Tacrolimus Therapeutic Drug Monitoring in Vietnamese Renal Transplant Recipients

Background: Use of tacrolimus (Tac) is pivotal to renal transplant (RT) immunosuppressive maintenance regiments. The most frequently used means of Tac monitoring is the measurement of the trough concentration (C0) in whole blood to maintain drug efficacy and minimize the consequences of overexposure. Most previous studies focused on therapeutic drug monitoring of Tac in renal transplant recipients and assessed the clinical response of patients. Our study aimed to describe a real Tacrolimus therapeutic drug monitoring transplantation and determine the clinical outcomes in Vietnamese adult renal transplant recipients. Methods: This retrospective study including 114 adult renal transplant patients (89 men and 25 women) with a mean age of 35.4 ± 8.98 years has been performed from August 2012 to March 2018 at Military Hospital 103 (Vietnam). Tac trough concentrations were adjusted according to the target range proposed by the European consensus conference on tacrolimus optimization. Samples for determination of tacrolimus blood levels were subdivided according to the posttransplantation period into three groups (0- 3 months (G1), 3-12 months (G2) and over 1 year (G3). Median Years of follow-up was 15.4 months [range 0.233 to 68.4 months]. Results: A total of 3037 blood samples for the determination of tacrolimus trough concentration were obtained. Median concentrations were 6.7 (4.5 – 10.2) ng/ml, 6.4 (5.1 – 8.3) and 5.6 (4.5 to 7.1) ng/ml for G1, G2, G3, respectively. After transplantation, three acute rejection (AR) events were documented (Cellular AR: 2, Humoral AR: 1). Cytomegalovirus, BK polyomavirus, Hepatitis B virus and Hepatitis C virus were detected in 7, 4, 7 and 3 renal post- transplant recipients, respectively. There were 5 patients with post-transplant diabetes (NODAT) and all of them had to convert to cyclosporine. 6 patients developed chronic kidney disease (CKD) after transplantation and 2 case with Tac-associated nephrotoxicity with proven biopsy. This observational study provided a real Tacrolimus therapeutic drug monitoring transplantation in Vietnamese renal transplant recipients. Main outcomes were acute rejection, post-transplant viral infections, neurotoxicity, NODAT, CKD, and Tac-associated nephrotoxicity.