Plastic filing from dialysis tubing induces prostanoid release from macrophages.

Multiorgan, abnormalities in dialysis patients (for example, hepatosplenomegaly, granulomatous hepatitis, cytopenia from hypersplenism) have recently been ascribed to the loading of macrophages (MO) with silicone particles released from the pump segment of dialysis tubing. In the present study, the effect of chronic intravenous or intraperitoneal loading of rats with silicone, polyvinylchloride (PVC) and polyurethane (PU) particles on arachidonic acid metabolism of peritoneal MO and splenic cells was examined in vitro. Intravenous injections of silicone, PVC, or PU particles caused accumulation of the material within the lysosomes of MO of spleen, liver, and lung. Spontaneous release of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) was significantly increased in peritoneal MO of rats injected with silicone, PVC, or PU (Control: 4.27 +/- 0.85 ng PGE2/ml/24 hr; silicone 51.9 +/- 13.2; PVC 57.5 +/- 10.6; PU 28.8 +/- 2.3). Zymosan or LPS stimulated PGE2 release from control MO, but caused no consistent further elevation of high basal PGE2 release from MO after particle loading. Furthermore, increased spontaneous and stimulated TXB2 release was also observed in spleen cells of rats given intravenous injection of silicone particles. It is concluded that storage of plastic particles (silicone, PVC, and PU) by macrophages stimulates arachidonic acid metabolism.