Serum glutamic-pyruvic transaminase (SGPT) or alanine aminotransferase (ALT) is an enzyme present primarily in the liver, though also in much smaller amounts in the kidneys, heart, and muscles. Raised levels in the blood indicate an injury to liver cells, which may be due to viruses, alcohol, drugs, metabolic disorders, genetic disease etc.
Among the most common reactions to allopurinol (seen in more than 1% of users) are a rise in alkaline phosphatase, serum glutamic-oxaloacetic transaminase (SGOT, aspartate aminotransferase AST) and SGPT (ALT) due to liver damage. You need to discuss with your doctor the need for the medicine as merely a rise in uric acid levels without any symptoms does not warrant therapy as this is neither beneficial nor cost-effective and, generally, is not recommended because of the risk involved.