Biomerica Inc. announced that it has launched a new patented Thiopurine methyltransferase (TPMT) test to detect patients who are at risk of developing severe or fatal side effects if treated with the class of thiopurine drugs that includes azathioprine, mercaptopurine, and thioguanine. Thiopurine drugs suppress the immune system and are used in the treatment of a wide range of diseases, such as inflammatory bowel disease, leukemia and lymphoma, autoimmune diseases and skin disorders such as psoriasis and severe eczema. They are also used to treat organ transplant patients. The most commonly used thiopurine drug is called azathioprine. It is estimated that one in every 300 people lacks TPMT, which is an enzyme that helps remove thiopurine drugs from the body when they are present. Individuals who lack the TPMT enzyme can become severely or fatally ill if treated with normal doses of thiopurine drugs because toxic levels of the drug accumulate. The new TPMT product is being launched internationally and will be sold in the U.S. only after FDA clearance.