Abstract
6-Mercaptopurine (6-MP) and its prodrug azathioprine (AZA) are well known for their lymphocytotoxic and bone marrow suppressive effects in the management of patients with leukemia. Although their immunosuppressive properties are mediated by the active AZA antimetabolite 6-thioguanine (6-TG), its mechanism of action is largely unknown. In IBD, a significant inverse correlation has been shown between erythrocyte 6-TG metabolite levels and disease activity, further supporting the proposed immunosuppressive role for 6-TG. Since leukocytes possess quantitatively different purine metabolic pathways compared to erythrocytes, this study aims to measure lymphocyte DNA 6-TG metabolites and correlate levels with the INF-γ and IL-10 cytokine profile in patients with Crohn's disease (CD). Forty-six adult patients with CD, either naive (17) or on long-term (>4-month) AZA therapy (29), had erythrocyte and lymphocyte DNA 6-TG levels measured by reverse-phase HPLC under UV detection (6-TG, 340 nm). Lymphocyte DNA 6-TG was expressed as picomoles per milligram of DNA. Lymphocyte DNA 6-TG metabolite levels were correlated with INF-γ and IL-10 cytokine profiles using the OptEIA kit (Pharmigen). Lymphocyte DNA 6-TG metabolite levels correlate with erythrocyte 6-TG levels (P < 0.03) but not total patient leukocyte levels. Erythrocyte 6-TG metabolite levels correlated (P < 0.01) inversely with INF-γ but not IL-10 cytokine levels. This study suggests a preferential dampening of the TH1 response on exposure to 6-TG and a possible immunosuppressive mechanism of action for AZA. Future studies are needed to determine if cytokine profiles can be used to predict recalcitrant CD to AZA therapy.
Similar content being viewed by others
REFERENCES
Pearson DC, May GR, Fick GH, Sutherland LR: Azathioprine and 6-mercaptopurine in Crohn's disease: a meta-analysis. Ann Intern Med 122:132–142, 1995
O'Brien JJ, Bayless TM, Bayless JA: Use of azathioprine or 6-mercaptopurine in the treatment of Crohn's disease. Gastroenterology 101:39–46, 1991
Ewe K, Press AG, Singe CC, Stufler M, Ueberschaer B, Hommel G, Buschenfelde KHMZ: Azathioprine combined with prednisolone or monotherapy with prednisolone in active Crohn's disease. Gastroenterology 105:367–372, 1993
Present DH, Korelitz BI, Wisch N: Treatment of Crohn's disease with 6-mercaptopurine.Along-term, randomized, double-blind study. N Engl J Med 302:981–987, 1989
Elion GB: The pharmacology of azathioprine. Ann NY Acad Sci 21:401–407, 1977
Fairchild CR, Maybaum J, Kennedy KA: Concurrent unilateral chromatid damage and DNA strand breaks in response to 6-thioguanine treatment. Biochem Pharmacol 35:3533–3541, 1986
Christie NT, Drake S, Meyn RE: 6-Thioguanine induced DNA damage as a determinant of cytotoxicity in cultured hamster ovary cells. Cancer Res 44:3665–3671, 1986
Weinshilboum RN, Sladek Sl: Mercaptopurine pharmacogenetics: monogenic inheritance of erythrocyte thiopurine methyl transferase activity. Am J Hum Genet 32:651–662, 1980
Lennard L: The clinical pharmacology of 6-mercaptopurine in acute lymphoblastic leukemia. Eur J Clin Pharmacol 43:329–339, 1992
Lennard L, Lilleyman JS: Variable mercaptopurine metabolism and treatment outcome in childhood lymphoblastic leukemia. J Clin Oncol 7:1816–1823, 1989
McLeod HL, Relling MV, Liu Q, Pui CH, Evans WE: Polymorphic thiopurine methyl transferase in erythrocytes is indicative of activity in leukemic blasts from children with acute lymphoblastic leukemia. Blood 85:1897–1902, 1995
Evans WE, Homer M, Chu YQ: Altered mercaptopurine metabolism, toxic effects, and dosage requirements in a thiopurine methyl transferase deficient child with acute lymphoblastic leukemia. J Pediatr 119:985–989, 1991
Colonna T, Korelitz B: The role of leukopenia in 6-mercaptopurine-induced remission of refractory Crohn's disease.Am J Gastroenterol 89:362–366, 1993
Tiede I, Wirtz S, Strand S, Strand D, Atreya R, Mudter J, Hildner K, Holtmann M, Bartsch B, Lehr HA, Blumberg RS, Walczak H, Galle PR, Neurath M: CD28-induced Rac-GTP activiy is the molecular target of azathioprine in primary human CD4+ T-lymphocytes: a mechanism for azathioprine mediated immunosuppression in IBD based on induction of T-cell apoptosis. Gastroenterology 122:A14, 2002
Pullman WE, Elsbury S, Kobayashi M, Hapel AJ, Doe WF: Enhanced mucosal cytokine production in inflammatory bowel disease. Gastroenterology 102:529, 1992
Nakamura M, Saito H, Kasanuki J, Tamura Y, Yoshida S: Cytokine production in patients with inflammatory bowel disease. Gut 33:933–937, 1992
Chomarat P, Rissoan MC, Banchereau J, and Miossec P: Contribution of IL-1, CD14, and CD13 in the increased IL-6 production induced by in vitro monocyte-synoviocyte interactions. J Immunol 155:3645–3652, 1995
Hibi T, Ogata H, Sakuraba A: Animal models of inflammatory bowel disease. J Gastroenterol 37:409–417, 2002
Kombluth A, Sachar DB, Salomon P: Crohn's disease. In Gastrointestinal Diseases. MH Sleisenger, JS Fordtran (eds). Philadelphia, PA, WB Saunders, 1998, pp 1708–1734
Cuffari C, Theoret Y, Latour S, Seidman EG: 6-Mercaptopurine metabolism in Crohn's disease correlation with efficacy and toxicity. Gut 39:401–406, 1996
Cuffari C, Seidman EG, Latour S, Theoret Y: Quantitation of 6-thioguanine in peripheral blood leukocyte DNA in Crohn's disease patients on maintenance 6-maintenance 6-mercaptopurine therapy. Can J Physiol Pharmacol 74:580–585, 1996
Lennard L, Rees CA, Lilleyman JS. Childhood leukemia: a relationship between intracellular 6-mercaptopurine metabolites and neutropenia. Br J Clin Pharmacol 16:359–363, 1993
Dubinsky MC, Feldman E, Abreu MT, Seidman EG, Baroni D, Kornbluth A, Targan SR, Vasiliauskas EA: Idiosyncratic adverse reactions to 6-mercaptopurine and azathioprine can be averted by switching to 6-thioguanine in patients with IBD. Gastroenterology 120:A56, 2001
Dubinsky MC, Lamothe S, Yang HY, Targan SR, Sinnett D, Theoret Y, Seidman EG: Optimizing and individualizing 6-MP therapy in IBD: The role of 6-MP metabolite levels and TPMT genotyping. Gastroenterology 118;705–713, 2000
Paterson ARP, Moriwaki A: Combination chemotherapy: synergistic inhibition of L5178Y ells in culure and in vivo with 6-mercaptopurine and 6-methyl mercapopurine ribonucleotides. Cancer Res 30:2379–2387, 1970
Mawatari H, Unei K, Nishimura S, Sakura N, Ueda K: Comparative pharmacokinetics of oral 6-mercaptopurine and intravenous 6-mercaptopurine riboside in children. Pediatr Int 43:673–677, 2001
Ansari AR, Marinaki T, Arenas M, Sumi S, Shobowale-Bakre El-M, Lewis K, Woodman I, Duley J, Sanderson J: Mutations in the ITPA gene predicts intolerance to azathioprine. Gastroenterology 124:A11, 2003
Hildner K, Marker-Hermann E, Schlaak JF, Becker C, Germann T, Schmitt E, Meyer Zum Buschenfelde KH, Neurath MF: Azathioprine, mycophenolate mofetil, and methotrexate specifically modulate cytokine production by T cells. Ann NY Acad Sci 859:204–207, 1998
Van den Berg AP, Twilhaar WN, Corver W, Geerts AB, Mesander G, Klompmaker IJ, Sloof MJH, The TH, de Leij LH: Cyclosporine A is associated with a shift of the TH1/TH2 balance in liver transplant patients. Transplant Proc 30:2378–2379, 1998
Durez P, Abramowicz D, Gerard C, Van Mechelen M, Amraoui Z, Dubois C, Leo O, Velu T, Goldman T: In vivo induction of interleukin 10 by anti-CD3 monoclonal antibody or bacterial lipopolysaccharide: Differential modulation by cyclosporin A J Exp Med 177:551–555, 1993
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cuffari, C., Li, D.Y., Mahoney, J. et al. Peripheral Blood Mononuclear Cell DNA 6-Thioguanine Metabolite Levels Correlate with Decreased Interferon-γ Production in Patients with Crohn's Disease on AZA Therapy. Dig Dis Sci 49, 133–137 (2004). https://doi.org/10.1023/B:DDAS.0000011614.88494.ee
Issue Date:
DOI: https://doi.org/10.1023/B:DDAS.0000011614.88494.ee