The effect of three surfactant preparations on in vitro lymphocyte functions

Respiratory distress can be successfully treated by endotracheal surfactant replacement therapy. The effects of two natural surfactant preparations, Alveofact and Survanta, and one synthetic, Exosurf, on lymphocyte functions were investigated. Peripheral blood lymphocytes from cord blood or buffy coat from adult healthy donors were stimulated with mitogens (PHA-P, Con A), allogenic cells (MLC) or antigen (SEB), and the proliferative response was measured by the uptake of tritiated thymidine. Immunoglobulin synthesis was stimulated by PWM and determined by an ELISA. Stimulation of lymphocytes in the presence of variable surfactant concentrations resulted in a concentration dependent suppression of the investigated lymphocyte function, with different results for the three products. Complex immunological function such as proliferation in response to allogenic cells were more sensitive to surfactant induced suppression than mitogen induced proliferation. Thus, it can not be excluded that surfactant replacement therapy may influence the local immune response of the lung.