Marc I. Lorber

Interferon-gamma elicits arteriosclerosis in the absence of leukocytes.

Atherosclerosis and post-transplant graft arteriosclerosis are both characterized by expansion of the arterial intima as a result of the infiltration of mononuclear leukocytes, the proliferation of vascular smooth muscle cells (VSMCs) and the accumulation of extracellular matrix. They are also associated with the presence of the immunomodulatory cytokine interferon-γ (IFN-γ). Moreover, in mouse models of atheroma formation or allogeneic transplantation, the serological neutralization or genetic absence of IFN-γ markedly reduces the extent of intimal expansion. However, other studies have found that exogenous IFN-γ inhibits cultured VSMC proliferation and matrix synthesis, and reduces intimal expansion in response to mechanical injury. This discrepancy is generally explained by the idea that IFN-γ either directly activates macrophages, or, by increasing antigen presentation, indirectly activates T cells within the lesions of atherosclerosis and graft arteriosclerosis. These activated leukocytes are thought to express the VSMC-activating cytokines and cell-surface molecules that cause the observed arteriosclerotic responses. Here we have inserted pig and human arteries into the aorta of immunodeficient mice, and we show that IFN-γ can induce arteriosclerotic changes in the absence of detectable immunocytes by acting on VSMCs to potentiate growth-factor-induced mitogenesis.

Everolimus versus Mycophenolate Mofetil in the Prevention of Rejection in De Novo Renal Transplant Recipients: A 3-year Randomized, Multicenter, Phase Iii Study

Background. This 36-month, randomized, parallel-group study compared safety and efficacy of two doses of everolimus with mycophenolate mofetil (MMF) in de novo renal-transplant recipients. Methods. Renal-allograft recipients received 1.5 mg/day or 3 mg/day of everolimus or 2 g/day of MMF, plus full-dose cyclosporine (CsA) and corticosteroids after randomization. For at least their first year, patients received study medication according to a double-blinded, double-dummy design. Concerns over nephrotoxicity led to a protocol amendment to an open-label design with reduced CsA troughs. Results. Incidences of primary efficacy failure at 36 months (biopsy-proven acute rejection, graft loss, death, or loss to follow-up) were everolimus 1.5 mg/day, 33.7% (65/193); everolimus 3 mg/day, 34.0% (66/194); and MMF, 31.1% (61/196) (P=0.810). Antibody-treated acute rejection at 36 months was significantly lower with everolimus 1.5 mg (9.8%) than MMF (18.4%, P=0.014). Discontinuation for adverse events was more frequent with everolimus and hemolytic uremic syndrome, lymphoproliferative disease, and proteinuria, and higher serum creatinine occurred at increased frequency relative to the MMF arm. Creatinine levels in the everolimus arms were stable in follow-up: the mean rise in creatinine over the first 6 months of the open-label phase was 3 &mgr;mol/L or greater with everolimus and 7 &mgr;mol/L with MMF. However, serum creatinine levels were lower in the MMF group throughout. Death and graft loss were higher in the everolimus arms (not significant). Conclusions. As part of triple-drug immunosuppression, everolimus (1.5 or 3 mg/day) was as efficacious as MMF, although the side-effect profile featured increased adverse events. Nephrotoxicity/calcineurin–inhibitor-related adverse events will require judicious lowering of CsA exposure with monitoring of everolimus troughs.

Reduced incidence of Epstein-Barr virus-associated posttransplant lymphoproliferative disorder using preemptive antiviral therapy.

BACKGROUND Posttransplant lymphoproliferative disorder (PTLD) has been observed with increasing frequency consequent to the availability of more effective and potent immunosuppression. Prior work suggested that a peripheral blood monitoring strategy detecting peripheral B lymphoproliferation was effective in the early diagnosis of PTLD among 7 of 179 (3.9%) consecutive transplant recipients. Each of those seven patients received at least one course of antithymocyte globulin, Minnesota antilymphocyte globulin, or OKT3 before developing PTLD. METHODS To determine whether antiviral prophylaxis might reduce the incidence of PTLD, a subsequent group of 198 consecutive recipients received either ganciclovir or acyclovir during antilymphocyte antibody administration. When the donor or recipient were cytomegalovirus-seropositive, ganciclovir was given; acyclovir was used when both were cytomegalovirus-seronegative. Baseline and protocol posttransplant cell surface profiles were obtained using immunofluorescence and flow cytometry to detect T cells, lymphocyte activation markers, and the CD19 B cell antigen. RESULTS Demographic factors, including the incidence of recipients more than 50 years of age, non-Caucasians, previous transplantation, and diabetes mellitus, were similar in both groups. Additionally, the number of patients receiving antilymphocyte preparations was similar. However, only one patient (0.5%) from the latter group who received preemptive antiviral therapy developed PTLD. Although elevations in CD19+ B cells preceded clinical PTLD among each of the seven earlier patients, evidence of peripheral B cell proliferation was not demonstrated for the sole patient from the latter group, which suggests a possible effect of antiviral therapy. CONCLUSIONS Prophylactic antiviral therapy may reduce the sensitivity of peripheral monitoring for B lymphoproliferation, but the dramatic reduction in PTLD incidence strongly supports its use among transplant recipients at risk.

A Phase I/II Randomized Open‐Label Multicenter Trial of Efalizumab, a Humanized Anti‐CD11a, Anti‐LFA‐1 in Renal Transplantation

Leukocyte function associated antigen‐1 (LFA‐1) has a multifaceted role in the immune response, including adhesion and trafficking of leukocytes, stabilizing the immune synapse of the MHC‐TCR complex and providing costimulation signals. Monoclonal antibodies to the CD11a chain of LFA‐1 have been seen to result in effective immunosuppression in experimental models. Efalizumab, a humanized IgG1 anti‐CD11a, is approved for use in psoriasis and may provide effective immunosuppression in organ transplantation. Thirty‐eight patients undergoing their first living donor or deceased renal transplant were randomized to receive efalizumab 0.5 or 2 mg/kg weekly subcutaneously for 12 weeks. Patients were maintained on full dose cyclosporine, mycophenolate mofetil and steroids or half dose cyclosporine, sirolimus and prednisone. At 6 months following transplant patient survival was 97% and graft survival was 95%. Clinical biopsy‐proven acute rejection in the first 6 months after transplantation was confirmed in 4 of 38 patients (11%). Three patients (8%) developed post transplant lymphoproliferative disease, all treated with the higher dose efalizumab and full dose cyclosporine. The two doses of efalizumab resulted in comparable saturation and modulation of CD11a. This phase II trial suggests that efalizumab may warrant further investigation in transplantation.

Hepatobiliary and pancreatic complications of cyclosporine therapy in 466 renal transplant recipients

Two hundred twenty-eight patients from a total of 466 (49%) receiving renal allografts under cyclospo-rine/prednisone (CsA/Pred) immunosuppression experienced at least one episode of posttransplant hepato-toxicity. All patients were documented to have normal serum bilirubin, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT), lactic acid dehydrogenase (LDH), and alkaline phosphatase (AP), as well as negative results of biliary ultrasound and upper gastrointestinal contrast examinations prior to transplantation. Hepatotoxic episodes usually were self-limited (82%), and generally occurred during the very early posttransplant period (76%). Liver function abnormalities included hyperbilirubinemia (48% of patients), elevated SGOT (47%), SGPT (73%), LDH (84%), and AP (59%). The CsA serum trough radioimmunoassay (RIA) was relatively high among hepatotoxic patients with a mean value of 225± 17 ng/ml. Pharmacokinetic parameters, including bioavailability and drug clearance, were significantly altered among this group of patients. The management strategy of CsA dose reduction was effective; however, 11 patients (2.4%) developed biliary calculous disease posttransplant while under CsA/Pred immunosuppression. Seven patients had cholelithiasis, and two patients underwent choledochoduodenostomy because of primary choledocholithiasis. The results contrast with 279 renal transplant recipients from an overlapping nonrandomized group treated with azathioprine (Aza)/Pred in whom cholelithiasis was not identified. Pancreatic abnormalities were relatively common, but clinical pancreatic disease occurred in only six patients. There were two episodes of acute pancreatitis, three patients developed pancreatic abscess, and one patient developed a pancreatic pseudocyst. The apparent proclivity of CsA-treated patients to develop biliary calculous disease, and the occurrence of serious pancreatic complications in a small percentage of patients did not affect the majority of CsA-treated patients. They may, however, represent important problems associated with the use of this immunosuppressive agent.

Complications of cyclosporine-prednisone immunosuppression in 402 renal allograft recipients exclusively followed at a single center for from one to five years.

The therapeutic efficacy of cyclosporine (CsA) as an immunosuppressive agent was complemented by a modest, long-term incidence of toxic complications in 402 renal allograft recipients engrafted one to five years prior to analysis. The overall patient and graft survivals at one year were 97% and 84% (actual), and at five years 92% and 67% (actuarial). The immunosuppressive therapeutic index was excellent: only 12% of allografts were lost from rejection, with 5% of patients succumbing to infection. While infections were common, tending to emanate in the urinary tract or to be viral in etiology, they were generally mild and readily controlled. Only four patients displayed malignancies; none succumbed to this cause. The most common toxic complication was hypertrichosis, which was accentuated in pediatric patients. While tremors occurred in 20% of patients, primarily during the first three months, other neuroectodermal complications of parethesias, depression, somnolence, and seizures were rare. Hepatotoxicity, which was noted in 50% of patients, particularly recipients of cadaveric grafts, generally was first seen as a transaminase elevation, at least partially reversible by dose-reduction and abating by the third year. Associated disturbances of cholelithiasis and pancreatitis were occasionally observed. Nephrotoxicity was the only persistent, long-term complication. Hypertension occurred in 72% of patients during the first month, 36% in the second year, and about 15% thereafter. Hyperuricemia, which occurred in about 30% of recipients during the first two years, was occasionally associated with symptomatic gout. The mean serum creatinine level remained elevated throughout the follow-up period at 1.8—1.9 mg/dl, suggesting persistent, but nonprogressive, drug-induced renal injury. The present analysis documents the relative safety of CsA for long-term therapy, and highlights the need for new approaches to ameliorate drug-induced nephrotoxicity.

Longitudinal assessment of everolimus in de novo renal transplant recipients over the first post‐transplant year: Pharmacokinetics, exposure‐response relationships, and influence on cyclosporine

Our objective was to characterize the steady‐state pharmacokinetics of everolimus and cyclosporine (INN, ciclosporin) when coadministered in de novo kidney allograft recipients during the first year after transplantation.

Donor kidney exchanges.

Kidney transplantation from live donors achieves an excellent outcome regardless of human leukocyte antigen (HLA) mismatch. This development has expanded the opportunity of kidney transplantation from unrelated live donors. Nevertheless, the hazard of hyperacute rejection has usually precluded the transplantation of a kidney from a live donor to a potential recipient who is incompatible by ABO blood type or HLA antibody crossmatch reactivity. Region 1 of the United Network for Organ Sharing (UNOS) has devised an alternative system of kidney transplantation that would enable either a simultaneous exchange between live donors (a paired exchange), or a live donor/deceased donor exchange to incompatible recipients who are waiting on the list (a live donor/list exchange). This Regional system of exchange has derived the benefit of live donation, avoided the risk of ABO or crossmatch incompatibility, and yielded an additional donor source for patients awaiting a deceased donor kidney. Despite the initial disadvantage to the list of patients awaiting an O blood type kidney, as every paired exchange transplant removes a patient from the waiting list, it also avoids the incompatible recipient from eventually having to go on the list. Thus, this approach also increases access to deceased donor kidneys for the remaining candidates on the list.

Demographic factors affecting the pharmacokinetics of cyclosporine estimated by radioimmunoassay

In order to assess the impact of demographic factors on serum levels of cyclosporine (CsA) estimated by radioimmunoassay (RIA) in renal allograft recipients, 493 pharmacokinetic studies were performed in 212 patients. Neither the presence of diabetes mellitus nor the CsA dosing frequency affected the measured pharmacokinetic parameters. Age over 45 years led to slower CsA clearance with resultant increase in maximum serum concentration (Cmax) per administered milligram, and increased volume of distribution. Female patients showed more rapid drug clearance, but greater volume of distribution. Concomitant hepatic impairment reduced drug clearance, increasing the area under the curve (AUC) per administered milligram of drug, and the Cmax. Patients treated with a rapid steroid taper showed a shorter half-life and lower Cmax than those receiving a slow steroid taper. Nephrotoxicity was associated with increased AUC per administered mg, while patients with acute tubular necrosis requiring dialysis showed poorer drug absorption, lower Cmax, and longer time to peak. The only effect of cimetidine administration was a slightly shortened time to peak. Serial analyses posttransplant in 17 patients suggested a tendency toward improved drug absorption with no effect on other parameters. These studies demonstrating the significant impact of demographic factors thus afford a basis on which to predict the trend of anticipated CsA levels as measured by RIA in renal allograft recipients

Liver Transplantation for Hepatoblastoma the American Experience

The current role of liver transplantation in treating malignant tumors of the liver is uncertain, except for select histologic types. Pooled data on the results of liver transplantation in 12 children with hepatoblastoma is presented here. One half of the children are alive 24 to 70 (44 +/- 19) months after transplantation with no evidence of recurrence. Three patients (25%) died of tumor recurrence and three (25%) died of other causes. Unifocal and intrahepatic tumors were associated with better prognosis compared to the multifocal tumors and tumors with extrahepatic spread (p = 0.04 and 0.13). Microscopically vascular invasion and the predominance of embryonal and/or anaplastic epithelium were associated with a poor prognosis compared to the tumors with no vascular invasion and with predominantly fetal epithelium (p = 0.08 and 0.1). It is concluded that continued efforts to treat unresectable hepatoblastomas by liver transplantation is justified and the role of adjuvant chemotherapy in improving the results needs to be better defined.