What is a Tpmt blood test used for?
It is often used to monitor drug treatments that are known to affect the bone marrow. TPMT enzyme activity is measured in red blood cells, so if you have recently received a transfusion of blood, the results of this test may be inaccurate.
What does Tpmt do to azathioprine?
Patients with TPMT deficiency treated with standard doses of azathioprine or 6-mercaptopurine are at significantly increased risk of myelosuppression, bleeding, infection, and death associated with increased levels of cytotoxic 6-thioguanine nucleotide levels in the red blood cells.
What should I check before starting azathioprine?
A further 10% of people have lower than normal TPMT and are likelier than people with normal activity to develop bone marrow suppression. Testing TPMT activity before starting azathioprine can identify people who are TPMT deficient and who should not receive the drug.
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.
Is 50mg of azathioprine a lot?
The usual dose is 150-200 mg a day but the dose can vary depending on your weight and tolerance of the medication. Start with one 50 mg tablet daily usually in the morning with a meal. After one week, you should have your blood drawn.
Why is azathioprine bad for you?
Azathioprine may increase your risk of developing certain types of cancer, especially skin cancer and lymphoma (cancer that begins in the cells that fight infection). If you have had a kidney transplant, there may be a higher risk that you will develop cancer even if you do not take azathioprine.
What are the most common side effects of azathioprine?
What are the possible side effects of azathioprine (Imuran®)?
- Increased stomach irritation, abdominal pain.
- Nausea and vomiting.
- Changes in hair color and texture, along with hair loss.
- Loss of appetite.
- Blood in the urine or stool.
- Unusual bruising.
- Fatigue.
- Development of mouth sores and ulcers.
Is thiopurine a chemotherapy?
Abstract. 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 is TPMT used to treat?
It is also commonly used for organ transplant recipients and when a diagnosis of Crohn’s disease has been confirmed. The purine antimetabolites might also be used should acute lymphoblastic leukemia need to be treated. A doctor may ordered a phenotype blood test or a genotype blood test to receive the needed TPMT results.
What does a normal TPMT test result mean?
Normal results mean that a doctor can treat a patient with a standard dose of a thiopurine drug on a regular basis. There are no counter-indications of a TPMT blood test being above average, although it is believed that having high levels of enzyme activity could prevent a thiopurine drug being as effective as it could be.
What is the NT (NUDT15 and TPMT) panel?
RPRD’s comprehensive NT (NUDT15 and TPMT) Panel investigates all clinically relevant variants of both NUDT15 (9 alleles) and TPMT genes (10 alleles), in a single test. Compared to testing only a limited number of common variants, the NT Panel yields thorough dosing guideline for thiopurines with high accuracy.
What are TPMT and NUDT15 genes?
Variants in the TPMT and/or NUDT15 genes are associated with an accumulation of cytotoxic metabolites leading to increased risk of drug-related toxicity with standard doses of thiopurine drugs. These effects on thiopurine catabolism can be additive. Inheritance: Autosomal codominant.