Increased macrophage inflammatory protein-1alpha and -1beta in BAL fluid of bronchiolitis obliterans organizing pneumonia.

Objective:  CC chemokines are mainly chemotactic for monocytes and lymphocytes. The aim of this study was to evaluate the involvement of the CC chemokines, macrophage inflammatory protein (MIP)-1α and MIP-1β, in the pathogenesis of bronchiolitis obliterans organizing pneumonia (BOOP). Methodology:  The concentrations of MIP-1α and MIP-1β in BAL fluid (BALF) obtained from patients with BOOP (n = 13) and control patients (CP, n= 18) were measured by enzyme-linked immunosorbent assay. Results:  MIP-1α in BALF was significantly higher in patients with BOOP (mean ± SD; 123.8 ± 98.0 pg/mL) than in CP (62.5 ± 46.1 pg/mL). Significantly higher MIP-1β was also detected in patients with BOOP (51.6 ± 72.5 pg/mL) than in CP (6.4 ± 3.7 pg/mL). The concentration of MIP-1α significantly correlated with the percentage of lymphocytes in BALF, and the concentration of MIP-1β significantly correlated with the numbers of lymphocytes, neutrophils and eosinophils in BALF. Both MIP-1α and MIP-1β in BALF were decreased after corticosteroid therapy and this was accompanied by decreased lymphocytes in BALF. Conclusion:  This study suggests that MIP-1α and MIP-1β may play important roles in the recruitment of immuno-inflammatory cells into the lungs, and may contribute to the pathogenesis of BOOP.