Serum Immunoglobulin Levels in the Course of Acute Pneumonia

Serum levels of 5 immunoglobulins (IgG, IgA, IgM, IgD and IgE) have been determined at frequent intervals in the course of acute pneumonia. 12 patients were examined, 8 with bacterial pneumonia, 4 with pneumonia caused by Mycoplasma pneumoniae.IgG increased to high levels in the third or fourth week of illness in 2 patients with long-standing and severe bacterial pneumonia. Simultaneously, there was a rise in IgA in both patients, and in IgD in one. No appreciable changes in IgM concentration occurred. Only minor immunoglobulin changes were revealed in the remaining 6 patients with bacterial pneumonia, responding readily to antibiotic therapy. In the cases of bacterial pneumonia, a significant decrease in IgE concentration was noticed, the lowest levels of IgE appearing in the fourth week.In the Mycoplasma pneumonia patients an increase in IgM was found, reaching a maximum in the fourth or fifth week. The IgM increase was greatest in a patient with complicating meningitis. No other remarkable changes in the immunoglobulin concentration were observed in the patients with Mycoplasma pneumonia, who all responded well to tetracycline therapy.