Reduced erythrocyte CR1 levels in patients with pulmonary tuberculosis is an acquired phenomenon

Complement receptor 1 expressed on erythrocytes is involved in the transport of circulating immune complexes from the circulation to the mononuclear phagocyte system for safe disposal. The prevalence of complement receptor 1 genotypes and the association between circulating immune complexes and expression of complement receptor 1 on erythrocytes in pulmonary tuberculosis are not fully understood. Observations from this study showed increased occurrence of HH genotype in patients with pulmonary tuberculosis. Patients with tuberculosis had decreased erythrocyte complement receptor 1 and increased immune complex levels compared to healthy controls which also correlated with increasing severity of the disease. In addition, the expression of complement receptor 1 on erythrocytes correlated inversely with the levels of circulating immune complexes. This study suggests that the presence of HH genotype is high in pulmonary tuberculosis patients and the reduced complement receptor 1 in patients may be an acquired phenomenon related to disease pathogenesis.