Bronchoalveolar lavage in bronchiolitis obliterans organizing pneumonia primed by radiation therapy to the breast

Background: Growing evidence indicates that unilateral lung irradiation for breast cancer may "prime" the development of migratory lung infiltrates with histologic features of bronchiolitis obliterans organizing pneumonia, Objective: Our purpose was to evaluate the cytologic and immunocytologic features of bronchoalveolar lavage in this condition. Methods: We analyzed the profile bronchoalveolar lavage cell differentials and lymphocyte subpopulations of 11 women with bronchiolitis obliterans organizing pneumonia syndrome after radiation therapy for breast cancer in comparison to 9 healthy women. Results: The bronchoalveolar lavage analysis demonstrated a significant increase in the percentage of lymphocytes (36.7% +/- 5.4% vs 8.6% +/- 1.1%, P =.0002), neutrophils (3.8% +/- 1.2% vs 0.6% +/- 0.2%, P =.005), eosinophils (2.4% +/- 1% vs 0.3% +/- 0.1 %, P =.01), and mast cells (1.4% +/- 0.6% vs 0.1% +/- 0.02%, P =.05) with a significant decrease in the percentage of macrophages (56.1% +/- 6% vs 90.3% +/- 1.4%, P =.0002) in patients with bronchiolitis obliterans organizing pneumonia compared with the control subjects. The percentage of CD3(+) cells was significantly increased in patients with bronchiolitis obliterans organizing pneumonia (93.7% +/- 1.3% vs 70.9% +/- 4%, P =.0004), with a significant decrease in CD4(+) cells (32.7% +/- 4.7% vs 55.4% +/- 2.6%, P =.002) and a significant increase in CD8(+) cells (61.2% +/- 4.8 % vs 37.5 % +/- 2.9%, P =.003) in comparison to control subjects. The CD4/CD8 ratio was significantly reduced in patients with bronchiolitis obliterans organizing pneumonia compared with control subjects (0.6% +/- 0.1% vs 1.5% +/-i 0.1%, P=.001), Conclusion: These data add to the view that unilateral lung irradiation for breast cancer may "prime" the development of a syndrome quite similar to idiopathic bronchiolitis obliterans organizing pneumonia.