Oxygen consumption measurement in lymphocytes for the diagnosis of pediatric patients with oxidative phosphorylation diseases

Objectives: To evaluate the results of oxygen consumption measurement in ly mphocytes for the diagnosis and treatment monitoring of pediatric patients with oxidative phosphorylation diseases. Design and Methods: Twenty-four children with an oxidative phosphorylation disease were studied. Results were compared with those of 87 healthy childr en. Oxygen consumption measurements in digitonine-permeabilized lymphocytes incubated with pyruvate plus malate and succinate were performed in a Clar k-type oxygen electrode. Results: A total of 58% of patients showed a decreased oxygen consumption i n lymphocytes incubated with pyruvate. In 4 patients, this analysis was the unique initial biochemical test, which revealed an impaired mitochondrial energy metabolism. Significant differences were observed in lymphocytes inc ubated with pyruvate between patients and reference values (p < 0.00005), a nd in lymphocytes incubated with pyruvate before and after treatment (p < 0 .05). Conclusions: This test is useful for diagnosing oxidative phosphorylation d iseases in patients who did not have other biochemical alterations, althoug h false-negative results can be found. It is not useful for treatment monit oring. Copyright (C) 2000 The Canadian Society of Clinical Chemists.