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)-1alpha and MIP-1beta, in the pathogenesis of bronchiolitis obliterans organizing pneumonia (BOOP). METHODOLOGY: The concentrations of MIP-1alpha and MIP-1beta 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-1alpha 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-1beta 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-1alpha significantly correlated with the percentage of lymphocytes in BALF, and the concentration of MIP-1beta significantly correlated with the numbers of lymphocytes, neutrophils and eosinophils in BALF. Both MIP-1alpha and MIP-1beta in BALF were decreased after corticosteroid therapy and this was accompanied by decreased lymphocytes in BALF. CONCLUSION: This study suggests that MIP-1alpha and MIP-1beta may play important roles in the recruitment of immuno-inflammatory cells into the lungs, and may contribute to the pathogenesis of BOOP.