Immunologic investigation in children with recurrent pneumonia.

In vitro lymphocyte stimulation by phytohemagglutinin (PHA) and pokeweed mitogen (PWM) and tests for granulocyte function were performed in 12 children with recurrent pneumonia. Reduced lymphocyte stimulation was found at repeated tests in 2 children and transiently decreased lymphocyte stimulation in 6 more children. In 3 patients, reduced bactericidal capacity of granulocytes was demonstrated, and in 1 cast stimulation showed decreased NBT activity of granulocytes. One patient examined had immunoglobulin deficiency.