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Background: The preoperative workup of orthotopic liver transplantation (OLT) patients is practically complex given the need for multiple imaging modalities. We recently demonstrated in our proof-of-concept study the value of a one-stop-shop approach using cardiovascular MRI (CMR) to address this complex problem. However, this approach requires further validation in a larger cohort, as detection of hepatocellular carcinoma (HCC) as well as cardiovascular risk assessment is critically important in these patients. We hypothesized that coronary risk assessment and HCC detectability is acceptable using the one-stop-shop CMR approach., Methods: In this observational study, patients underwent CMRI evaluation including cardiac function, stress CMR, thoracoabdominal MRA, and abdominal MRI on a standard MRI scanner in one examination., Results: Over 8 years, 252 OLT candidates underwent evaluation in the cardiac MRI suit. The completion rates for each segment of the CMR examination were 99% for function, 95% completed stress CMR, 93% completed LGE for viability, 85% for liver MRI, and 87% for MRA. A negative CMR stress examination had 100% CAD event-free survival at 12 months. A total of 63 (29%) patients proceeded to OLT. Explant pathology confirmed detection/exclusion of HCC., Conclusions: This study further defines the population suitable for the one-stop-shop CMR concept for preop evaluation of OLT candidates providing a road map for integrated testing in this complex patient population for evaluation of cardiac risk and detection of HCC lesions., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: This study explored the safety of early steroid withdrawal in recipients of expanded criteria deceased-donor kidney transplants., Materials and Methods: Using the Organ Procurement and Transplant Network-United Network of Organ Sharing database, we identified patients who underwent expanded criteria deceased-donor kidney transplant between January 2000 and December 2008 after receiving induction with rabbit-antithymocyte globulin (n = 3717), alemtuzumab (n = 763), or interleukin 2 blocking agent (n = 2600) followed by calcineurin inhibitor and mycophenolate mofetil-based maintenance with and without steroid therapy., Results: Adjusted overall graft survival (hazard ratio 1.32; 95% confidence interval, 1.1-1.56; P = .002) and patient survival (hazard ratio 1.46, 95% confidence interval, 1.16-1.83, P = .001) were inferior, whereas death-censored graft survival (hazard ratio 1.13; 95% confidence interval, 0.87-1.47; P = .35) was similar for chronic steroid maintenance versus early steroid withdrawal groups in rabbit-antithymocyte globulin-induced patients. Graft and patient outcomes were similar for chronic steroid maintenance versus early steroid withdrawal groups among alemtuzumab and interleukin 2 blocking agent-induced patients. Among rabbit-antithymocyte globulin-induced patients, adjusted overall graft survival (hazard ratio 1.57; 95% confidence interval, 1.2-2.0; P < .001) and patient survival (hazard ratio 1.5; 95% CI, 1.15-2.1; P = .004) were inferior, whereas death-censored graft survival (hazard ratio 1.5; 95% confidence interval, 0.97-2.43; P = .07) trended inferior for chronic steroid maintenance versus early steroid withdrawal groups in recipients > 60 years old (n = 1729)., Conclusions: Our study showed safety of early steroid withdrawal in recipients of expanded criteria deceased-donor kidney transplants who underwent perioperative induction followed by calcineurin inhibitor and mycophenolate mofetil maintenance. Among rabbit-antithymocyte globulin-induced patients, chronic steroid maintenance was associated with inferior graft and patient outcomes, an effect limited to older recipients.

Aim: To analyze the impact of steroid maintenance on the outcomes in kidney transplant recipients stratified by induction agent received., Methods: Patients who underwent first-time deceased donor kidney transplantation between 2000 and 2008 after receiving induction therapy with rabbit-antithymocyte globulin (r-ATG), alemtuzumab or an interleukin-2 receptor blocker (IL-2B) and discharged on a calcineurin inhibitor (CNI)/mycophenolate mofetil (MMF)-regimen along with or without steroids were identified from the Organ Procurement and Transplant Network/United Network of Organ Sharing database. For each induction type, adjusted overall and death-censored graft as well as patient survivals were compared between patients discharged on steroid vs no steroid. Among r-ATG induced patients, analysis was repeated after splitting the group into low and high immune risk groups., Results: Among the 37217 patients included in the analysis, 17863 received r-ATG (steroid = 13001, no-steroid = 4862), 3028 alemtuzumab (steroid = 852, no-steroid = 2176) and 16326 IL-2B (steroid = 15008, no-steroid = 1318). Adjusted overall graft survival was inferior (HR = 1.16, 95%CI: 1.06-1.27, P = 0.002) with similar death-censored graft survival (HR = 0.99, 95%CI: 0.86-1.14, P = 0.86) for steroid vs no-steroid groups in r-ATG induced patients. Both adjusted overall and death-censored graft survivals for steroid vs no-steroid groups were similar in alemtuzumab (HR = 0.92, 95%CI: 0.73-1.15, P = 0.47 and HR = 0.87, 95%CI: 0.62-1.22, P = 0.43 respectively) and IL-2B (HR = 1.05, 95%CI: 0.91-1.21, P = 0.48 and HR = 0.94, 95%CI: 0.75-1.18, P = 0.60 respectively) induced groups. Adjusted patient survivals were inferior for steroid vs no-steroid groups in r-ATG induced (HR = 1.31, 95%CI: 1.15-1.49, P < 0.001) but similar in alemtuzumab (HR = 1.02, 95%CI: 0.75-1.38, P = 0.92) and IL-2B (HR = 1.17, 95%CI: 0.97-1.40, P = 0.10) induced patients. Among the r-ATG induced group there were 4346 patients in the low immune risk and 13517 patients in the high immune risk group. Adjusted overall graft survivals were inferior for steroid vs no steroid groups in both low immune (HR = 1.34, 95%CI: 1.09-1.64, P = 0.001) and high immune (HR = 1.18, 95%CI: 1.07-1.30, P = 0.005) risk groups. Adjusted death-censored graft survivals for steroid vs no steroid groups were similar in both low (HR = 1.06, 95%CI: 0.78-1.45, P = 0.70) and high (HR = 1.04, 95%CI: 0.98-1.20, P = 0.60) immune risk groups. Adjusted patient survivals were inferior for steroid vs no steroid groups in both low immune (HR = 1.54, 95%CI: 1.18-2.02, P < 0.001) and high immune (HR = 1.32, 95%CI: 1.16-1.51, P = 0.002) risk groups. Overall, there were significantly higher deaths from infections and cardiovascular causes in patients maintained on steroids., Conclusion: Our study showed an association between steroid addition to a CNI/MMF-maintenance regimen and increased death with functioning graft in patients receiving r-ATG induction for first-time deceased donor kidney transplantation.

Background: Preoperative cardiovascular risk stratification in orthotopic liver transplantation candidates has proven challenging due to limitations of current noninvasive modalities. Additionally, the preoperative workup is logistically cumbersome and expensive given the need for separate cardiac, vascular, and abdominal imaging. We evaluated the feasibility of a "one-stop shop" in a magnetic resonance suite, performing assessment of cardiac structure, function, and viability, along with simultaneous evaluation of thoracoabdominal vasculature and liver anatomy., Methods: In this pilot study, patients underwent steady-state free precession sequences and stress cardiac magnetic resonance (CMR), thoracoabdominal magnetic resonance angiography, and abdominal magnetic resonance imaging (MRI) on a standard MRI scanner. Pharmacologic stress was performed using regadenoson, adenosine, or dobutamine. Viability was assessed using late gadolinium enhancement., Results: Over 2 years, 51 of 77 liver transplant candidates (mean age, 56 years; 35% female; mean Model for End-stage Liver Disease score, 10.8; range, 6-40) underwent MRI. All referred patients completed standard dynamic CMR, 98% completed stress CMR, 82% completed late gadolinium enhancement for viability, 94% completed liver MRI, and 88% completed magnetic resonance angiography. The mean duration of the entire study was 72 min, and 45 patients were able to complete the entire examination. Among all 51 patients, 4 required follow-up coronary angiography (3 for evidence of ischemia on perfusion CMR and 1 for postoperative ischemia), and none had flow-limiting coronary disease. Nine proceeded to orthotopic liver transplantation (mean 74 days to transplantation after MRI). There were six ascertained mortalities in the nontransplant group and one death in the transplanted group. Explant pathology confirmed 100% detection/exclusion of hepatocellular carcinoma. No complications during CMR examination were encountered., Conclusions: In this proof-of-concept study, it appears feasible to perform a comprehensive, efficient, and safe preoperative liver transplant imaging in a CMR suite-a one-stop shop, even in seriously ill patients.

Background: Pre-transplant dialysis duration exerts a graded negative influence on outcomes after kidney transplantation. Higher immune reactivity associated with prolonged dialysis with consequent increased acute rejection could be contributory., Methods: Using the Organ Procurement and Transplant Network/United Network of Organ Sharing database, we identified patients ≥ 18 years of age who received deceased-donor kidney (DDK) transplants from 2000 to 2008 after being on maintenance dialysis for ≥ 4 years. Patients received induction therapy with rabbit antithymocyte globulin (r-ATG), alemtuzumab, or an interleukin-2 receptor blocker (IL-2B) and were discharged on calcineurin inhibitor (CNI)/mycophenolate mofetil (MMF)-based immunosuppression with or without steroid. Unadjusted and adjusted graft/patient survivals were compared in steroid versus no-steroid groups by induction type., Results: A total of 14,459 patients were identified, of which 7,684 received r-ATG (steroid, 6,098; no-steroid, 1,586), 1,292 alemtuzumab (steroid, 362; no-steroid, 930), and 5,483 an IL-2B agent (steroid, 5,107; no-steroid, 376). Adjusted graft survivals were similar for steroid versus no-steroid groups in r-ATG (hazard ratio [HR] 1.10, 95% confidence interval (CI) 0.96-1.26, P = .16), alemtuzumab (HR 0.88, 95% CI 0.65-1.19; P = .40), and IL-2B (HR 0.91, 95% CI 0.73-1.13; P = .38) groups. Adjusted patient survival for steroid versus no-steroid groups was inferior in r-ATG (HR 1.41, 95% CI 1.17-1.71; P < .001) but similar in alemtuzumab (HR 1.05, 95% CI 0.70-1.59; P = .80) and IL-2B (HR 1.17, 95% CI 0.86-1.58; P = .32) groups., Conclusions: Our analysis failed to show a graft survival benefit for the addition of steroid to a CNI/MMF-based immunosuppression after induction with r-ATG, alemtuzumab, or an IL-2B agent in DDK recipients exposed to prolonged pretransplantation dialysis., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background and Objectives: Delayed graft function (DGF) is associated with adverse long-term outcomes after deceased-donor kidney (DDK) transplantation. Ischemia-reperfusion injury plays a crucial role in the development of DGF. On the basis of promising animal data, this study evaluated any potential benefits of erythropoietin-alfa (EPO-α) given intra-arterially at the time of reperfusion of renal allograft on the degree of allograft function, as well as tubular cell injury measured by urinary biomarkers in the early post-transplant period., Design, Setting, Participants, & Measurements: A prospective, randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the influence of EPO-α administered intraoperatively on the outcomes of DDK transplantations performed at the study center between March 2007 and July 2009., Results: Seventy-two patients were randomly assigned to EPO-α (n=36) or placebo (n=36). The incidences of DGF, slow graft function, and immediate graft function did not significantly differ between the treatment and control groups (41.7% versus 47.2%, 25.0% versus 36.1%, and 33.3% versus 16.7%, respectively; P=0.24). The groups had similar levels of urinary biomarkers, including neutrophil gelatinase-associated lipocalin and IL-18 at multiple times points soon after transplantation; urinary output during the first 3 postoperative days; 1-month renal function; and BP readings, hemoglobin, and adverse effects during the first month., Conclusions: This study did not show any clinically demonstrable beneficial effects of high-dose EPO-α given intra-arterially during the early reperfusion phase in DDK transplant recipients in terms of reducing the incidence of DGF or improving short-term allograft function.

Background: Kidney transplantation in hepatitis C virus-seropositive (HCV+) recipients improves survival compared to staying on the waiting list. A concern for using depleting (versus nondepleting) induction agent during kidney transplantation in HCV+ recipients is the possibility that the associated enhanced immunosuppression might favor the progression of hepatitis C infection, leading to adverse outcomes., Methods: Utilizing data from the Organ Procurement and Transplant Network, we identified HCV+ patients ≥ 18 years of age who underwent deceased donor kidney (DDK) transplants from either HCV+ or HCV- donors between 1998 and 2008. Patients were divided into two groups based on the induction type they received during the transplant: depleting agent (rabbit-antithymocyte globulin or alemtuzumab) or nondepleting agent (basiliximab or daclizumab) groups. Unadjusted and adjusted graft and patient survivals (Cox regression) between the groups were compared., Results: A total of 3490 HCV+ DDK recipients were identified (1859 in the depleting and 1631 in the nondepleting groups). When compared to nondepleting agent, adjusted graft (hazard ratio [HR] 1.11, 95% confidence interval [CI] 0.96-1.28, P = .16) and patient (HR 1.15, 95% CI 0.93-1.42, P = .2) survivals were similar with depleting agent induction. HCV donor seropositivity did not adversely impact either graft (HR 1.11, 95% CI 0.96-1.29, P = .17) or patient (HR 1.15, 95% CI 0.93-1.42, P = .2) outcomes., Conclusions: Our analysis supports the practice of transplanting HCV+ donor kidneys into HCV+ recipients to alleviate waiting list burden. Recipient HCV positivity should not influence selection of induction agent., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Over last several years, alemtuzumab induction has been increasingly used in kidney transplantation especially in patients maintained on steroid-free immunosuppression. It is unclear which induction agent is associated with better graft and patient outcomes in these patients., Methods: Using Organ Procurement and Transplant Network/United Network of Organ Sharing database, graft and patient survivals were compared with multivariate analysis for deceased donor kidney transplant recipients from January 2000 to December 2008 who received induction with rabbit-antithymocyte globulin (r-ATG), alemtuzumab, or an interleukin-2 (IL-2) receptor blocker and were discharged on a calcineurin inhibitor/mycophenolate mofetil/steroid-free immunosuppression., Results: When compared with r-ATG (n=5348), adjusted graft survival was inferior with alemtuzumab (n=2428, hazards ratio [HR] 1.26, 95% confidence interval [CI] 1.10-1.43, P=0.001) and IL-2 receptor blocker (n=1396, HR 1.19, 95% CI 1.01-1.39, P=0.04) inductions and patient survival was inferior with alemtuzumab (HR 1.29, 95% CI 1.08-1.55, P=0.006). Alemtuzumab induction was associated with higher adjusted graft failure risks in patients with panel reactive antibody more than 20% (HR 1.30, 95% CI 1.01-1.68, P=0.04), recipients of expanded criteria donor kidneys (HR 1.58, 95% CI 1.23-2.02, P<0.001), and kidneys with cold ischemia time more than 24 hr (HR 1.31, 95% CI 1.04-1.65, P=0.02) and higher patient death risks in recipients of expanded criteria donor kidney (HR 1.66, 95% CI 1.20-1.30, P=0.002) and kidneys with cold ischemia time more than 24 hr (HR 1.44, 95% CI 1.04-2.00, P=0.03). Adjusted graft survival rates were similar for different induction agents in the low-immune risk group., Conclusions: When compared with alemtuzumab and IL-2 receptor blocker, r-ATG induction seems to be associated with superior outcomes in deceased donor kidney transplant recipients maintained on calcineurin inhibitor/mycophenolate mofetil/steroid-free regimen.

Antibody-mediated rejection (AMR) following renal transplantation is less responsive to conventional anti-rejection therapies. Plasmapheresis (PP), intravenous immunoglobulin (IVIg), rabbit antithymocyte globulin (rATG) and rituximab deplete immature B-cells but not mature plasma cells. The proteasome inhibitor bortezomib has activity against mature plasma cell, the source of damaging donor-specific antibody (DSA).We present the successful use of bortezomib in 2 patients who developed AMR following kidney transplantation. The first patient was a 54-year-old white female who received living-unrelated kidney transplantation from her husband. She developed severe AMR early after transplantation with rising DSA titers consistent with an anamnestic immune response by memory cells to the donor antigens. Renal function deteriorated despite treatment with pulse methylprednisolone (MP), PP and IVIg. After initiation of therapy with bortezomib, DSA titers became negative and serum creatinine returned to baseline with histological resolution of AMR. The second patient was a 19-year-old white male who received deceased donor kidney transplantation and developed AMR within 2 weeks, refractory to therapy with pulse MP, PP and IVIg with rising DSA. Bortezomib use resulted in disappearance of DSA and renal function improvement. Both patients tolerated the treatment well with stable renal function at last follow-up. The novel mechanisms of action and preliminary results with bortezomib are encouraging, but require larger studies and longer follow-up.

Background: Antibody preconditioning with tacrolimus monotherapy has allowed many renal allograft recipients to be maintained on spaced weaning., Methods: Of 279 renal allograft recipients transplanted between March 2003 and December 2004, 222 (80%) had spaced weaning (i.e., reduction of tacrolimus monotherapy dosing to every other day, three times a week, twice a week, or once a week) attempted. Routine monitoring for donor-specific antibody (DSA) was begun in September 2004. Mean follow-up is 34+/-6.5 months after transplantation and 26+/-8.1 months after the initiation of spaced weaning., Results: One hundred and twenty-two (44%) patients remained on spaced weaning. One- and 2-year actual patient/graft survival was 99%/99%, and 97%/96%. Fifty-six (20%) patients experienced acute rejection after initiation of spaced weaning. One- and 2-year actual patient/graft survival was 100%/98%, and 94%/78%. Forty-two (15%) patients with stable renal function had spaced weaning stopped because of the development of DSA, which disappeared in 17 (40%). One- and 2-year actual patient and graft survival was 100% and 100%., Conclusion: Adult renal transplant recipients who are able to be maintained on spaced weaning have excellent outcomes. Patients with stable renal function who have reversal of weaning because of the development of DSA also have excellent outcomes. Routine monitoring for DSA may allow patients to avoid late rejection after spaced weaning.

Development of type 1 diabetes has been attributed to T-cell-mediated autoimmunity, which is regulated by antigen-presenting cells. To study the role of liver-derived B220(+) regulatory dendritic cells (DCs) in the development of diabetes in non-obese diabetic (NOD) mice, we found that liver 220(+) DCs could easily be propagated from young NOD mice, but that such propagation was extremely difficult from mice older than 11 weeks, when insulitis began. This was not simply an age-related phenomenon, because liver B220(+) DCs were readily propagated from both young and old congenic non-obese diabetic-resistant (NOR) and normal BALB/c mice. It was therefore speculated that the development of diabetes might be associated with a lack of precursors of B220(+) DC in the liver in this animal model. Unfortunately, the specific marker for precursors of liver B220(+) DC has not been identified. An alternative approach to supplement liver B220(+) DCs by intravenous administration significantly inhibited the development of diabetes by inducing T-cell hyporesponsiveness via enhancement of their apoptotic death. Liver B220(+) DCs were capable of effectively presenting antigens but, unlike plasmacytoid DCs, did not express CD11c and were not interferon-alpha producers. These observations may throw new light on the aetiopathology of type 1 diabetes.

Background: Alemtuzumab induction and tacrolimus-based immunosuppression has been effective in pancreas transplantation. Despite the encouraging results of this minimalistic approach to immunosuppression, infection still remains a significant cause of morbidity. The Cylex ImmuKnow [corrected] assay was used in this study to compare pancreas recipient clinical states (stable, rejection, infection) with T cell responses., Methods: Blood samples were taken from pancreas recipients pretransplant and at approximately three-month intervals posttransplant for analysis of T cell responses. When possible, T cell responses were also quantified during changes in clinical status (infection or rejection)., Results: A range between 100-300 ng/ml adenosine triphosphate (ATP) was found in stable patients (mean 194+/-123, n = 51) with good graft function and no infection or rejection. A low T cell response was highly correlated with infectious states. The fourteen patients with infections/posttransplant lymphoproliferative disease had a mean ATP of 48 ng/ml. Risk hazard analysis showed that patients with ATP levels <100 ng/ml were four to seven times more susceptible to infection compared to stable patients. Four patients with rejection showed a T cell response of 550 ng/ml ATP, which was statistically significant compared to stable patients, although the sampling numbers (9) were too small to be conclusive., Conclusion: The Cylex ImmuKnow [corrected] assay is a valuable tool to more precisely modulate immunosuppression in pancreas transplant patients. In particular, the assay is extremely useful in detecting overly immunosuppressed patients vulnerable to infections.

Background: Alemtuzumab (Campath-1H) induction with tacrolimus monotherapy has been shown to provide effective immunosuppression for kidney, liver, lung, and small bowel transplantation. This drug combination was evaluated in pancreas transplant recipients., Methods: Sixty consecutive pancreas transplants (30 simultaneous pancreas-kidney, 20 pancreas after kidney, and 10 pancreas alone) were carried out under this protocol between July 2003 to January 2005. The mean follow-up was 22 months (range 17-33)., Results: One-year patient, pancreas, and kidney allograft survival were 95%, 93%, and 90%, respectively. With 22 months follow-up, patient, pancreas, and kidney survival were 94%, 89%, and 87%, respectively. The rejection rate was 30% (18/60), with four patients (7%) experiencing steroid-resistant rejection. Major infection occurred in three (5%) patients resulting in two (3.3%) deaths from disseminated histoplasmosis and a herpes virus infection. One patient with cryptococcal meningitis was successfully treated. Seven (11.7%) patients experienced cytomegalovirus infection, all of whom responded to treatment with ganciclovir. One (1.7%) case of polymorphic posttransplant lymphoproliferative disease was seen, which regressed with a temporary discontinuation of tacrolimus and high-dose ganciclovir. The mean serum creatinine of the 30 simultaneous pancreas-kidney transplants at one year posttransplant was 1.37+/-0.33 mg/ml. The preexisting creatinine in pancreas after kidney transplants was not adversely affected by this immunosuppressive protocol., Conclusion: A single dose of perioperative alemtuzumab followed by daily tacrolimus monotherapy provides effective immunosuppression for pancreas transplantation, but the optimal use of this drug combination is not yet clear.

Background: Administration of immature dendritic cells (DC) prolongs but does not result in indefinite allograft survival. We attempted to achieve this goal by adding a sub-therapeutic dose of immunosuppression., Methods: DC propagated from B10 (H-2(b)) mouse bone marrow (BM) were transfected with nuclear factor-kappaB (NF-kappaB)-binding-site-specific oligodeoxyribonucleotide (ODN). The allostimulatory activity of transfected and normal DC were examined in mixed-lymphocyte reaction (MLR) and cytotoxic T-lymphocyte (CTL) assays in vitro, and their influence on allograft survival by systemic administration of DC in vivo., Results: Transfection of DC with NF-kappaB ODN resulted in complete abrogation of NF-kappaB activity and inhibition of co-stimulation. Allogeneic (C3H, H-2(k)) T cells stimulated by ODN DC demonstrated impairment in MLR and CTL activity. Administration of ODN DC significantly prolonged B10 allograft survival. In contrast to cyclosporine, which failed to enhance the effect of ODN DC, a combination of ODN DC with sirolimus at 6 mg/kg/day for 6 days achieved long-term survival in all allografts. This was associated with low CTL activity of either graft-infiltrating cells or splenic T cells and increased TUNEL-positive cells in T-cell areas of recipient mesenteric lymph nodes. Analysis of transcription factor nuclear translocation with Cellomics indicated that stimulation with ODN DC showed inhibited T-cell nuclear translocation of signal transducer and activator of transcription (Stat)1 and Stat3, extracellular signal-related kinase (ERK) and activating transcription factor (ATF)-2, but not NF-kappaB and P38, compared with mature DC. The selective inhibition was enhanced by sirolimus, but not cyclosporine., Conclusions: Sirolimus enhances immature DC tolerogenicity by induction of T-cell apoptosis, and promotes immature DC-induced inhibition of Stat1, ERK and ATF-2 activation.

Campath-1H preconditioning with tacrolimus monotherapy is an effective immunosuppressive regimen for pancreas transplantation, with acceptable patient and graft survival rates early after transplantation. Rejection rates are low under this protocol if the tacrolimus level is kept consistently >10 ng/ml. This immunosuppressive protocol, combined with recent technical refinements, has resulted in lower rates of thrombosis and overall complications. Pancreatic transplantation en-bloc with visceral grafts has the following unique features: Diabetes is a rare indication, and HLA matching is not required. The gland is immunologically protected by the simultaneously transplanted visceral organs. Disease gravity, surgical complexity and gut alloimmunity influence the overall pancreatic allograft survival. The current UNOS listing criteria and data registry should be modified for obvious logistic and scientific reasons.

Interleukin-2 (IL-2), interleukin-12 (IL-12) or interleukin-4 (IL-4) were administered postoperatively to otherwise spontaneously accepting mouse liver allograft recipients (C57BL/10-->C3H) to test whether TH1 cytokines are critical mediators of rejection in this model. The induction of rejection at days 5 to 7 by exogenously administered IL-2 and IL-12, but not IL-4, suggests that mouse liver allograft rejection can be induced by TH1 cytokines; however, there appeared to be differences in the mechanism by which these cytokines induce liver rejection. IL-2 administration was accompanied by an increased intragraft infiltration of CD4+ and CD8+ cells and an up-regulation of natural killer (NK), lymphokine-activated killer (LAK), allospecific cytotoxic killer (CTL) activity and perforin mRNA when compared with media-treated controls. In contrast, exogenous IL-12 treatment was associated with a suppression of CTL, NK, and LAK activity compared with controls but an enhanced infiltration of F4/80+ macrophages as determined by immunohistochemistry. Determination of cytokine mRNA profiles by semi-quantitative reverse transcription polymerase chain reaction showed the up-regulation of interferon (IFN)-gamma, IL-4, IL-6, and IL-10 mRNA with IL-2 treatment when compared with media-treated controls. Interestingly, IL-2 mRNA was down-regulated in these animals, suggesting a negative feedback mechanism in IL-2 regulation. IL-12 treatment resulted in the up-regulation of IFN-gamma, IL-6, and IL-10 mRNA, but not IL-2 or IL-4 mRNA. Higher complement-directed cytotoxic antibody titers were seen in IL-12-treated recipients compared with controls, whereas IL-2 treatment showed no apparent differences in antibody titers compared with media treatment. These in vivo observations were mimicked in a mixed leukocyte reaction by supplementing the reaction with IL-2, IL-12, or media. These results suggest that rejection of mouse liver allografts may involve more than one distinct cellular immunological effector mechanism. One is mediated by IL-2 and appears to favor alloreactive CTL, whereas the other pathway is mediated by IL-12/IFN-gamma and involves macrophages and cytotoxic antibodies largely resembling a delayed-type hypersensitivity reaction.

Livers are accepted spontaneously when transplanted orthotopically from B10 (H2b) or BALB/c (H2d) to C3H (H2k) mice without host immunosuppression. Presensitization to donor can, however, be induced by skin grafting two weeks prior to liver transplantation, resulting in second-set or "accelerated" liver graft rejection, within 4-5 days. In this study, the role of liver nonparenchymal cells (NPC) in second-set rejection was tested by donor whole-body irradiation and replacement of donor B10 liver NPC with those of either third-party (BALB/c) or recipient strain (C3H) bone marrow. Irradiation alone (9.5 Gy) of normal B10 donors before liver transplantation significantly prolonged graft survival in presensitized C3H recipients. Three months after bone marrow transplantation (BMT), chimeric livers expressing third-party or recipient haplotype, were transplanted orthotopically into unmodified C3H recipients. Graft survival was prolonged significantly compared with livers from normal or syngeneically reconstituted B10 donors. Prolonged survival of chimeric (BALB/c->B10) livers was also evident in C3H mice presensitized to alloantigens expressed on both the liver parenchymal (B10) and third-party NPC (BALB/c) by simultaneous grafting of skin from each donor strain. Determination of graft cytokine mRNA profiles 4 days posttransplant showed that replacement of donor with third-party or recipient strain BM-derived cells was associated with reduced expression of IL-2 and IFN-gamma mRNA compared with that in grafts from syngeneically reconstituted donors. IL-10 transcripts, however, were not significantly affected. The results are consistent with a key role of radiation-sensitive, donor-specific NPC of bone marrow origin in second-set liver rejection in presensitized hosts. In this process, competent donor-strain NPC appear to augment the activity of primed T cells responsible for the second-set rejection.

Although mouse liver allografts are spontaneously accepted without immunosuppression in many strain combinations, rejection can be induced by presensitization with a donor skin graft two weeks prior to transplantation. In this study, the semiquantitative reverse transcription polymerase chain reaction (RTPCR) was used to assess the involvement of T helper (TH) cell subsets in liver allograft acceptance by determining cytokine mRNA in the graft and spleen of recipients with (A) spontaneously accepting allografts (B) rejecting liver allografts after previous skin sensitization, and (C) syngeneic controls. Spontaneously accepted liver allografts showed upregulation of TH1 (IL-2, IFN-gamma) and TH2 (IL-4, IL-10) intragraft cytokine mRNA, which peaked at day 6 and tapered off thereafter, when compared with levels in syngeneic grafts, but both IFN-gamma and IL-10 mRNA persisted up to day 30. This cytokine mRNA profile correlated with the transient intragraft inflammation associated with spontaneously resolving rejection. Presensitized recipients that rejected their grafts revealed marked upregulation of TH1 (IL-2 and IFN-gamma) and TH2 (IL-4, IL-6) intragraft cytokine mRNAs compared with spontaneously accepting recipients, although IL-10 mRNA levels showed no differences between the two groups. The most striking difference was seen in IFN-gamma levels, which correlated well with the preferential deposition of IgG2a antibody isotype in the rejecting compared with the spontaneously accepting liver allograft recipients. These results suggested an association between liver allograft rejection and enhanced TH1 cytokine immune response. The ability to reject liver allografts by the adoptive transfer of splenocytes, but not serum, from a sensitized mouse ruled out preformed antibodies alone as a cause of rejection. However, spleen cytokine mRNA profiles showed no differences or trends in TH1 or TH2 expression in spontaneously accepting versus rejecting recipients, which suggested that the spleen is not a major site of alloreactive immune expansion. These data suggest that spontaneous acceptance of mouse liver allografts is associated with an insufficient intragraft TH1 cytokine response, the cause of which is currently under investigation.

Background: Many of the physiologic derangements resulting in septic shock are caused by inflammatory mediators such as nitric oxide (NO) and cytokines produced in response to bacterial endotoxin or, more specifically, lipopolysaccharide. The recent development of a novel class of lipopolysaccharide antagonists offers the opportunity to block this response selectively. In this article we investigated the ability of one of these antagonists, B464 (Eisai), to block lipopolysaccharide-induced release of macrophage NO and cytokines., Methods: The mouse macrophage cell line RAW264.7 was grown in vitro and exposed to (1) media control, (2) B464 alone, (3) lipopolysaccharide alone, or (4) lipopolysaccharide plus graded concentrations of B464. Supernatants were assayed for nitrite plus nitrate, the stable end products of NO, as well as tumor necrosis factor-alpha and interleukin-6. Total cellular RNA was examined for inducible NO synthase and interleukin-6 mRNA., Results: Lipopolysaccharide-stimulated increases in NO, tumor necrosis factor, and interleukin-6 production were blocked by B464. Reduction of NO was also seen at the level of inducible NO synthase mRNA. Induction of interleukin-6 mRNA was also suppressed., Conclusion: B464 is a novel potent specific antagonist of lipopolysaccharide-induced macrophage NO and cytokine production.

Two distinct subsets of CD4+ Th lymphocytes have been characterized by their cytokine profiles: Th 1 (TH1) and Th 2 (TH2). While TH1 cells predominate in cell-mediated responses, TH2 cells support the humoral response. We have examined the mRNA cytokine profile of normal mouse lymphocytes in response to alloantigen versus xenoantigen (rat) in MLC, and present evidence to suggest that early in proliferative responses, alloreactivity is dominated primarily by TH1-type lymphocytes, while xenoreactivity is predominantly TH2. Normal mouse lymphocyte-responding cells were cultured in a one-way MLR with either allo or xeno antigen and examined for production of mRNA for cytokines characteristically produced by TH1 (IL-2, IFN-gamma) or TH2 (IL-4, IL-10) cells. Semiquantitative reverse transcription-polymerase chain reaction analysis was performed for mouse IL-2, IL-4, IL-10, and IFN-gamma mRNA. In the mouse anti-rat xeno response, mRNA for TH2 gene products were upregulated, with greater levels of IL-4 and IL-10 at 24 and 48 hr when compared with controls. In contrast, upregulation of mRNA for TH1 gene products occurred in the mouse anti-mouse allo response, with higher levels of IL-2 and IFN-gamma at 24 and 48 hr. In the anti-xeno response, upregulation of all 4 cytokines occurred by day 4 and peak levels of mRNA for all cytokines examined were 2-3 times that seen for the peak anti-allogeneic response. These data suggest that early xenorecognition may differ from allorecognition by differential activation of the TH2 subset. A better understanding of the balance between Th subset function and cytokine profile in allo and xeno reactivity may allow a more targeted and specific approach to control the early events in xenograft rejection.

Intragraft levels of cytokine mRNA were studied in an orthotopic rat left lung transplant model. Three groups of rats were compared at 7 days after transplantation. Isogeneic (Lewis to Lewis), allogeneic (Brown-Norway to Lewis) untreated, and cyclosporine-treated (25 mg/kg/day, intramuscularly) allogeneic animals underwent analysis of cytokine mRNA isolated from total RNA in freshly excised grafts. Reverse transcription-polymerase chain reaction amplification of interleukin (IL)-2, IL-4, and actin (control) mRNA was performed with custom-synthesized oligonucleotide amplimers targeted to known sequences of rat IL-2 and IL-4 cDNA. Semiquantitative analysis was performed by radioanalytic scanning of gel preparations. Sample specimens from the retrieved grafts were also graded histologically for rejection on a five-point scale. Rejection was most severe in the untreated allografts (p < 0.003). IL-2 mRNA was significantly greater in the untreated allografts when compared with isografts (p < 0.05) and cyclosporine-treated allografts (p < 0.05). No significant differences in IL-4 mRNA between groups were observed. We conclude that semiquantitative analysis of cytokine mRNA by reverse transcription-polymerase chain reaction is a useful and sensitive method for the study of acute rejection in lung grafts and that this technique may become an important tool in future studies of cytokine-mediated responses in cyclosporine-treated allografts.