Pharmacogenetic association with adverse drug reactions to azathioprine immunosuppressive therapy following liver transplantation.

Azathioprine (AZA) is a thiopurine prodrug commonly used in triple-immunosuppressive therapy following liver transplantation. Approximately 1 in 10 patients suffers side effects in response to the drug, the most problematic being bone marrow toxicity. There is evidence that polymorphisms in the genes encoding thiopurine methyltransferase (TPMT) and inosine triphosphate pyrophosphatase (ITPase) predict adverse drug reactions to AZA therapy. Furthermore, common genetic polymorphisms in the gene encoding methylenetetrahydrofolate reductase (MTHFR) may have an indirect impact on thiopurine drug methylation by influencing levels of the methyl donor S-adenosylmethionine (SAM). The aim of this study was to determine whether polymorphisms in these candidate pharmacogenetic loci predict adverse drug reactions to AZA immunosuppressive therapy in liver transplant patients. A series of 65 liver transplant recipients were recruited to the study from the Liver Transplant Out-Patient clinic at The Royal Infirmary of Edinburgh. Clinical response to AZA was retrospectively correlated against TPMT activity, TPMT*2, *3A, and *3A genotypes, inosine triphosphatase (ITPA) 94C>A and IVS2+21A>C genotypes, and MTHFR 677C>T and 1298A>C genotypes. Variant TPMT, ITPA, and MTHFR genotypes were not significantly associated with adverse drug reactions to AZA, including bone marrow suppression. However, the 2 patients who suffered nodular regenerative hyperplasia (NRH) were both heterozygous for the TPMT*3A mutation. In conclusion, our findings suggest that TPMT, ITPA, and MTHFR genotypes do not predict adverse drug reactions, including bone marrow suppression, in liver transplant patients. However, the possible association between NRH and a heterozygous TPMT genotype should be investigated further.     

Cholestasis After Pediatric Liver Transplantation–Recurrence of a Progressive Familial Intrahepatic Cholestasis Phenotype as a Rare Differential Diagnosis: A Case Report

Introduction

Nonobstructive cholestasis after pediatric liver transplantation is a common diagnostic and therapeutic dilemma. We describe a girl with neonatal cholestasis because of progressive familial intrahepatic cholestasis 2 (PFIC-2) and presence of a homozygous splice site mutation in the ABCB11 gene. Liver transplantation was performed because of end-stage liver disease at the age of 6. Cholestasis with normal gamma-glutamyl transferase (GGT) developed 8 years after liver transplantation. A liver biopsy showed canalicular cholestasis and giant cell hepatitis without evidence of rejection, mimicking PFIC-2. Immunofluorescence staining of normal human liver sections with patient's serum revealed reactivity toward a canalicular epitope, which could be identified as bile salt export pump (BSEP) using BSEP–yellow fluorescent protein (YFP) transfected cells. Our patient developed a recurrence of a PFIC-2 phenotype due to production of antibodies against BSEP (alloimmune BSEP disease [AIBD]). Intensification of immunosuppressive therapy as well as antibody treatment with plasmapheresis and Rituximab were initiated, leading to stabilization of the clinical condition and depletion of anti-BSEP antibodies in serum. However, after 1 year liver transplantation was necessary again because of end-stage liver insufficiency. Afterward, immunomodulatory treatment consisted of tacrolimus, mycophenolate mofetil, prednisone, immunoadsorption, and high-dose immunoglobulin therapy (1 g/kg/d).

肝移植术后免疫抑制剂引起肝损害的病理学改变(附26例肝活检报告)

目的探讨肝活检在肝移植术后药物性肝损害诊断中的作用.方法回顾26例肝穿提示药物性肝损害的样本,将组织学改变按肝细胞损伤、淤胆、以上两种方式并存的混合型、纤维淤胆性肝炎等类型进行分类,结合临床病史及相关辅助检查排除其他引起肝功能损害的因素,分析不同免疫抑制剂引起肝组织病理学改变的特点.结果大剂量的糖皮质激素易引起肝细胞的肿胀和脂肪变性,FK506或环孢霉素相关肝损害以淤胆为主,纤维淤胆性肝炎存在时肝细胞内有大量的HBV病毒复制.结论肝活检可提示与药物损伤有关的组织学表现,判断损伤的严重程度,并能排除一些引起肝功能异常的其他因素,在临床的诊断和鉴别诊断中有着重要的价值.     

Monitoring of TPMT in Heart Transplant Recipients under Immunosuppressive Therapy with Azathioprine

Abstract: Azathioprine (AZA) is routinely used in double and triple immunosuppressive therapy after cardiac transplantation. In some cases it causes severe myelosuppres–sion. The interindividual differences in AZA toxicity is probably due to differences in the drug metabolism. Thi–opurine methyltransferase (TPMT) is thought to be the most important enzyme in the catabolism of AZA. A deficiency in this enzyme will presumably increase the availability of 6–mercaptopurine for the anabolic pathway thereby leading to increased cytotoxicity. A 65–year–old male underwent heart transplantation at our institution with an uncomplicated course. Immunosuppression consisted of cyclosporine, prednisolone, and AZA. Several weeks after the administration of AZA, the patient developed severe leukopenia. TPMT activity was then measured in this patient and found to be below the detection limit. Subsequently the patient died from multiorgan failure due to septicaemia. As a result of this experience, we started to screen all patients for TPMT deficiency. In 58 healthy controls, the mean activity was found to be 11. 8 nmol/h/ml of red blood cells (RBC) while in 13 patients on our waiting list, the mean activity was found to be 11. 97 nmol/h/ml of RBC. In 15 patients after heart transplantation and azathioprine treatment, the mean activity was found to be 17. 2 nmol/h/ml of RBC. We suggest screening for TPMT activity in transplant patients with leukopenia under AZA therapy. If TPMT deficiency is present, the AZA dosage should be adjusted or alternative immunosuppressive regimens should be considered.     

Long-term results of TPMT activity monitoring in azathioprine-treated renal allograft recipients

Thiopurine methyltransferase (TPMT) is implicated in the metabolism of azathioprine. The consequences of differential TPMT activity induction by azathioprine on the long-term results after renal transplantation were investigated. The erythrocyte TPMT activity in 82 patients on days 0, 7, and 30 was prospectively evaluated. Because various patterns of TPMT activity variation were noted, the population was subsequently divided between inductors (n = 47) and noninductors (n = 35). Data regarding patient and graft survival and acute rejection episodes were collected. Renal allograft assessment was performed at 3 mo and 2 yr to evaluate the renal function and the histologic lesions on routine biopsies. Data regarding azathioprine-related toxicity also were collected. In a subgroup of patients (n = 19), azathioprine blood levels were determined at day 7 and day 30. The graft survival censoring death was statistically improved in TPMT inductor patients when compared with non-TPMT inductors (P < 0.05). Among TPMT inductors, an acute rejection episode was observed in 34% of the patients versus 69% among non-TPMT inductors (P = 0.002). At 3 mo, serum creatinine was significantly lower among TPMT inductors when compared with non-TPMT inductors (123.1 +/- 7.6 and 161.4 +/- 13.9 micromol/L, respectively; P = 0.01). On routine allograft biopsies at 2 yr (n = 61), grade 2 or 3 chronic lesions were present in 19% versus 25%, respectively (P = NS). At days 7 and 30, the azathioprine blood levels were higher among patients who experienced acute rejection (P < 0.02). TPMT activity induction was observed in 57% of renal transplant recipients who received azathioprine. This induction was associated with better graft outcome. The appropriate conversion from azathioprine, which is a pro-drug, into 6-mercaptopurine could explain both better graft outcome and TPMT induction. Assessing the ability of azathioprine metabolism at an individualized level before transplantation may allow a more accurate choice among the different immunosuppressive treatments.     

供体热缺血时间对移植肝的影响

目的 探讨大鼠动脉化原位肝移植中供体热缺血时间对移植肝的影响.方法 实验分为4组:对照组(C)和移植组,移植组根据供肝获取前经历供体心脏停搏时间的不同分为三组:热缺血0 min(W0)、热缺血15 min(W15)和热缺血30 min(W30),其后建立近交系大鼠动脉化原位肝移植模型,每组均为30只大鼠,分别于术后3、7、14和30 d处死,每个时间点各取6只大鼠,分别测定移植肝组织学、肝功能的变化.此外,移植组各组随机选取6只大鼠观察长期生存率(＞100 d).结果 随着供肝热缺血时间的延长,移植肝损伤加重,恢复过程延长.移植组和对照组术后3、7、14和30 d血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)变化无显著性差异.血清碱性磷酸酶(ALP)随着供肝热缺血时间的延长逐渐增高,14 d达到高峰后逐渐下降.术后3、7、14和30 d ALP与供肝热缺血时间具有显著相关性.术后热缺血0、15、30 min长期生存率组分别为100.0%(6/6)、83.3%(5/6)、66.7%(4/6),3组间比较差异无统计学意义(P=0.285).结论 肝移植过程中供肝热缺血主要损伤肝细胞,并随着供肝热缺血时间的延长移植肝细胞损伤加重,肝细胞功能恢复早于其形态学恢复.肝移植术后早期存在胆汁淤积,供肝热缺血时间的延长明显加重胆汁淤积的程度,胆汁淤积的恢复明显晚于肝细胞损伤指标的恢复.在热缺血30 min内来自于心脏停搏的供肝肝移植术后是安全的.     

血清sIL-2R、IL-6及胆汁IL-6监测对早期预测肝移植急性排斥反应的作用

目的　评价血清sIL 2R、IL 6及胆汁IL 6水平在预测肝移植急性排斥反应中的意义。方法　连续 3周监测 2 8例肝移植受者术后血清sIL 2R、IL 6及胆汁IL 6水平 ,观察其与急性排斥反应的关系。结果　在急性排斥反应 (AR)组 ,血清sIL 2R及胆汁IL 6水平在排斥发作时明显升高 ,与非排斥组比较有显著性差异 (P <0 .0 1)。当AR经激素冲击治疗逆转后 ,血清sIL 2R及胆汁IL 6下降至排斥前的水平。在AR组 ,仅有 3例受者在排斥发作时血清IL 6水平升高 ,与非排斥组相比 ,血清IL 6水平无明显差异 (P >0 .0 5 )。结论　胆汁IL 6水平有望作为预测AR敏感、较具特异性及非侵袭性的手段。同时 ,其水平还可作为观察抗排异治疗是否有效的指标。     

Activation pattern of mitogen-activated protein kinases in early phase of different size liver isografts in rats.

Mitogen-activated protein kinases (MAPK) play a pivotal role in ischemia reperfusion injuries of heart and liver, but the activation pattern of MAPKs in the early phase of different size liver isografts remains unclear. The experiment is designed to investigate the activation pattern and role of MAPKs in isografts of the rat with different size liver transplantation. The animal models of different size graft liver transplantation (whole graft, 50% size, or 30% size, respectively) were established and the sham operation group served as a control. The recipients were sacrificed at 0.5-, 2-, 6-, and 24-hour time points after transplantation to harvest the graft specimens and blood samples. The serum aspartate amino transferase (AST), alanine amino transferase (ALT) and tumor necrosis factor-alpha (TNF-alpha) levels, and histological findings were evaluated. The expressions of the total and phosphorylated p46/p54 JNKs, p38 MAPK, and p42/p44 ERKs were detected by Western blot. The serum ALT and AST levels increased significantly at the 0.5-hour time point and maintained high with the peak levels at the 6-hour time point after liver transplantation. The different sizes of liver isografts did not change the expressions of total p46/p54JNKs, p38MAPK, and p42/p44 ERKs. While the expressions of phosphorylated p46/p54JNKs, p38 MAPK, and p42/p44 ERKs were either negative or mildly up-regulated in the sham operation group, they were significantly activated in the transplanted liver at the 0.5-hour time point, especially in the 30% size liver transplantation group. In conclusion, the activation of three MAPKs in liver isografts correlates with graft size and the JNK and p38 MAPK are responsible for the graft injury while the ERK signal pathway maybe participate in the regulation of cell growth and differentiation after small-for-size liver transplantation.     

Protection of Reduced-Size Liver for Transplantation

The shortage of available organs for liver transplantation has motivated the development of new surgical techniques such as reduced-size liver transplantation. Ischemia-reperfusion (I/R) associated with liver transplantation impairs liver regeneration. Ischemic preconditioning is effective against I/R injury in clinical practice of liver tumour resections. The present study evaluated the effect of ischemic preconditioning on reduced-size liver for transplantation and attempted to identify the underlying protective mechanisms. Hepatic injury and regeneration (transaminases, proliferating cell nuclear antigen [PCNA] labeling index, and hepatocyte growth factor [HGF]) were assessed after reduced-size orthotopic liver transplantation (ROLT). Energy metabolism, oxidative stress, tumor necrosis factor-alpha (TNF) and interleukin-6 (IL-6) were examined as possible mechanisms involved in liver regeneration. Ischemic preconditioning reduced transaminase levels and increased HGF levels and the percentage of PCNA-positive hepatocytes after ROLT. This was associated with a decrease in oxidative stress following ROLT, whereas energy metabolism and hepatic IL-6 and TNF release were unchanged. The benefits of ischemic preconditioning on hepatic injury and liver regeneration could be mediated, at least partially by nitric oxide. These results suggest a new potential application of ischemic preconditioning in reduced-size liver transplantation.     

Subnormothermic machine perfusion protects against rat liver preservation injury: a comparative evaluation with conventional cold storage

Hypothermic machine perfusion (MP) of the liver has been reported to improve graft function reclaiming marginal livers, such as those from non-heart-beating donors. Livers from obese donors often have fatty infiltrates and are more susceptible to hypothermic conditions. No data exist about MP at temperatures >4 degrees C. This study evaluated liver function after organ preservation by comparing MP at 20 degrees C with conventional cold storage. METHODS: For MP, rat livers were perfused for 6 hours using an oxygenated Krebs-Henseleit (KH) solution at 20 degrees C (pH 7.4). For cold storage, livers were perfused in situ and preserved with Celsior solution at 4 degrees C for 6 hours. The reperfusion period with KH (2 hours at 37 degrees C) was performed under the same conditions both among livers preserved by MP or cold storage. Hepatic enzyme release (aspartate aminotransferase [AST], alanine aminotransferase [ALT], lactate dehydrogenase [LDH], and gamma-glutamyl transferase [GGT]), bile production, and ATP levels were measured during MP and reperfusion. RESULTS: At the end of reperfusion, livers preserved by MP showed significantly decreased liver damage compared with cold storage: AST, 18 +/- 4 vs. 45 +/- 6 mU/mL (P < .01); ALT, 1.5 +/- .07 vs. 6 +/- 0.5 mU/mL (P < .01); and LDH, 82 +/- 2 vs. 135 +/- 29 mU/mL (P < .05). No difference was observed between bile production between MP and cold storage. High levels of biliary GGT and LDH were found in cold preserved livers. ATP levels were higher in livers preserved with MP compared with those preserved by cold storage. CONCLUSIONS: MP at 20 degrees C resulted in a better quality of liver preservation, improving hepatocyte survival, compared with conventional cold storage. This may provide a new method for successful utilization of marginal livers, in particular fatty livers.     

Circulating serum levels of interleukin 6 and C-reactive protein after liver transplantation.

The study objectives were to investigate serum levels of interleukin-6 and C-reactive protein (CRP) after liver transplantation to correlated measurements with various clinical parameters. Twenty-three patients were studied after orthotopic liver transplantation. Serum IL-6 activity was evaluated by testing its capacity to induce proliferation of the IL-6-dependent hybridoma cell line B9. CRP was assessed by a nephelometric method. Only two of seven patients with acute cellular rejection developed an increase of serum IL-6 and CRP. In contrast to this rejection group, elevated IL-6 levels were observed in 7/9 patients with bacterial infections. Peak values for IL-6 were observed one day and for CRP two days after clinical diagnosis of infection. CMV disease was also associated with markedly increased IL-6 and CRP levels in 5/7 patients. Surprisingly, levels in this condition were approximately in the same range as in bacterial infection. IL-6 and CRP serum levels seen in bacterial infection and CMV disease were significantly higher than those in rejection (P less than 0.001). Serum IL-6 activity was neutralized by an antiserum directed against recombinant human IL-6. Preferential elevations of IL-6 and CRP represent one feature of bacterial and viral infections. Elevation of TNF during rejection as described earlier is only rarely accompanied by increased serum IL-6 levels.     

Thiopurine S-Methyltransferase Genotype Predicts Azathioprine-Induced Myelotoxicity in Kidney Transplant Recipients

Azathioprine (AZA) is an immunosuppressive prodrug that undergoes metabolism by thiopurine S-methyltransferase (TPMT). Eighty to ninety-five percent of low or deficient TPMT enzyme activity is genetically determined by the presence of three nonfunctional mutant alleles: TPMT*2, TPMT*3A and TPMT*3C. Using TPMT as a pharmacogenetic paradigm, we explored the association between these genetic mutations and development of adverse drug effects in an ethnically diverse renal transplant population receiving azathioprine. Biochemical and clinical data were retrospectively evaluated during the first four weeks after kidney transplantation. TPMT nonfunctional mutant alleles were identified by polymerase chain reaction-based methods. Of 89 patients initially consented, 36 met inclusion criteria for this retrospective study. Five patients possessing a single TPMT nonfunctional mutant allele were identified: TPMT*3A: n = 2 Caucasians; TPMT*3B: n = 1 Caucasian; TPMT*3C: n = 2 African-Americans. TPMT nonfunctional mutant alleles were associated with significant reductions in hematological indices and a significant increase in cyclosporine plasma concentrations in the first month post-transplant. TPMT genotype was an independent predictor for hemoglobin, hematocrit and red blood cell changes while mean azathioprine dose (mg/kg/day), azathioprine dose (mg/kg/day) at day 30 and cyclosporinemia at day 30 were not. Prospective application of pharmacogenetic principles may assist in optimization of immunosuppressive drug therapy and minimize drug toxicities.     

Case Report of FLT3-ITD–Positive AML Patient 11 Years After Living Donor Liver Transplantation

With the increasing number of long-term survivors of living donor liver transplantation, the occurrence of secondary cancer is sometimes reported. Solid tumors such as lymphomas are mainly observed. However, only 8 cases of leukemia have been reported so far. For patients younger than 15 years old, leukemia developed in 4 within 3 years after the liver transplantation, whereas acute lymphoblastic leukemia developed in only 1 patient. This is the first case report of a patient in whom FLT3-ITD–positive acute myeloid leukemia (AML) developed more than 10 years after living donor liver transplantation for congenital biliary atresia. AML developed in a 14-year-old boy 11 years after living donor liver transplantation from his father. The patient received the transplant at the age of 3 years and was treated with tacrolimus and methylprednisolone for transplant rejection. Eleven years posttransplantation, he visited the hospital with general malaise and anemia. Blood tests revealed an elevated white blood cell count of 60,100/μL, and the patient was diagnosed with AML. Chromosome analysis revealed a t(6; 9) (p23 q34) translocation; moreover, genetic testing revealed a FLT3-ITD–positive mutation. We started treatment in accordance with the Tokyo Children's Cancer Study Group AML99 protocol. With chemotherapy treatment, the patient achieved complete remission. After chemotherapy, we performed stem cell transplantation from his father. Other patients were reported in relatively early stages after liver transplantation, but our case was more than 10 years posttransplantation. The association with the onset of congenital bile duct atresia and leukemia is still not clear, but we consider the possibility that long-term immunosuppressive drugs contribute to developing leukemia.     

The calcium channel blocker nisoldipine minimizes the release of tumor necrosis factor and interleukin-6 following rat liver transplantation

Kupffer cells, when activated, release toxic cytokines such as tumor necrosis factor (TNF), which can cause tissue injury. Takei et al. have reported that nisoldipine, a calcium channel blocker which decreases phagocytotic activity by Kupffer cells, also diminishes liver and lung injury and dramatically improves survival following liver transplantation [27]. Therefore, we studied the effect of nisoldipine on the time course of TNF and interleukin-6 (IL-6) release following cold storage and liver transplantation in the rat. Livers were stored under survival and non-survival conditions in cold Euro-Collins solution in the presence or absence of nisoldipine (1.4 µM). After storage, the effluent was collected for determination of cytokines. The liver was then transplanted orthotopically and serum was collected at various time intervals for up to 5 h. In the effluent, TNF levels were very low in both the control and nisoldipine-treated groups and IL-6 was not measurable. Furthermore, when livers were stored under survival conditions and transplanted (liver stored in the cold for 4 h), serum TNF (2 U/ml) and IL-6 (350 U/ml) values were minimal in both the control and nisoldipine-treated groups. In contrast, when livers were stored under non-survival conditions and transplanted (liver stored in the cold for 10 h), TNF levels increased to 15 ± 2 U/ml, 150 min after graft reperfusion, an increase which was prevented by nisoldipine (6.5 U/ml). Serum IL-6 levels were also elevated 300 min after transplantation in livers stored for 10 h. Nisoldipine also reduced the release of this cytokine. Serum transaminases (SGOT) were elevated to values around 2000 U/l 5 h following transplantation. In the nisoldipine-treated group, values were lower between 60 and 300 min. In the lung, interstitial and alveolar edema and cellular infiltration were detectable 5 h post-operatively and were diminished by nisoldipine. These data confirmed that TNF and IL-6 release were minimal following cold storage and transplantation of livers stored under survival conditions, but were elevated transiently after transplantation under non-survival conditions. Nisoldipine prevented cytokine release, most likely by blocking the activation of Kupffer cells, which may explain how it decreases liver and lung injury very early following liver transplantation.     

Benefit of Kupffer cell modulation with glycine versus Kupffer cell depletion after liver transplantation in the rat: effects on postischemic reperfusion injury, apoptotic cell death graft regeneration and survival.

Inhibition or destruction of Kupffer cells (KC) may protect against ischemia-reperfusion (IR) induced primary graft nonfunction (PNF) in liver transplantation. Besides KC activation, PNF is characterized by microvascular perfusion failure, intrahepatic leukocyte accumulation, cell death and hepatocellular dysfunction. KCs can be inactivated by different agents including gadolinium chloride (GdCl3), methyl palmitate (MP) and glycine. The effects of three KC inactivators on IR-injury after rat liver transplantation were compared in the present study. Lewis liver donors were treated with GdCl3, MP, glycine or saline (control). Liver grafts were transplanted following 24 h storage (UW solution). KC populations and IR damage were assessed by histologic analysis, quantitative real-time polymerase chain reaction (RT-PCR) and intravital microscopy. The number of hepatic ED-1 positive macrophages was diminished after GdCl3 (114.8+/-4.4/mm2 liver tissue) and MP treatment (176.0+/-5.0), versus the glycine (263.9+/-5.5) and control (272.1+/-5.6) groups. All three treatment modalities downregulated phagocytic activity for latex particles, paralleled by reduced microvascular injury (acinar perfusion index, GdCl3: 0.75+/-0.03; MP: 0.83+/-.03; glycine: 0.84+/-0.03; 0.63+/-0.03). Quantitative RT-PCR revealed elevated myeloperoxidase mRNA after glycine versus GdCl3 and MP pretreatment (3.2- and 3.4-fold, P=0.011, respectively), without difference to controls (2.9-fold of glycine). TNFalpha-mRNA was reduced after glycine- (5.2-fold), GdCl3- (19.7-fold), MP-treatment (39.5-fold) compared with controls. However, profound prevention of intrahepatic cell death and liver graft failure was solely achieved with glycine preconditioning. Different than GdCl3 and MP, glycine modulates rather than destroys KCs. Glycine appears to preserve cell viability and to TNFalpha/leukocyte dependent organ regeneration capacity, which is related to increase graft survival following liver transplantation.     

Low-dose hormonal contraception after liver transplantation

OBJECTIVES: End-stage liver failure is associated with extremely reduced fertility. After liver transplantation, restoration of menstrual function is observed; thus effective contraceptive methods should be employed in patients who do not plan to conceive. The aim of this study was to assess tolerability and safety of hormonal contraceptives in female liver transplant recipients. MATERIALS AND METHODS: We retrospectively analyzed data on 15 female liver graft recipients, aged 24 to 35 years, who used hormonal contraceptives after liver transplantation for a time not shorter than 12 months. The period from grafting to administration of hormonal contraceptives varied from 6 months to 7 years. Biochemical parameters of liver function, fasting glucose levels, body mass index (BMI) as well as blood pressure were monitored at 0, 3, 6, and 12 months of therapy. Side effects of the treatment were noted on regular follow-up examinations. RESULTS: No case of pregnancy or graft rejection was observed on therapy. Changes of biochemical parameters were not significant (aspartate transferase 22.92 +/- 6.67 vs 25.54 +/- 7.90, alanine transferase 22.08 +/- 5.66 vs 24.27 +/- 7.57, total bilirubin 0.96 +/- 0.17 vs 1.02 +/- 0.15). Blood pressure and BMI remained stable in the group. None of the patients discontinued therapy for medical indications. CONCLUSION: Hormonal contraception was administered as soon as liver transplant function was stable. It was effective, well tolerated, and did not seem to impair graft function. However, a long-term prospective study is necessary to assess the safety of hormonal contraception in transplant recipients.     

Attenuation of acute rejection in a rat liver transplantation model by a liver-targeted dextran prodrug of methylprednisolone

BACKGROUND: The use of methylprednisolone (MP) and other corticosteroids for the treatment of acute liver allograft rejection is associated with severe toxicities in nontarget tissues. Therefore, selective delivery of MP to the liver may improve its efficacy and alleviate its side effects. We investigated the effects of a novel liver-targeted dextran prodrug of MP (DMP) in an orthotopic rat liver transplantation (OLT) model. METHODS: The model consisted of a high responder rejection strain combination (Dark Agouti donors and Lewis recipients). Liver recipients were intravenously administered saline or a single subtherapeutic dose of MP (5 mg/kg) as the parent drug (MP) or its prodrug (DMP). Different groups were then monitored for graft survival or euthanized 5 or 9 days posttransplantation. Plasma chemistry, including alkaline phosphatase and bilirubin, allograft histology, and survival duration were determined. RESULTS: Untreated recipients exhibited elevated plasma levels of liver injury markers, progressive portal and venous inflammation and cellular infiltration in liver allografts, and a mean graft survival time (MST) of 10.5 days. MP treatment did not alter any of these parameters. In contrast, a single dose of DMP resulted in a decrease in plasma levels of liver injury markers, a decrease in histological grade of rejection on day 5, and a substantial increase in MST (27.5 days). CONCLUSIONS: These results demonstrate attenuation of acute rejection following local (allograft) immunosuppression with a single subtherapeutic dose of MP delivered as a liver-targeted prodrug. Dextran prodrugs may be useful for selective delivery of immunosuppressants to the liver following liver transplantation.     

缺血再灌注损伤对肝移植受者术后早期胆红素代谢影响的临床及病理分析

目的分析缺血再灌注损伤对同种异体原位肝移植后受者胆红素变化的影响。方法30例入选患者监测术前及术后15天内肝功能数据进行统计学分析,同时在手术中获取冷缺血时及再灌注后供体肝脏组织进行光学显微镜及电子显微镜检查。结果肝移植术后存在一过性高胆红素血症(术后11天内),血总胆红素术后第1天(78.84±34.59)mmol/L,较术前(21.60±8.03)mmol/L明显升高(P<0.05),碱性磷酸酶术前中位数40.46IU/L,术后第1天中位数19.27IU/L,术后1天较术前降低(P<0.05)。胆汁酸术前中位数32.93μmmol/L,术后第1天中位数20.85μmmol/L,术后1天较术前降低(P<0.05)。γ-谷氨酰转肽酶术前中位数28.81IU/L,术后第1天中位数29.17IU/L,术后1天γ-谷氨酰转肽酶较术前升高没有显著差异(P>0.05)。术前直接胆红素/总胆红素比值为(39.85%±12.51%),术后1天比值为(54.25%±7.6%),术后较术前升高(P<0.05)。同时,光学显微镜及电子显微镜检查没有发现肝细胞外胆汁瘀积,胆红素主要瘀积于肝细胞内。结论缺血再灌注损伤导致患者肝移植术后早期出现以直接胆红素升高为主的一过性高胆红素血症,并在术后11天左右降至术前水平。胆汁瘀积主要发生于肝细胞水平。     

肾移植受者红细胞硫嘌呤甲基转移酶活性与硫唑嘌呤所致不良反应的关系

目的 探讨肾移植受者红细胞中硫嘌呤甲基转移酶(TPMT)活性与硫唑嘌呤导致的血液毒性和肝脏毒件等不良反应的关系.方法 应用高效液相色谱法(HPLC)测定98例肾移植受者红细胞中TPMT活性,分析TPMT活性在服用硫唑嘌呤期间发生不良反应与未发生不良反应受者中的差异.结果 98例受者红细胞中TPMT活性范围在15.00～65.02 U,＜24 U者占8.2%(8例),24～50 U者占77.5%(76例),＞50 U者占14.3%(14例),未发现有TPMT活性缺乏者.76例未发生不良反应组的受者TPMT活性范围在19.21～61.54 U,平均(40.48±9.66)U.7例发生血液毒性的受者,其TPMT活性范围在15.00～39.16 U,平均(27.80±10.70)U,明显低于未发牛不良反应组,差异有统计学意义(Z=-2.655,P＜0.05);15例发生肝脏毒性的受者,其TPMT活性范围在20.74～65.02 U,平均(36.47±10.90)U,与未发生不良反应组比较,差异无统计学意义(Z=-1.658,P＞0.05).结论 硫唑嘌呤所致的血液毒性与TPMT活性水平低下有关,活性低下的肾移植受者应避免使用硫唑嘌呤或减少起始剂量,从而减轻或避免该药产生的严重毒副作用.而硫唑嘌呤所致的肝脏毒性是否与TPMT活性较高相关,还需进一步研究证实.     

Kidney Transplantation Decreases the Level and Procoagulant Activity of Circulating Microparticles

Microparticles (MP) are important players in cardiovascular disorders. Renal transplantation significantly improves the survival of hemodialyzed patients, in part because cardiovascular disease (CVD) progression is lessened. We hypothesized that the beneficial effect of renal transplantation on cardiovascular outcome might involve decreased levels of circulating MP. We evaluated the kinetics of MP subpopulations and their procoagulant activity (MP-PCA) in 52 patients before and 3, 6, 9 and 12 months after graft with reference to 50 healthy controls and we evaluated the impact of cardiovascular complications. During the follow-up, the increased levels of MP observed before graft were significantly decreased and reached normal values with different kinetics according to their cellular origin whereas MP-PCA remained significantly higher than in controls. From multivariate analysis, the levels of MP were negatively correlated with renal function. At 12 months, the decrease in MP and MP-PCA was more pronounced in patients without history of CVD than those with. In conclusion, we demonstrated that renal graft is associated with decreased levels of MP levels and MP-PCA, even more pronounced so in patients without history of CVD. Therefore, we suggest that MP lowering could be involved in the vascular dysfunction improvements reported after transplantation.