Phenotypic characteristics of immunocompetent cells in the blood of patients with pneumonia

Abstract Rationale Prevention of secondary immunodeficiency in pneumonia is clinically important. Methods We studied bactericidal phagocyte activity, functional lymphocyte activity in blast-transformation reaction with PHA; CD3, CD4, CD8, CD16, CD20, IgA, IgM, IgG, circulating immune complexes in the blood of patients with mild, moderate and severe pneumonia. Results Phenotypic characteristics of peripheral blood immunocompetent cells included a decrease in the number of CD3 + , CD4 + , CD16 + , IgA level, functional lymphocyte activity, and an increase in the level of circulating immune complexes and CD20 + (p Conclusions Quantitative subsets and functional activity of immune regulatory cells may be adversely affected in pneumonia, these changes leading to a secondary immunodeficiency which is relatively proportional to the clinical severity of the pneumonia. Future therapies involving immune modulation to restore the immune parameters to a normal profile may help to decrease the development of secondary pneumonia-dependent immunodeficiency.