[The clinical importance of determining protein C and protein S in patients with nonspecific aortoarteritis]

Solid-phase enzyme immunoassay estimated S and C protein levels in 10 patients with nonspecific aortic arteritis (NAA). Lowered concentrations of total protein S (< 70%) occurred in 8 (80%) of 10 NAA patients, in 3 of them protein C was also low. Isolated reduction of protein C was encountered only in one patient. Four patients (44%) of 9 had antibodies to phospholipids, as a rule, in low concentrations. 3 of them had low total protein S concentrations against normal C protein. 4 patients (40%) showed elevated concentrations of WF antigen concentrations. No relationship was noted between a fall in total protein S, C concentrations and clinical presentation of NAA, the disease activity, presence of antibodies to neutrophil cytoplasm and antibodies to endothelial cells. Thus, a reduction in the levels of total protein S in NAA patients is induced by endothelial dysfunction unrelated to production of antibodies to phospholipids, neutrophil cytoplasm and vascular endothelium.