Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.67 (thiopurine methyltransferase)
 551 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Azathioprine is a frequently used immunosuppressant for managing inflammatory bowel disease (IBD). In recent years the hepatotoxic profile of thiopurines has been recognised. We report the case of a 40-year-old man with Crohn's disease treated with azathioprine. After taking azathioprine (2.2 mg/kg daily) for two years, his liver function tests were found to be elevated. Moreover, a myelodepression was established as platelet and leucocytes counts were lowered. The 6-thioguaninenucleotide level was 738 picomoles/8 x 10(8) per red blood cell, which is well above the proposed upper limit of efficacy and associated with an increased risk of developing a myelodepression. Genotyping of the enzyme thiopurine methyltransferase revealed no mutant alleles. The ultrasonography and CT scan showed signs of portal hypertension (spleen 17 cm and widened splenic vein). A liver biopsy was performed and an incomplete septal liver cirrhosis was found. An upper endoscopy revealed oesophageal varices (grade 2 to 3). Autoimmune and viral liver diseases were ruled out by laboratory parameters. After cessation of therapy, all laboratory parameters normalised. Therefore, azathioprine is believed to be the causative factor for inducing the liver cirrhosis. Continuous monitoring of patients taking thiopurines is mandatory. The role of 6-thioguaninenucleotide levels in inducing myelotoxicity and hepatotoxicity is discussed.
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PMID:Myelotoxicity and hepatotoxicity during azathioprine therapy. 1639 13

Nodular regenerative liver hyperplasia (NRH) is a very rare but potentially severe complication of thiopurine-containing immunosuppressive therapy for autoimmune disorders, organ transplantation, and/or oncological treatment. Here we report a case of a 40-year-old female patient with Crohn's disease and genetic hypercoagulability disorder-factor V Leiden, who in the course of azathioprine immunosuppressive treatment for inflammatory bowel disease developed NRH, which was clinically manifested by thrombocytopenia and delicate hepato-splenomegaly. Moreover, her endoscopic examination of upper gastrointestinal tract demonstrated esophageal varices. Genetic analysis revealed heterozygous genotype (*1/*3A) of thiopurine S-methyltransferase (TPMT), a key enzyme of thiopurines' metabolism, which results in lower activity of TPMT enzyme, thereby making our patient more susceptible to azathioprine-related hepato and myelotoxicity development. Treatment was started with the immediate cessation of azathioprine therapy, and administration of propranolol as primary prophylaxis for bleeding from esophageal varices. Currently (3 years after diagnosis) remission of Crohn's disease is achieved, however, progression of features of portal hypertension is observed. Propranolol administration is continued and the patient is constantly monitored in our Department. Our Case Study highlights the clinical difficulties and challenges associated with diagnosing of azathioprine-induced NRH, as well as, supports previous observations that hypercoagulability disorders and abnormal TPMT activity may contribute to NRH development.
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PMID:Nodular regenerative liver hyperplasia as a complication of azathioprine-containing immunosuppressive treatment for Crohn's disease. 2072 8