Rituximab (chimeric anti-CD20 antibody) for posttransplant lymphoproliferative disorder after solid organ transplantation in adults: long-term experience from a single center

BACKGROUND

Occurrence of posttransplant lymphoproliferative disorder (PTLD) after transplantation is known. Drastic reduction or withdrawal of immunosuppression with anti-viral therapy for Ebstein-Barr virus (EBV) is the primary treatment for all PTLD. Many PTLD are B cell in origin have CD20 antigen on the cell surface. Rituximab is a chimeric anti CD20 antibody, which has been used to treat PTLD with variable success. This study aims to report long-term experience with rituximab for PTLD from a single center.

METHODS

Seventeen patients (13 male, 4 female, mean age 51.2 years) received rituximab to treat PTLD. Five patients received rituximab with drastic reduction in immunosuppression (primary). Nine patients received rituximab after failure of primary therapy (rescue) and three patients received it after resolution of PTLD (prophylactic). Mean follow-up period was 60 months.

RESULTS

Overall 1-, 3-, and 5-year patient survivals were 64.7%, 47.1% and 35.3%, respectively. In the primary group, three patients had complete and one had partial response; however, only two (40%) patients are currently alive. In the rescue group, none of the patients had a complete response, four patients had partial response, and only two (22%) patients are currently alive. In the prophylactic group, two patients died at 28 and 41 months due to recurrence and graft failure, respectively.

CONCLUSION

Sixty percent (3 of 5) of patients who received rituximab as primary therapy had complete resolution, and 44% (4 of 9) of patients who received it as rescue therapy had partial response. Overall 5-year patient survival was a disappointing 35%.

Mechanistic insights into achievement of cardiac allograft long-term survival by treatment with immature dendritic cells and sub-dose sirolimus

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.

A randomized trial of inhaled cyclosporine in lung-transplant recipients

BACKGROUND

Conventional regimens of immunosuppressive drugs often do not prevent chronic rejection after lung transplantation. Topical delivery of cyclosporine in addition to conventional systemic immunosuppression might help prevent acute and chronic rejection events.

METHODS

We conducted a single-center, randomized, double-blind, placebo-controlled trial of inhaled cyclosporine initiated within six weeks after transplantation and given in addition to systemic immunosuppression. A total of 58 patients were randomly assigned to inhale either 300 mg of aerosol cyclosporine (28 patients) or aerosol placebo (30 patients) three days a week for the first two years after transplantation. The primary end point was the rate of histologic acute rejection.

RESULTS

The rates of acute rejection of grade 2 or higher were similar in the cyclosporine and placebo groups: 0.44 episode (95 percent confidence interval, 0.31 to 0.62) vs. 0.46 episode (95 percent confidence interval, 0.33 to 0.64) per patient per year, respectively (P=0.87 by Poisson regression). Survival was improved with aerosolized cyclosporine, with 3 deaths among patients receiving cyclosporine and 14 deaths among patients receiving placebo (relative risk of death, 0.20; 95 percent confidence interval, 0.06 to 0.70; P=0.01). Chronic rejection-free survival also improved with cyclosporine, as determined by spirometric analysis (10 events in the cyclosporine group and 20 events in the placebo group; relative risk of chronic rejection, 0.38; 95 percent confidence interval, 0.18 to 0.82; P=0.01) and histologic analysis (6 vs. 19 events, respectively; relative risk, 0.27; 95 percent confidence interval, 0.11 to 0.67; P=0.005). The risks of nephrotoxic effects and opportunistic infection were similar for patients in the cyclosporine group and the placebo group.

CONCLUSIONS

Inhaled cyclosporine did not improve the rate of acute rejection, but it did improve survival and extend periods of chronic rejection-free survival. (ClinicalTrials.gov number, NCT00268515.).

Regulatory dendritic cells modulate immune responses via induction of T-cell apoptotic death

We describe a regulatory lymphoid dendritic cell (LDC) population propagated from mouse liver nonparenchymal cells (NPC) in IL-3 and anti-CD40 monoclonal antibody that are phenotypically mature, and induce T-cell hyporesponsiveness by promoting T-cell apoptotic death, which is partially caspase-dependent, but is unlikely to be mediated by soluble factor(s). In vivo administration of liver LDC significantly prolonged the survival of vascularized cardiac allografts in an alloantigen-specific manner. This is associated with enhanced T-cell death in secondary lymphoid organs.

Immune regulatory activity of liver-derived dendritic cells generated in vivo

Hepatic tolerance is demonstrated by spontaneous acceptance of liver allografts in mice. Hepatic dendritic cells (DC) play a crucial role in determining immunity or tolerance. In this study, we adopted an approach to transfect gene(s) into the mouse liver by tail-vein injection of plasmid-carrying genes. Transfection with GM-CSF expanded liver CD11c+ myeloid DC (LMDC), while liver B220+CD11c- lymphoid DC (LLDC) were expanded after transfection of IL-3 and CD40L. Flow analysis revealed that these liver DC subsets were phenotypically mature following overnight culture. However, in contrast to LMDC, LLDC induced hyporesponsiveness in allogeneic T-cells, with suppressed secretion of both IL-2 and IFN-gamma, and prolonged cardiac allograft survival. This immune regulatory DC population in the liver may play a role in modulating T-cell immunity in the liver.

Percutaneous Ultrasound-Guided Pancreas Allograft Biopsy: A Single-Center Experience

Percutaneous ultrasound-guided pancreas allograft biopsy is the preferred technique for evaluating pancreas allograft rejection. Experience from large centers has shown it to be safe and effective. We report our experience with 120 percutaneous allograft biopsies performed at a single center. Biopsy tissue was obtained in 54 patients. Thirty-three patients received simultaneous pancreas and kidney transplants, 14 received isolated pancreas transplants, and 7 received a pancreas transplant after kidney transplantation. Biopsies were performed by pancreas transplantation surgeons with the assistance of radiologists under ultrasound guidance using an Acuson XP 128/10 ultrasound machine. One hundred twenty allograft biopsies were performed in 54 patients. Twenty-seven (50%) patients underwent multiple biopsies. In 102 (85%) biopsies the specimens were adequate for examination. Eighteen (15%) biopsy samples had no pancreatic tissue and showed surrounding fat and small bowel. 1 (1.8%) patient bleeding developed that required transfusion of 3 units of packed red blood cells, but no surgical intervention was necessary. One (1.8%) patient had a pancreatic fistula, which healed with nonoperative management. Biochemical evidence of pancreatitis was noted in 5 (9.2%) patients, but none of these patients had clinical signs of pancreatitis. Percutaneous ultrasound-guided pancreas allograft biopsy is a safe procedure with a low complication rate and a high tissue yield for histopathologic examination.

Pretransplant survival is shorter in HIV-positive than HIV-negative subjects with end-stage liver disease

Despite improved survival after liver transplantation (OLTX) in HIV-positive individuals treated with highly active antiretroviral therapy (HAART), some transplant candidates do not survive to OLTX. To determine if pretransplant outcome is related to severity of liver disease and/or HIV infection, we prospectively evaluated 58 consecutive HIV-positive candidates seen at a single center from 1997-2002. Of the 58, 15 (25.9%) were transplanted, whereas 21 (36.2%) died before OLTX, a median one month of evaluation, with more than half of those (12 of 21, 57.1%) dying from infection. By contrast, of 1,359 HIV-negative candidates, 860 (63.3%) were transplanted, whereas 211 (15.5%) died before OLTX (P < 0.001). The cumulative survival following initial evaluation was significantly shorter among HIV-positive than HIV-negative candidates (880 vs. 1,427 days, P = 0.035, Breslow) but was not related to the initial pretransplant MELD score (16 vs. 15), INR (1.5 vs. 1.5), creatinine (1.3 vs. 1.3 mg/dL), or total bilirubin (6.6 vs. 5.7 mg/dL), respectively, all P > 0.05. Among untransplanted HIV-positive candidates, the 21 who died did not differ from the 22 surviving in initial MELD (15 vs. 13), CD4 (230 vs. 327/microL), HIV load (both < 400 copies/mL), HAART intolerance (10/21, 47.6% vs. 10/22, 45.4%), or HCV infection (16/21, 76.2% vs. 16/22, 72.3%), all P > 0.05. Further, the 21 did not differ from the 15 transplanted in pre-OLTX CD4, HIV load, or MELD score, all P > 0.05. In conclusion, pretransplant survival appears shorter in HIV-positive OLTX candidates and is unrelated to severity of liver or HIV disease. Further study is warranted to determine risk factors for poorer pretransplant outcomes.

Immunosuppression for liver transplantation in HCV-infected patients: mechanism-based principles

We retrospectively analyzed 42 hepatitis C virus (HCV)-infected patients who underwent cadaveric liver transplantation under two strategies of immunosuppression: (1) daily tacrolimus (TAC) throughout and an initial cycle of high-dose prednisone (PRED) with subsequent gradual steroid weaning, or (2) intraoperative antithymocyte globulin (ATG) and daily TAC that was later space weaned. After 36 +/- 4 months, patient and graft survival in the first group was 18/19 (94.7%) with no examples of clinically serious HCV recurrence. In the second group, the three-year patient survival was 12/23 (52%), and graft survival was 9/23 (39%); accelerated recurrent hepatitis was the principal cause of the poor results. The data were interpreted in the context of a recently proposed immunologic paradigm that is equally applicable to transplantation and viral immunity. In the framework of this paradigm, the disparate hepatitis outcomes reflected different equilibria reached under the two immunosuppression regimens between the relative kinetics of viral distribution (systemically and in the liver) and the slowly recovering HCV-specific T-cell response. As a corollary, the aims of treatment of the HCV-infected liver recipients should be to predict, monitor, and equilibrate beneficial balances between virus distribution and the absence of an immunopathologic antiviral T-cell response. In this view, favorable equilibria were accomplished in the nonweaned group of patients but not in the weaned group. In conclusion, since the anti-HCV response is unleashed when immunosuppression is weaned, treatment protocols that minimize disease recurrence in HCV-infected allograft recipients must balance the desire to reduce immunosuppression or induce allotolerance with the need to prevent antiviral immunopathology.

EBV-specific memory CD8+ T cell phenotype and function in stable solid organ transplant patients

Immune responses to EBV in immunosuppressed (IS) solid organ transplant (SOTx) recipients have not been well characterized. Here we evaluate the phenotype and function of EBV-specific CD8+ T cells in peripheral blood isolated from "stable" IS SOTx recipients. The EBV-specific CD8+ T cell memory subset distribution in the peripheral blood of patients was examined by flow cytometric analysis using HLA-A2 tetramers incorporating BMLF1 (lytic), and LMP2 and EBNA3A (latent)-derived peptides, in conjunction with mAbs against the CD45RO, CD45RA, and CD62L markers. The ability of CD8+ T cells to produce IFN-gamma in response to the same EBV-derived peptides was measured by ELISPOT assay. Patients and healthy normal donors exhibited similar anti-EBV CD8+ T cell frequencies and specificities against the EBV epitopes evaluated. When compared to healthy normal donors, an overall significant expansion of the CD8+ T cell "effector memory" (CD45RO+/CD62L-) pool, including that of EBV "latent" (LMP2 and EBNA3A)-specific CD8+ T cells was detected in IS SOTx patients. However, the patients' EBV-specific CD8+ T cells showed decreased IFN-gamma production to the EBV-peptide stimulation. These results indicate that the impairment of EBV-specific CD8+ T cell activity is not due to clonal depletion, but is mainly due to impaired functional activation.

Kidney transplantation under minimal immunosuppression after pretransplant lymphoid depletion with Thymoglobulin or Campath

BACKGROUND

Multiple drug immunosuppression has allowed the near elimination of rejection, but without commensurate improvements in longterm graft survival and at the cost of quality of life. We have suggested that transplantation outcomes can be improved by modifying the timing and dosage of immunosuppression to facilitate natural mechanisms of alloengraftment and acquired tolerance.

STUDY DESIGN

Two therapeutic principles were applied for kidney transplantation: pretransplant recipient conditioning with antilymphoid antibody preparations (Thymoglobulin [Sangstat] or Campath [ILEX Pharmaceuticals]), and minimal posttransplant immunosuppression with tacrolimus monotherapy including "spaced weaning" of maintenance doses when possible. The results in Thymoglobulin- (n = 101) and Campath-pretreated renal transplantation recipients (n = 90) were compared with those in 152 conventionally immunosuppressed recipients in the immediately preceding era.

RESULTS

Spaced weaning was attempted in more than 90% of the kidney transplant recipients after pretreatment with both lymphoid-depleting agents, and is currently in effect in two-thirds of the survivors. Although there was a much higher rate of acute rejection in the Thymoglobulin-pretreated recipients than in either the Campath-pretreated or historic control recipients, patient and graft survival in both lymphoid depletion groups is at least equivalent to that of historic control patients. In the Thymoglobulin-conditioned patients for whom followups are now 24 to 40 months, chronic allograft nephropathy (CAN) progressed at the same rate as in historic control patients. Selected patients on weaning developed donor-specific nonreactivity.

CONCLUSIONS

After lymphoid depletion, kidney transplantation can be readily accomplished under minimal immunosuppression with less dependence on late maintenance immunosuppression and a better quality of life. Campath was the more effective agent for pretreatment. Guidelines for spaced weaning need additional refinement.

Induction of tumor immunity and cytotoxic t lymphocyte responses using dendritic cells transduced by adenoviral vectors encoding HBsAg: comparison to protein immunization

Dendritic cells (DC) are specialized antigen-presenting cells with powerful immunostimulatory properties. Their use for induction of anti-tumor immunity has been limited by several factors, including identification of appropriate tumor-associated antigens, delivery of antigens to DC, and maintaining DC in a highly activated state. Here, DC propagated in vitro were transduced with an adenoviral (Ad) vector to express hepatitis B surface antigen (HBsAg), an antigen present in hepatocellular carcinoma (HCC). Many patients with HCC demonstrate evidence of prior HBV exposure, suggesting that the presence of the virus in a quiescent state may promote tumorigenesis. Ad-HBsAg-transduced DC stimulated strong cytotoxic T lymphocyte (CTL) responses to HBsAg-expressing tumor cells, and protected mice from lethal tumor challenge. Immunity was antigen-specific, as wild-type tumor (HBsAg -) grew normally. Furthermore, DC transduced with an irrelevant vector had no effect. Vaccination with HBsAg protein, a clinically utilized preparation that confers immunity to HBV infection, did not protect against tumor challenge even though it induced a strong antibody response. These studies describe for the first time the contributions of humoral and cellular immune responses to tumor immunity induced by Ad-transduced DC compared to protein vaccination.

Prolongation of cardiac allograft survival by systemic administration of immature recipient dendritic cells deficient in NF-kappaB activity

OBJECTIVE

To develop a more applicable approach that uses recipient-derived dendritic cells (DC) for organ transplantation.

SUMMARY BACKGROUND DATA

Systemic administration of immature donor DC that are deficient in costimulatory molecules delays the onset of allograft rejection. However, this approach requires in vitro DC propagation and would not be applicable to deceased donor organ transplantation.

METHODS

DC were propagated from C3H (H2) mouse bone marrow with GM-CSF; their maturation was arrested by treatment with oligodeoxyribonucleotides (ODN) specifically against nuclear factor (NF)-kappaB. The DC were pulsed with B10 (H2) splenocyte lysate. DC phenotype was examined by flow cytometry. Their allostimulatory activity was assessed in vitro by MLR and CTL assays and in vivo by the influence on B10 cardiac allograft survival. Cytokine profiles were analyzed by ELISA and RNase protection assay. NF-kappaB activity in DC nuclear protein was detected by gel shifting assay.

RESULTS

Compared with mature DC, NF-kappaB ODN-treated immature DC pulsed with B10 (H2) spleen cell lysate elicited markedly lower proliferative responses and correlated with reduced IFN-gamma and increased IL-10 production. In contrast to administration of mature C3H DC pulsed with B10 antigen that accelerated rejection of B10 cardiac allografts, a single injection of NF-kappaB ODN DC pulsed with donor antigens significantly prolonged allograft survival in an antigen-specific manner. This was associated with induction of T-cell hyporesponsiveness and enhanced T-cell apoptosis.

CONCLUSIONS

An approach to use recipient DC as a "vaccine" strategy provides a more feasible approach for deceased-donor organ transplantation.

Application of recipient-derived dendritic cells to induce donor-specific T-cell hyporesponsiveness

Administration of donor-derived immature dendritic cells (DC) treated with NF-kappaB oligodeoxyribonucleotides (ODN) prevents allograft rejection. We attempted to explore the use of recipient-derived DC pulsed with donor antigens, in which the donor antigens were presented to host T cells via an indirect pathway (cross-priming). Expression of CD40, CD80, and CD86 on DC was significantly inhibited by treatment with NF-kappaB ODN, whereas MHC class I and II were minimally affected. Normal C3H DC pulsed with B10 antigens stimulated proliferative responses and donor-specific CTL activity in C3H T cells, both of which were, however, markedly inhibited when DC were treated with NF-kappaB ODN. This manipulation was associated with reduced IFN-gamma and increased IL-10 production in the supernate, suggesting a Th2 bias. More frequent apoptotic T cells were observed in cultures with NF-kappaB ODN DC. In contrast to administration of normal DC pulsed with donor antigens that accelerated rejection of B10 cardiac allografts (median survival time [MST] 7 days versus 10 days in no-DC treatment control, P < .05), a single injection of 2 x 10(6) NF-kappaB ODN DC significantly prolonged allograft survival (MST 50 days, P < .05 compared with no-DC treatment control). The anti-donor CTL activity in infiltrating T cells isolated from cardiac grafts in recipients that received NF-kappaB ODN DC was significantly suppressed. These data indicate that vaccination with immature DC, propagated from recipient BM is an attractive approach to induce T-cell hyporesponsiveness.

Reversal of Acute Cellular Rejection After Renal Transplantation With Campath-1H

Between September 2002 and February 2004, 40 kidney transplant (27 from deceased and 13 from living donors) recipients (25 male and 15 female, aged 50.3 +/- 15.1 years) were treated with Campath 1H (C 1H; 30 mg/dose IV) for biopsy-proven steroid-resistant rejection (SRR) or rejections equal to or worse than Banff 1B. All transplantations occurred between August 2001 and May 2003. All patients had received antibody preconditioning (RATG 5 mg/kg, n = 34; C 1H 60 mg, n = 4; C 1H 30 mg, n = 2) preoperatively and were treated with Tacrolimus monotherapy (target level 10 ng/ml) postoperatively and subsequent spaced weaning. Elevated creatinine levels at follow-up were evaluated by renal transplant biopsy. Rejection was treated with steroids, reversal of weaning, addition of sirolimus, and/or antibody treatment, depending on grade of rejection. The mean duration of follow-up was 453 +/- 163 days after C 1H administration. Twenty-nine patients received C 1H for SRR and 11 patients for Banff 1B or worse rejections; 26 patients received more than 1 dose of C 1H. Graft survival was 62.5% (25 patients); 6 of the 15 allografts (40%) that failed had presented with rejections because of noncompliance. Graft survival in compliant patients with SRR or rejections equal to or worse than Banff 1B was 73.5% (25 of 34). Fourteen patients (35%) had infectious complications, of whom 2 patients (5%) died. C 1H is an effective agent for SRR and Banff 1B or worse rejections, with 95% patient survival and 73.5% graft survival (in compliant patients). The number of doses of 30 mg C 1H should be restricted to two, as there is a high incidence of potentially fatal infectious complications.

Augmentation of type-1 polarizing ability of monocyte-derived dendritic cells from chronically immunosuppressed organ-transplant recipients

BACKGROUND

Chronic immunosuppressive (IS) therapy impairs normal T-cell immune surveillance and may predispose to opportunistic infections and malignancies that represent life-threatening complication of solid-organ transplantation (SOTx). Our study was designed to ascertain the impact of chronic in vivo administration of IS on the ability of monocyte-derived dendritic cells (MoDC) to differentiate, mature, and function ex vivo. The potential of these cells to be implemented for DC-based adoptive immunotherapy was also considered.

METHODS

MoDCs were propagated by conventional procedures, their phenotype was analyzed by flow cytometry, and their function was assessed by mixed leukocyte reaction, enzyme-linked immunoadsorbent assay, and ELISPOT assays. Nuclear translocation of nuclear factor (NF)-kB was analyzed by electrophoretic mobility shift assay.

RESULTS

Circulating DC1s in peripheral blood were reduced in SOTx patients. MoDCs generated from patients displayed higher endocytic activity versus normal DCs, indicating their comparative immaturity. Patients' DCs exposed to pro-inflammatory cytokines (tumor necrosis factor-alpha, interleukin [IL]-1beta, and IL-6) were less able to mature, to stimulate recall antigen (Ag)- or allo-Ag-induced proliferation responses, or to secrete IL-12p70. These deficiencies were associated with a decrease in NF-kB translocation. In contrast, combination of pro-inflammatory cytokines and interferon (IFN)-gamma (a Th1-polarizing factor) augmented patients' DC1-type function and IL-12p70 production by way of an NF-kB-independent mechanism.

CONCLUSIONS

Chronic IS restrains DC differentiation, maturation, and function at a transcriptional level; however, type-1 polarizing potential of patients' DC1 can be augmented ex vivo by a two-signal stimulation provided by pro-inflammatory cytokines and IFN-gamma. These results may have implications for DC-based immunotherapy of malignancies in the transplantation setting.

Porcine cell microchimerism but lack of productive porcine endogenous retrovirus (PERV) infection in naive and humanized SCID-beige mice treated with porcine peripheral blood mononuclear cells

Pigs are considered a suitable source of cells and organs for xenotransplantation. All known strains of pigs contain porcine endogenous retrovirus (PERV) and PERV released by porcine cells may infect human cells in vitro and severe-combined immunodeficient (SCID) mice in vivo. Humanized SCID (hu-SCID) mice develop immune response to porcine antigens. Here we investigated PERV transmission in humanized SCID-beige mice using porcine peripheral blood mononuclear cells (PBMC) as the donor tissue (and the source of PERV). Mice were infused in the peritoneal cavity with 1.5-3.0 x 10(7) unfractionated human PBMC. Unfractionated porcine PBMC (1.5-3.0 x 10(7) cell/mouse) were infused to the mice simultaneously with human PBMC or 3 weeks after human PBMC infusion. The treated mice were monitored for weight and skin changes, donor cell chimerism, anti-pig antibodies and PERV transmission. All humanized mice tested 5-12 weeks after human PBMC transplantation were macrochimeric (up to 40% of cells in blood) for human cells, where 99% of the human cells were T-lymphocytes. Although human B lymphocytes were very rare in the blood of humanized mice at that point, the mice were positive for human anti-pig natural antibodies. The control SCID-beige mice or mice treated with porcine PBMC alone were negative for anti-porcine antibodies. Approximately 70% of the humanized mice treated with porcine PBMC were also microchimeric for porcine cells. Although some tissue samples of these mice were positive for PERV DNA in the absence of porcine DNA indicating PERV infection, the infection was non-productive as PERV transcripts were not detectable in those tissues. PERV infection of human and mouse cells in vitro by co-culturing with porcine PBMC was also non-productive. Humanized SCID-beige mice suffered weight loss and occasional minor skin changes due to graft vs. host disease caused by human PBMC but none of the mice showed observable effect attributable to the apparent PERV infection alone.

Hepatic resection in 170 patients using saline-cooled radiofrequency coagulation

BACKGROUND

Hepatic resection for malignancies or symptomatic benign liver lesions remains the standard of treatment. Historically, the principal cause of mortality during liver resection was intraoperative bleeding. Advances in surgical and anesthetic techniques, along with application of new technologies, have decreased blood loss and dramatically improved the outcomes for major liver surgery.

METHODS

The purpose of this prospective study was to determine the utility of a saline-cooled radiofrequency coagulation device (TissueLink Medical, Inc.) for hepatic resection. Intraoperative bleeding, blood transfusion, postoperative bile leak, and other complications were noted.

RESULTS

The results are described for 170 patients undergoing hepatic resection over a three-year period. There were no intraoperative or postoperative deaths. Six patients in the series received blood transfusions for a transfusion rate of 3.5%. Four patients experienced a transient postoperative bile leak. Three of the four closed spontaneously prior to discharge home, and the fourth closed promptly after ERCP. There were no episodes of postoperative hemorrhage, hepatic failure, liver abscess, or reoperation.

CONCLUSIONS

The saline-cooled radiofrequency coagulation device is very effective in achieving intraoperative hemostasis and facilitates liver parenchymal transection during hepatic resection.

Preliminary report on surgical technique in hepatic parenchymal transection for liver tumors in the elderly: a lesson learned from living-related liver transplantation

BACKGROUND AND OBJECTIVES

Availability of hi-tech surgical devices has elaborated the technique of parenchymal transection during hepatectomy from classic crushing clamp technique 1,2 to a combination of an ultrasonic dissection with special type of cautery 3,4. We have developed a new technique to resect hepatic parenchyma using an ultrasonic surgical aspirator in association with a monopolar floating ball. This combination has been utilized in 42 liver resections.

METHODS

A retrospective analysis of perioperative mortality, length of hospitalization, and blood transfusion during surgery in two patient groups who underwent liver resection was carried out. We divided the patient population into Group A (42 patients), who underwent the new technique, and Group B (107 patients), who experienced the crushing clamp technique. A second analysis was performed, where we divided the same patient population group in Group 1 with age less than 65, and Group 2 including patients older than 65 years.

RESULTS

We found that the new technique reduced length of stay, procedure length, and use of perioperative blood. We determined that the two age groups performed similarly in comparison to LOS, length of procedure, blood use, and complications.

CONCLUSION

This enforces the fact that the elderly can receive such surgical treatment without hesitation.

Living-Related Donor Renal Transplantation in HIV+ Recipients using Alemtuzumab Preconditioning and Steroid-Free Tacrolimus Monotherapy: A Single Center Preliminary Experience

BACKGROUND

End-stage renal disease (ESRD) is an increasing problem in patients infected with the human immunodeficiency virus (HIV). The use of highly active antiretroviral therapy (HAART) has decreased the morbidity associated with HIV and has prompted renewed interest in renal transplantation.

METHODS

We performed four cases of deceased donor renal transplantation in HIV+ recipients and three cases where laparoscopic live donor nephrectomy (LLDN) was utilized to obtain the kidney for transplantation into living-related HIV+ recipients. In the four deceased donor cases, conventional tacrolimus-based immunosuppression, without antibody induction was used. In the three living-related cases, the immunosuppressive regimen was based on two principles: recipient pretreatment and minimal posttransplant immunosuppression. Alemtuzumab 30 mg (Campath 1-H) was used for preconditioning followed by low-dose tacrolimus monotherapy.

RESULTS

Of the four deceased donor cases, one patient continues to have good graft function, and another is not yet on dialysis but has significant graft dysfunction. Rejection was observed in three patients (75%). Infectious complications occurred in one patient (25%), all non-acquired immunodeficiency syndrome (AIDs) defining. In the three living-related cases, all had good graft function, and none have experienced acute rejection. HIV viral loads remain undetectable. CD4 counts are slowly recovering. No infectious or surgical complications occurred. There were no deaths in either group.

CONCLUSIONS

These data suggest that living-related donor renal transplantation with steroid-free tacrolimus monotherapy in a "tolerogenic" regimen can be efficacious. However, long-term follow-up is needed to confirm this observation.

Inhibition of T-cell responses by hepatic stellate cells via B7-H1-mediated T-cell apoptosis in mice

In the injured liver, hepatic stellate cells (HSCs) secrete many different cytokines, recruit lymphocytes, and thus participate actively in the pathogenesis of liver disease. Little is known of the role of HSCs in immune responses. In this study, HSCs isolated from C57BL/10 (H2b) mice were found to express scant key surface molecules in the quiescent stage. Activated HSCs express major histocompatibility complex class I, costimulatory molecules, and produce a variety of cytokines. Stimulation by interferon gamma (IFN-gamma) or activated T cells enhanced expression of these molecules. Interestingly, addition of the activated (but not quiescent) HSCs suppressed thymidine uptake by T cells that were stimulated by alloantigens or by anti-CD3-mediated T-cell receptor ligation in a dose-dependent manner. High cytokine production by the T cells suggests that the inhibition was probably not a result of suppression of their activation. T-cell division was also found to be normal in a CFSE dilution assay. The HSC-induced T-cell hyporesponsiveness was associated with enhanced T-cell apoptosis. Activation of HSCs was associated with markedly enhanced expression of B7-H1. Blockade of B7-H1/PD-1 ligation significantly reduced HSC immunomodulatory activity, suggesting an important role of B7-H1. In conclusion, the bidirectional interactions between HSCs and immune cells may contribute to hepatic immune tolerance.

Use of alemtuzumab and tacrolimus monotherapy for cadaveric liver transplantation: with particular reference to hepatitis C virus

We have proposed that the mechanisms of alloengraftment and variable acquired tolerance can be facilitated by minimum posttransplant immunosuppression. It was further suggested that the efficacy of minimalistic treatment could be enhanced by preoperative recipient conditioning with an antilymphoid antibody preparation. A total of 76 adults (38 hepatitis C virus [HCV], 38 HCV) were infused with 30 mg alemtuzumab before primary cadaveric liver transplantation and maintained afterward on daily monotherapy unless breakthrough rejection mandated additional agents. In stable patients, the intervals between tacrolimus doses were lengthened ("spaced weaning") after approximately 4 months. Eighty-four contemporaneous nonlymphoid-depleted liver recipients (58 HCV, 26 HCV) were treated with conventional postoperative immunosuppression. The overall incidence of rejection was similar with the two strategies of immunosuppression. With follow-ups of 14 to 22 months, patient and primary graft survival in HCV cases are 97% and 90%, respectively, with alemtuzumab depletion plus minimal immunosuppression versus 71% and 70%, respectively, under conventional immunosuppression. In HCV recipients, current patient and graft survival in the alemtuzumab-pretreated group are 71% and 70% versus 65% and 54%, respectively, under conventional treatment. With both strategies of immunosuppression, the adverse effect of preexisting HCV on survival parameters and graft function already was significant at the 1-year milestone, but its extent was not evident until the second year. With or without HCV, 62% of the 64 surviving lymphoid-depleted patients are on spaced immunosuppression, and four patients receive no immunosuppression. Lymphoid depletion with alemtuzumab and minimalistic maintenance immunosuppression is a practical strategy of liver transplantation in HCV recipients but not HCV recipients.

Clostridium difficile colitis in patients after kidney and pancreas-kidney transplantation

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.

Synergistic effect of cold and warm ischemia time on postoperative graft outcome in human liver transplantation

BACKGROUND/AIMS

Prolonged cold ischemia time (CIT) during graft preservation and warm ischemia time (WIT) defined as a rewarming time have been reported to cause postoperative graft dysfunction after orthotopic liver transplantation (OLT). However, a synergistic effect of both CIT and WIT on patients of graft survival has not been confirmed. The aim of this study was to determine whether simultaneously prolonged CIT and WIT was associated with early graft outcome after clinical OLT.

METHODOLOGY

Between May 1997 and July 1998, 186 consecutive OLT cases were divided into 4 groups as follows: group A, CIT < or =12 hrs and WIT < or =45 min; group B, CIT >12 hrs and WIT < or =45 min; group C, CIT < or =12 hrs and WIT >45 min; and group D, CIT > 12 hrs and WIT >45 min. Liver graft survival within 90 days of OLT and early postoperative graft function were analyzed.

RESULTS

The graft loss rates were 5.4% in group A, 9.8% in group B, 11.1% in group C, and 42.9% in group D. The mean highest aspartate aminotransferase (AST) values after OLT in group D (3352.3+/-569.4 U/L) was significantly higher than those in groups A (1411.7+/-169.2 U/L) and B (1931.3+/-362.6 U/L).

CONCLUSIONS

The simultaneously prolonged cold and warm ischemia time significantly caused hepatic allograft injury and failure, suggesting some synergistic effects of CIT and WIT on postoperative graft function.