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Inflammatory bowel disease, azathioprine, TPMT, GSTM1, ITPA
Thiopurines ( Azathioprine (AZA) and 6 -Mercaptopurine (6-MP ) are considered a well -established therapy for patients with Inflammatory Bowel Disease (IBD) including ulcerative colitis (UC) and Crohn’s Disease (CD ). However, nearly 20% of patients discontinue thiopurines due to adverse events. Functional polymorphisms of several enzymes involved in the metab olism of thiopurine s have been linked with toxicity. The clinical value of variant carriers such as TPMT, ITPA and GSTs in predict ing toxicity and adverse events for IBD patients treated with thiopurines remains to be clarified .
To determine if variation in TPMT, ITPA and GST genotypes can predict adverse effects such as neutropenia, pancreatitis, liver enzyme elevation , as well as clinical response for patients with IBD treated with thiopurines .
Patients known to have IBD and treated with AZ A or 6MP were enrolled. Adverse effects were calculated and their correlation with TPMT, ITPA and GST genotypes was evaluated. Further, the correlation between clinical response and TPMT , ITPA and GST genotypes w ere assessed .
A total of 53 patients were enrolle d. 16/53 patients (28.6%) responded to AZA therapy. 17 patients experienced adverse events with 10 having to discontinue treatment . Three patients (5.4%) developed severe myelosuppression (WBC< 2.0 or neutrophils < 1.0). Loss of function TPMT genotype was associated with adverse events (OR 3.64, 95% CI 0.55 - 24.23, p=0.0313) . ITPA and GST polymorphisms were not associated with toxicity. GSTM1 deletion was associated with poor clinical response to therapy (OR 3.75, 95% CI 0.940 - 14.97, p= 0.1028 ), however, neither TPMT*3A nor ITPA polymorphisms were associated with clinical response.
In addition to TPMT for adverse events, genotyping for GSTM1 appears to predict clinical response in IBD patients treated with thiopurines .
2. Chocair PR, Duley JA, Simmonds HA, Cameron JS. The importance of thiopurine methyltransferase activity for the use of azathioprine in transplant recipients. Transplantation 1992 May;53(5):1051- 6.
3. Tidd DM, Paterson AR. A biochemical mechanism for the delaye d cytotoxic reaction of 6-mercaptopurine. Cancer Res 1974 Apr;34(4):738 -46.
4. Bean RH. The treatment of chronic ulcerative colitis with 6 -mercaptopurine. Med J Aust 1962 Oct 13;49(2):592- 3.
5. Brooke BN, Hoffmann DC, Swarbrick ET. Azathioprine for Crohn's disea se. Lancet 1969 Sep 20;2(7621):612- 4.
6. Cuffari C, Theoret Y, Latour S, Seidman G. 6 - Mercaptopurine metabolism in Crohn's disease: correlation with efficacy and toxicity. Gut 1996 Sep;39(3):401- 6.
7. Gisbert JP, Gomollon F, Cara C, e t al. Thiopurine methyltrans ferase activity in inflammatory bowel disease. A study on 7046 Spanish patients. Med Clin (Barc) 2005 Sep 10;125(8):281- 5.
8. Lamers CB, Griffioen G, van Hogezand RA, Veenendaal RA. Azathioprine: an update on clinical efficacy and safety in inflammatory bowel disease. Scand J Gastroenterol Suppl 1999;230:111- 5.
9. Garat A, Cauffiez C, Renault N, et al. Characterisation of novel defective thiopurine S - methyltransferase allelic variants. Biochem Pharmacol 2008 Aug 1;76(3):404- 15.
10. Lennard L. TPMT in the treatment of Crohn's disease with azathioprine. Gut 2002 Aug;51(2):143- 6.
11. Dubinsky MC, Lamothe S, Yang HY, et al. Pharmacogenomics and metabolite measurement for 6 -mercaptopurine therapy in inflammatory bowel disease. Gastroenterology 2000 Apr;118(4):705- 13.
12. Marinaki AM, Ansari A, Duley JA, et al. Adverse drug reactions to azathioprine therapy are associated with polymorphism in the gene encoding inosine triphosphate pyrophosphatase (ITPase). Pharmacogenetics 2004 Mar;14(3):181 - 7.
13. Stocco G, Martelossi S, Barabino A, et al. Glutathione -S-transferase genotypes and the adverse effects of azathioprine in young patients with inflammatory bowel disease. Inflammatory Bowel Diseases 2007 Jan;13(1):57- 64.
14. Cuffari C, Dassopoulos T, Turnbough L, Thompson RE, Bayless TM. Thiopurine methyltransferase activity influences clinical response to azathioprine in inflammatory bowel disease. Clin Gastroenterol Hepatol 2004 May;2(5):410- 7.
15. Gonzalez -Lama Y, Bermejo F, Lopez -Sanroman A, et al. Thiopurine methyl -transferase activity and azathiop rine metabolite concentrations do not predict clinical outcome in thiopurine -treated inflammatory bowel disease patients. Aliment Pharmacol Ther 2011 Sep;34(5):544- 54.
16. Ansari A, Arenas M, Greenfield SM, et al. Prospective evaluation of the pharmacogenetics of azathioprine in the treatment of inflammatory bowel disease. Aliment Pharmacol Ther 2008 Oct 15;28(8):973- 83.
17. Osterman MT, Kundu R, Lichtenstein GR, Lewis JD. Association of 6 -thioguanine nucleotide levels and inflammatory bowel disease activity: a met a-analysis. Gastroenterology 2006 Apr;130(4):1047- 53.
18. Stocco G, Cuzzoni E, De Iudicibus S, et al. Deletion of Glutathione -S-Transferase M1 Reduces Azathioprine Metabolite Concentrations in Young Patients With Inflammatory Bowel Disease. J Clin Gastroentero l 2014 Jan;48(1):43- 51.
19. Zabala -Fernandez W, Barreiro -de Acosta M, Echarri A, et al. A pharmacogenetics study of TPMT and ITPA genes detects a relationship with side effects and clinical response in patients with inflammatory bowel disease receiving Azathioprine. J Gastrointestin Liver Dis 2011 Sep;20(3):247- 53.
20. Heller T, Oellerich M, Armstrong VW, von Ahsen N. Rapid detection of ITPA 94C>A and IVS2 + 21A>C gene mutations by real -time fluorescence PCR and in vitro demonstration of effect of ITPA IVS2 + 21A>C polymorphism on splicing efficiency. Clin Chem 2004 Nov;50(11):2182- 4.
21. Gearry RB, Roberts RL, Barclay ML, Kennedy MA. Lack of association between the ITPA 94C>A polymorphism and adverse effects from azathioprine. Pharmacogenetics 2004 Nov;14(11):779 -81.
22. Booth RA, Ansari MT, Loit E, e t al. Assessment of thiopurine S -methyltransferase activity in patients prescribed thiopurines: a systematic review. Ann Intern Med 2011 Jun 21;154(12):814- 23- W-295 -8.
23. Schroeder KW, Tremaine WJ, Ilstrup DM. Coated oral 5-aminosalicylic acid therapy for mildly to moderately active ulcerative colitis. A randomized study. N Engl J Med 1987 Dec 24;317(26):1625- 9.
24. Harvey RF, Bradshaw JM. A simple index of Crohn's -disease activity. Lancet 1980 Mar 8;1(8167):514.
25. Yates CR, Kryn etski EY, Loennechen T, et al. Molecular diagnosis of thiopurine S - methyltransferase deficiency: genetic basis for azathioprine and mercaptopurine intolerance. Ann Intern Med 1997 Apr 15;126(8):608- 14.
26. Verlaan M, te Morsche RH, Roelofs HM, et al. Glutathio ne S -transferase Mu null genotype affords protection against alcohol induced chronic pancreatitis. Am J Med Genet A 2003 Jul 1;120A(1):34 -9.
27. Dervieux T, Boulieu R. Simultaneous determination of 6 -thioguanine and methyl 6 - mercaptopurine nucleotides of azath ioprine in red blood cells by HPLC. Clin Chem 1998 Mar;44(3):551- 5.
28. Chen CL, Liu Q, Pui CH, et al. Higher frequency of glutathione S -transferase deletions in black children with acute lymphoblastic leukemia. Blood 1997 Mar 1;89(5):1701- 7.
29. Stocco G, Cheok MH, Crews KR, Dervieux T, French D, Pei D, et al. Genetic polymorphism of inosine triphosphate pyrophosphatase is a determinant of mercaptopurine metabolism and toxicity during treatment for acute lymphoblastic leukemia. Clinical Pharmacology and Therapeuti cs 2009 Feb;85(2):164- 72.
30. Barabino A, Torrente F, Ventura A, Cucchiara S, Castro M, Barbera C. Azathioprine in paediatric inflammatory bowel disease: an Italian multicentre survey. Aliment Pharmacol Ther 2002 Jun;16(6):1125- 30.
31. Chouchana L, Narjoz C, Beaun e P, Loriot MA, Roblin X. Review article: the benefits of pharmacogenetics for improving thiopurine therapy in inflammatory bowel disease. Aliment Pharmacol Ther 2012 Jan;35(1):15- 36.
32. Colombel JF, Sandborn WJ, Reinisch W, et al. Infliximab, azathioprine, o r combination therapy for Crohn's disease. N Engl J Med 2010 Apr 15;362(15):1383- 95.
33. Weersma RK, Peters FT, Oostenbrug LE, et al. Increased incidence of azathioprine- induced pancreatitis in Crohn's disease compared with other d iseases. Aliment Pharmacol Th er 2004 Oct 15;20(8):843- 50.
34. Present DH, Meltzer SJ, Krumholz MP, Wolke A, Korelitz BI. 6 -Mercaptopurine in the management of inflammatory bowel disease: short - and long- term toxicity. Ann Intern Med 1989 Oct 15;111(8):641- 9.
35. Kirschner BS. Safety of azathi oprine and 6- mercaptopurine in pediatric patients with inflammatory bowel disease. Gastroenterology 1998 Oct;115(4):813- 21.
36. Gisbert JP, Gomollon F. Thiopurine -induced myelotoxicity in patients with inflammatory bowel disease: a review. Am J Gastroenterol 2008 Jul;103(7):1783- 800.
37. Lennard L, Van Loon JA, Lilleyman JS, Weinshilboum RM. Thiopurine pharmacogenetics in leukemia: correlation of erythrocyte thiopurine methyltransferase activity and 6 -thioguanine nucleotide concentrations. Clin Pharmacol Ther 1987 Jan;41(1):18- 25.
38. Lennard L, Lilleyman JS, Van Loon J, Weinshilboum RM. Genetic variation in response to 6 -mercaptopurine for childhood acute lymphoblastic leukaemia. Lancet 1990 Jul 28;336(8709):225- 9.
39. Schutz E, Gummert J, Armstrong VW, Mohr FW, Oellerich M. Azathioprine pharmacogenetics: the relationship between 6 -thioguanine nucleotides and thiopurine methyltransferase in patients after heart and kidney transplantation. Eur J Clin Chem Clin Biochem 1996 Mar;34(3):199- 205.
40. Hindorf U, Lindqvist M, Peterson C, et al. Pharmacogenetics during standardised initiation of thiopurine treatment in inflammatory bowel disease. Gut 2006 Oct;55(10):1423- 31.
41. Reinisch W, Angelberger S, Petritsch W, et al. Azathioprine versus mesalazine for prevention of postoperative clin ical recurrence in patients with Crohn's disease with endoscopic recurrence: efficacy and safety results of a randomised, double -blind, doubl e-dummy, multicentre trial. Gut 2010 Jun;59(6):752 -9.
42. Sumi S, Marinaki AM, Arenas M, et al. Genetic basis of inosin e triphosphate pyrophosphohydrolase deficiency. Hum Genet 2002 Oct;111(4- 5):360- 7.
43. Holmes SL, Turner BM, Hirschhorn K. Human inosine triphosphatase: catalytic properties and population studies. Clin Chim Acta 1979 Oct 1;97(2- 3):143- 53.
44. von Ahsen N, Armstro ng VW, Behrens C, et al. Association of inosine triphosphatase 94C>A and thiopurine S -methyltransferase deficiency with adverse events and study drop -outs under azathioprine therapy in a prospective Crohn disease study. Clin Chem 2005 Dec;51(12):2282- 8.
45. Ek lund BI, Moberg M, Bergquist J, Mannervik B. Divergent activities of human glutathione transferases in the bioactivation of azathioprine. Mol Pharmacol 2006 Aug;70(2):747- 54.