INTERACTION WITH AUTOLOGOUS PLATELETS MULTIPLIES INTERLEUKIN-1 AND TUMOR-NECROSIS-FACTOR PRODUCTION IN MONONUCLEAR-CELLS

The effect of activated platelets on cytokine production by human peri pheral blood mononuclear cells (PBMC) was investigated. When PBMC were coincubated with activated autologous platelets amid lipopolysacchari de (LPS, 50-100 pg/mL) for 8 h, the production of interleukin (IL)-1 a lpha increased 11- to 18-fold and tumor necrosis factor (TNF)-alpha 3- to 5-fold compared with PBMC without platelets. Activated platelets i n a dual-chamber well that prevented platelet-PBMC contact but permitt ed passage of soluble factors enhanced IL-1 alpha production (P < .01) . Platelet-PBMC contact in the chamber resulted in a further enhanceme nt of IL-1 alpha production. These data suggest that platelet-PBMC int eraction, both directly and with platelet-derived factors, enhances pr oduction of shock-producing IL-1 alpha and TNF-alpha, albeit different ly. The interaction of platelets with monocytes may play an important role in the pathophysiology of sepsis and disseminated intravascular c oagulation.