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\% +/- 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.