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 lymphocytes 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 children. Oxygen consumption measurements in digitonine-permeabilized lymphocytes incubated with pyruvate plus malate and succinate were performed in a Clark-type oxygen electrode. Results: A total of 58% of patients showed a decreased oxygen consumption in 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 incubated with pyruvate between patients and reference values (p < 0.00005), and in lymphocytes incubated with pyruvate before and after treatment (p< 0.05). Conclusions: This test is useful for diagnosing oxidative phosphorylation diseases in patients who did not have other biochemical alterations, although false-negative results can be found. It is not useful for treatment monitoring.