Low prekallikrein and high angiotensin-converting enzyme activity in patients with chronic renal failure on haemodialysis.

Low prekallikrein is found in the plasma of patients with chronic renal failure (CRF) on intermittent haemodialysis (HD) (337 +/- 20.42 U/l before haemodialysis and 394.60 +/- 24.97 U/l after haemodialysis) versus normal data in the control group (755.80 +/- 24.37 U/l). Plasma activity of angiotensin converting enzyme (ACE) in patients with CRF is significantly decreased (14.91 +/- 0.57 U/l) in comparison to the control group (22.30 +/- 0.30 U/l). Intermittent haemodialysis increases plasma ACE activity. No differences exist after one haemodialysis procedure. There are no correlations between dialysis duration, plasma ACE activity, and prekallikrein. The ACE activity increase does not correlate with blood pressure but correlates significantly with the activation of complement and macrophage activity.