Type B Lactic Acidosis Secondary to Thiamine Deficiency in a Child With Malignancy

Abstract

Type B lactic acidosis is an underrecognized clinical entity that must be distinguished from type A (hypoxic) lactic acidosis. We present the case of a 4-year-old boy with medulloblastoma who presented with lactic acidosis in the setting of septic shock. His hyperlactatemia persisted to high levels even after his hemodynamic status improved. After administration of intravenous thiamine, his lactate level rapidly normalized and remained stable. It was determined that his total parenteral nutrition was deficient in vitamins due to a national shortage. Because thiamine is an important cofactor for pyruvate dehydrogenase, he was unable to use glucose through aerobic metabolism pathways. We briefly review type A versus type B lactic acidosis in this case report.

Lactic acidosis: an update

“…The lactic acidosis associated with MELAS (mitochondrial epilepsy, lactic acidosis and stroke-like episodes) is due to a mutation in the MT-TL1 gene, which encodes the mitochondrial tRNA (Leu(UUR)), resulting in impaired mitochondrial energy production [50]. Thiamine deficiency is also a recognised cause of type B lactic acidosis since thiamine is an important cofactor for pyruvate dehydrogenase and aerobic glycolysis [51,52].…”

B-Cell Lymphoma, Thiamine Deficiency, and Lactic Acidosis

“…Th erefore, its defi ciency promotes anaerobic metabolism, which results in the production of lactate ( 3 ). Only a few reported cases illustrate this phenomenon in patients with lymphomas ( 4,5 ). Th e cases have generally been reported in pediatric patients receiving parenteral nutrition without vitamin supplementation.…”

Clinical use of plasma lactate concentration. Part 1: Physiology, pathophysiology, and measurement

“…Thiamine deficiency (vitamin B 1 ) is an uncommon but well‐documented cause of hyperlactatemia . Thiamine plays an important role in several metabolic pathways after conversion to thiamine pyrophosphate .…”

“…62,[145][146][147] Thiamine deficiency Thiamine deficiency (vitamin B 1 ) is an uncommon but well-documented cause of hyperlactatemia. [148][149][150][151][152][153][154][155] Thiamine plays an important role in several metabolic pathways after conversion to thiamine pyrophosphate. 22 Thiamine pyrophosphate is a cofactor in the PDH complex, alpha-ketoglutarate dehydrogenase in the TCA cycle, transketolase in the pentose phosphate pathway, and ketoacid dehydrogenase.…”