Plasma plasmin-α2-plasmin inhibitor complex levels are increased in systemic sclerosis patients with pulmonary hypertension

Objective. To determine the frequency and clinical significance of plasma plasmin-alpha(2)-plasmin inhibitor complex (PIC) in patients with systemic sclerosis (SSc). Methods. Plasma samples from 74 patients with SSc and 32 healthy volunteers were examined by a specific enzyme-linked immunosorbent assay. Results. Elevated plasma PIC levels were present in 35 of the 74 patients (47.3%) with SSc. The patients with elevated plasma PIC levels had pulmonary hypertension (PH) at a significantly higher incidence than those with normal PIC levels (31.4 vs 7.7%, P < 0.01). When PH was classified into isolated PH (IPH) and secondary PH (SPH), the presence of IPH was significantly greater in patients with elevated PIC levels than in those with normal levels (25.7 vs 5.1%, P < 0.02). Conclusions. These results suggest that plasma PIC levels may be a marker of PH, especially IPH, in patients with SSc.