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Prostaglandins have been evaluated for their ability to reduce IRI after liver transplantation; however, poor stability, side effects and the inability to show a significant difference in primary endpoint have limited their clinical application. Treprostinil, a prostacyclin (PGI(2) ) analog, has a higher potency and longer elimination half-life than other commercially available PGI(2) analogs. We examined the efficacy of treprostinil to prevent IRI during OLT. OLT was performed in syngeneic Lewis rats after 18 h of cold preservation (4°C) in the UW solution. IRI significantly increased serum ALT and AST levels, neutrophil infiltration, hepatic necrosis and mRNA levels of proinflammatory cytokines post-OLT, while treatment with treprostinil decreased all the parameters. Cold storage of liver grafts significantly reduced ATP levels and treprostinil restored energy levels in liver grafts early postreperfusion. In addition, treprostinil preserved the sinusoidal endothelial cell lining and reduced platelet deposition early post-transplantation compared to placebo. Hepatic tissue blood flow was significantly compromised in the placebo group, whereas treprostinil maintained blood-flow similar to normal levels. Treprostinil protected the liver graft against IRI during OLT. Treprostinil has the potential to serve as a therapeutic option to protect the liver graft against I/R injury in patients undergoing OLT.

Chronic allograft nephropathy (CAN) is a major indication for initiation of sirolimus (SRL) in renal transplantation (TX) to prevent deterioration of renal function. We evaluated whether the CAN score at time of sirolimus rescue (SRL-R) predicts renal allograft function. CAN score is the sum of the following 4 categories: glomerulopathy (cg, 0-3), interstitial fibrosis (ci, 0-3), tubular atrophy (ct, 0-3), and vasculopathy (cv, 0-3). This is a retrospective cohort study of renal transplant recipients from July 2001 to March 2004. Immunosuppression consisted of preconditioning with rabbit anti-thymocyte globulin or alemtuzumab and maintenance with tacrolimus (TAC) monotherapy with spaced weaning, if applicable, SRL-R was achieved by conversion from TAC, or by addition to reduced doses of TAC. Ninety patients received SRL. Thirty-three of these patients met the inclusion criteria of the following: (1) receipt of SRL for >6 months, and (2) follow-up of > or =6 months. There were 16 patients in the low-CAN (0-4) group and 17 patients in the high-CAN (>4) group. Cockcroft-Gault (C-G) glomerular filtration rate (GFR) was calculated at SRL-R and at 1, 3, 6, and 12 months. The DeltaGFR was significantly better in the low-CAN group at 1, 3, and 6 months. A trend toward an improved DeltaGFR was present at 12 months in the low-CAN group (P = .16). CAN scoring at the time of SRL-R predicts recovery of renal allograft function (as measured using DeltaGFR), and should be used in preference to biochemical markers (Cr and C-G GFR), which may not be reliable predictors.

During the past 30 years orthotopic liver transplantation has become a highly successful form of surgical treatments. The significant advances achieved in this field have led to an increased demand for organs and created a wide gap between organ availability and organ supply. A wider availability of organs for transplantation would allow an expansions rather than a contraction of the indications for transplantation, and, at the same time a relaxation of the patient selection criteria. All these facts clearly justify the renewed interest observed in the last decade in xenotransplantation. The original concept of xenografting, meaning the transplantation of cells, tissues, or organs between different species, is so ancient that it is easily recognizable in Greek and Roman mythology. The centaur Chiron, the teacher of Esculapius, and the Chimera are legendary examples of discordant xenogeneic creatures. However, it is only during this century that scientists have been able to bring this idea into the clinical arena. The early efforts were prompted by the shortage of humans organs at a time when there were few alternatives for treating end-stage organ failure.

Since the advent of the potent immunosuppressive agent FK 506, intestinal transplantation has become a feasible therapeutic option for patients with irreversible intestinal failure. In this chapter, we present our clinical experience with intestinal transplantation, focusing on the technical aspects of both the donor and recipient operations. The logistics of the operative procedure have been described previously.

An attempt was made to select donors for human kidney transplantation on the basis of lymphocyte antigen matching. Compatibility was assayed by reactions of individual antisera on donor and recipient lymphocytes, as well as by matching on the basis of the six recognized leukocyte groups. The donor judged to be the best match was chosen from pools of related and unrelated donors. Although the choice was often limited, a group of donors was selected which, as a whole, was slightly more compatible than that achieved by random matching. Mismatches which were extremely high or from group 6 were avoided whenever possible. Eighteen transplants were done from related donors: sixteen of these recipients lived for at least 4 months postoperatively; three more died after 1012, 812 and 8 months. Thirteen of the original 18 patients are still alive, 6, after 4 to 8 months, four, after 8 to 21 months and three, after more than one year. This represents a slight improvement over the first unmatched Denver series treated 2 to 312 years ago. Of the 14 recipients in the present series who received kidneys from matched unrelated donors, ten lived for more than 4 months; two more died after 5 and 10 months respectively. Eight of the original patients are still alive with a minimum follow-up of 612 months; four of these patients are surviving 9 to 12 months after operation, and the other three, more than one year. These results are improved over that of an original nonselected series of unrelated homotransplants performed in Denver. Furthermore, the survival curve in these nonrelated donors and recipients now approximates that which was obtained in the past Denver experience with randomly selected related donors. Because of the relatively small numbers involved, however, this improvement is not statistically significant. Pathological studies of the kidneys from the recipients who died were compared to the kidneys of the dead recipients of the first Denver series in which donors were randomly selected. Acute vascular lesions which result from severe rejection were less frequent in this series as compared to the earlier un-matched series. It was concluded that coincidental to matching for provisional leukocyte types, an improved early clinical outcome of transplantation was obtained with respect to survival and minimization of pathologic changes associated with rejection. Whether the improvements are attributable to the matching procedure or to other unrecognized factors in the clinical management of the patients could not be determined.

Alemtuzumab was used as an induction agent in 205 renal transplant recipients undergoing 207 living donor renal transplants. All donor kidneys were recovered laparoscopically. Postoperatively, patients were treated with tacrolimus monotherapy, and immunosuppression was weaned when possible. Forty-seven recipients of living donor renal transplants prior to the induction era who received conventional triple drug immunosuppression without antibody induction served as historic controls. The mean follow-up was 493 days in the alemtuzumab group and 2101 days in the historic control group. Actuarial 1-year patient and graft survival were 98.6% and 98.1% in the alemtuzumab group, compared to 93.6% and 91.5% in the control group, respectively. The incidence of acute cellular rejection (ACR) at 1 year was 6.8% in the alemtuzumab group and 17.0% (p < 0.05) in the historic control group. Most (81.3%) episodes of ACR in the alemtuzumab group were Banff 1 (a or b) and were sensitive to steroid pulses for the treatment of rejection. There was no cytomegalovirus disease or infection. The incidence of delayed graft function was 0%, and the incidence of posttransplant insulin-dependent diabetes mellitus was 0.5%. This study represents the largest series to date of live donor renal transplant recipients undergoing alemtuzumab induction, and confirms the short-term safety and efficacy of this approach.

Hepatitis C virus (HCV)-induced cirrhosis is the leading indication for liver transplantation throughout the world.32 Unfortunately, reinfection is nearly universal and recurrent disease occurs in a majority of recipients. HCV replication can be detected in the RNA-positive recipients within days after transplantation.27 Allograft dysfunction can occur as early as 1 week following transplantation in patients with high viral loads before transplantation,6 but the majority of HCV-positive recipients usually first show signs of recurrent disease between 2 and 3 months.11,31 Distinguishing among recurrent viral hepatitis and AR and CR and other causes of allograft dysfunction is based primarily on liver biopsy evaluation, Guidelines to recognize individual syndromes were proposed more than a decade ago, 13,16 but experience has shown the distinction to be problematic.1,19,25 Steatosis is an early nonspecific finding in recurrent HCV5; spotty hepatocyte necrosis, lobular disarray, and Kupffer’s cell hypertrophy are more reliable features that specifically point toward recurrent HCV as the cause of allograft injury.31,33 Later in the course of recurrent HCV, predominantly mononuclear portal inflammation with variable interface activity and low-grade bile duct damage signal the transition from acute to chronic hepatitis. Chronic HCV is characterized by mononuclear portal inflammation that is frequently arranged into nodular aggregates and mild bile duct damage that is neither as severe nor as widespread as is seen in acute rejection (AR) or chronic rejection (CR).31 Interface activity, including a type II ductular reaction, is also more common in hepatitis than in rejection. Retrospective analysis of case material to determine whether specific histopathologic criteria are useful in distinguishing among recurrent HCV and other causes of allograft dysfunction is fraught with pitfalls. The Electronic Data Interface for Transplantation (EDIT)15 software simultaneously creates an information portal for patient management and populates a research database. Real-time entry of all pertinent treatment, laboratory, and histopathology data into this software has enabled us to accomplish our primary goal. This objective was to prospectively and rigorously test our ability to distinguish among recurrent HCV, rejection, and other various causes of liver allograft dysfunction in HCV RNA-positive recipients enrolled in a recent “immunosuppression minimization protocol.”36 A secondary goal was to retrospectively analyze errors and determine how they might be avoided. The treatment protocol used in this patient population is based on the concept that alloantigen migration to the central lymphoid tissues of the recipient early after transplantation is an important event that simultaneously triggers rejection and tolerogenic immune responses.35–37 Pretransplant immunodepletion with anti-leukocyte antibodies is used to rein in the expected early alloresponse into a manageable range. This is combined with minimal posttransplantation monotherapy immunosuppression in an attempt to facilitate activation-induced apoptosis of donor-reactive lymphocytes.36 A final goal of this study was to determine whether histopathologic observations in this unique patient population shed any insight into our conceptual understanding of HCV pathogenesis in the allografted liver.

Limited data exist about Clostridium difficile colitis (CDC) in solid organ transplant patients. Between 1/1/99 and 12/31/02, 600 kidney and 102 pancreas–kidney allograft recipients were transplanted. Thirty-nine (5.5%) of these patients had CDC on the basis of clinical and laboratory findings. Of these 39 patients, 35 have information available for review. CDC developed at a median of 30 days after transplantation, and the patients undergoing pancreas–kidney transplantation had a slightly higher incidence of CDC than recipients of kidney alone (7.8% vs. 4.5%, P> 0.05). All but one patient presented with diarrhea. Twenty-four patients (64.9%) were diagnosed in the hospital, and CDC occurred during first hospitalization in 14 patients (40%). Treatment was with oral metronidazole (M) in 33 patients (94%)and M + oral vancomycin (M + V) in 2 patients. Eight patients had recurrent CDC, which occurred at a median of 30 days (range 15–314) after the first episode. Two patients (5.7%) developed fulminant CDC, presented with toxic megacolon, and underwent colectomy. One of them died; the other patient survived after colectomy. CDC should be considered as a diagnosis in transplant patients with history of diarrhea after antibiotic use, and should be treated aggressively before the infection becomes complicated.

Background. Survival after liver transplantation has improved significantly over the last decade with pediatric recipients faring better than adults. The 20-year experience of pediatric liver transplantation at Children's Hospital of Pittsburgh is reported in terms of patient survival; graft survival in relation to age, gender, and immunosuppressive protocols; causes of death; and indications for retransplantation. Method. From March 1981 to April 1998, 808 children received liver transplants at Children's Hospital of Pittsburgh. All patients were followed until March 2001, with a mean follow-up of 12.2±3.9 years (median=12.6; range=2.9-20). There were 405 female (50.2%) and 403 male (49.8%) pediatric recipients. Mean age at transplant was 5.3±4.9 years (mean=3.3; range 0.04-17.95), with 285 children (25.3%) being less than 2 years of age at transplant. Cyclosporine (CsA)-based immunosuppression was used before November 1989 in 482 children (50.7%), and the subsequent 326 recipients (40.3%) were treated with tacrolimus-based immunosuppression. Actuarial survival was calculated using the Kaplan-Meier statistical method. Differences in survival were calculated by log-rank analysis. Results. Overall patient survival at 1, 5, 10, 15, and 20 years was 77.1%, 72.6%, 69.4%, 65.8%, and 64.4%, respectively. There was no difference in survival for male or female patients at any time point. At up to 10 years posttransplant, the survival for children greater than 2 years of age (79.5%, 75.7%, and 71.6% at 1, 5, and 10 years, respectively) was slightly higher than those at less than 2 years of age (72.6%, 66.9%, and 65.3% at 1, 5, and 10 years, respectively). However, at 15 and 20 years posttransplant, survival rates were similar (>2 years=67.3% and 65.8%

Tacrolimus (TAC) and mycophenolate mofetil (MMF) are currently approved immunosuppressants for prevention of rejection in liver transplantation (LTx). They have different modes of action and toxicity profiles, but the efficacy and safety of MMF in primary liver transplantation with TAC has not been determined.An Institutional Review Board-approved, open-label, single-center, prospective randomized trial was initiated to study the efficacy and toxicity of TAC and steroids (double-drug therapy (D)) versus TAC, steroids, and MMF (triple-drug therapy (T)) in primary adult LTx recipients. Both groups of patients were started on the same doses of TAC and steroids. Patients randomized to T also received 1 gm MMF twice a day.Between August 1995 and May 1998, 350 patients were enrolled at a single center-175 in the D and 175 in the T groups. All patients were followed until May 1998, with a mean follow-up of 33.8+/-9.1 months. Using an intention-to-treat analysis, the 1-, 2-, 3-, and 4-year patient survival was 85.1%, 81.6%, 78.6%, and 75.8%, respectively, for D and 87.4%, 85.4%, 81.3%, and 79.9%, respectively, for T. The 4-year graft survival was 70% for D and 72.1% for T. Although the rate of acute rejection in the first 3 months was significantly lower for T than for D (28% for triple vs. 38.9% for double, P=0.03), the overall rate of rejection for T at the end of 1 year was not significantly lower than for the D (38.9% triple vs. 45.2% double). The median time to the first episode of rejection was 14 days for D versus 24 days for T (P=0.008). During the study period, 38 of 175 patients in D received MMF to control ongoing acute rejection, nephrotoxicity, and/or neurotoxicity. On the other hand, 103 patients in the T discontinued MMF for infection, myelosuppression, and/or gastrointestinal disturbances. The need for corticosteroids was less after 6 months for T and the perioperative need for dialysis was lower with use of MMF.This final report confirms similar patient survival and graft survival up to 4 years with a trend towards fewer episodes of rejection, lower need for steroids, and better perioperative renal function. However, the complex nature of LTx patients and their posttransplantation course prevents the routine application of MMF.

Background The long-term safety and efficacy of tacrolimus in pancreas transplantation has not yet been demonstrated. The observation of prolonged pancreatic graft function under tacrolimus would indicate that any potential islet toxicity is short-lived and clinically insignificant. We report herein the results of pancreas transplantation in patients receiving primary tacrolimus immunosuppression for a minimum of 2 years. Methods. From July 4, 1994 until April 18, 1996, 60 patients received either simultaneous pancreas-kidney transplant (n=55), pancreas transplant only (n=4), or pancreas after kidney transplantation (n=1). Baseline immunosuppression consisted of tacrolimus and steroids without antilymphocyte induction. Azathioprine was used as a third agent in 51 patients and mycophenolate mofetil in 9. Rejection episodes within the first 6 months occurred in 48 (80%) patients and were treated with high-dose corticosteroids. Antilymphocyte antibody was required in eight (13%) patients with steroid-resistant rejection. Results. With a mean follow-up of 35.1±5.9 months (range: 24.3-45.7 months), 6-month and 1-, 2-, and 33-year graft survival is 88%, 82%, 80%, and 80% (pancreas) and 98%, 96%, 93%, and 91% (kidney), respectively. Six-month and 1-, 2-, and 3-year patient survival is 100%, 98%, 98%, and 96.5%. Mean fasting glucose is 91.6±13.8 mg/dl, and mean glycosylated hemoglobin is 5.1±0.7% (normal range: 4.3-6.1%). Mean tacrolimus dose is 6.5±2.6 mg/day and mean prednisone dose 2.0±2.9 mg/day at follow-up. Complete steroid withdrawal was possible in 31 (65%) of the 48 patients with functioning pancreases. Conclusions. These data show for the first time that tacrolimus is a safe and effective long-term primary agent in pancreas transplantation and provides excellent long-term islet function without evidence of toxicity while permitting steroid withdrawal in the majority of patients.

We employed antibody pre-conditioning with alemtuzumab and posttransplant immunosuppression with low-dose tacrolimus monotherapy in 26 consecutive pediatric kidney transplant recipients between January 2004 and December 2005. Mean recipient age was 10.7 +/- 5.8 years, 7.7% were undergoing retransplantation, and 3.8% were sensitized, with a PRA >20%. Mean donor age was 32.8 +/- 9.2 years. Living donors were utilized in 65% of the transplants. Mean cold ischemia time was 27.6 +/- 6.4 h. The mean number of HLA mismatches was 3.3 +/- 1.3. Mean follow-up was 25 +/- 8 months. One and 2 year patient survival was 100% and 96%. One and 2 year graft survival was 96% and 88%. Mean serum creatinine was 1.1 +/- 0.6 mg/dL, and calculated creatinine clearance was 82.3 +/- 29.4 mL/min/1.73 m(2). The incidence of pre-weaning acute rejection was 11.5%; the incidence of delayed graft function was 7.7%. Eighteen (69%) of the children were tapered to spaced tacrolimus monotherapy, 10.5 +/- 2.2 months after transplantation. The incidence of CMV, PTLD and BK virus was 0%; the incidence of posttransplant diabetes was 7.7%. Although more follow-up is clearly needed, antibody pre-conditioning with alemtuzumab and tacrolimus monotherapy may be a safe and effective regimen in pediatric renal transplantation.

Fibrolamellar hepatoma (FL-HCC) is an uncommon variant of hepatocellular carcinoma (HCC), distinguished by histo-pathological features suggesting greater differentiation than conventional HCC. However, the optimal treatment and the prognosis of FL-HCC have been controversial. Follow-up studies are available from 1 year to 27 years, after 41 patients with FL-HCC were treated with partial hepatectomy (PHx) (28 patients) or liver transplantation (13 patients). In this retrospective study, the effect on outcome was determined for the pTNM stage and other prognostic factors routinely recorded at the time of surgery. Cumulative survival at 1, 3, 5, and 10 years was 97.6%, 72.3%, 66.2%, and 47.4%. Tumor-free survival at these times was 80.3%, 49.4%, 33%, and 29.3%. The TNM stage was significantly associated with tumor-free survival. Patients with positive nodes had a shorter tumor-free survival than those with negative nodes (P < .015). Patient survival was most adversely affected by the presence of vascular invasion (P < .05). FL-HCC is an indolently growing tumor of the liver, which usually was diagnosed in our patients at a stage too advanced for effective surgical treatment of most conventional HCC. Nevertheless, long-term survival frequently was achieved with aggressive surgical treatment. When a subtotal hepatectomy could not be performed, total hepatectomy (THx) with liver transplantation was a valuable option.

Lymphoreticular malignancies, collectively called posttransplant lymphoproliferative disorders (PTLD), eventually develop in 2-5% of organ transplant recipients. They frequently undergo regression when immunosuppression is reduced or stopped. This feature has been associated with a previous or de novo Epstein-Barr virus (EBV) infection. We herein describe immunotherapy with autologous lymphokine-activated killer (LAK) cells in seven patients with PTLD (four EBV-positive patients and three EBV-negative patients). Autologous peripheral blood mononuclear cells were obtained by leukapheresis, depleted of monocytes, and cultured in the presence of interleukin 2 for 10 to 11 days. A single dose of 5.2 x 10(9) to 5.6 x 10(10) LAK cells was given intravenously. Systemic interleukin 2 was not administered. The four patients with EBV+ PTLD had complete tumor regression; two of them developed controllable rejection. Three patients are well 13-16 months after treatment; the fourth patient died of pneumonia 41 days after infusion. Three patients with EBV- lymphomas had no response despite prior evidence that their tumors also were subject to immune surveillance. Two of these three patients died after being given other treatment, and the third patient has persistent tumor. In conclusion, autologous LAK cell infusion was effective for treatment of four EBV+ organ transplant recipients. LAK cell efficacy for three patients with EBV- PTLD was not evaluable under the management circumstances in which this treatment was utilized.

In organ allograft recipients, the persistence of donor leukocytes within recipient tissues for indefinite periods has been construed as evidence of the transfer of hematopoietic stem and progenitor cells (1, 2). Moreover, multilineage donor leukocyte microchimerism has been postulated to be an essential condition for organ allograft acceptance (1–3). Accounts of the multilineage nature of microchimerism have emphasized the invariable prominence of donor-derived dendritic cells (DC*) (1–5). Both DC progenitors and other leukocytes of donor origin that engage the host immune system may have tolerogenic properties (6). Current efforts to enhance “spontaneous microchimerism” in human organ transplantation focus on the administration of unmodified donor bone marrow (BM) by either single or multiple infusions (7, 8). This is undertaken without recipient cytoablation. Conventional immunosuppressive therapy is believed to facilitate donor cell survival and to promote the reciprocal donor-recipient leukocyte engagement that may provide the basis of allograft acceptance (9). A potential chimerism-enhancing strategy that is well-recognized in BM transplantation, but that has not been evaluated formally in organ allograft recipients, is the use of hematopoietic growth factors. Many of these can either enhance, inhibit, or bi-functionally affect the proliferation and differentiation of hematopoietic progenitor cells (10–13). They comprise granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), and a variety of other cytokines that act at an earlier point in the hematopoietic cascade, such as interleukin (IL) 3, stem cell factor (c-kit ligand), and the recently cloned flt3 ligand (FL) (14). In the hemopoietic system, the expression of flt3 (a member of the type III receptor tyrosine kinase family that also includes c-kit and fms) is believed to be restricted to primitive progenitor cells that respond to FL (.14–17) PL potently synergizes with the colony-stimulating factors and c-kit ligand to enhance growth of hemopoietic progenitors (14–19). Notably, there is recent evidence that in contrast to the case with GM-CSF, G-CSF, and c-kit ligand, administration of FL to normal mice leads to dramatic increases in DC numbers, both in lymphoid and nonlymphoid tissues (20). In this study, we examined the influence of short-term (7-day) FL treatment on donor leukocyte microchimerism, both in normal (noncytoablated) and tacrolimus (formerly FK506)-immunosuppressed recipients of unmodified allogeneic BM. For comparative purposes, similar experiments were undertaken with GM-CSF. The results show that when administered with tacrolimus, FL dramatically augments hematopoietic cell chimerism within recipient lymphoid tissue. We also show that donor major histocompatibility complex (MHC) class II+ cells with distinct DC characteristics are a prominent feature of the greatly enhanced donor cell population. These findings may have important implications for the therapeutic application of FL to augment chimerism and to promote donor-recipient leukocyte interactions that may predispose to improved organ allograft survival.

THE MORBIDITY arising from the chronic use of .1. anti-rejection medications is an incentive to establish the lowest posSIble level of immunosuppression necessary to maintain stable graft function. The finding that freedom from immunosuppression was sporadically possible in longsurviving recipients of liver allografts and the concurrent evidence that chimerism was uniformly demonstrable in such tolerant patients! have led to a prospective trial of complete drug weaning. In our initial experience, it was shown that significant reductions in medication or their discontinuance could be safely accomplished in liver,: and even in a handful of living-related kidney recipients who have been drug free for as long as 30 years.3 However, the danger of consequent allograft rejection has not been completely assessed and guidelines for judicious weaning need to be clarified. We present here further follow-up on our previously reported weaning trial in liver allograft recipients2 and results from additiona.l patients subsequently entered.

Over the 5 year period from 7/14/1989 until 5/24/1994, we have attempted graft salvage with tacrolimus conversion in a total of 169 patients (median age 33 years, range 2-75 years) with ongoing rejection on baseline CsA immunosuppression after failure of high dose corticosteroids and/or antilymphocyte preparations to reverse rejection. The indications for conversion to tacrolimus were ongoing, biopsy confirmed rejection in all patients. The median interval to tacrolimus conversion was 2 months (range 2 days to 55 months; mean 4.3+2.6 months) after transplantation. All patients had failed high dose corticosteroid therapy and 144 (85%) of the 169 patients had received at least one course of an antilymphocyte preparation plus high dose corticosteroid therapy prior to conversion. Twenty-eight patients (17%) were dialysis-dependent at the time of conversion owing to the severity of rejection. With a mean follow-up of 30.0±2.4 months (median 36.5 months, range 12-62 months), 125 of 169 patients (74%) have been successfully rescued and still have functioning grafts with a mean serum creatinine (SCR) of 2.3±1.1mg/dl. Of the 144 patients previously treated with antilymphocyte preparations, 117 (81%) were salvaged. Of the 28 patients on dialysis at the time of conversion to tacrolimus, 13 (46%) continue to have functioning grafts (mean SCR 2.15+0.37 mg/dl) at a mean follow-up of 37.3±16.7 months. In the 125 patients salvaged, prednisone doses have been lowered from 28.0+9.0mg/d (median 32, range 4-60mg/d) pre-conversion to 8.5±4.1mg/d (median 12 mg/d, range 2.5-20 mg/d) postconversion. Twenty-eight patients (22.4%) are currently receiving no steroids. This 5 year experience demonstrates that tacrolimus has sustained efficacy as a rescue agent for ongoing renal allograft rejection. Based on these data, we recom-mend that tacrolimus be used as an alternative to the conventional drugs used for antirejection therapy in renal transplantation.

The influence of donor major histocompatibility complex (MHC) class I- or class II-deficiency on the initiation of first- and second-set rejection of mouse heart and liver allografts was examined. C3H (H-2k) mice received heterotopic cardiac or orthotopic liver grafts from unmodified B10 (H-2b), B6 (H-2b), b2m (H-2b; class I deficient) or AB0 (H-2b; class II deficient) donors. Organ survival was also investigated in C3H recipients that had been presensitized by a normal B10 skin graft 2-3 weeks before heart or liver transplantation. The absence of cell surface MHC class I or class II resulted in significant prolongation of primary cardiac allograft survival. Three of seven (43%) MHC class I-deficient, and two of five (40%) class II-deficient heart grafts were accepted indefinitely (survival time > 100 days). Thus both MHC class I and class II molecules appear to be important for the elicitation of first-set rejection in the heart allograft model. All liver allografts survived > 100 days in normal recipients. In C3H recipients that had been presensitized by a B10 skin graft, however, both heart and liver grafts from AB0 (class II deficient) donors underwent accelerated rejection (median survival time [MST] 3 and 4 days, respectively). In contrast, liver grafts from class I-deficient mice (b2m) were still accepted indefinitely by B10 skin-presensitized C3H recipients, whereas class I-deficient hearts survived significantly longer than those from class II-deficient or normal donors. These data demonstrate that the expression of donor MHC class I, and not class II is crucial in initiating second-set organ allograft rejection. In vitro monitoring revealed that at the time of organ transplant, both splenocytes and serum of the skin-presensitized animals displayed high cytotoxicity against AB0 (class II-deficient) but not against b2m (class I-deficient) targets.

FK506 (Tacrolimus) recently has been shown to be an effective immunosuppressant after renal transplantation. It is associated with less hypertension, hypercholesterolemia and steroid use compared with cyclosporine. We report 10 patients on FK506 who showed fibrin thrombi within the glomerular capillaries and/or arterioles at renal allograft biopsy. These biopsies were generally performed to assess increasing serum creatinine levels; laboratory evidence of hemolytic uremic syndrome was present in one instance. Plasma or whole blood FK506 levels were elevated in eight of 10 cases. Reduction of immunosuppression led to clinical improvement or biopsy-proven resolution of thrombi in all cases. These observations suggest that FK506 may occasionally produce microvascular changes in the renal allograft. The estimated incidence of this occurrence (1%) is comparable with that reported with cyclosporine (3%).

Although the rat is commonly used for basic immunology and transplantation research, phenotypic and functional characterization of rat dendritic cells (DCs) lags behind similar studies in the human and mouse. Therefore, these features were examined using DCs propagated from cultures of rat bone marrow maintained in a medium supplemented with granulocyte-monocyte colony-stimulating factor. Analysis of cytospin preparations of cultured cells showed that DCs arise from OX7+ myelomonocytic precursors. Typical mature rat DCs were morphologically similar to their mouse and human counterparts and expressed major histocompatibility complex (MHC) class II (common part determinant of Ia), OX62 (integrin molecule), OX7 (CD90), ICAM-1 (CD54), and CTLA4 counterreceptor, but were negative for OX8 (CD8), OX19 (CD5), W3/25 (CD4), and ED2, a rat macrophage marker. Functional analysis of OX62+ sorted DCs showed that they could effectively present the soluble antigen ovalbumin to naive T cells in vitro. A combination of anti-MHC class II monoclonal antibody and CTLA4-immunoglobulin inhibited allostimulatory ability more effectively than either reagent alone. Implications for studying the role of DCs in immune responses in the rat are discussed.

To determine the role of NK cells in regulation of tissue growth, the phenotype and function of liver-resident NK cells were studied after 70% partial hepatectomy in rats. The process of liver regeneration was generally completed by day 14. In contrast, the number of liver-resident NK cells (NKR-P1bright) was restored as early as day 3 after partial hepatectomy. However, spontaneous functions of liver-resident NK cells, including killing of YAC-1 and P815 targets, Ab-dependent cellular cytotoxicity, and redirected killing via NKR-P1, were continuously suppressed throughout the entire period of liver regeneration (from 3 h to 14 days). Augmentation of NK cytotoxicity against P815 targets and induction of NK cell adherence to plastic following 24 h of IL-2 stimulation showed a similar pattern of suppression. However, IL-2-induced augmentation of YAC-1 killing, proliferation and generation of adherent NK cells, and LAK activity in 5- to 7-day cultures were found to be suppressed only during the first 24 h and increased between days 2 and 7 after hepatectomy. Sorted NK cells (> or = NKR-P1bright) from liver-resident mononuclear leukocytes 24 h after partial hepatectomy showed the same pattern of suppression as unsorted mononuclear leukocytes. In contrast to liver-resident NK cells, no significant changes were detected in peripheral blood or spleen NK cells of rats following partial hepatectomy. Of particular interest, in normal liver, hepatocytes were resistant to NK lysis, while resident NK cells were cytotoxic for various NK-sensitive targets. In contrast, during the early period of liver regeneration, when hepatocytes were sensitive to lysis by liver-resident NK cells of normal rats, NK cells obtained from regenerating liver tissues were unable to mediate cytotoxicity. At the final phase of liver regeneration (days 7-14 after hepatectomy), both resistance of hepatocytes to killing by NK cells and cytotoxicity of liver-resident lymphocytes against hepatocytes from regenerating liver were simultaneously restored. In vivo depletion of NK cells by injection of rats with anti-NKR-P1 mAb resulted in a significant augmentation of liver regeneration subsequent to partial hepatectomy. Our data suggest that liver-resident NK cells may be involved in regulation of the extent of liver regeneration.

Although liver biopsy is a very useful procedure used frequently in the diagnosis and management of liver dysfunction occurring after orthotopic liver transplantation, complications can occur with its use. An unusual complication of arterioportal fistula is reported here. Based upon this small series of an unusual event and the knowledge that the posttransplant liver may be more hypervascular than prior to OLTx and that it is uniquely susceptible to hepatic infarction and abscess formation, any attempt at fistula closure should be considered carefully prior to initiating the therapy (15). Unless a serious complication occurs [such as a transient biliary obstruction due to hemobilia as occurred in case 2, portal hypertension as also occurred in case 2, or systemic sepsis or other symptoms develop related directly to the fistula], simple observation may be the best choice of action. Should therapy be required, hepatic arterial embolization should be reserved for adults with intrahepatic fistulas. Primary surgical closure of intrahepatic fistula should be reserved for cases of extrahepatic fistula.

In order to assess the incidence and possible predisposing and contributing factors in the development of acute pancreatitis after liver transplantation, we reviewed the medical records of all 1832 adult patients who underwent 2161 orthotopic liver transplantation (OLTx) procedures in our center between January 1987 and September 1992. Of these patients, 55 (3 % incidence) developed clinical pancreatitis and 247 (13.4 % incidence) developed hyperamylasemia (biochemical pancreatitis). Overall mortality in cases of clinical pancreatitis was 63.6 %. The mortality in cases of hyperamylasemia was similar to that found in the general liver transplant population (i. e., 23 %). A strong correlation was found between pancreatitis after liver transplantation and end-stage liver disease due to hepatitis B (30 % of the cases, P = 0.00001). Extensive surgical dissection around the pancreas (P < 0.05), the type of biliary reconstruction following liver transplantation (P < 0.05), and the number of liver grafts received by the same patient (P = 0.00001) appeared to be possible contributing factors as did the duration of venovenous bypass and the quantity of IV calcium chloride administered intraoperatively.

We have previously postulated that donor cell chimerism in organ transplantation is needed to attain a tolerant state. Here we show that donor cell chimerism can be augmented in organ recipients if they are infused perioperatively with 3 x 10(8) per kg of unmodified donor bone marrow cells and are kept on a conventional immunosuppressive regimen of tacrolimus (FK506) and prednisolone. 36 patients took part, of whom the first 18 patients have good transplanted kidney (n = 10), liver (n = 7), and heart (n = 7) function when followed up between 4 and 16 months. All patients are well. We found persistent multilineage leucocyte chimerism in blood of 17 recipients by flow cytometry and PCR techniques to detect donor alleles or Y chromosomes in female recipients of male organs. The use of the 5-antigben HLA matched same sex donor precluded detection of chimerism in one patient.

Intestinal transplantation is often the only alternative form of treatment for patients dependent on total parenteral nutrition for survival. Although a limited number of intestinal transplantations have been performed, results with FK 506 immunosuppression are comparable to those for other organ transplants. The impact of successful intestinal transplantation on gastroenterology will likely be similar to the impact of kidney and liver transplantation on nephrology and hepatology.

Survival for children is significantly higher than for adults after liver transplantation (LTx).1 A center-specific 20-year retrospective analysis of all pediatric transplant recipients was implemented to determine patient and graft survival, graft survival, and differences in survival related to immunosuppressive protocols.

Techniques for multiple organ procurement of the heart, liver, and kidneys were first described by Starzl1 and have been adopted throughout the world. Although this conventional technique provides usable organs in the majority of cases it has certain limitations principally due to the need for time-consuming dissection of the hepatic hilar structures. These limitations, which became critically evident in the unstable donor, have led to the evolution and refinement of this technique2 and its eventual standardization. The final simplified version, commonly referred to as the rapid flush technique, requires no preliminary hilar dissection and allows for rapid organectomy in a bloodless field after early in situ core cooling.3 This report describes a 2-year retrospective review of 437 donor hepatectomies comparing our experience with both the conventional and rapid flush techniques.

This report provides our initial experience on islet isolation and intrahepatic allotransplantation in 20 patients. In Group 1, 10 patients underwent combined liver-islet allotransplantation following upper-abdominal exenteration for cancer. One patient underwent pancreatic islet allograft after near total pancreatectomy for chronic pancreatitis. In Group 2, 3 Type I diabetic patients received a combined liver-islet allograft for cirrhosis and diabetes. In Group 3, 7 Type I diabetic patients received 8 combined cadaveric kidney-islet grafts (one retransplant) for end stage renal disease. The islets were separated by a modification of the automated method for human islet isolation and the preparations were infused into the portal vein. Immunosuppression was with FK-506 (Group 1) plus steroids (Groups 2 and 3). Six patients in Group 1 did not require insulin treatment for 5 to >16 mo. In Groups 2 and 3 none of the patients became insulin-independent, although ongoing C-peptide secretion, decreased insulin requirement and stabilization of diabetes were observed. Our results indicate that islet transplantation is most effective in pancreatectomy induced diabetes. However, rejection is still a major factor limiting the clinical application of islet transplantation in patients with Type I diabetes mellitus. Other factors such as steroid treatment may contribute to deteriorate islet engraftment and/or function.

The outcome of human islet isolation procedures can be significantly effected by the technique used for pancreas procurement. In fact, the final step of islet purification using discontinuous density gradients requires a significant difference between the density of the islets and the density of the non-endocrine component of the gland. Therefore, any procedure during multi-organ procurement that will result in edema or degranulation of the acinar tissue will result in failure of the islet purification step. In this report a technique for combined harvesting of liver and pancreas is presented. The use of this procedure can be of assistance to avoid damage to the pancreas that could result in a compromised islet purification for improper handling of the gland even before it arrives to the isolation facility.

The clinical characteristics and neuropathological findings of 22 organ transplant recipients with CNS aspergillosis were reviewed. Thirteen patients had liver, six kidney, two heart and one had cluster transplants. The most frequent neurological symptoms were alteration of mental status (86%), seizures (41%) and focal neurological deficits (32%). Meningeal signs were less common (19%). Aspergillus spp invasion of the blood vessels with subsequent ischaemic or haemorrhagic infarcts, and solitary or multiple abscesses were the predominant neuropathological findings. The lungs were the probable portal of entry; however, isolated CNS aspergillosis was seen in two patients. Antemortem diagnosis of the infection was made in half of the patients. Concomitant diabetes mellitus was noted in 59% of the patients and bacterial or other severe infections in 86%. No specific clinical or pathological pattern could be identified among patients with different types of organ transplants. In addition CNS aspergillosis was preceded by organ rejection and the need for intense immunosuppression and retransplantation in the majority of the patients.

The efficacy of the University of Wisconsin (UW) solution was compared with conventional Euro-Collins solution, as well as with 3 variants of a silica gel solution developed at the University of Minnesota (UM). Protection of the liver grafts with UW was superior after 24 hour preservation, although the results were inferior to those with immediate transplantation, as judged by animal survival, liver function tests, coagulation, and histopathologic parameters. The UM-III solution allowed similar animal survival as with the UW solution. Lactobionate and raffinose that are contained in both the UW and UM-III solutions were thought to be essential constituents for long-term preservation of liver grafts. The study not only establishes, under controlled circumstances, the superiority of the UW solution, but it also provides insight about the reasons for its effectiveness as well as a caution against its over exploitation.