented by periorbital edema in 8 (13.6 %) cases, episcleritis in 5 (8.5 %) patients, scleritis in 5 (8.5 %) cases, uveitis in 4 (6.8 %) cases, conjunctivitis in 4 (6.8 %) cases, blepharitis in 3 (5.1 %) cases, orbital myositis in 2 (3.4 %) cases. A diagnosis of systemic immune-mediated disease was observed in 15 (55.6 %) cases, with relapsing polychondritis diagnosed in 12 patients. A significant association was observed between relapsing polychondritis and orbital/ocular involvement in VEXAS syndrome (Relative Risk: 2.37, 95 % C.I. 1.03-5.46, p = 0.048). Six deaths were observed in the whole cohort of patients after a median disease duration of 1.2 (IQR=5.35) years, 5 (83.3 %) of which showed orbital/ocular inflammatory involvement. In conclusion, this study confirms that orbital/ocular inflammatory involvement is a common finding in VEXAS patients, especially when relapsing polychondritis is diagnosed. This makes ophthalmologists a key figure in the diagnostic process of VEXAS syndrome. The high frequency of deaths observed in this study seems to suggest that patients with orbital/ocular involvement may require increased attention and more careful follow-up.

An Autopsy Case of COVID-19 with New Diffuse Pulmonary Ossification.

We present the case of a 61-year-old man who developed coronavirus disease 2019 (COVID-19) and died during treatment for relapsing polychondritis. The patient was intubated and treated with steroid pulse therapy, remdecivir, antibacterial agents, baricitinib, and tocilizumab. However, his respiratory condition worsened, and he died 108 days after disease onset. An autopsy revealed diffuse alveolar damage in the fibrotic phase in all lung lobes, diffuse pulmonary ossification, and cytomegalovirus-infected cells in the middle lobe of the right lung. We herein discuss the clinical features and pathological findings of COVID-19 in immunosuppressed patients.

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.

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)

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.

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.

[Macrocytic anemia and polychondritis: VEXAS syndrome]. / Makrozytäre Anämie und Polychondritis: VEXAS-Syndrom.

An adult-onset autoinflammatory syndrome caused by somatic mutations in the UBA1 gene on the X chromosome was first reported in 2020. This VEXAS syndrome (acronym for vacuoles, E1 enzyme, X­linked, autoinflammatory, somatic) is characterized by an overlap of rheumatic inflammatory diseases with separate hematologic abnormalities. A substantial number of affected patients suffer from treatment refractory relapsing polychondritis and nearly always show signs of macrocytic anemia. This case report illustrates the diagnostic key points to recognizing patients with VEXAS syndrome.

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.

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.