Pharmacokinetics of tacrolimus in living donor liver transplant and deceased donor liver transplant recipients

INTRODUCTION: Hepatic dysfunction is an important determinant of the clearance of tacrolimus; however, the impact of reduced hepatic mass in living donor liver transplant (LDLT) patients on the drug exposure and clearance of tacrolimus is not known. AIM.: The aim of the present study is to compare the dosage, concentration and pharmacokinetics parameters of tacrolimus between LDLT and deceased donor liver transplant (DDLT) recipients. PATIENTS AND METHODS: Daily doses used and trough concentrations measured were compared in 12 LDLT and 12 DDLT patients. Multiple blood samples were taken over one dosing interval after oral tacrolimus administration, and pharmacokinetics differences were compared. RESULTS: The mean tacrolimus dosage in first 14 postoperative days was (0.06 mg/kg/day) for LDLT and (0.09 mg/kg/day) for DDLT (P=0.0001). Despite the lower doses used, mean trough concentration was significantly greater in LDLT as compared with DDLT (8.8+/-2.5 ng/mL vs. 6.79+/-1.5 ng/mL, respectively, P=0.013). On the day of the pharmacokinetic study, minimum Concentration (Cmin), 12-hr postdose concentration (Clast), and average concentration (Cavg) were significantly greater in LDLT as compared with DDLT (LDLT: 6.6+/-2.4 ng/mL, 7.2+/-1.8 ng/mL, 8.9+/-3.0 ng/mL; DDLT: 4.3+/-1.0 ng/mL, 4.9+/-1.6 ng/mL, 5.9+/-1.4 ng/mL, P=0.02, 0.04, and 0.02, respectively). Dose normalized AUC was 37.7% greater and clearance, 47.5% lower in LDLT as compared with DDLT. CONCLUSION: Although not statistically significant, the dose normalized AUC was 37.7% greater and clearance 47.5% lower in LDLT as compared with DDLT. An initial tacrolimus dose reduction of about 30-40% may be prudent in LDLT compared with DDLT recipients.     

Living donor liver transplant recipients achieve relatively higher immunosuppressant blood levels than cadaveric recipients

Two recent brief reports suggest that recipients of living donor liver transplants achieve higher levels of immunosuppressive agents than cadaveric (CAD) liver transplant recipients administered the same dose. These results could have important implications regarding the dosing of immunosuppressives in living donor liver transplant recipients. We report our findings relative to immunosuppressive doses and levels in a cohort of 46 living donor liver transplant recipients. Immunosuppressive blood levels and doses were recorded weeks 1, 2, 3, and 4 and months 2, 3, 4, 5, and 6 for 46 living donor liver transplant recipients and 66 matched CAD liver transplant recipients who underwent transplantation between August 1997 and May 2001. The ratio of level to dose also was recorded at each interval. The mean overall cyclosporine A dose was similar in living donor liver transplant recipients (323 mg/d) compared with CAD recipients (344 mg/d; P = not significant [NS]). The mean overall tacrolimus dose was 15% lower in patients who underwent living donor liver transplantation (LDLT; 5.7 mg/d) than CAD transplantation (6.7 mg/d), although statistical significance was not achieved (P = .08). The mean overall cyclosporine A level was 18% higher in those undergoing LDLT (275 ng/mL) than CAD transplantation (234 ng/mL; P = .015). The mean overall tacrolimus level was the same in living donor liver transplant recipients (10.8 ng/mL) and CAD recipients (10.2 ng/mL; P = NS). The overall cyclosporine A level-dose ratio was 26% higher for those undergoing LDLT (0.83) than CAD transplantation (0.66; P = .01). The overall tacrolimus level-dose ratio was 26% higher for those undergoing LDLT (1.82) than CAD transplantation (1.44; P = .01). In conclusion, (1) living donor liver transplant recipients achieve higher blood levels of tacrolimus and cyclosporine A for a given dose compared with CAD recipients, and (2) this difference is observed up to 6 months after transplantation, when hepatic regeneration is completed. (Liver Transpl 2002;8:212-218.)     

Daclizumab induction therapy associated with tacrolimus-MMF has better outcome compared with tacrolimus-MMF alone in pediatric living donor liver transplantation

AIMS: Immunosuppression therapy for the control of immunologic rejection is a key aspect in liver transplantation. The objective of this study was to evaluate induction therapy with daclizumab (DAC) in living donor liver transplantation (LDLT) in children. METHODS: We compared 2 different immunosuppression protocols in 30 children undergoing LDLT. The patients were divided into 2 groups: 12 patients received tacrolimus with mycophenolate mofetil (TAC-MMF), and 18 patients received tacrolimus with MMF and DAC induction therapy at days 0 and 14 after LDLT (DAC-TAC-MMF). Both groups were similar with regard to age, sex, weight, and indication for liver transplantation. The incidence of biopsy-proved rejection episodes, posttransplantation lymphoproliferative disease (PTLD), and renal dysfunction were evaluated. Tacrolimus levels at posttransplantation day 14 and at 2 months after transplantation were compared in the 2 groups. RESULTS: Acute rejection episodes were observed in 8 patients in the TAC-MMF group (66%), and none in the DAC-TAC-MMF group (0%; P < .05). Neither PTLD nor renal dysfunction was seen in any patient. Mean Tacrolimus level on posttransplantation day 14 was 10.67 +/- 5.4 ng/mL in the TAC-MMF group and 5.65 +/- 3.6 ng/mL in the DAC-TAC-MMF group (P < .05). After the second month the mean tacrolimus levels were 7.2 +/- 2.9 ng/mL and 6.8 +/- 3.5 ng/mL in the TAC-MMF and DAC-TAC-MMF groups, respectively. (P = NS). CONCLUSION: Induction therapy with DAC is safe and associated with a lower incidence of rejection episodes among children undergoing LDLT.     

Pharmacokinetics of mizoribine in adult living donor liver transplantation

We investigated the pharmacokinetics of mizoribine in the acute phase after adult living donor liver transplantation (LDLT). Between February 2004 and October 2009, 16 recipients received immunosuppressive therapy that included mizoribine (100 to 200 mg/d) after undergoing LDLT. We determined the serum levels of mizoribine before (C0) and 3 (C3), 4 (C4), and 10 (C10) hours after administration on postoperative days 3, 7, and 21. We assessed area under the concentration time curve (AUC) (hour · μg/mL), normalized serum concentration (NSC) at C0 [concentration (μg/mL)/dose (mg/kg body weight)], and estimated glomerular filtration rate (eGFR). The mizoribine concentration showed increases at C3 and C4 followed by a decrease at C10 on all days. AUC was 4.3, 5.9, and 8.3 in the 200-mg/d dose group on days 3, 7, and 21, respectively. NSC at C0 increased for 3 weeks after LDLT. There was a significant correlation between the NSC at C0 and eGFR on day 21, but not on days 3 and 7. There were no correlations between the NSC at C0 and either aspartate aminotransferase, total bilirubin, albumin, trough cyclosporine, or trough tacrolimus on any day. The pharmacokinetics of mizoribine in the acute phase after LDLT seems to be affected by postoperative day and renal function.     

The renal-sparing efficacy of basiliximab in adult living donor liver transplantation.

The purpose of this study is to find out whether basiliximab administration will improve postoperative renal function by delaying the start of tacrolimus and decreasing of dosage requirement for tacrolimus in adult living donor liver transplantation (LDLT). Forty-five adult LDLT recipients were enrolled in the study. The induction group (n = 27) was given basiliximab 20 mg on days 0 and 4; tacrolimus administration was delayed until renal function improved. The control group (n = 18) did not receive basiliximab; tacrolimus was given on the first postoperative day. Trough levels of tacrolimus in the induction and control groups were aimed to be maintained at 5-10 ng/ml and 10-15 ng/ml during the first week after transplant, respectively. The median follow-up was 22 months (range 10-34 months). The preoperative conditions were poorer in the induction group (Child C, 56% vs. 33%, P = 0.01; UNOS 2a, 15% vs. 0%, P = 0.02). The intraoperative blood loss was also higher in the induction group than in the control group (median 2,180 ml vs. 495 ml, P < 0.01). The median delay in tacrolimus administration in the induction group was 36 hours (range 24-108 hours). Serum creatinine levels at second and third postoperative months were significantly lower in the induction group. The creatinine clearance rate in the induction group was higher at the third month posttransplant (median 72 vs. 57 ml/minute, P = 0.04). The incidence of renal insufficiency was significantly lower in the induction group at the third month posttransplant (26% vs. 67%, P < 0.01). Blood cholesterol level at the sixth month posttransplant was lower in the induction group (median 152 vs. 196 mg/dl P = 0.03). The incidences of acute cellular rejection, bacteremia, and cytomegalovirus (CMV) infection were similar in both groups. In conclusion, for pretransplant critical patients with more intraoperative blood loss, basiliximab induction could prevent early renal dysfunction by delaying the start of tacrolimus and reducing the dose requirement of tacrolimus without increasing graft rejection and infection. Furthermore, it also improved renal function as well as lowered cholesterol levels within 6 months after transplantation.     

Preliminary experience with alemtuzumab (Campath-1H) and low-dose tacrolimus immunosuppression in adult liver transplantation

BACKGROUND: The administration of alemtuzumab (Campath-1H [C1H]; Berlex Laboratories, Montville, NJ) at transplantation prevents a vigorous immune response and is believed to allow a gradual engagement of the host immune system. We report our preliminary experience with C1H and tacrolimus (Tac) immunosuppression in adult liver transplantation. METHODS: We administered C1H and low-dose Tac to 40 adult recipients of cadaveric liver allografts between December 2001 and April 2003. A control group who met the same eligibility criteria consisted of 50 liver transplant recipients treated with our standard Tac and steroids protocol. RESULTS: Baseline characteristics and patient and graft survival were similar (P >0.15). The incidence of acute rejection was significantly lower during the first 2 months posttransplantation (P =0.002) and slightly lower overall in the study group versus the control group at 12 months (46% vs. 55%, P =0.12, log-rank test). Median time to rejection among those experiencing rejection was significantly longer in the study group versus control group (2.76 vs. 0.34 months, P =0.0007). The mean Tac dose, 12-hr trough level, and percentage of patients receiving maintenance steroids were significantly lower in the group receiving C1H and Tac (P <0.0001 during the first 3 months, P <0.05 thereafter), as were the mean creatinine levels (P <0.05) and incidence of nephrotoxicity (P =0.004, conversion from Tac to other agents). Finally, in the group receiving C1H/Tac, patients with an average Tac trough level less than 6.5 ng/mL during the first 2 months post-transplantation demonstrated a significantly higher rejection rate beyond that time (P =0.02). CONCLUSION: C1H and low-dose Tac seems to be at least as effective as our standard Tac and steroids regimen in preventing acute rejection in adult liver allotransplantation with less renal toxicity and less use of maintenance steroids.     

A safe immunosuppressive protocol in adult-to-adult living related liver transplantation

BACKGROUND: In this series of 32 adult-to-adult living related liver transplantations, we assessed the efficacy and safety of basiliximab in combination with a tacrolimus-based regimen. Basiliximab, a chimeric monoclonal antibody directed against the alpha chain of the interleukin-2 (IL-2) receptor (CD25), has been extensively evaluated as induction therapy for cadaveric liver transplant recipients. PATIENTS AND METHODS: Thirty-two adult-to-adult living related liver transplantations were performed in the last 3 years. All patients received two 20 mg doses of basiliximab (days 0 and 4 posttransplantation) followed by tacrolimus (0.15 mg/kg/d; 10-15 ng/mL target trough levels) and steroids (starting with 20 mg IV switched to PO as soon as the patient was able to eat and weaned within 1-2 months). The average follow-up was 395 days after transplantation. RESULTS: Of the patients, 93.75% remained rejection-free during follow-up with an actuarial rejection-free probability of 92.59% within 3 months. Two patients (6%) had one episode of biopsy-proven acute cellular rejection (ACR). Actuarial patient and graft survival rates at 3 years were 86.85% and 81.25%. One patient (3%) experienced one episode of sepsis. There was no evidence of cytomegalovirus infections or side effects related to the basiliximab. We found zero de novo malignancy but we observed two patients with metastatic spread of their primary malignancy during the follow-up. CONCLUSION: Basiliximab in association with tacrolimus and steroids is effective as prophylaxis of ACR among adult living related liver transplant recipients.     

Observations regarding the use of sirolimus and tacrolimus in high-risk cadaveric renal transplantation

BACKGROUND: Balancing the risk of acute rejection (AR) with drug-induced toxicities complicates the selection of the optimal immunosuppressive regimen, especially in the high-risk renal transplant recipient. This study was designed to determine the optimal dosage combinations of tacrolimus and sirolimus in a high-risk cadaveric renal transplant population. METHODS: Primary cadaveric renal transplant recipients were randomly assigned to receive either standard tacrolimus (trough levels of 10-15 ng/mL) plus reduced sirolimus (trough levels of 5-10 ng,mL) (Group I) or to receive reduced tacrolimus (trough levels of 5-10 ng,mL) plus standard sirolimus (trough levels of 10-15 ng/mL) (Group II). All patients received Thymoglobulin induction and steroids. RESULTS: Thirty-nine (16 in Group I and 23 in Group II) high-risk renal transplant recipients (100% cadaveric donors, 79% African-American recipients, and 59% delayed graft function) are the subjects of this report. At 6 months, the patient survival rate was 94 and 100% and the graft survival rate was 94 and 83% in Groups I and II, respectively. The incidence of biopsy-proven AR was 6 and 5% in Groups I and II, respectively. Eight patients (50%) in Group I required discontinuation of tacrolimus, seven because of biopsy-proven tacrolimus nephrotoxicity and one secondarily to interstitial pneumonitis. Wound complications were the most frequent adverse event reported in both groups. CONCLUSIONS: The combination of tacrolimus and sirolimus was associated with a low risk of AR in this cohort of high-risk renal transplant recipients. However, 50% of patients who received standard tacrolimus and reduced sirolimus combination had to be discontinued from the regimen because of biopsy-proven nephrotoxicity. These preliminary results provide evidence that sirolimus should not be added to tacrolimus without dosage adjustments. We have discontinued recruitment of patients to the standard tacrolimus and reduced sirolimus combination and we have tightened our criteria for selection of marginal donor kidneys with our high-risk renal transplant recipients.     

Hepatic vein anastomotic stricture after living donor liver transplantation

This report discusses the pathophysiology of and therapeutic methods to address hepatic vein anastomotic stricture after living donor liver transplantation (LDLT). From 1994 to 2002, our 15 LDLTs using the lateral segments or left lobes included four recipients who experienced 28 occurrences of this complication after the operation. The period between LDLT and the first stricture was 4.0 +/- 1.2 months. The age of the affected recipients (31.0 +/- 8.2 years) was significantly higher than that of the nonaffected patients (7.0 +/- 4.1 years, P < .05). Graft liver/standard liver volume ratio was 39.1% +/- 3.8% in the former and 77.9% +/- 12.7% in the latter cases (P < .05). Initial symptoms of stricture were ascites (42.9%), abdominal distention (42.9%), liver enzyme elevation (10.7%), and gastrointestinal bleeding (3.6%). In addition, 14 of 28 stricture cases (50%) showed increased blood trough levels of tacrolimus. Doppler ultrasonography was used for diagnosis, and balloon dilatations performed in all stricture patients, thereby hepatic significantly reducing venous blood pressure from 33.5 +/- 1.7 to 20.3 +/- 1.5 cmH2O. All patients finally resolved the strictures after several treatments. The stricture after LDLT was associated with small-for-size grafts, suggesting that liver regeneration may lead to anatomical changes and strictures. Since tacrolimus is metabolized by the liver, its blood trough level is one initial symptoms of stricture. Balloon dilatation was useful and safe as the treatment, while problems have been reported after stent insertion in the hepatic vein.     

Corticosteroid-free immunosuppression with tacrolimus following induction with daclizumab: a large randomized clinical study.

This open, randomized (1 : 1), multicenter, 3-month study compared a dual tacrolimus plus steroids (Tac / steroids) regimen with a steroid-free immunosuppressive regimen of tacrolimus following daclizumab induction therapy (Tac / Dac) in adult liver transplant recipients. The full analysis set comprised 347 patients in the Tac / steroids group and 351 in the Tac / Dac group. Mean tacrolimus dose during month 3 was 0.11 mg/kg/day in both groups; mean whole-blood trough levels during month 3 were 10.9 ng/mL (Tac / steroids) and 10.6 ng/mL (Tac / Dac). The incidence of biopsy-confirmed acute rejection that required treatment was similar in both groups: 26.5% in the Tac / steroids group and 25.4% in the Tac / Dac group (P = .727). However, the incidence of biopsy-confirmed corticosteroid-resistant acute rejection was higher in the Tac / steroids group than in the Tac / Dac group (6.3 vs. 2.8%; P = .027). Kaplan-Meier estimates of graft survival (92.2 vs. 90.5%) and patient survival (94.5 vs. 93.7%) were similar in both groups. While also the overall adverse event profiles were similar, the incidences of diabetes mellitus (15.3 vs. 5.7%, respectively; P < .001) and cytomegalovirus infection (11.5 vs. 5.1%, respectively; P = .002) were higher in the Tac / steroids group compared with the Tac / Dac group. Mean cholesterol levels increased by 16% in the Tac / steroids group, but were unchanged in the Tac / Dac group during the study. In conclusion, tacrolimus monotherapy following daclizumab induction is an effective and safe regimen, with an advantage over concomitant steroid-maintenance therapy in terms of a lower incidence of diabetes and viral infection, and a lower incidence of steroid-resistant acute rejection.     

Initial liver graft function is a reliable predictor of tacrolimus trough levels during the first post‐transplant week

Lock JF, Malinowski M, Schwabauer E, Martus P, Pratschke J, Seehofer D, Puhl G, Neuhaus P, Stockmann M. Initial liver graft function is a reliable predictor of tacrolimus trough levels during the first post‐transplant week.
Clin Transplant 2011: 25: 436–443. © 2010 John Wiley & Sons A/S. Abstract: The narrow therapeutic range of tacrolimus requires careful management after liver transplantation (LT). The aim of this study was to investigate the influence of graft function on tacrolimus trough levels during the first post‐transplant week. Ninety‐three patients receiving deceased‐donor LT were observed in a prospective observational study. Graft function was determined by the new LiMAx test (maximal liver function capacity). Significant correlations between LiMAx readouts and consecutive tacrolimus levels, up to r = ?0.529 (p < 0.0001), were determined throughout the observed period of time. Patients with initially poor graft function revealed higher trough levels (n = 24; 20.1 ± 11.6 ng/mL) in comparison with fair (n = 40; 13.7 ± 7.8 ng/mL) and good function (n = 29; 9.5 ± 4.4 ng/mL; p < 0.0001) already at the second post‐transplant day. Toxic levels could be predicted with an area under receiver operating characteristic analysis AUROC=0.751 (p = 0.001) with high sensitivity and specificity. Insufficient levels could be predicted with AUROC=0.800 (p = 0.003). In conclusion, initial graft function is a major factor influencing the pharmacokinetics of tacrolimus and can be validly determined by the LiMAx test. Thus, recipients with poor functioning grafts are prone of developing toxic levels within the first week after LT, whereas patients with good functioning grafts frequently develop insufficient levels with the current immunosuppressive protocols.     

Delayed Introduction of Reduced-Dose Tacrolimus, and Renal Function in Liver Transplantation: The 'ReSpECT' Study

We report a multicenter, prospective, randomized, open-label trial investigating the effect of lower levels and delayed introduction of tacrolimus on renal function in liver transplant recipients. Adult patients with good renal function undergoing primary liver transplant were randomized to either: group A (standard-dose tacrolimus [target trough levels >10 ng/mL] and corticosteroids; n = 183); group B (mycophenolate mofetil [MMF] 2g/day, reduced-dose tacrolimus [target trough levels ≤8 ng/mL], and corticosteroids; n = 170); group C (daclizumab induction, MMF, reduced-dose tacrolimus delayed until the fifth day posttransplant and corticosteroids, n = 172). The primary endpoint was change from baseline in estimated glomerular filtration rate (eGFR) at 52 weeks. The eGFR decreased by 23.61, 21.22 and 13.63 mL/min in groups A, B and C, respectively (A vs C, p = 0.012; A vs B, p = 0.199). Renal dialysis was required less frequently in group C versus group A (4.2% vs. 9.9%; p = 0.037). Biopsy-proven acute rejection rates were 27.6%, 29.2% and 19.0%, respectively. Patient and graft survival was similar. In conclusion, daclizumab induction, MMF, corticosteroids and delayed reduced-dose tacrolimus was associated with less nephrotoxicity than therapy with standard-dose tacrolimus and corticosteroids without compromising efficacy or tolerability.     

A randomized long-term trial of tacrolimus and sirolimus versus tacrolimus and mycophenolate mofetil versus cyclosporine (NEORAL) and sirolimus in renal transplantation. I. Drug interactions and rejection at one year

BACKGROUND: To reduce long-term nephrotoxic calcineurin inhibitor dosage, adjunctive sirolimus or mycophenolate mofetil (MMF) was used in a 150-patient, randomized, three-armed trial in cadaveric or human leukocyte antigen non-identical living-donor first renal transplant recipients (n=50/group). METHODS: Group A received tacrolimus and sirolimus. Target tacrolimus trough levels postoperatively were 10, 8, and 6 ng/mL at 1 month, 6 months, and 1 year, respectively. Group B received tacrolimus and MMF. Target tacrolimus trough levels were 10 and 8 ng/mL at 1 month and 1 year, with a targeted dose of MMF of 1 g twice daily. Group C received cyclosporine A (CsA) (Neoral, Novartis, Basel, Switzerland) and sirolimus with target CsA trough levels of 225 and 175 ng/mL at 1 month and 1 year. Maintenance sirolimus target trough levels were 8 ng/mL in groups A and C. Each group received daclizumab induction and methylprednisolone maintenance. This first of two companion 1-year reports details demographics, drug-dosing interactions, and rejection. RESULTS: There were no notable differences in group demographics, but a somewhat less favorable course occurred in group C, despite higher bioavailability of sirolimus in group C versus group A (P<0.001). Acute rejection rates were lower in groups A (4%) and B (4%) combined versus group C (14%) (P=0.03). Histopathologic findings were supported by comparing perioperative with 1-year postoperative protocol biopsies. CONCLUSIONS: This 1-year interim analysis indicates that a decreasing dosage of tacrolimus with either adjunctive sirolimus or MMF may optimize future graft survival versus a less favorable outcome using a similar algorithm with CsA and sirolimus.     

Use of living donor liver transplantation varies with the availability of deceased donor liver transplantation

The demographics of patients in the United States who undergo living donor liver transplantation (LDLT) versus patients who undergo deceased donor liver transplantation (DDLT) are interesting with respect to the demographics of the donor service areas (DSAs). We examined adult recipients of primary, non-status 1 liver-only transplants from 2003 to 2009. The likelihood of undergoing LDLT was compared to the likelihood of undergoing DDLT by multivariate logistic regression. We examined the adjusted odds ratio (OR) for undergoing LDLT versus DDLT for patients with the same diagnosis and blood type after we stratified the DSAs into quintiles by the median match Model for End-Stage Liver Disease (MELD) scores. LDLT was performed for 1497 of 32,927 liver transplants (4.5%). LDLT decreased in frequency by approximately 30% from 2003 to 2009. In comparison with DDLT recipients, LDLT recipients were younger and had higher albumin levels, lower body mass indices, and lower match MELD scores. Females had increased odds of LDLT in comparison with males (OR = 1.74, P < 0.001). Patients with MELD exception scores were less likely to undergo LDLT (OR = 0.22, P < 0.001). Patients with cholestatic liver disease (adjusted OR = 2.04, P < 0.001) or malignant neoplasms other than hepatocellular carcinoma (adjusted OR = 3.33, P < 0.001) were more likely than patients with hepatitis C virus to undergo LDLT. Other characteristics associated with decreased odds of LDLT were black race (adjusted OR = 0.41, P < 0.001) and government insurance (adjusted OR = 0.51, P < 0.001). LDLT was more frequent in DSAs with high median MELD scores; the adjusted OR for LDLT was 38 for the DSAs in the highest quintile (P < 0.001). In conclusion, there are significant differences associated with race, insurance, sex, MELD exceptions, and DSA MELD scores between patients who undergo LDLT and patients who undergo DDLT. These differences can be hypothesized to be driven in part by the relative availability of LDLT versus DDLT at both the patient level and the DSA level.     

Intraoperative fluid management of living donor versus cadaveric liver transplant recipients

Living donor liver transplantation has increasingly become an alternative to cadaveric donor liver transplants for select adult patients. Because these cases can be performed electively, living donor recipients may have better compensated liver disease at the time of surgery than cadaver donor recipients. However, it is unknown if this difference would have a significant effect on their intraoperative course. Therefore, we compared the intraoperative fluid management of patients receiving liver grafts from either living or cadaveric donors (n = 25, each group). Patient groups did not differ in demographics or baseline laboratory values. The duration of anesthesia and anhepatic phases were significantly longer in living donor cases (651 +/- 80 minutes vs 409 +/- 20 and 55 +/- 14 vs 45 +/- 6, P < .05). Adjusted for anesthesia time and patient weight, fluid administration (crystalloid and albumin) was not different between the two groups. Intraoperative transfusion requirements were also not significantly different in recipients from living donors versus cadaveric donors with regard to red blood cells, fresh frozen plasma, platelets, and cryoprecipitate. However, arterial oxygenation was better preserved in recipients from living donors. The PaO2/FiO2 (P/F) ratio at the end of the procedure was significantly better in patients receiving livers from living rather than from cadaveric donors (P/F ratio 335 +/- 114 mm Hg vs 271 +/- 174, P < .05). Our results indicate that while intraoperative fluid and transfusion requirements are similar, the impact of transplantation on pulmonary gas exchange is more pronounced in patients receiving organs from cadaveric donors. This difference may arise from longer cold ischemia times present in the cadaveric donor group.     

活体部分供肝移植术后他克莫司的用量及代谢特点

目的 探讨和比较成人尸体全肝移植与活体部分供肝移植术后他克莫司(Tac)的用量、血药浓度和代谢特点.方法 回顾性分析2007年4月至2009年9月行肝移植的85例受者Tac的用量以及血药浓度等临床资料.其中,进行活体部分肝移植的受者34例(A组),进行尸体全肝移植的受者51例(B组).结果 肝移植术后,在使用相同的Tac初始剂量下,A组达到治疗窗的时间明显少于B组,A、B组分别为(3.4±1.0)d和(4.5±2.0)d,差异有统计学意义(P＜0.01).A组Tac的用量在术后28 d内明显低于B组,但两者差距逐步接近,在术后28 d以后趋于一致.比较术后第7、14、21和28 d时的用药量,A组分别为B组的72.74%、82.26%、83.92%和88.87%.在相关性分析中,A组移植物重量/受者体重(GR/WR)与其术后第7天所用Tac剂量(mg·kg-1·d-1)呈显著正相关(r=0.728,P＜0.01);与全血Tac浓度/剂量(C/D值)之间呈显著负相关(r=-0.644,P＜0.01).结论 活体部分肝移植术后,其早期Tac用量与植入供肝体积显著相关;成人活体右半供肝移植术后的早期用量约相当于尸体全肝移植术后的70%.随着植入供肝的不断再生,至术后28 d时Tac的用量可基本接近尸体全肝移植水平.     

Reappraisal of seventh-day syndrome following living donor liver transplantation

Seventh-day syndrome (7DS) is characterized by sudden failure of a liver graft that had been working normally at about 1 week after transplantation, without an identifiable cause. A nonnegligible percentage of cadaveric liver transplants have shown this type of acute graft failure, whereas 7DS has not been reported after living donor liver transplantation (LDLT). Among 580 adult LDLT recipients in our institution between 1997 and 2003, 3 (0.5%) showed clinical sequences typical of 7DS. All three recipients showed similar but unique clinical sequences, consisting of initial uneventful recovery, dramatic rise of serum liver enzyme levels about 1 week later despite potent antirejection therapy, and subsequent graft loss. Liver biopsy findings were compatible with massive hemorrhagic necrosis. Sustained fever lasting for 2 days preceded deterioration of liver function. All three patients died prior to the opportunity for retransplantation. Our findings suggest that, as in cadaveric donor liver transplantation, 7DS can also occur following LDLT and that a preceding episode of sustained fever may be a prodrome of 7DS although its pathogenesis is yet poorly understood.     

A randomized, prospective, pharmacoeconomic trial of neoral 2-hour postdose concentration monitoring versus tacrolimus trough concentration monitoring in de novo liver transplant recipients.

Two-hour postdose cyclosporine (C2) monitoring is becoming an accepted method of therapeutic drug monitoring, although it is not known whether C2 monitoring is superior to tacrolimus (FK)-based immunosuppression. The purpose of this trial was to compare the safety, efficacy, and pharmacoeconomics of cyclosporine A (CsA) monitored by C2 levels versus FK monitored by trough levels in de novo liver transplant recipients. After informed consent, 60 de novo liver transplant recipients were randomized in a 1:1 fashion to receive either FK (trough, 6-10 ng/mL) or CsA (C2, 600-1200 ng/mL) and corticosteroids. The 2 groups were similar for gender, race, indication for liver disease, and age. At 1 year, patient survival was similar (93% for FK versus 90% for C2). One patient in the FK arm was retransplanted because of recurrent hepatitis C virus (HCV). Early acute rejection occurred in 27% of FK-treated patients and 23% of CsA-treated recipients [P = not significant (NS)]. Recurrent HCV occurred in 21% of FK-treated patients and 61% of CsA-treated patient (P = 0.04). The incidence of other infections, new onset diabetes mellitus, requirement for antihypertensives, and requirement for cholesterol medications were similar between the groups. Annual calcineurin inhibitor costs were lower in the C2 arm ($5432 +/- 2091 for C2 versus $8291 +/- 3948 for FK, P = 0.001). Annual pretransplant drug costs ($2292 +/- 2331 for C2 versus $2831 +/- 2358 for FK, P = NS) and 1-year posttransplant drug costs ($17,214 +/- 16,600 for C2 versus $15,151 +/- 11,699 for FK, P = NS) were similar. In conclusion, immunosuppression with CsA, monitored by C2 levels, is safe, effective, and economical in liver transplant recipients and provides immunosuppression at least equivalent to that of FK.     

Critical graft size and functional recovery in living donor liver transplantation

With a high prevalence of chronic hepatitis B and a low cadaveric organ donation rate, living donor liver transplantation (LDLT) remains the only option for many patients in Hong Kong. In such cases, the liver graft volume is smaller owing to a partial liver graft; therefore, a problem of small-for-size grafts often occurs. Between September 1999 and April 2003, 25 cadaveric, 16 living related, and 1 auto-LTs were performed at our center. The outcomes of LDLT were analyzed to assess the critical graft size and functional recovery. Among the 16 LDLT recipients (mean age, 44.4 +/- 14.4 years; mean weight, 61.9 +/- 11.4 kg), 1 patient received a graft from a donor left lobe (weight, 400 g) in an auxillary partial orthotopic LT (APOLT), 12 received right lobes, and 3 received left lobes. Besides the APOLT case, the overall graft/recipient weight ratio (GRWR) for the 15 LDLTs was 1.11 (0.76 to 1.75). The GRWR in the 25 cadaveric LTs was 1.92 (1.05 to 3.69) (P < .001). Among the 12 successful LDLTs, there were 5 (41.7%) cases of small-for-size graft syndrome: 3 of 3 (100%) in GRWR < or = 0.8%; 5 of 6 (83.3%) in GRWR < 1%; and 0 of 6 with GRWR > 1%. The initial post-LT graft function parameters were significantly higher among the LDLT group: International normalized ratio (INR), 1.42 vs 1.24, P = .03; alanine aminotransferase (ALT, 387 vs 201 IU/L, P = .005, and bilirubin, 170 vs 48 micromol/L, P < .001 as compared to the cadaveric transplant group). Small-for-size graft syndrome can be avoided if GRWR > 1%, but often occurs when GRWR < 0.8%. Graft function in LDLT recovers more slowly than in cadaveric liver transplant.