[Improvement in alveolar macrophage function after therapeutic lung lavage in pulmonary alveolar proteinosis]

Alveolar macrophage (AM) function was investigated in 4 cases of pulmonary alveolar proteinosis (PAP). Therapeutic bronchoalveolar lavage (BAL) with a flexible bronchofiberscope was done 7-13 times during periods of 4-24 weeks. In the initial BAL, the total cell count was only 0.18-0.92 x 10(5)/ml. Also low AM, lymphocytosis and eosinophilia values were noted. The phagocytic activity of AM was only 3-14% and nitroblue tetrazonium (NBT) reduction of AM was under 5% before therapeutic BAL. However, the phagocytic activity was from 25-63% and NBT reduction from 15-35% after therapeutic BAL, AM function with periods of remission of PAP was normal but AM function decreased during relapse and exacerbation of PAP. After therapeutic BAL, two patients have been in remission for three years, one patient with incomplete restoration of AM function relapsed after one year, and one patient without restoration of AM function showed further deterioration after developing pulmonary tuberculosis. These findings indicate that the defect in AM function found in PAP is reversible with therapeutic BAL, and that the severity of PAP is closely associated with AM function.