Immunoglobulin E and other immunoglobulins in patients with eosinophilic pleural effusions

Paired serum and pleural fluids from seven patients with eosinophilic pleural effusions (EPE) and seven control patients with noneosinophilic exudative pleural effusions (non-EPE) were quantitatively assayed for IgG, IgA, IgM, and IgE. A comparison of the absolute serum values, pleural fluid values, and pleural fluid/serum concentration ratios obtained for each immunoglobulin, including IgE, failed to detect any significant differences in the two groups. It is concluded that IgE in exudative effusions reflects passive filtration and diffusion from serum and that immunoglobulin concentrations have no apparent value when assessing EPE.