Possible role of mononuclear phagocytes in clearance of immune complexes in pulmonary tuberculosis.

Phagocytic activity of peripheral blood mononuclear cells (PBMC) was investigated in 30 patients with pulmonary tuberculosis. The test was done using neutral red. Higher percentages of phagocytic cells were detected with PBMC of tuberculosis patients as compared with controls. An inverse relationship was observed between neutral red positive cell counts vs. relative percentages of several proteins (IgG, C3 and C4) in PEG precipitates in tuberculosis patients. It was interpreted that phagocytes might have mopped up the CICs via their surface Fc receptors.