KININ KINETICS DURING DIFFERENT DIALYSIS PROTOCOLS WITH AN69 DIALYZERIN ACEI-TREATED PATIENTS

The effect of different dialysis modes on kinin kinetics was studied i n seven stable haemodialysis patients treated with AN69 dialysers and ACE inhibitors (ACEI). AN69 haemodiafiltration with calcium-enriched s ubstitution (HDF), AN69 haemodialysis with 1.75 (HD 1.75) and 1.50 (HD 1.50) mmol/l dialysate calcium, AN69 haemodialysis with 1.25 mmol/l d ialysate calcium and substitution of 2.25 mmol/h calcium (HD + Ca), an d cellulose acetate haemodiafiltration (CA HDF) were compared. Dialysi s was uneventful in all patients. During dialysis, serum calcium, sodi um, pH, albumin, and bradykinin were measured at the start and after 5 min at arterial, venous, and postinfusion side of the extracorporeal circuit. Serum predialysis bradykinin was 107 +/- 18 fmol/ml (mean +/- SEM) in patients on HDF, 61 +/- 9 fmol/ml in patients on HD 1.50, 49 +/- 13 fmol/ml in patients on HD 1.75, 35 +/- 3 fmol/l in patients on HD + Ca, and 75 +/- 27 fmol/ml in CA HDF. No significant change of mea n bradykinin levels occurred after 5 min at the arterial and venous si de of the dialyser or postinfusion. Individual high bradykinin levels, up to 2672 fmol/ml, were observed but without clinical consequences, suggesting that the threshold value is difficult to determine. No sign ificant correlations were evidenced between bradykinin levels and any of the biochemical measurements. The present data show an intraindivid ual variability of the bradykinin levels with variation coefficients r anging from 0.386 to 2.783. The present study illustrates that haemodi alysis and haemodiafiltration with AN69 in ACEI-treated patients, unde r the present conditions, does not result in anaphylactoid reactions o r in a clinically significant release of bradykinin. The occurrence of anaphylactoid reactions with high bradykinin levels is probably the r esult of several concurrent bioincompatible factors in sensitized pati ents.