Biochemical monitoring of the treatment in paediatric patients with mitochondrial disease

Treatment strategies in mitochondrial diseases consist of several drugs tha t diminish the deleterious effects of the abnormal respiratory chain functi on, reduce the presence of toxic agents or correct deficiencies in essentia l cofactors. In this study we evaluated the monitoring of tocopherol, carni tine and ubiquinone concentrations in a group of paediatric patients during a follow-up period of 18 months and the response to treatment of these pat ients by means of the determination of blood lactate, plasma alanine and ox ygen consumption by lymphocytes in relation to the clinical status of the p atients. Tocopherol, carnitine and ubiquinone concentrations were easily co rrected with therapy. Blood lactate proved the best biochemical tool to ass ess the response to treatment in paediatric patients. According to our resu lts, improvement or stabilization of the clinical course seems to be more r elated to the biochemical or molecular defect than to the effectiveness of the treatment.