Assay of circulating immunoglobulins in patients with fibrosing alveolitis.

One or more classes of immunoglobulins were increased above normal in twenty-one of thirty-two patients with fibrosing alveolitis. One class of immunoglobulins only was raised in fourteen sera: IgG in eight, IgA in three and IgM in three. More than one type of immunoglobulin was increased in eight instances. In five sera the increase of IgA was sufficiently great to cause an early `hump' on the electrophoretic strip. The presence of a range of non-organ specific autoantibodies correlated with increased immunoglobulins and their absence with normal immunoglobulin levels in twenty-six of our thirty-two patients. In this study the presence of individual autoantibodies could not be related to individual types of immunoglobulins, owing to the multiplicity of immunoglobulins and autoantibodies in individual sera.