CD52-Negative NK Cells Are Abundant in the Liver and Less Susceptible to Alemtuzumab Treatment.

BACKGROUND: T-cell depleting strategies have become an integral part of immunosuppressive regimens in organ transplantation. Alemtuzumab is a humanized monoclonal antibody against CD52, a cell-surface antigen on several immune cells. It has been suggested that lymphocyte depletion increases the risk of serious infections. However, this has not been observed with short-term alemtuzumab treatment in an organ transplant setting. For induction therapy using alemtuzumab following liver transplantation, we found that T- and B-cell numbers declined rapidly after alemtuzumab therapy; however, the natural killer (NK) cell number was sustained. NK cells are important effectors of innate immunity. Since the effects of alemtuzumab on NK cell functions, especially those of liver NK cells, are unknown, this study aimed to investigate this in detail. METHODS: To assess the effect of alemtuzumab on NK cells, samples were obtained from 7 organ donors and examined by flow cytometry using Annexin V and propidium iodide. Phenotypical and functional differences within subsets of NK cells with different levels of CD52 expression were determined by flow cytometry and in vitro cytotoxicity assays. RESULTS: CD52 expression on NK cells was lower than that on other lymphocyte subsets. The liver contained a large number of CD52- NK cells compared with the peripheral blood. In vitro treatment of liver-derived NK cells with alemtuzumab did not result in cell death. In contrast, co-incubation with alemtuzumab induced cell death in peripheral blood mononuclear cells and non-NK cells in the liver. Furthermore, CD52- liver NK cells were more cytotoxic and produced more IFN-γ than CD52+ NK cells after cytokine activation. CONCLUSION: The liver contains a large number of CD52- NK cells. These cells are refractory to alemtuzumab and have robust activity. These findings indicate that CD52- NK cells persist and could protect against infection after alemtuzumab-based lymphocyte depletion.

Longterm outcomes of auxiliary partial orthotopic liver transplantation in preadolescent children with fulminant hepatic failure.

By preserving part of the native liver, auxiliary partial orthotopic liver transplantation (APOLT) provides the advantage of potential immunosuppression (ISP) withdrawal if the native liver recovers but has had limited acceptance, especially in the United States, due to technical complications and low rates of native liver regeneration. No previous study has evaluated APOLT specifically for preadolescent children with fulminant hepatic failure (FHF). This population might benefit especially based on greater capacity for liver regeneration. Data from 13 preadolescent children who underwent APOLT were compared to 13 matched controls who underwent orthotopic liver transplantation (OLT) for FHF from 1996 to 2013. There were no significant differences in patient demographics or survival between the 2 groups. However, all surviving OLT recipients (10/13) remain on ISP, while all but 1 surviving APOLT recipient (12/13) showed native liver regeneration, and the first 10 recipients (76.9%) are currently off ISP with 2 additional patients currently weaning. In our experience, APOLT produced excellent survival and high rates of native liver regeneration in preadolescent children with FHF. This represents the largest series to date to report such outcomes. Liberating these children from lifelong ISP without the downside of increased surgical morbidity makes APOLT an attractive alternative. In conclusion, we therefore propose that, with the availability of technical expertise and with the technical modifications above, APOLT for FHF should be strongly considered for preteenage children with FHF.

Abdominal transplantation for unresectable tumors in children: the zooming out principle.

PURPOSE: To present our experience in abdominal transplantations to manage unresectable abdominal neoplasms in children and to describe the role of extensive surgeries in such cases. METHODS: This is a retrospective study of 22 abdominal transplantations in 21 patients for abdominal tumors over 16 years. Transplantation techniques included liver transplant (LT), multivisceral transplant (MVTx), and intestinal autotransplant (IA). Follow-up intervals ranged from 0.3 to 168 months (median 20 months). RESULTS: LT alone was performed in 15 patients for primary malignant (11) and benign (4) liver tumors. Pathological classification included HB hepatoblastoma (6), HCC hepatocellular cancer (3), hepatic epithelioid hemangioendothelioma HEH (1), angiosarcoma (1), benign vascular tumors (3), and adenoma (1). IA was performed in four patients for lesions involving the root of the mesentery; tumors of the head of pancreas (3) and mesenteric hemangioma (1). MVTx was performed in 2 patients for malignancies; pancreaticoblastoma (1), recurrent hepatoblastoma (1), and in one patient as a rescue procedure after IA failure. Four of the eleven patients who underwent LT for malignant liver tumor had metastatic disease at presentation. Six of them died of recurrent neoplasm (3), transplant-related complications (2), and underlying disease (1). All LT patients who had benign tumors are alive with functioning grafts. All IA patients survived and are on an oral diet, with one patient requiring TPN supplementation. One of the three patients who underwent MVTx died of metastatic disease. CONCLUSIONS: Allo/auto transplantation for abdominal tumors is a valuable modality when conventional treatments fail or are not feasible.

Clinical significance of intragraft miR-122 and -155 expression after liver transplantation.

AIM: Recurrent hepatitis C (RHC) and acute cellular rejection (AR) remain critical problems following liver transplantation (LT) in hepatitis C virus (HCV) positive recipients because of the similar clinical features. Discrimination between these conditions can be problematic, and adjunctive biomarkers would be useful to discriminate these processes. The aim of our study was to investigate the possibility of the intragraft miR-122 and -155 expression as new biomarkers after LT. METHODS: A total of 29 HCV positive recipients were enrolled in this study. Intragraft expressions of miR-122 and -155 were studied between RHC predominant (n = 17) and AR predominant cases (n = 12) using quantitative reverse transcription polymerase chain reaction. Furthermore, we investigated the correlations between these expression levels and clinical serum parameters. RESULTS: Intragraft miR-122 expression had a good correlation with serum alkaline phosphatase (P = 0.02), but it was not correlated with the serum HCV viral load. The expression levels of miR-122 in the AR group were significantly higher than those in the RHC group (P = 0.0006) and, inversely, the expression levels of miR-155 in the AR group were significantly lower than those in the RHC group (P = 0.01). CONCLUSION: Our study emphasizes a useful pattern of miR-122 and -155 as ancillary markers to discriminate AR predominant cases from RHC in HCV positive patients after LT.

Role of innate and acquired immune mechanisms in clinical intestinal transplant rejection.

BACKGROUND: Long-term outcomes of intestinal transplantation are limited by infection and rejection. To understand the underlying immune mechanisms, graft infiltrating and peripheral blood cells were analyzed using multiple ex vivo assays in intestinal transplantation recipients. METHODS: Infiltrating cells from rejected (graft enterectomy for rejection) and accepted or quiescent (stoma closure in stable transplant recipients) grafts were isolated and phenotypically characterized as to subsets and Toll-like receptor expressions as well as functionally tested for antimicrobial and antidonor immune responses. Multiparameter antidonor immunity was also assessed serially in the peripheral blood. RESULTS: The graft infiltrating lymphocytes were mostly of recipient origin in all patients tested. In rejecting grafts, the predominant populations were TcRαß(+)CD3(+)CD8(+) T cells, and CD14(+) monocytes that coexpressed Toll-like receptor-2, receptor-3, receptor-4, receptor-5, and receptor-9, suggesting innate immune activation. In quiescent allografts the major cell subsets were CD13(+)CD14(-) monocytes and CD4(+)CD25(+) T cells with possible regulatory functions. Infiltrating cells from rejected but not quiescent grafts proliferated in response to enteric bacterial and donor antigens as well as killed donor targets. Serial follow-up of peripheral blood indicated donor-specific posttransplant unresponsiveness in micro-cell-mediated lympholysis (m-CML) and mixed lymphocyte reaction (MLR) in recipients with quiescent grafts, but not in recipients with multiple rejection episodes. Enzyme-Linked ImmunoSpot assays yielded parallel results: granzyme-B with micro-cell-mediated lympholysis and interferon-γ with MLR tests. CONCLUSION: These results were consistent with the notion that rejection was associated with innate and acquired antimicrobial and antidonor immune reactivity and that patients with stable grafts were free from these deleterious effects.

Mannose binding lectin (mbl2) haplotype frequencies in solid organ transplant patients and correlation with MBL protein levels--evaluation of complement-mediated effector pathway deficiency.

Mannose-binding lectin (MBL) is a protein critical in activating complement. Patients with wild-type and variant mbl2 genotypes have high or low concentrations of MBL protein, which is known to increase susceptibility to transplant rejection or infection, respectively. Our objective was to determine mbl2 genotype frequencies in future solid organ transplant recipients in order to optimize their induction and maintenance immunosuppressive therapies, and to provide MBL reference data for this unique population. We genotyped 1687 patients, and concurrently measured protein in 807 of them, during 2010-2011. Frequencies of the structural allele SNPs in our population were similar to those of other studied populations; however, Black patients with the same intermediate and deficient mbl2 genotypes as Caucasians produced significantly lower levels of MBL protein; therefore, within this population more genotypes should be considered MBL-deficient. Overall, the most critical parameter in determining serum MBL protein concentration was genotype, which was independent of other factors including ethnicity, gender, or diseased native organ type.

Tregs expanded in vivo by TNFRSF25 agonists promote cardiac allograft survival.

BACKGROUND: Thymic-derived Foxp3(+)CD4(+) regulatory T cells (Tregs)-also called natural Tregs-are critical for the induction and maintenance of transplantation tolerance. Using an agonistic tumor necrosis factor-receptor super family (TNFRSF) 25 antibody, clone 4C12, we showed that TNFRSF25 is a powerful regulator of Treg proliferation-mediating expansion of natural Tregs in vivo. In the present study, we investigate the role of Tregs expanded in vivo by TNFRSF25 on cardiac allograft survival in a mouse model of fully major histocompatibility complex-mismatched ectopic heart transplants. METHODS: C57BL/6 mice were treated with 20 µg of TNFRSF25 agonist 4C12 4 days before heterotopic allogeneic heart transplantation. The survival of the graft was monitored daily by abdominal palpation until the cessation of cardiac contraction. The severity of immune rejection was evaluated by histopathology. Infiltration of inflammatory cells and Tregs into the graft were characterized by flow cytometry. The expression of cytokines and other regulatory proteins was measured by quantitative real-time polymerase chain reaction. RESULTS: Treatment with 4C12 resulted in expansion of Tregs to 30%-35% of CD4(+) cells and was associated with a significant prolongation of median graft survival from 8 days to 17 days (P=0.0049). On day 7 after transplantation, the time point when controls reject the graft, the transplants of 4C12-treated animals beat strongly and showed increased accumulation of Foxp3(+) Tregs within the graft and decreased infiltration of inflammatory cells. CONCLUSIONS: TNFRSF25 agonists expand Tregs in vivo and delay allograft rejection.

Clinical-scale isolation of interleukin-2-stimulated liver natural killer cells for treatment of liver transplantation with hepatocellular carcinoma.

Tumor recurrence is the main limitation of liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) and can be promoted by immunosuppressants. However, there is no prevention or treatment for HCC recurrence after LT. Here we describe a clinical-scale method for an adoptive immunotherapy approach that uses natural killer (NK) cells derived from deceased donor liver graft perfusate to prevent tumor recurrence after LT. Liver mononuclear cells (LMNCs) that were extracted from deceased donor liver graft perfusate contained a high percentage of NK cells (45.0 ± 4.0%) compared with peripheral blood mononuclear cells (PBMCs) (21.8 ± 5.2%) from the same donor. The CD69 activation marker and the natural cytotoxicity receptors, NKp44 and NKp46, were expressed at high levels in freshly isolated liver NK cells. Furthermore, interleukin-2 (IL-2)-stimulated NK cells showed greater upregulation of activation markers and the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is critical for NK cell-mediated antitumor cell death and increased production of interferon. Moreover, IL-2 stimulation induced LMNCs to exhibit a strong cytotoxicity against NK-susceptible K562 target cells compared with PBMCs (p < 0.01). Finally, we also showed that the final product contained a very low T-cell contamination (0.02 ± 10(6) cells/kg(-1)), which reduces the risk of graft-versus-host disease (GVHD). Collectively, our results suggest that the adoptive transfer of IL-2-stimulated NK cells from deceased donor liver graft perfusate could be a promising treatment for LT patients with HCC.

Liver transplantation with preservation of the inferior vena cava: lessons learned through 2,000 cases.

BACKGROUND: We aim to demonstrate the utility and efficacy of the "piggyback technique" (PBT); liver transplant (LT) with caval preservation. STUDY DESIGN: Adult LTs were performed with intent to use the PBT except in cases of juxtacaval malignancy or technical difficulty. Hepatic venous outflow was established between the donor suprahepatic cava and the joined ostia of all recipient suprahepatic veins. Technical variants with the donor cava and recipient retrohepatic cava were used as needed. The experience was divided into 2 eras: E1 (1994-2002), E2 (2002-2010). RESULTS: We completed 945 of 1080 LTs in E1 (87.5%) and 851 of 920 LTs in E2 (92.5%) using the PBT. Thirty day mortality was 4.6% in E1, 3% in E2 (p = 0.02) with 2 intra-operative deaths in E1. One, 3, 5 year patient survival was 83.7, 75.6, 69.3% in E1 vs. 86, 78.4, 73.8% in E2 (p = 0.057). Graft survival was 77.7, 69, 62.3% in E1 vs. 84, 76.2, 71.2% in E2 (p < 0.0001). Median operative time and hospital length of stay improved in E2 (p < 0.0001, 0.0001). Outflow variants were used more frequently in E2 (11.3% vs. 6.1%). Nine patients (0.5%) developed outflow obstruction, 6 in E1, and 3 in E2. Twice, it was recognized and corrected intraoperatively. Seven patients presented with refractory ascites. Six were successfully treated (4 balloon dilatation, 2 surgical revision), one patient died after attempted dilatation. CONCLUSIONS: The PBT can be used as the preferred technique in adult LT. With experience, the technique was used more frequently, with more variants, with improved outcomes. Outflow obstruction was a rare complication.

Peripheral blood gene expression analysis in intestinal transplantation: a feasibility study for detecting novel candidate biomarkers of graft rejection.

INTRODUCTION: We investigated the putative candidate biomarkers of graft rejection in peripheral blood of intestinal transplant patients. MATERIALS AND METHODS: Peripheral blood gene expression analysis was performed in intestinal transplant patients. The results were matched with concurrent graft biopsies using bioinformatics. RESULTS: Peripheral blood samples (n=11), of 3 adult patients [transplant day (n=1), no rejection (n=1), minimal rejection (n=2), mild rejection (n=5) and severe rejection (n=2)] were collected. Bioinformatics: Enrichment Analysis: The three most affected pathways differentially expressed in rejection versus a pool of healthy volunteers were related to protein translation: translation initiation, translation elongation termination, and translation in mitochondria, with p-values for all rejection stages in all patients in the 10-4 to 10-18 range. No significant enrichment was observed for these categories in the day of transplant sample. In addition to translation, significant enrichment of several immune response categories was observed in rejection samples. Subsequent gene set enrichment analysis verified these results. The level of enrichment was very high (p-values of 10-5-10-60) and increased with the level of rejection in all patients. Genes significantly down-regulated in translation related gene sets included ribosomal proteins RPL13A, RP L22, RPS23, RPL13 and RPL10A, that could be used as potential biomarkers for future experiments. CONCLUSION: In this pilot study we found a list of genes (involved in translation) significantly downregulated in the peripheral blood of three intestinal transplant patients during rejection. These results will be verified in further studies with increased number of patients and with isolation of peripheral blood subpopulations.

Association between donor-specific antibodies and acute rejection and resolution in small bowel and multivisceral transplantation.

BACKGROUND: Donor-specific antibodies (DSA) are associated with acute kidney graft rejection, but their role in small bowel/multivisceral allograft remains unclear. We carried out a prospective study to understand the impact of DSA in the setting of intestinal allograft rejection. METHODS: Thirteen patients (15 grafts) were serially evaluated for DSA levels pre- and posttransplant. DSA was determined by Luminex and the results were interpreted as fluorescence intensity (FI), with FI more than 3000 considered positive. RESULTS: The clinical rejection episodes in allografts were significantly associated with the presence of DSA (P=0.041).We obtained 291 biopsy samples from graft ileum and date-matched DSA assay reports. Sixty-three (21.65%) of the biopsies showed acute rejection. The appearance of DSA were preformed (n=5, anti-human leukocyte antigen class II=3, anti-class I and II=2), de novo (n=4, 15.25±4.72 days after transplantation, anti-class II=1, and anti-class I and II=3) and never (n=6). Among the 63 biopsies, 30(47.6%) had significant correlations with positive DSA (kappa=0.30, P<0.001) and manifested severe rejection grade (P=0.009). CONCLUSIONS: In this cohort of small bowel/multivisceral transplantation patients, there was a high incidence of DSA. The presence of DSA should alert the clinical team of a higher risk of rejection, and reduction of the FI is clinically associated with resolution. Serial endoscopy guided biopsies combined with simultaneous DSA measurement in postintestinal transplantation follow-up is an effective means of screening for cellular and humoral-based forms of acute rejection.

The effect of donor-recipient cytomegalovirus serology on adult liver transplantation: a single center experience.

INTRODUCTION: We investigated the outcomes of adult liver transplants, according to their donor-recipient cytomegalovirus (CMV) serology. MATERIALS AND METHODS: We included in the study all adult primary liver transplants, from January 1, 2002, to December 31, 2005. Follow-up was until December 31, 2007. According to the donor-recipient CMV serology, patients were divided into positive-negative (PN), positive-positive, negative-negative, and negative-positive groups, and all received CMV prophylaxis for 4 months posttransplantation. Hepatitis C patients received conventional immunosuppression, whereas all other patients received either conventional treatment or alemtuzumab (Campath-1H) induction. RESULTS: We studied 438 adult liver transplants. Comparisons were made between high-risk group patients (PN) versus all others: 5-year patient survival was 74.31% vs. 78.8%, (P=NS) and graft survival 63.87% vs. 74.77%, (P=0.042). Five-year freedom from rejection was 42.84% vs. 51.95% (P=0.036). CMV infection (n=3) or disease (n=27) was observed in 30 patients (PN [n=23], positive-positive [n=6], and negative-positive [n=1]). Incidence of CMV infection was 9.8% overall and 34.84% and 2.5%, respectively, for the PN group versus all others (P=0.0000). Patients who received Campath-1H induction did not have an increased incidence of CMV infections compared with those who received conventional immunosuppression. CONCLUSIONS: In our center, in adult liver transplantation, CMV donor-recipient PN serology is associated with rejection, graft survival, and CMV infection but is not correlated with patient survival, Epstein-Barr virus (EBV) occurrence, or viral hepatitis recurrence. The introduction of more potent induction immunosuppression did not accentuate these negative outcomes.

Characteristic immune, apoptosis and inflammatory gene profiles associated with intestinal acute cellular rejection in formalin-fixed paraffin-embedded mucosal biopsies.

Small bowel transplantation (SBT) is becoming a preferred treatment for patients with irreversible intestinal failure. Despite continuous improvement of immunosuppression, SBT is plagued by a high incidence of acute cellular rejection (ACR) that is frequently intractable. Therefore, there is a need for reliable detection markers and novel immunosuppressive strategies that can achieve better control of ACR. We hypothesized that particular transcriptomes provide critical regulation of the intragraft immune response. The aim of our study was to detect potential molecular biomarkers for identifying ACR in minute mucosal biopsies. We examined 30 intestinal mucosal biopsies (AR/NR; 17/13) obtained from recipients after SBT or multivisceral transplantation. We utilized TaqMan® Gene Signature Arrays (immune, inflammation and apoptosis) and investigated the expression of 280 genes. As one of our validations, we performed immunohistochemistry for selected targets. We detected 252 mRNAs in total, 92 of which were found with significantly different expression levels between the AR and NR groups. Immunohistochemistry showed significantly increased staining for IL1R2, ICAM1, GZMB, and CCL3 (P < 0.05) during ACR. For the first time, we characterize the potential molecular changes that are associated with modulation of histological appearances of intestinal ACR. These differences in transcriptome patterns can be used to identify robust biomarkers and potential novel therapeutic targets for immunosuppressive agents.

Long-term follow-up of 23 operational tolerant liver transplant recipients.

INTRODUCTION: This is a follow-up of a withdrawal study that we previously performed on 104 liver transplant patients in which immunosuppression was gradually withdrawn over a period of 3 years. Eighty-one patients were not able to be withdrawn (rejectors), and 23 patients were successfully weaned off immunosuppression (tolerants). METHODS: In this study, we present their follow-up after the end of the withdrawal study: we compared the results of the tolerant patients (n=23) with those of the rejectors (n=81). Follow-up was until February 2010. RESULTS: Operational tolerant patients were off immunosuppression for an average of 7.27±0.28 years. Patient survival in the tolerant and the rejector groups was 63.66% and 74.25%, respectively (P=not significant). A patient in the rejector group received two retransplants for chronic rejection. In the rejector group, 19 patients presented 26 rejection episodes: clinically suspected (n=19) and biopsy-proven mild (n=4), moderate (n=2), and severe (n=1) rejection episodes. A tolerant patient had a moderate rejection episode of 5.3 years after immunosuppression withdrawal. In the rejector group, five patients received a kidney transplant and four more are on dialysis versus a tolerant patient on dialysis. Freedom from rejection in the tolerant and rejector groups was 95% and 73%, respectively (P<0.05), and freedom from renal replacement treatment was 83.33% vs. 44.58%, respectively (P=not significant). CONCLUSIONS: Long-term outcomes of operationally tolerant liver transplant patients are at least as good as those of control patients. Operational tolerance is not a permanent state, and continuous vigilance is required to detect rejection episodes.

Liver transplantation for hepatocellular carcinoma in the model for end-stage liver disease era.

BACKGROUND: Since March 2002, the United Network for Organ Sharing liver allocation policy has given extra priority to patients with hepatocellular carcinoma (HCC) who meet specific medical criteria. This study reviews our experience with liver transplantation for HCC under this system. STUDY DESIGN: Between March 2002 and April 2009, 244 patients with HCC underwent primary liver or liver-kidney transplantation under the current allocation system at the University of Miami. Outcomes including HCC recurrence-free survival (RFS) and patient survival (PS) were assessed retrospectively. Clinical variables that predicted outcomes were analyzed. RESULTS: The median time from listing to transplantation was 48 days. The median follow-up was 27.4 months, with an observed recurrence rate of 10.7%. The RFS rates at 1, 3, and 5 years after transplantation were 96.0%, 89.0%, and 83.6%, respectively. The PS rates at 1, 3, and 5 years after transplantation were 86.3%, 71.5%, and 61.7%, respectively. Among patients diagnosed with T2 HCC, a trend toward improved RFS was observed for those who received preoperative ablative therapy; PS was similar (p > 0.05). Outcomes (RFS and PS) for patients with T3 HCC were similar to those in patients with T2 HCC (p > 0.05). Patients with an alpha-fetoprotein >100 ng/mL had an RFS that was inferior to that in patients with an alpha-fetoprotein < or =100 ng/mL (p < 0.0001). CONCLUSIONS: Under the current allocation system, transplantation for HCC results in excellent RFS; PS depends on factors other than HCC; the value of preoperative ablative therapy for patients with T2 HCC is uncertain; the current criteria could be expanded to include selected patients with T3 HCC; and an elevated AFP level is associated with an increased risk of HCC recurrence after transplantation.

Effect of liver transplantation on spleen size, collateral veins, and platelet counts.

BACKGROUND: The aim of this study was to evaluate the effect of liver transplantation on the spleen size, spontaneous splenorenal shunt (SRS) function, and platelet counts in patients with hypersplenism. METHODS: Between December 2001 and February 2007, 462 adult patients underwent orthotopic liver transplantations (OLTX) at our institution. Of these patients, CT or MRI information was reviewed retrospectively in 55 patients. Volume measurements of the spleen and liver, spleen/liver volume ratio (S/L ratio), presence and size of SRS, and platelet counts were evaluated before and after OLTX. RESULTS: Mean spleen volume decreased from 827 +/- 463 ml to 662 +/- 376 ml after OLTX (p < 0.01). Five (11%) patients returned to normal-range spleen size after OLTX. SRS was observed in 19 patients before OLTX (35%). The diameter of SRS also significantly decreased from 1.0 +/- 0.5 cm before OLTX to 0.7 +/- 0.5 cm after OLTX (p < 0.05). SRS disappeared in 16% of patients (3/19). S/L ratio significantly decreased from 0.65 +/- 0.33 to 0.38 +/- 0.17 (p < 0.01) after OLTX. Platelet counts significantly increased after OLTX (p < 0.01). Improvement of the platelet count in the group with postoperative S/L ratio >0.35 was not as good as that in the group with S/L ratio <0.35 (p < 0.01). CONCLUSIONS: Spleen size and SRS size became significantly smaller after OLTX. However, patients with postoperative S/L ratio >0.35 tend to have lower platelet counts after OLTX.

Heterotopic uterus transplantation in a swine model.

BACKGROUND: The aim of our study was to examine the feasibility of allogeneic uterine transplantation in a large animal model. METHODS: We performed heterotopic uterine transplants in genetically defined mini-pigs. Immunosuppression was tacrolimus administered intravenously for the first 12 days posttransplantation followed by oral cyclosporine maintenance immunosuppression. The graft was transplanted heterotopically in the lower abdominal cavity of the recipient. The vaginal vault was exteriorized as a stoma in the lower right abdominal wall. The uterine grafts were followed with endoscopies and biopsies. RESULTS: Ten transplants were performed. Follow-up was until July 2008. At the end of the follow-up period, 5 animals were alive and healthy, 0.5 to 12 months posttransplantation. There were 5 deaths due to pneumonia (n=1), intussusception of the graft (n=1), cardiorespiratory arrest during anesthesia (n=1), and complications of the stoma (n=2). Acute rejections of the graft presented during the 2nd and 3rd month posttransplantation were treated successfully with increase of the maintenance immunosuppression and steroids. Other complications included prolapse and infections of the graft stoma. Pathological changes seen in the endometrial biopsies included acute rejection and acute endometritis. CONCLUSION: These findings demonstrate that successful uterus transplantation in a large animal model (miniature swine) is feasible using this heterotopic model, and it can be useful for the study of these transplants.

Mass clamping of the hilum to facilitate difficult hepatectomy during liver transplantation: a single center 10 year experience.

INTRODUCTION: Classic dissection of the hilar structures during the hepatectomy portion of the liver transplant procedure is sometimes extremely difficult and even dangerous. In such cases, clamping of the hepatic hilar structures en mass can be an effective alternative. In this study, we describe our center's experience with this technique. PATIENTS AND METHODS: This is a retrospective analysis of all patients who received a liver allograft using this technique at our center, between September 1996 and September 2007 (n = 150). Postoperative follow-up was through November 30, 2007. RESULTS: One hundred fifty patients underwent 155 liver transplants using hilar mass clamping. These cases represent 7% of the total number of cases performed at our center during that time interval (n = 2219). This included 93 male and 57 female patients, 18 children and 132 adults. There were 103 primary liver transplants, 52 retransplants. Three of the primary transplants were combined liver/kidney transplants. In 7 cases (4.5%), portacaval hemitransposition was performed to establish portal flow.The decision to perform the hepatectomy with mass clamping of the hilar structures was an intraoperative judgment made when severe vascular adhesions and scarring of the hilum (n = 137) or extensive hilar varices (n = 18) were encountered. The hilar pathology was often associated with hepatic artery (n = 15) or portal vein thrombosis (n = 14).Mean surgical time was 11.33 +/- 0.28 hours. Average blood replacement was 26.27 +/- 2.05 units of packed red blood cells. One patient died intraoperatively (0.64%) while perioperative (30 day) mortality was 6.4%. Venovenous by pass was used in 1 patient (0.64%).One and 5 year patient survival was 75.3% and 61.2%, respectively. One and 5 year graft survival was 73.7% and 48.2%, respectively. There was no patient mortality, graft loss, or technical complications that could be attributed to the mass clamp technique. CONCLUSION: Mass clamping of the hepatic hilum can be an effective alternative to classic hilar dissection in cases when the latter is difficult or impossible.

Successful treatment with bortezomib of a refractory humoral rejection of the intestine after multivisceral transplantation.

Graft rejection is a serious complication after intestinal and multivisceral transplantation. Classic anti-rejection strategies often focus on addressing the cellular component, however mounting evidence suggests that antibody mediated rejection may also play an important role in patient and graft survival. Bortezomib, a proteasome inhibitor used in the treatment of multiple myeloma, has been found to be useful in treating antibody mediated rejection in kidney transplant recipients. The following case illustrates how bortezomib was used to successfully reverse refractory rejection in a patient following multivisceral transplantation. While the rejection was able to be controlled, this patient's course was complicated by an aggressive viral infection after bortezomib therapy. Bortezomib may be a useful agent in the treatment of rejection after intestinal and multivisceral transplantation; however more data is needed to assess its impact on infectious complications in this complex group of patients.