Serum carnitine levels in bone marrow transplant recipients

This study investigated plasma carnitine levels in patients undergoing allogenic bone marrow transplantation. The patients received fat-based TPN (50% fat, 50% CHO; calorie: nitrogen ratio 125:1) for an average of 33 +/- 7.5 days. TPN was started before transplantation and stopped when patients were able to eat. Caloric needs were estimated using the Harris-Benedict equation; 150% of the estimated BEE was given for the first two weeks after transplantation. The amount of TPN was gradually decreased as patients resumed their oral intake. All patients had low-normal serum carnitine levels before transplantation. There was no significant change in total or free serum carnitine levels during the course of TPN. However, in patients who had symptoms of graft vs. host reaction (GVH), the highest carnitine values during GVH (total 72.3 +/- 6.5 and free 61.2 +/- 12.4 mumol/l) were significantly higher (p < 0.001) than the baseline values (total 27.1 +/- 9.3 and free 24.9 +/- 9.6 mumol/l) or the highest non GVH values after transplantation (total 32.0 +/- 10.7 and free 29.0 +/- 10.7 mumol/l, respectively). The serum triglyceride, total cholesterol, and HDL cholesterol remained within normal range. In conclusion, bone marrow transplant patients receiving fat-based TPN have normal circulating levels of carnitine. GVH reaction caused an increase in the carnitine levels, which was probably due to increased tissue catabolism.