ASSOCIATION OF INTERLEUKIN-6 RELEASE FROM ENDOTHELIAL-CELLS AND PULMONARY-HYPERTENSION IN SLE

Objective. To investigate how sera from 37 patients with systemic lupu s erythematosus (SLE) stimulate interleukin (IL) 6 release from IL-1 b eta pretreated endothelial cells and compare these effects to those of sera from 16 normal controls. Methods. Endothelial cells pretreated 1 8 h with IL-1 beta (5 U/ml) were incubated 2 h with sera diluted 10-fo ld with phosphate buffered saline (PBS). IL-6 concentrations in endoth elial culture super natants collected after incubation were measured b y ELISA. Results. Compared with PBS, sera from controls and 24 patient s with SLE suppressed IL-6 release from IL-1 beta pretreated cells. Ho wever, sera from 13 patients with SLE augmented IL-6 release. Of note, sera from 5 patients with pulmonary hypertension induced the highest level of IL-6 release. IgG from control sera suppressed IL-6 release, whereas F(ab')(2) did not. Both IgG and F(ab')(2) from the sera of pat ients with SLE with pulmonary hypertension augmented IL-6 release from IL-1 beta pretreated cells. Conclusion. IgG antiendothelial cell anti bodies from patients with SLE may be associated with the pathogenesis of SLE and pulmonary hypertension.