Predictive factors for relapse of cryptogenic organizing pneumonia.

BACKGROUND: Relapse of cryptogenic organizing pneumonia (COP) may lead to poor long-term prognosis and necessitates multiple rounds of steroid treatment with potential adverse effects. The objective of this study is to identify predictive factors of COP relapse by comparing demographic and clinical variables between relapse and non-relapse groups.

METHODS: During 2008-2013, 33 COP patients were treated, of which 23 (69.7%) and 10 patients (30.3%) were assigned to the non-relapse and relapse group, respectively. From medical records, we compared the following variables at initial episode: clinical characteristics, serum parameters, chest CT scan findings, and steroid treatment.

RESULTS: Clinical characteristics, cumulative prednisone dose, and steroid treatment duration were similar between groups. In univariate analysis, alternatively, the proportion of patients with bilateral shadow pattern, traction bronchiectasis, and partial remission after steroid treatment was significantly higher in the relapse group. These differences were not significant by multivariate Cox regression analysis.

CONCLUSIONS: We identified radiographic findings, such as bilateral shadow pattern, traction bronchiectasis, and partial remission, may have possibility of predictive factors for COP relapse. Larger-scale studies are required to confirm if any are independent predictors of COP relapse.