RBC Transketolase Activity (For Thiamine Deficiency)

Yes — transketolase is thiamine‑dependent. It requires thiamine’s active form, thiamine pyrophosphate (TPP), as a cofactor (with magnesium as a stabilizer) to catalyze two‑carbon transfers in the pentose phosphate pathway. Low thiamine/TPP reduces transketolase activity; erythrocyte transketolase activation is used clinically to detect deficiency. Deficiency may impair nucleotide synthesis and redox balance.

Erythrocyte transketolase activity is characteristically low in thiamine (vitamin B1) deficiency. Thiamine pyrophosphate is a required cofactor for transketolase (pentose phosphate pathway) and for pyruvate dehydrogenase and α‑ketoglutarate dehydrogenase; the decreased transketolase activity (often measured in red cells) is a sensitive clinical marker and rises after thiamine administration.

Red blood cell (RBC) transketolase activity measures the function of the enzyme transketolase in erythrocytes, which requires thiamine (vitamin B1) as a cofactor. Low baseline activity or a marked increase after adding thiamine pyrophosphate suggests thiamine deficiency. It’s used clinically to assess functional B1 status and to monitor response to supplementation, especially in malnutrition or alcohol-related risk.

Erythrocyte transketolase activity is used to assess thiamine (vitamin B1) deficiency. Transketolase is a thiamine pyrophosphate–dependent enzyme; low baseline activity and a marked increase after adding thiamine pyrophosphate indicate deficiency. This test helps diagnose deficiency in malnutrition, chronic alcoholism, malabsorption, or unexplained neurological or cardiac signs. Results can guide thiamine supplementation; an activation coefficient >1.25 is typically diagnostic.

Diagnose suspected thiamine deficiency with clinical assessment (history, signs of beriberi or Wernicke) plus laboratory tests: whole-blood thiamine (thiamine diphosphate/TDP) measured by HPLC or erythrocyte transketolase activity with activation coefficient. Plasma or urine thiamine can be supportive but are less reliable. In acute cases, prompt therapeutic thiamine trial and specialist input are indicated; interpret labs alongside clinical findings.

Transketolase is a thiamine-dependent enzyme in the non-oxidative branch of the pentose phosphate pathway. It transfers two-carbon units between sugar phosphates, interconverting pentoses and hexoses to generate ribose-5-phosphate for nucleotide synthesis and to balance carbohydrate metabolism with glycolysis. Erythrocyte transketolase activity is also used clinically to assess thiamine (vitamin B1) status.