Effects of L-carnitine on leukocyte function and viability in hemodialysis patients: A double-blind randomized trial

Excess morbidity and mortality among long-term hemodialysis patients because of infectious complications is partly caused by an impairment of cellular immune defense. We hypothesized this impairment is related to an abnormal carnitine metabolism also present in these patients. In a double-blind, randomized, placebo-controlled trial, we investigated the effect of L-carnitine on phagocytic function and viability of blood leukocytes in 17 patients undergoing maintenance hemodialysis. After an observation period of 1 month, the patients received either 10 mg/kg of L-carnitine or placebo intravenously at the end of each hemodialysis session over a period of 4 months, Leukocyte oxidative metabolism was measured by means of luminol-enhanced chemiluminescence and superoxide generation after stimulation with Staphylococcus aureus or phorbol myristate acetate. Killing capacity and phagocytosis of radiolabeled staphylococci were determined. A lactate dehydrogenase (LDH) release test was applied to assess cell viability, We were unable to show an effect of L-carnitine on phagocytic function and viability in vivo. Several clinical parameters were observed during the trial, No statistically significant differences concerning dialysis-related morbidity, anemia, or reduction of blood urea nitrogen and creatinine levels were detected. Additionally we tested the effect of L-carnitine on phagocytic function after in vitro incubation of blood leukocytes, which also showed no changes, LDH release was decreased, indicating an improved viability of these cells. The latter results were found after in vitro incubation of cells, but could not be confirmed in vivo, In summary, we could not show beneficial effects of L-carnitine administration in hemodialysis patients for the dosage and duration of treatment stated, either on phagocytic function and viability or on the clinical and biochemical parameters observed. (C) 1999 by the National Kidney Foundation, Inc.