Relapsing Polychondritis with Tracheobronchial Involvement

Summary: Background - Relapsing Polychondritis (RP) is a rare autoimmune condition characterized by recurrent inflammation of the cartilaginous structures and organs rich in proteoglycan. Inflammation and damage of auricular, nasal and articular structures represent the most common clinical manifestations. Case Presentation - 56-year-old male who was previously diagnosed with rheumatoid arthritis managed on 20 mg methotrexate (MTX) weekly and daily folic acid transferred care to our clinic. At his initial visit, he had redness, warmth and pain of bilateral ears and nose. He also noted progressive dyspnea over the previous 2 years. He had sensorineural deafness status post bilateral cochlear implants. Redness was also noted in both eyes with photophobia but no blurry vision or changes in visual acuity. Examination revealed redness and warmth in the cartilaginous part of his ears sparing the ear lobule and saddle nose deformity (Figure 1). Ophthalmology was consulted for ocular symptoms which confirmed bilateral episcleritis. We diagnosed the patient with RP based on McAdam et al. criteria. Laboratory testing confirmed elevated inflammatory markers, with normal serologies (Table 1). CT scan of the chest showed RP related tracheobronchial involvement. (Figure 1). A slow prednisone taper and sarilumab 200 mg subcutaneous injection every 2 weeks was added. At subsequent visits, his symptoms improved, and he remains in remission on MTX and sarilumab, off prednisone. Figure 1 – (Top) Redness with erythema and warmth of bilateral helix, antihelix, scapha and antitragus, sparing the ear lobule. (Left) Saddle nose deformity (Right) (Bottom) - CT scan of the chest showing narrowing of the trachea (green) with anterior and lateral tracheal wall thickening(orange), sparing of posterior membranous wall (yellow) Discussion – RP occurs most frequently between the ages of 40 and 60 years with approximate prevalence of 4.5-9 cases/million. Circulating and tissue-specific antibodies against collagen types II, IX and XI are seen in patients with RP. In addition to humoral immunity, cellular immunity propagates inflammation of cartilage. Common clinical features include chondritis affecting auricular, nasal and tracheobronchial cartilages, as seen in our patient. Other features can include audio-vestibular manifestations, inflammatory eye disease, inflammatory arthritis, aortic insufficiency and oral aphthosis. Tracheobronchial involvement affects up to 20 to 50% of patients, including thickening of the tracheobronchial wall which can be seen in up to 40% of cases. As in our patient, the posterior wall of the trachea is spared as it does not contain cartilage. Tracheobronchial wall disease can be confirmed on dynamic expiratory CT, which would demonstrate collapse of the tracheal or bronchial lumen during expiration. Most commonly used immunosuppressive agents include methotrexate, azathioprine, and cyclosporine. Elevated levels of IL-1, TNF and IL-6 are noted in RP. IL-6 augments the recruitment of monocytes and macrophages which then release proteolytic enzymes, MMP-3 resulting in cartilage destruction. The development of biological therapies (monoclonal antibodies) to these cytokines has potential for improved outcomes in RP. Conclusion As a results of the rarity, episodic nature and the diverse clinical presentation, RP is difficult to diagnose and study. The diagnostic delay in RP results in significantly higher morbidity and mortality. The presence of respiratory symptoms in a patient known to have RP, should raise the clinical suspicion of tracheobronchial involvement.