Patel et al. Molecular Cytogenetics 2014, 7(Suppl 1):P98 http://www.molecularcytogenetics.org/content/7/S1/P98 POSTER PRESENTATION Open Access Influence of CYP3A5 polymorphism on tacrolimus drug dosing in Indian renal allograft recipients: initial experience Mohan Patel1*, Manoj Gumber1, Vivek Kute1, Pankaj Shah1, Himanushu Patel1, Hargovind Trivedi1, Aruna Vanikar2, Jayesh Sheth3 From International Conference on Human Genetics and 39th Annual Meeting of the Indian Society of Human Genetics (ISHG) Ahmadabad, India. 23-25 January 2013 Background Tacrolimus (Tac) is the mainstay of standard immunosuppressive regime in renal transplantation today. However, it needs regular drug level monitoring in view of narrow therapeutic window to keep blood level in therapeutic range. The objective of the study was to assess the potential influence of a functional polymorphism in CYP3A5*3 gene on dose requirements and trough blood levels of tacrolimus in renal transplant patients Materials & methods This prospective observational study included 20 patients of end stage renal disease who underwent renal transplantion and a follow up of 1 year at our hospital. All the patients were started on standard immunosuppressive regime of Tacrolimus-Mycophenolate mofetil along with steroids with a starting dose of Tac 0.08 mg/kg/day. Genotype of CYP3A5 was studied in 20 patients requiring low dose of Tac. At 7th and 30th day, and 3 monthly after transplant, Tac dosages (mg/kg/d), were adjusted based on blood levels and complications. Polymerase chain reaction, followed by restriction fragment length polymorphism analysis was used for genotyping CYP3A5*3 gene (A6986G) in intron 3. Results Out of 20 patients (17 males and 3 females) included in the study, 16 had live related renal transplantation and 4 had diseased donor renal transplantation. Out of 1 Department of Nephrology and Clinical Transplantation, Institute of Kidney Diseases and Research Center, Dr HL Trivedi Institute of Transplantation Sciences, Ahmedabad, India Full list of author information is available at the end of the article 20 patients 16 were found to have CYP3A5 homozygous status (A3986G polymorphism in CYP3A5*3 gene-wild allele) and 4 with heterozygous status. Patients of CYP3A5 homozygous status had mean Tac level of 16.84 ng/dL, median of 15.5 ng/dL (range- 13.2-25 ng/dL) on 7th day of transplant. So Tac dose was reduced to achieve TDL and mean Tac level at 30th day of transplant was 6.6 ng/dL and median of 7.4 ng/dL (range- 5.5-12.5 ng/dL). At 6th month and 12th month of transplant, mean Tac levels were 6.1 ng/dL and 5.9 ng/dL. In patients having CYP3A5 homozygous status, mean and median Tac dose after 4 weeks was 0.03 mg/kg/day (range- 0.008 to 0.05 mg/kg/ day) and mean creatinine was 1.17 mg/dL (range-0.8 to 1.4 mg/dL) after 30th day. Remaining 4 patients having CYP3A5 heterozygous status were maintaining TDL at Tac dose of 0.06 mg/kg/day. Five patients had graft biopsy during first 4 weeks of renal transplant showing acute tubular necrosis (ATN) in three patients, acute cellular rejection in one patient and cellular rejection with evidence of calcineurine inhibitor (CNI) toxicity in one patient. Conclusion This study demonstrates the usefulness of CYP3A5 genotype in transplant patients taking TacrolimusMycophenolate mofetil and also shows that majority of our patients carry mutant allele A3986G in CYP3A5*3 gene. Authors’ details Department of Nephrology and Clinical Transplantation, Institute of Kidney Diseases and Research Center, Dr HL Trivedi Institute of Transplantation Sciences, Ahmedabad, India. 2Department of Pathology and Immunohematology, IKDRC-ITS, Ahmedabad, India. 3Foundation for Research in Genetics and Endocrinology (FRIGE) Institute Of Human Genetics, Ahmedabad, India. 1 © 2014 Patel et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Patel et al. Molecular Cytogenetics 2014, 7(Suppl 1):P98 http://www.molecularcytogenetics.org/content/7/S1/P98 Page 2 of 2 Published: 21 January 2014 doi:10.1186/1755-8166-7-S1-P98 Cite this article as: Patel et al.: Influence of CYP3A5 polymorphism on tacrolimus drug dosing in Indian renal allograft recipients: initial experience. Molecular Cytogenetics 2014 7(Suppl 1):P98. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color figure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit