Workup of the Patient with Lactic Acidemia: Mitochondrial Disease

Abstract

Genetically determined causes of lactic acidemia fall into two categories: abnormalities in gluconeogenesis and defects of oxidative phosphorylation or mitochondrial disease. This distinction is important because management and prognosis are different. First of all, factitious and secondary elevations of lactic acid must be excluded, which are more common, and even D-lactic acidemia. For the evaluation of energy metabolism, lactate should be determined repeatedly throughout the day (especially before and after meals). Postprandial rise or fall in lactate gives important information. Definitive diagnosis is documented by deficiencies in activity of a growing group of enzymes and mutations in DNA, first of mitochondrial and lately also of nuclear DNA.