Antigen-specific immunosuppression induced by liver transplantation in the rat

We have demonstrated that DA hearts grafted into PVG rats were completely protected from rejection by simultaneous liver transplantation from the same donor. In subsequent experiments PVG animals were given DA hearts followed 5 or 6 days later by livers from the same donor strain. Instead of the expected rapid rejection, all the grafts survived for at least 18 days, despite showing definite graft-swelling, a reliable clinical sign of early rejection, immediately prior to liver transplantation. In all 13 rats the heart size returned to normal and a strong beat returned within a few days. 6 animals survived indefinitely with healthy, beating heart grafts and the remaining 7 animals died of liver transplant rejection, but in these animals also the hearts were beating normally immediately prior to death. Histological examination of the hearts revealed no active rejection, but there was extensive myocardial scarring, compatible with resolution of a rejection reaction. It seems, therefore, that the liver grafts had entirely absorbed the vigorous immune response, terminating that which had already begun in the heart. This immunosuppressive effect was donor-specific and far more powerful than that of the immunosuppressive agent cyclosporine.     

Conversion from tacrolimus to cyclosporine--a based immunosuppression following liver transplantation

We examined the frequency, reasons and outcome after conversion from Tacrolimus to Cyclosporine A. From August 1989 to December 1992, 1000 consecutive liver transplantation patients were studied, which included 834 adults (age>18 yr.) and 166 children with mean follow-up of 77 months (range 56 to 96). A prospectively populated electronic database was queried to identify patients that underwent conversion, the clinical indication and outcomes. Thirty-seven out of 834 adult recipients (4.43%), mean age of 48.4+/-12.9 years, 19 male (51.35%) and 18 females (48.64%) required conversion from Tacrolimus to Cyclosporine A baseline immunosuppressive therapy. No pediatric patient required conversion. The mean time interval from liver transplantation to Cyclosporine A conversion was 443.45+/-441.44 days (range 22 to 1641). The clinical indications for conversion included: 20 neurological (54%), 6 gastrointestinal (16%), 5 hematological (14%), and 6 other (16%) scenarios. Seven of the 37 patients (18.9%) died. The causes of death were multi-organ failure (2), sepsis (2), pancreatitis (1), hepatic failure due to relapse of ethanol abuse (1), and unknown cause (1). Nine out of 37 patients (24.32%) had to be reconverted to Tacrolimus (mean 282.22+/-499.79 days; range 15 to 1583 day with a median of 135) after institution of Cyclosporine A; none showed recurrence of the original symptoms. The reasons for these re-conversions were acute cellular rejection (44%, n=4), chronic rejection (11%, n=1), increased hepatic enzymes (33%, n=3) and progressively worsening neurological symptoms (11%, n=1). The frequency of conversion from Tacrolimus to Cyclosporine A was 4.43%. Conversion is safe and efficacious if done in a controlled setting. Additionally, re-conversion to Tacrolimus for lack of efficacy of Cyclosporine A did not appear to be associated with a recurrence of the condition that caused the initial switch.     

Anti-CD2 monoclonal antibody and tacrolimus in adult liver transplantation

BACKGROUND: Blockade of costimulation and adhesion signaling is an attractive approach to interfere with graft rejection METHODS: Between January 1997 and May 1999, forty adults having benign liver diseases were included in a prospective, randomized study comparing tacrolimus plus low-dose short-term steroids without (n=20, TAC group) or with a 10-day course of antihuman CD2 monoclonal antibody (n=20, BTI group). RESULTS: At day 7, histological rejection expressed by mean Banff scores (2.3+/-1.6 vs. 5.4+/-1.6 in the TAC group; P<0.0001) and incidence of moderate to severe rejection (score>or=6) (0 vs. 10 [50%] in the TAC group; P<0.001) were significantly lower in the BTI group. Rejection was treated in 10% (two patients) of BTI patients during the first 3 months and in 15% during the whole follow-up and in 25% (five patients) of TAC patients (P=NS). None of the BTI-patients presented with an adverse event. Three-month, 1-year, and 5-year actual patient survival rates were 100%, 95%, and 95% in the BTI group and 100%, 100%, and 85% in the TAC group. Graft survival rates were 100%, 90%, and 90% in the BTI group and 95%, 95%, and 80% in the TAC group (P=NS). The mAb had no negative impact on infectious or tumor events. CONCLUSIONS: Antihuman CD2 monoclonal antibody is a safe immunosuppressive drug which has a favorable impact on early immunological follow-up of liver transplanted patients. The antibody had no impact on late patient and graft survival.     

他克莫司对脂肪肝供体大鼠肝移植围手术期移植物功能保护作用的研究

目的探讨他克莫司对脂肪肝供体大鼠肝移植围手术期移植物功能的保护作用及机制。方法建立脂肪肝供体Wistar大鼠肝移植模型,实验组与对照组受体大鼠分别在术中、术后注射他克莫司(0.3mg/kg)或生理盐水,在移植物再灌注0h、24h、72h和1周后分别检测两组受体大鼠的血清肝酶[丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)]、内皮素(ET)和脂质过氧化指标[超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛(MDA)],同时取肝组织制成匀浆检测其SOD、CAT和MDA水平,取小块肝组织制成切片在电镜下观察肝脏超微结构,采用原位末端标志法(TUNEL)检测肝组织的细胞凋亡情况。结果实验组大鼠的血清ALT、AST、LDH、ET和MDA水平明显低于对照组,SOD和CAT高于对照组(P0.05),实验组大鼠的肝组织匀浆中MDA水平也显著低于对照组,SOD和CAT高于对照组(P0.05)。实验组肝脏超微结构的损伤程度和细胞凋亡程度均较对照组有所减轻。结论他克莫司能在一定程度上保护脂肪肝供体大鼠肝移植围手术期移植物的功能,其作用机制可能与其抑制脂质过氧化、细胞凋亡和减轻再灌注损伤有关。     

Angioedema in pediatric liver transplant recipients under tacrolimus immunosuppression

BACKGROUND: The authors report on their experience with food-induced angioedema in tacrolimus-immunosuppressed pediatric liver recipients. METHODS: Among 121 children treated with tacrolimus after liver transplantation, those who presented with angioedema are reported. RESULTS: Twelve children (10%) experienced angioedema related to food allergy while on tacrolimus. Mean ages at transplantation and angioedema were 1.3 years and 3.75 years, respectively. Angioedema occurred within a mean of 28 months from onset of tacrolimus. Eleven children experienced two or more angioedema attacks without consequences. One child presented with anaphylactic shock that caused postischemic cerebral damage. Besides eviction of food allergens, eight children were switched from tacrolimus to cyclosporine, whereas tacrolimus dosage was decreased in four. Reintroduction of food allergens was successfully performed only in those who were switched to cyclosporine. CONCLUSION: A causal relationship between tacrolimus and the occurrence of food-induced angioedema is suggested. The switch from tacrolimus to cyclosporine should be considered.     

Results of pancreas transplantation after steroid withdrawal under tacrolimus immunosuppression

PURPOSE: The results of steroid withdrawal in pancreas transplant recipients under tacrolimus immunosuppression were analyzed. METHODS: From July 4, 1994 until April 30, 1998, 147 pancreas transplantations were performed in 141 patients, including 126 simultaneous pancreas-kidney transplantations, 13 pancreas after kidney transplantation, and 8 pancreas transplantations alone. Baseline immunosuppression consisted of tacrolimus and steroids without antilymphocyte induction. Twenty-three patients were excluded from analysis because of early graft loss in 17 cases, retransplantation in 5 cases, and simultaneous pancreas-kidney transplantation after heart transplantation in 1 patient. RESULTS: With a mean follow-up of 2.8+/-1.1 years (range 1.0 to 4.8 years), complete steroid withdrawal was achieved in 58 (47%) patients with a mean time to steroid withdrawal of 15.2+/-8 months (range 4 to 40 months after transplantation). Of the entire cohort of 141 patients, overall 1-, 2-, and 4-year patient survival rates were 98%, 95.5%, and 86%, respectively. Overall 1-, 2-, and 4-year graft survival rates were 83%, 80%, and 71% (pancreas) and 95%, 91%, and 84% (kidney), respectively. Of the 124 patients analyzed for steroid withdrawal, 1-, 2-, and 4-year patient survival rates were 98%, 97%, and 92%, respectively. Overall 1-, 2-, and 4-year graft survival rates were 98%, 91.5%, 83% (pancreas) and 97%, 95%, and 91% (kidney). Patient, pancreas, and kidney survival rates at 1 year were 100%, 100%, and 98% (off steroids) versus 97%, 91%, and 96% (on steroids, all NS) and at 4 years were 100%, 94%, and 95% (off steroids) versus 78%, 68%, and 85% (on steroids, P = 0.01, 0.002, and NS, respectively). The cumulative risk of rejection at the time of follow-up was 76% for patients on steroids versus 74% for patients off steroids (P = NS). Seven patients originally tapered off steroids were treated for subsequent rejection episodes, which were all steroid sensitive, and two of these seven patients are currently off steroids. Thirteen patients received antilymphocyte therapy for steroid-resistant rejection, five of whom are now off steroids. Tacrolimus trough levels were 9.3+/-2.4 ng/ml (off steroids) and 9.7+/-4.3 (on steroids, P = NS). Mean fasting glucose levels were 98+/-34 mg/dl (off steroids) and 110+/-41 mg/dl (on steroids, P = NS). Mean glycosylated hemoglobin levels were 5.2+/-0.9% (off steroids) and 6.2+/-2.1% (on steroids, P = 0.02), and mean serum creatinine levels were 1.4+/-0.8 mg/dl (off steroids) and 1.7+/-1.0 mg/dl (on steroids, P = 0.02). CONCLUSION: These data show for the first time that steroid withdrawal can be safely accomplished in pancreas transplant recipients maintained on tacrolimus-based immunosuppression. Steroid withdrawal is associated with excellent patient and graft survival with no increase in the cumulative risk of rejection.     

Pregnancy after liver transplantation with tacrolimus immunosuppression: a single center's experience update at 13 years

BACKGROUND: Chronic liver disease often leads to amenorrhea in women of childbearing age. There are several reports of successful pregnancy after liver transplantation (LTx) with cyclosporine A immunosuppression. Tacrolimus has been increasingly used in solid-organ transplantation, and the effect of the drug on pregnancy is still of interest to clinicians. This study updates our single-center experience. METHODS: All pregnancies after LTx with tacrolimus immunosuppression were followed prospectively. Patients' clinical courses during pregnancy and labor along with gestational period and birth weight were catalogued. Changes in liver function, renal function, and immunosuppression also were recorded. The birth weight percentile was calculated on the basis of the gestational period using a standard chart. RESULTS: Thirty-seven mothers delivered 49 babies. Three mothers delivered three times, and six mothers delivered two times. Thirty-six mothers (97%) survived the pregnancy, and 36 allografts (97%) survived. The one death and graft loss was in a patient who demonstrated infra-aortic arterial graft, which clotted by the gravid uterus during labor. The patient developed a gangrenous liver and died before she could undergo retransplantation. The mean gestational period was 36.4+/-3.2 weeks, excluding two premature deliveries at 23 and 24 weeks gestation. Twenty-two babies (46.9%) were delivered by cesarean section, and the other babies were delivered vaginally. In addition to the two premature babies, one baby, who was born to a mother with Alagille syndrome, died from congenital birth defects. The rest of the newborns survived. The mean birth weight was 2,797+/-775 g, with 38 babies (78%) weighing more than 2,000 g. The mean birth weight percentile to gestational period was 54+/-23. Four babies (8.5%) had a birth weight percentile of less than 25, and 28 babies (59.6%) had a birth weight percentile greater than 50. Twelve patients demonstrated an increase in hepatic enzymes without jaundice during the pregnancy. All of them responded to augmentation of immunosuppression. CONCLUSION: The present report reconfirms the safety of tacrolimus during pregnancy after LTx. Preterm delivery and low birth weight seem to be a persistent problem in all solid-organ transplantation under any form of immunosuppression. However, toxemia of pregnancy and new onset of hypertension seem to be have a low occurrence with the use of tacrolimus.     

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.     

Triple immunosuppression with tacrolimus in pediatric renal transplantation: single-center experience

AIM: In this single-center cohort, we retrospectively analyzed the efficacy and safety of tacrolimus in pediatric renal transplantation. METHODS: We examined the medical records of 22 consecutive renal transplantation recipients (12 boys, 10 girls) receiving tacrolimus, to evaluate occurrence of acute rejection (AR) episodes, glomerular filtration rates (GFR), and side effects. RESULTS: The mean recipient age was 15.07 +/- 3.96 years. Seven grafts came from cadaveric, and 15 from living related donors. The patients were placed on immunosuppression with prednisolone and tacrolimus plus azathioprine (n = 8) or mycophenolate mofetil (MMF) (n = 12) or enteric-coated mycophenolate sodium (n = 2). Eighteen patients received basiliximab on days 0 and 4. There were three AR episodes at 5, 9, and 12 months. Mean GFR at the end of 1 and 2 years were 97.1 +/- 24.0 mL/min/1.73 m(2) and 116.9 +/- 42.2 mL/min/1.73 m(2), respectively. There was no graft loss. Hypertension, hyperlipidemia, and hyperglycemia were present in 14 (63.6%), 3 (13.6%), and 3 (13.6%) patients, respectively, without gingival hyperplasia, tremor, or hypertrichosis. Supraventricular tachycardia was noticed in five patients (22.7%), three of whom needed antiarrhythmic drugs (13.6%). CONCLUSION: Our single-center experience with tacrolimus, steroid plus azathioprine or MMF or enteric-coated mycophenolate sodium regimen in pediatric kidney recipients showed a low rate of AR with excellent graft survival and function at 1 and 2 year posttransplantation. The increased rate of supraventricular tachycardia in this regimen had not been previously reported; this association merits further studies.