Complement activation by vascular prostheses and its role in progression of arteriosclerotic lesions.

This study, using C3a, C4a, and C5a assay and crossed immunoelectrophoresis in vitro and in vivo, was designed to determine whether vascular prostheses activate the complement system. The degree of complement activation and the pathway of activation were also studied. The complement levels (C3, C4, CH50) in different arterial diseases were measured, and the relationship of complement levels to serum lipids in patients with arteriosclerosis obliterans (ASO) was also investigated, in order to clarify a relationship between the complement system and arteriosclerosis or other arterial diseases. Bovine graft, dacron, and PTFE activated the complement system in vitro. In order of the degree of complement activation, bovine graft ranked first, followed by dacron and PTFE. The patient group with acute arterial occlusion showed high C3 and C4 levels. The healthy elderly group showed higher C3 and C4 levels than the healthy persons in their twenties. In ASO patients, C3 levels correlated with serum lipid levels. Judged from the relation of complement activation by vascular prostheses to the progression of arteriosclerotic changes, vascular prostheses should be assessed with regard to complement activation.