Tumor necrosis factor alpha regulation of immunoglobulin secretion in trauma patients.

Major trauma-related immune dysfunction is observed at the time of augmented release of immunopathologic mediators. In the present study, T cell-dependent immunoglobulin (Ig) synthesis in peripheral blood mononuclear cell (PBMC) cultures from blunt trauma patients (N = 12, injury severity score (ISS) 27-50), was reduced by 30- > 90%. This coincided with significantly (P < 0.001-0.01) elevated secretion of the biologically active tumor necrosis factor alpha (TNF alpha). Modulation of the TNF alpha activity by anti-TNF alpha antibody (anti-TNF alpha Ab) led to dose-dependent alterations in IgG synthesis. IgG production increased (up to 300%) in cultures treated with 0.5-2 micrograms/ml of the antibody, where low levels of TNF alpha activity often persisted. However, immunoglobulin synthesis was eradicated in preparations exposed to higher concentrations (10 micrograms/ml) of anti-TNF alpha Ab and devoid of TNF alpha biological activity. The treatment with anti-TNF alpha Ab had no effect on mitogen- or alloantigen-induced PBMC proliferation. Thus, in severely traumatized patients, biological activities of endogenous TNF alpha may include modulation of T cell-dependent B lymphocyte function. Immunoregulatory potential of TNF alpha should, therefore, be considered in therapeutic strategies to abrogate its activity.