Total proteins, IgG and IgA concentrations are shown in Table 1. Each pleural fluid or serum sample was further diluted to the same IgG (0.5 g/L) or IgA (1 g/L) concentration before assaying specific antimycobacterial reactivities.
Table 1—Trial IgG and IgA Concentrations (g/L) tn Serum (S) and Pleural Fluid (P) (Mean±SD)
Results are shown in Figure 1. Pleural fluids and sera of tuberculous patients contained a higher proportion of anti-P32 antibodies than in nontuberculous patients. In tuberculous patients, the proportion of specific antibodies IgA or IgG were higher in pleural effusion than in serum in four of five cases leading to a better discrimination of this pathologic condition.
FIGURE 1. Antimycobacterial IgG and IgA titers in sera (S) and respective pleural fluids (PL) after adjusting the total IgG concentrations to 0.5 g/L and IgA to 1 g/L. Small closed circles are nontuberculous patients; large closed circles are tuberculous patients.