Analysis of bronchoalveolar lavage cells and fluids in patients with hypersensitivity pneumonitis: possible role of chemotactic factors in the pathogenesis of disease.

The current study concerns immunological mechanisms involved in the pathogenesis of hypersensitivity pneumonitis (HP) by an analysis of the cells and chemotactic factors (CF) obtained by bronchoalveolar lavage (BAL). Nine patients at an acute stage (HP acute, 8 summer type and 1 pigeon breeder's lung) and 4 patients at a quiescent stage (HP quiescent, 3 summer type and 1 pigeon breeder's lung) were included. The results indicate that: CF for polymorphonuclear cells (PMN) in HP acute were significantly more potent than in HP quiescent; CF for mononuclear cells were not significantly different in the groups; the percentage of lymphocytes in HP acute was significantly greater even though HP quiescent revealed greater percentages of lymphocytes as compared to normal controls; determination of T cell subsets employing OKT antibodies revealed the ratio of OKT8+ cells to OKT4+ cells in HP acute was significantly higher than in HP quiescent, and chemotaxis for PMN was marginally correlated with the percentage of OKT8+ cells at the acute stage of disease.