Overexpression of bcl-2 protein in bronchoalveolar lavage lymphocytes and macrophages in sarcoidosis.
OBJECTIVE
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.


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.
Mermigkis
C
C
3rd Pulmonary Department, Sismanoglio General District Hospital, Athens, Greece. mermigis@hotmail.com
Polychronopoulos
V
V
Mermigkis
D
D
Tsakanika
K
K
Heretis
M
M
Karagianidis
N
N
Bouros
D
D
D000328:Adult; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D001999:Bronchoscopy; D016022:Case-Control Studies; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012507:Sarcoidosis / Q000378:metabolism* / Q000473:pathology
D019253:Proto-Oncogene Proteins c-bcl-2