Clinical Features and Prognostic Significance of Limited and Diffuse Endobronchial Sarcoidosis

Abstract

Aims: Airway involvement is a common feature of sarcoidosis   and mucosal abnormalities may be evident in the respiratory tract. However, firm data establishing the clinical features and prognosis of sarcoidosis in these patients is lacking although the incidence of   endobronchial disease is high. The purpose of this study was to evaluate   the   clinical   features   of   the   patients   with   limited,   diffuse and no endobronchial involvement. Another aim was to investigate the prognostic differences between these patients. Methods: We conducted a retrospective study to evaluate the clinical and laboratory findings of 48 patients with endobronchial sarcoidosis and 50 patients without endobronchial involvement seen at our institution. The patients fulfilled the clinical, radiologic or both features of sarcoidosis supported by the histopathologic evidence of noncaseiting granulomas. Six to ten bronchial biopsies were taken from each patient. The sample was considered positive if it demonstrated noncaseiting granulomas with negative fungal and mycobacterial cultures. The patients were classified into three groups according to the histopathologic biopsy results: 1) No endobronchial involvement, 2) Limited endobronchial involvement: One biopsy site positive and 3) Diffuse endobronchial involvement: Two or more biopsy sites positive for noncaseaiting granulomas. Results: Bronchial biopsy was positive in 82% of the abnormal appearing airways while it was diagnostic in 36% of the normal appearing mucosa.  The most frequent bronchoscopic appearence was miliary infiltration. Nodular, erythematous lesions and edematous mucosal swelling were other bronchoscopic findings. There were no significant differences between the three groups for FEV1, FVC, TLC, DLCO/VA serum and 24 h urinary calcium levels. Serum ACE levels were significantly higher (p<0.001) in patients with limited and diffuse bronchial involvement compared to patients with no endobronchial disease. The extrapulmonary organ involvement (p<0.001) and progressive disease incidence was more frequent (p<0.001) in patients with limited and diffuse endobronchial disease. Conclusions: Endobronchial involvement in sarcoidosis appears to be a significant predictive risk factor for progressive disease. Patients with limited or diffuse endobronchial disease have more severe extrapulmonary organ involvement and a worse prognosis than patients without endobronchial disease. Bronchoscopy may identify such patients carrying a risk factor for progressive sarcoidosis.