ABSTRACT
BACKGROUND AND OBJECTIVES: Apoptosis, also known as programmed cell death, probably correlates with the pathophysiologic mechanisms of alveolitis in sarcoidosis. Our purpose was to investigate any changes in the expression of the antiapoptotic protein Bcl-2, one of the most important inhibiting factors of apoptosis, in bronchoalveolar lavage fluid (BALF) cell populations in patients with sarcoidosis. SUBJECTS AND METHODS: Fiberoptic bronchoscopy with BAL was performed in 13 patients with active sarcoidosis (10 patients with stage I and 3 with stage II disease based on chest radiography). None of them was under treatment with corticosteroids. Cellular Bcl-2 expression was identified using an immunoperoxidase staining method. Ten normal subjects served as control group. RESULTS: BALF lymphocytes and macrophages in sarcoid patients exhibited a significant increase in the expression of Bcl-2 compared with the control group (p < 0.001). A Bcl-2 expression of 80.7 +/- 8.5% in the lymphocytes and 77.4 +/- 8.9% in the macrophages was observed in sarcoidosis versus 32.2 +/- 13.8% and 19.6% +/- 7.6% in normal subjects, respectively. The percentages of Bcl-2 expression in the lymphocytes were positively correlated with BALF CD4/CD8 ratio values (p = 0.02, r = 0.63). CONCLUSIONS: Our results suggest that the antiapoptotic protein Bcl-2 is overexpressed in alveolar lymphocytes and macrophages, which characterize the alveolitis in sarcoidosis and could provide insights into the pathogenesis of the disease and prove useful as a marker of disease activity or response to therapy.
Subject(s)
Bronchoalveolar Lavage Fluid/cytology , Lymphocytes/metabolism , Macrophages/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Sarcoidosis/metabolism , Adult , Aged , Bronchoscopy , Case-Control Studies , Female , Fiber Optic Technology , Humans , Male , Middle Aged , Sarcoidosis/pathologyABSTRACT
OBJECTIVE: To investigate changes in the expression of the antiapoptotic protein bcl-2 in bronchoalveolar lavage fluid (BALF) cell populations in patients with idiopathic pulmonary fibrosis (IPF). STUDY DESIGN: Ten patients with IPF underwent fiberoptic bronchoscopy and bronchoalveolar lavage (BAL) in the area of maximal radiographic shadowing (based on high-resolution computed tomography findings). Results were compared with those of 10 normal people in the control group. Cellular bcl-2 expression was identified using an immunoperoxidase staining method. RESULTS: A statistically significant (P < .001) increase in the expression of bcl-2 in BALF neutrophils and eosinophils was observed in patients with IPF as compared with controls. BAL macrophages exhibited only a slight (statistically insignificant) increase in bcl-2 expression in IPF patients. No bcl-2 expression was observed in BAL lymphocytes from IPF patients in contrast to the control group. CONCLUSION: The overexpression of bcl-2 on BALF neutrophils and eosinophils, cells that characterize the special cellular profile of alveolitis in IPF, could be one of the pathophysiologic mechanisms of this disease.
