[Quantitative evaluation of airway involvement in a patient with relapsing polychondritis using computed tomography]

A 63-year-old woman was admitted to our hospital because of auricular chondritis, conjunctivitis, polyarthralgia, productive cough and dyspnea. On admission, pulmonary function test demonstrated an obstructive pattern, and flow-volume curve (FVC) revealed a constrictive upper airway flow pattern. Chest CT showed a thickened tracheal wall and narrowing of the airway. The laboratory findings revealed an elevation of CRP and high titer of anti-type II collagen antibody. She was diagnosed as relapsing polychondritis (RP) according to Damiani's criteria. After the initiation of the therapy with 32 mg/day of methylprednisolone, her symptoms, pulmonary function, FVC and CT findings ameliorated promptly, and the titer of anti-type II collagen antibody became normalized. Moreover, we measured the airway wall thickness, percentage wall area (WA%) and percentage wall thickness (WT%), by CT and HRCT, and also evaluated the airway involvement quantitatively. Both WA% and WT% were inversely correlated with FEV1.0%. The airway inlolvement is most important prognostic factor in patients with RP, and sequential evaluation of airway manifestation are necessary. We suggest that a quantitative evaluation of bronchial structures by sequential CT is useful for the evaluation of RP as well as pulmonary function tests.