A study of acute-phase reactant proteins in Indonesian patients with pulmonary tuberculosis

The levels of 8 acute phase reactants (alpha 1-antitrypsin, alpha 2-macroglobulin, transferrin, alpha 1-acid glycoprotein, C-reactive protein, ceruloplasmin, haptoglobin and the third component of complement) and immunoglobulin in the IgG, IgM and IgA classes were assayed, by laser nephelometry, in sera from 107 East Japanese patients with smear-positive pulmonary tuberculosis and 144 healthy subjects. These levels were correlated with clinical, haematological and radiological features, the levels of antibody to Mycobacterium tuberculosis, and the diameters of the tuberculin skin test read at various times. Levels of all acute phase reactants increased significantly in tuberculosis except for that of transferrin which was lowered. The correlations between the various acute phase reactants in health and disease were calculated. In general, the correlations were lower in disease than in health, except for the third component of complement and a greatly increased correlation between the levels of alpha 1-antitrypsin and ceruloplasmin. There was a significant correlation between levels of some of the acute phase reactants and those of antibodies to M. tuberculosis, mainly with IgG, less with IgA and least with IgM antibodies. By contrast correlations between acute phase protein and total immunoglobulin levels were most evident in the IgM class, less with IgA and not at all with IgG. Although there were some associations between protein levels and age, sex and weight of controls and patients, these were not great enough to account for the differences between the two groups. There was a tendency for patients, but not controls, with intestinal helminthiasis to have higher levels of total IgM than those without evidence of parasites. In general, the levels of proteins bore very little relation to the clinical and radiological features of disease and were, with the exception of the antimycobacterial antibodies, of no diagnostic value. Likewise, protein levels were not associated with the extent of disease; better correlations were found with the ESR and leucocyte count. Transferrin levels tended to be higher in those with chronic disease and showed a correlation with the diameters of the dermal reactions to tuberculin at 24 hours, which were also significantly larger in chronic disease. Among the haematological findings, the most significant was a negative correlation between the lymphocyte count and haptoglobin levels in disease, suggesting a possible regulatory role for this protein.