Iatrogenic multiorgan silicone inclusions in dialysis patients.

Abstract

Listen

Translate article

We studied autopsy material of 47 patients who were dialysed between 1969 and 1980 in one center in which silicone tubing was used. In addition, we examined ten patients from two other centers where silicone tubing was not routinely used. In 40 patients with exposure to silicone tubing who were dialysed for up to 53 months, no foreign material was demonstrable. In seven patients who were dialysed for periods between 52 and 165 months, light microscopy and electron microscopy showed varying amounts of foreign material in macrophages and giant cells of lung, liver, spleen, bone marrow, skin, thoracic and abdominal lymph nodes. No such material was found in brain, heart, kidney or endocrine organs. No epitheloid cell reaction, necrosis or fibrosis was observed. The material was non-isotropic, non-crystalline, and did not take up routine stains. Electron microscopy showed its presence within lysosomal membranes. In addition, in some patients who had been dialysed for much shorter periods of time, similar material could be demonstrated in liver biopsies obtained in vivo. No such material was observed in ten long-term dialysis patients of two centers where silicone tubing was not routinely used. All positive patients had hepatosplenomegaly, some had elevated transaminases, one patient had hypersplenism with pancytopenia and one patient had bile duct carcinoma. Gaschromatography with mass spectrometry of livers of dialysed patients showed high concentrations of phthalate plasticizer (5–10 ppm) and in one patient cholesterol-like steroids which were not found in normal livers. Surface scanning electron microscopy with non-dispersive X-ray fluorescence analysis revealed the presence of numerous particles up to 10 µ, in liver and spleen of dialysed patients but of not control patients. The particles showed a characteristic Si peak with a concomitant small contribution of Al and Cl. The particles were identical with filing of silicone tubing exposed to roller pumps. No material exhibiting a pure Cl peak (as evidence for PVC) was demonstrable in patients with positive silicone inclusions. Because of its clinical consequences, the observation will have implications for manufacturing of dialysis devices.