What is a thiopurine metabolites test?

Clinical Information This test is primarily used to verify compliance, optimize therapy, and identify elevated metabolite concentrations that may result in toxicity after initiation of thiopurine drug therapy for the treatment of inflammatory bowel disease.

What does low thiopurine metabolites mean?

Thiopurine S-methyltransferase (TPMT) deficiency is a condition characterized by significantly reduced activity of an enzyme that helps the body process drugs called thiopurines. These drugs, which include 6-thioguanine, 6-mercaptopurine, and azathioprine, inhibit (suppress) the body’s immune system.

What is a thiopurine drug?

The thiopurine drugs are purine antimetabolites widely used in the treatment of acute lymphoblastic leukemia, autoimmune disorders (e.g., Crohn’s disease, rheumatoid arthritis), and organ transplant recipients. Metabolism is catalyzed by S-methyltransferase.

What is TPMT enzyme activity?

The TPMT gene provides instructions for making an enzyme called thiopurine S-methyltransferase (TPMT). This enzyme carries out a specific chemical reaction called S-methylation of a group of molecules known as aromatic and heterocyclic sulphydryl compounds.

Is thiopurine a chemotherapy?

The thiopurines, azathioprine, 6-mercaptopurine and 6-thioguanine are one of the success stories of chemotherapy. They are effective immunosuppressants and anti-cancer agents and are prescribed increasingly to treat inflammatory diseases.

What enzyme does azathioprine inhibit?

Azathioprine inhibits DNA and RNA synthesis by preventing interconversion among the precursors of purine synthesis and suppressing de novo purine synthesis.

What is the TPMT enzyme blood test for?

Why is TPMT Testing Important? Detection of individuals with low thiopurine methyltransferase (TPMT) activity who are at risk for excessive myelosuppression or severe hematopoietic toxicity when taking thiopurine drugs.

Is Thioguanine an immunosuppressant?

Azathioprine, 6-mercaptopurine, and 6-thioguanine are immunosuppressive drugs indicated in the prevention of graft rejection, and treatment of auto-immune disease or inflammatory bowel disease. Their anti-nucleotidic properties are also used for the treatment of acute leukaemia.