Lipoperoxides as an index of free radical activity in bone marrow transplant recipients; preliminary observations.

Hunnisett A G, Davies S, McLaren Howard J, Gravett P J, Finn M, Gueret-Wardle D Presented at the Fourth Conference on Trace Elements in Medicine and Biology, Chamonix, France, April 5-9, 1993 (Full paper J Biol Trace Element res 1995;47:125-132) It has been previously demonstrated that the conditioning therapy given to bone marrow transplant (BMT) recipients creates a high oxidant stress, resulting in a measured reduction in antioxidants such as glutathione peroxidase (GSH-Px), vitamin E and cell peroxide fragilities. As part of a current intervention trial of antioxidant therapy (AOT) in BMT recipients, plasma malondialdehyde (MDA) concentration was measured to assess the degree of peroxidation and free radical activity. Measurements were performed before and after conditioning therapy, and then at weekly intervals after transplantation in 20 patients (10 controls and 10 AOT recipients). The MDA results were compared with concurrent measurements of more specific elements of the antioxidant pathways (GSH-Px, selenium and vitamin E). In all case MDA concentration was significantly increased after conditioning compared with baseline levels (p<0.0001), an increase which correlated inversely with GSH-Px (r=-0.81, p<0.01). The MDA concentration fell gradually after conditioning in all patients. This fall was, however, more rapid in the AOT group when compared to the controls and paralleled the gradual return towards normal levels of the other antioxidants. The change in MDA concentration occurred faster than changes in other indices, suggesting that MDA might be a better index of overall free radical activity. Although the patient numbers are small, there is some evidence to suggest that MDA may act as a prognostic marker. In 83% of the patients with a poor post-operative course and who eventually died, the MDA concentration was significantly higher than that in the successful transplants. Also the fall of MDA concentration either did not occur, or was much slower in this group of patients. This point is currently being investigated in a larger number of patients.