PRODUCTION OF INTERLEUKIN-1 RECEPTOR ANTAGONIST AND INTERLEUKIN-1 DURING HEMODIALYSIS WITH CELLULOSE MEMBRANES

An in vivo cross-over study has investigated plasma and cellular levels of IL-1 (IL-1 alpha IL-1 beta and IL-1Ra) when using Cuprophan (C) and cellulose triacetate (CTA) membranes to assess the roles of complement activation and dialysate endotoxin content in the induction of cytokines during the dialysis procedure. The mean C5a level during Cuprophan dialysis was 29.9 +/- 0.63 ng/ml (Mean +/- SEM), while for the cellulose triacetate dialysis was 3.09 +/- 0.7 ng/ml. The endotoxin content of the dialysate was 0.31 +/- 0.34 EU/ ml and 0.68 +/- 1.39 EU/ml. These two factors failed to produce measurable changes in plasma or cellular IL-1 alpha and IL-1 beta levels during treatment. The plasma IL-1Ra levels predialysis were similar to those for normal controls (CTA 769 +/- 156 ng/ml, C739 +/- 93, normal controls 635 +/- 33) with a considerable day to day variation. A membrane independent fall in plasma IL-1Ra at 15 minutes was noted (CTA 420 +/- 92 ng/ml, C 503 +/- 139) with a return to pre-dialysis levels by the end of treament. Cellular IL-1Ra levels pre-dialysis were similar to the normal group - (CTA 1904 +/- 291 ng/ml, C 1564 +/- 292 and normal control 1971 +/- 368). However, on average, the values when using cellulose triacetate were 655 +/- 623 pg/ml higher than for Cuprophan (p=0.03). These findings indicate that the measurement of plasma cytokine levels is of limited use in the study of cytokine induction by the haemodialysis procedure and that IL-1Ra may be a better indicator of the host response fo cytokine stimuli during treatment. However, a considerable infer-patient and intra-treatment variation is present and further studies are required to elucidate the factors involved.