Complement activation by angiographic catheters in vitro.

Abstract

PURPOSE: Four different polymers used in commercial angiographic catheters were compared in vitro with respect to their ability to activate the complement system. MATERIALS AND METHODS: Commercially available angiographic catheters made from one of the following plastics were used: polyamide, polyethylene, polyurethane, and polytetrafluoroethylene. Silicone-coated latex urinary catheters served as the reference standard. Each catheter was cut into 20-mm segments, immersed in a polypropylene tube containing fresh serum from a volunteer donor, and incubated at 37 degrees C. Samples were drawn at 15 minutes, 1 hour, and 6 hours; C3 activation products (C3AP) and the terminal complement complex (TCC) content were estimated with enzyme immunoassays. RESULTS: By 1 hour, a significant increase in C3AP and TCC concentrations was observed with all angiographic catheters relative to controls (P < .01-.001). The time-concentration plots for both C3AP and TCC were steepest for polyamide. C3AP concentrations relative to controls were significantly higher with exposure to polyamide compared with polyurethane at 1 hour (P < .01), and with both polyethylene and polyurethane at 6 hours (P < .01). Polytetrafluoroethylene induced larger amounts of C3AP formation by 6 hours than polyethylene and polyurethane (P < .05). However, polytetrafluoroethylene was associated with the lowest relative median concentrations of TCC; the difference with polyamide was significant at 6 hours (P < .001). As with C3AP, differences in TCC generation between polyethylene and polyurethane were marginal at all observation points (P > .05). CONCLUSIONS: All the polymers tested activated the complement system. Activation was most prominent with exposure to polyamide and least marked with polyurethane.