ABCB1、CYP3A4、CYP3A5、POR基因多型性對肝臟移植病人tacrolimus血中濃度之影響

Abstract

研究背景與目的： 臨床上發現肝臟移植病人，即使服用相同劑量的tacrolimus（TAC），個體間及個體內的血中谷濃度差異還是很大。在過去有許多研究發現不同因素會影響TAC的藥動學或血中濃度，但在台灣肝臟移植病人，尚未有研究不同因素及基因對TAC的影響，也沒有合併臨床因素及基因的研究，故本研究將所有可能影響TAC藥動學或血中濃度的臨床與基因因素納入分析，探討台灣肝臟移植病人各種因素及基因對於TAC劑量校正谷濃度的影響。 方法： 本研究分兩步驟分析：首先為受贈者臨床因素分析，再來為合併受贈者臨床因素與基因多型性的分析。病人納入條件包含在2008年1月1日至2015年7月31日肝臟移植的病人，並且在移植後使用TAC作為免疫抑制劑且須持續服用至少6個月，有檢測特定基因多型性，此外移植時的年齡須介於20到 65歲；排除條件包含再移植或多重器官移植、非亞裔以及人類免疫缺乏病毒反應呈陽性的病人；經過篩選後的病人，在回門診期間，自願提供檢體做基因檢測者則納入本試驗分析。TAC用劑量校正谷濃度（dose normalized trough concentrations，dnC0；與dosing weight and dose normalized trough concentrations，dnC0/DW）來表示，使用三個評估點：移植手術住院期間、移植後3個月以及移植後6個月。統計方法使用單變項分析因素及基因，當其p值＜0.2則放入多元迴歸分析，並用逐步選取法找出顯著影響（p＜0.05）TAC劑量校正血中濃度的因素，其他統計方法包含獨立樣本t檢定、ANOVA（analysis of variance）、Chi-squared test以及Fisher's exact test。 結果： 本研究納入123個肝臟移植病人，首先分析臨床因素，移植手術住院期間的多元迴歸分析，發現會顯著影響TAC dnC0或dnC0/DW的因素有TAC的劑型（Prograf ®或Advagraf ®）、direct bilirubin值、活體或屍體肝臟器官移植、PPI之使用以及hematocrit（Hct）值。在移植後3個月的多元迴歸分析，發現會顯著影響TAC dnC0或dnC0/DW的因素有Hemoglobin（Hb）、AST（aspartate aminotransferase）、TAC的劑型（Prograf ®或Advagraf ®）、感染以及BUN值。在移植後6個月的多元迴歸分析，發現會顯著影響TAC dnC0或dnC0/DW的因素有AST、total bilirubinu以及Hb。這些因素的個別解釋力範圍落在3-14％之間。 接者合併受贈者臨床因素及基因多型性分析，發現在移植後的三個評估點，一致顯示會顯著影響TAC dnC0與dnC0/DW的基因是CYP3A5*3，解釋力位於8-13％之間。將病人分成CYP3A5表現型和CYP3A5非表現型，CYP3A5非表現型的TAC dnC0與dnC0/DW是CYP3A5表現型的1.5至1.8倍。將病人分成CYP3A5*1/*1、CYP3A5*1/*3及CYP3A5*3/*3，CYP3A5*3/*3的TAC dnC0與dnC0/DW是CYP3A5*1/*1的2.2至2.7倍。其他顯著臨床因素跟一開始的臨床因素分析一樣，但納入基因之後整體的解釋力有上升，從原本的20％至26％變為33％至37％。此外，TAC劑量校正谷濃度隨著移植後的時間而增加， 結論： 在肝臟移植的病人，移植後六個月內，納入受贈者臨床與基因因素之迴歸分析顯示：顯著影響TAC dnC0或dnC0/DW的臨床因素有TAC的劑型（Prograf ®或Advagraf ®）、屍體或活體器官移植、PPI之使用、Hb、Hct、BUN、AST、bilirubin以及感染。基因型的部分，受贈者的CYP3A5基因變異在肝臟移植後的3個評估點皆會顯著影響TAC的dnC0與dnC0/DW。由當上述因子有顯著改變時，需要密切監測病人的TAC血中濃度。

Background： The large interindividual and intraindividual variations of tacrolimus (TAC) dose requirement are often observed in liver transplant recipients. According to the literature, many factors affected the pharmacokinetics (PK) of TAC. However, there was no study on the clinical and genetic factors analysis in liver transplant patients Taiwan. This study investigates clinical and genetic factors that significantly affected the pharmacokinetics of TAC in Taiwanese liver transplant recepients. Methods； The analysis was divided into two steps. Firstly, clinical factors of transplant recipients were analyzed. Then genetic polymorphisms of recepients were incorporated in the analyses. The cohort included liver transplant recipients who underwent transplants between January 1, 2008, and July 31, 2015, received TAC as immunosuppressant for at least 6 months, were tested specific genetic polymorphisms and transplanted at the age of 20 to 65 years. Exclusion criteria were retransplantation, multiorgan transplantation, non-Asian, and human immunodeficiency virus (HIV) positive patients. The concentrations of TAC were dose normalized, including dnC0 (dose normalized trough concentrations) and dnC0/DW (dosing weight and dose normalized trough concentrations). This study evaluates the dnC0 and dnC0/DW of TAC at three time points: the last C0 of steady state during hospitalization for transplant surgery, 3 months after transplant and 6 months after transplant. Covariates (clinical factors and genetic factors) with a p value of <0.20 in a univariate regression analysis were retained and entered into the multivariate regression analysis. Subsequently, multivariate regression analysis was performed with selected factors using a stepwise procedure. Other methods for statistical analysis include independent t-test, ANOVA (analysis of variance), Chi-squared test and Fisher's exact test. Result： A total of 123 liver transplant recipients were enrolled in the study. During hospitalization for transplantation, dosage form of TAC, direct bilirubin, living or deceased liver organ, PPI use and hematocrit (Hct) were significantly associated with TAC dnC0 or dnC0/DW. Three months after transplant, hemoglobin (Hb), aspartate aminotransferase (AST), dosage form of TAC, infection and blood urea nitrogen (BUN) were significantly associated with TAC dnC0 or dnC0/DW. Six months after transplant, AST, total bilirubin and Hb were significantly associated with TAC dnC0 or dnC0/DW. The coefficient of determination of individual factors were 314 %. Genetic polymorphisms of recepients were then incorporated in the analysis. After multiple regression with stepwise procedure, CYP3A5*3 was significantly associated with TAC dnC0 or dnC0/DW at all three time points and the coefficient of determination were 813%. TAC dnC0 and dnC0/DW of CYP3A5 non-expressers are 1.51.8 times of those in the CYP3A5 expressers. TAC dnC0 and dnC0/DW in patients with CYP3A5*3/*3 are 2.22.7 times of those with CYP3A5*1/*1. Clinical factors were the same as the initial analysis for clinical factors. But the coefficient of determination increased from 2026% to 3337%. Conclusion: Dosage form of TAC (Prograf ® or Advagraf ®), living or deceased liver organ, PPI use, Hb, Hct, BUN, AST, bilirubin and infection were significantly associated with TAC dnC0 or dnC0/DW in liver transplant recipients within 6 months after transplantation. CYP3A5*3 of liver transplant recipients was significantly associated with TAC dnC0 or dnC0/DW for all time points. TAC C0 should be closely monitored when there is a change in the factors mentioned above.