Safety and Outcomes in 100 Consecutive Donation After Circulatory Death Liver Transplants Using a Protocol That Includes Thrombolytic Therapy.

Donation after circulatory death (DCD) liver transplantation (LT) reportedly yields inferior survival and increased complication rates compared with donation after brain death (DBD). We compare 100 consecutive DCD LT using a protocol that includes thrombolytic therapy (late DCD group) to an historical DCD group (early DCD group n = 38) and a cohort of DBD LT recipients (DBD group n = 435). Late DCD LT recipients had better 1- and 3-year graft survival rates than early DCD LT recipients (92% vs. 76.3%, p = 0.03 and 91.4% vs. 73.7%, p = 0.01). Late DCD graft survival rates were comparable to those of the DBD group (92% vs. 93.3%, p = 0.24 and 91.4% vs. 88.2%, p = 0.62). Re-transplantation occurred in 18.4% versus 1% for the early and late DCD groups, respectively (p = 0.001). Patient survival was similar in all three groups. Ischemic-type biliary lesions (ITBL) occurred in 5%, 3%, and 0.2% for early DCD, late DCD, and DBD groups, respectively, but unlike in the early DCD group, in the late DCD group ITBL was endoscopically managed and resolved in each case. Using a protocol that includes a thrombolytic therapy, DCD LT yielded patient and graft survival rates comparable to DBD LT.

Phaeohyphomycosis fungal infections in solid organ transplant recipients: clinical presentation, pathology, and treatment.

BACKGROUND: Dematiaceous, or dark-pigmented, fungi are known to cause infections such as phaeohyphomycosis, chromoblastomycosis, and mycetoma. These fungi are becoming increasingly important opportunistic pathogens in solid organ transplant recipients (SOTR). We present a retrospective chart review of 27 SOTR who developed phaeohyphomycosis infections post transplant from 1988 to 2009. METHODS: Cases were reviewed for fungal species isolated, date and source of culture, immunosuppressive and fungal therapy used, and outcome. The majority of isolates obtained were from the skin and soft tissue, with 3 pulmonary and brain abscesses. RESULTS: The time from transplantation to onset of infection ranged from 2 months to 11 years. The species isolated were Exophiala (11), Ochroconis (3), Alternaria (2), Phoma (2), Wangiella (1), Cladosporium (1), Aureobasidium (1), Chaetomium (1), Coniothyrium (1), and non-sporulating fungi (2). An additional 4 patients had infections confirmed by pathology, but no cultures were done. Most of the affected skin lesions were surgically debrided and treated with itraconazole; 2 patients were treated with voriconazole and 2 with amphotericin D. Death from fungal disease occurred only in patients with pulmonary and brain abscesses. CONCLUSIONS: As the number of SOTR increases, so does the incidence of fungal infections in that population. Surgery, along with antifungal therapy and a reduction in immunosuppression, are the cornerstones of treatment.

Excellent liver retransplantation outcomes in hepatitis C-infected recipients.

UNLABELLED: Survival outcomes for liver retransplantation (LRTx) after graft loss in HCV patients (HCV-LRTx) are generally considered inferior to those after non-HCV-LRTx. Between January 1, 2005 and June 30, 2011, our center performed 663 LTx, including 116 (17.5%) LRTx, 41 (35.3%) of which were more than 90 d after the LTx. Twenty-nine (70.7%) LRTx were performed in HCV antibody-positive individuals. We compared patient demographics, baseline characteristics and outcomes of our HCV-LRTx group with the HCV-LRTx patients from the most recent OPTN database covering the same time period. Our Kaplan-Meier HCV-LRTx one-, three-, and five-yr HCV-LRTx patient survival rates were 86.2%, 79.0%, and 72.4%, respectively compared with the OPTN one-, three-, and five-yr HCV-LRTx survival rates of 73.3%, 59.0%, and 51.3% respectively. Likewise, our graft survival rates were higher than OPTN rates at all time points studied. We performed a higher percentage of HCV-LRTx as simultaneous liver/kidney transplants (SLK) (37.9% vs. 21.8%) and recorded shorter warm (30 ± 4 vs. 45 ± 23 min) and cold ischemic times (5:44 ± 1:53 vs. 7:36 ± 3:12 h:min). CONCLUSION: In our experience, HCV-LRTx patient and graft survival rates are comparable to LTx survival rates and are higher than the rates described by OPTN.

The requirement for DM in class II-restricted antigen presentation and SDS-stable dimer formation is allele and species dependent.

Recently several cell lines have been identified with mutations in a major histocompatibility complex (MHC)-linked protein that lead to defects in class II-restricted antigen presentation and a defect in the formation of class II SDS-stable dimers. The defect in these cells has recently been shown to result from the inability to express the MHC-encoded nonclassical class II molecule called DM. To further examine the role of DM in class II-restricted antigen presentation, we asked if this defect would equally affect different allelic and species variants of class II molecules. To investigate this, we transfected the parent cell lines T1 and 8.1.6 and their respective antigen presentation mutants T2 and 9.5.3 with the genes encoding I-Ad and examined the derived transfectants for their ability to present antigen, the conformation of I-Ad at the cell surface, association of I-Ad with invariant chain (Ii), and the ability to form I-Ad SDS-stable dimers. The lack of functional DM expression did not affect any of the anti-I-Ad monoclonal antibody (mAb) epitopes tested or the ability of I-Ad to associate and dissociate with Ii. Surprisingly, these studies also revealed that the antigen presentation defect observed for DR in the 9.5.3 cells did not compromise I-Ad-restricted antigen presentation. In addition, we found that the level of SDS-stable dimer formation did not correlate with antigen presentation capacity for I-Ad and that the amount of SDS-stable I-Ad dimer depends on the cellular context in which the class II molecule is expressed. Our results suggest that the ability to form SDS-stable dimer is not strictly correlated with class II-restricted antigen presentation. Finally, when two allelic forms of murine class II molecules were compared in the defective T2 cell line, it was found that I-Ak but not I-Ad forms SDS-stable dimers equivalent to that seen in the parental cell lines. Overall, our results suggest that DM may modulate rather than play a requisite role in I-Ad-restricted antigen presentation and SDS-stable dimer formation and that dependency on DM may be allele or species specific.

Major histocompatibility complex class II-restricted presentation of an internally synthesized antigen displays cell-type variability and segregates from the exogenous class II and endogenous class I presentation pathways.

Although reported examples of endogenous antigen (Ag) presentation by major histocompatibility complex (MHC) class II molecules have increased, the mechanisms governing this process remain poorly defined. In this communication, we describe an experimental system designed to examine the mechanisms governing class II presentation of internal Ag. Our target peptide is processed from a transmembrane protein constitutively expressed by a variety of nucleated cells (MHC class I, H-2Ld), is naturally displayed by MHC class II molecules in vivo, and is recognized by a class II-restricted, CD4+ T cell hybridoma. Our results indicate that presentation of the Ld target Ag is independent of its plasma membrane expression, may not involve endosomal proteolysis, and thus may be distinct from the classically defined class II presentation pathway. In addition, the observations that Ld presentation does not require a functional TAP-1 complex, is not blocked by invariant chain, and cannot utilize cytoplasmic forms of H-2Ld, suggest that a classical class I pathway is not involved in this presentation event. Finally, our data suggest that different cofactors participate in MHC class II presentation of exogenous and endogenous Ag, and that disparate Ag presenting cells, such as B, T, and pancreatic islet cells, may differentially express these two class II pathways of Ag presentation.

Incidence and outcome of infection by vancomycin-resistant Enterococcus following orthotopic liver transplantation.

Vancomycin-resistant Enterococcus (VRE) has become a significant nosocomial pathogen. For this study, the records of 325 patients who underwent orthotopic liver transplantation (OLT) were reviewed. Thirty-four patients were infected by VRE (incidence of 10.5%, 14% in adults vs. 5% in children, P < 0.01). Common features of patients who developed infections with VRE included previous antibiotic use (25 patients, 15 of whom received vancomycin), co-infection by other pathogens (28 patients), and relaparotomy following OLT (20 patients). Pulmonary and/or renal failure preceded infection by VRE in 11 and 4 adult patients, respectively. Biliary complications were exceedingly common in patients infected by VRE (28 patients) and significantly increased the risk of infection by VRE (21.5% vs. 3.1% for patients without biliary complications, P < 0.0001). Mortality associated with VRE infections was high (56% vs. 19% for patients not infected by VRE, P < 0.0005). The most frequent cause of death was sepsis (16 of 19 patient deaths), often polymicrobial. The high incidence of infection by VRE following OLT, the lack of effective antibiotics for the treatment of VRE, and the association of VRE with patient mortality emphasizes the need to define the risk factors associated with VRE infection. We suggest early surgical intervention to treat complications that may predispose patients to infection by VRE.

Combined liver and kidney transplantation in children.

BACKGROUND: Preexisting renal dysfunction has been reported to significantly increase the morbidity and mortality associated with orthotopic liver transplantation (OLT). OLT alone has been recommended for adults and children with end-stage liver disease and reversible causes of renal failure (i.e., hepatorenal syndrome), whereas combined liver and kidney transplantation (LKT) has been shown to be an effective treatment for adults with combined end-stage liver and kidney disease. The purpose of this study was to examine the role of LKT in children. METHODS: Between October of 1984 and 1997, 385 children less than 18 years of age underwent OLT at the University of Chicago. During this same time period 12 patients underwent LKT. Data were gathered by retrospective review of the patients medical records and by interviews conducted with the patients' families. RESULTS: Actuarial patient survival was comparable for children who underwent OLT alone and LKT (69% versus 67% at 5 years). All allograft losses in the LKT group were the result of patient death and occurred within the first 90 postoperative days. Factors associated with decreased patient survival included severity of illness as reflected by United Network of Organ Sharing status and LKT after failed OLT or cadaveric renal transplant. CONCLUSIONS: In children with concomitant endstage liver and kidney disease, LKT can be considered an effective therapeutic option in selected patients. Long-term patient survival in patients undergoing LKT is comparable to that of patients with normal renal function undergoing OLT alone.

Reduction of immunosuppression for transplant-associated skin cancer: expert consensus survey.

BACKGROUND: Reduction of immunosuppression is considered a reasonable adjuvant therapeutic strategy in solid-organ transplant recipients experiencing multiple or high-risk skin cancers. However, the literature provides no guidance about what threshold of cancer development would warrant initiation of reduction of immunosuppression. OBJECTIVES: To develop expert consensus guidelines for initiation of reduction of transplant-associated immunosuppression for solid-organ transplant recipients with severe skin cancer. METHODS: An expert consensus panel was convened by the International Transplant Skin Cancer Collaborative and Skin Care for Organ Transplant Patients Europe Reduction of Immunosuppression Task Force. Thirteen hypothetical patient scenarios with graduated morbidity and mortality risks were presented and mean and mode expert opinions about appropriate level of reduction of systemic immunosuppression (mild, moderate, severe) were generated. RESULTS: Mild reduction of transplant-associated immunosuppression was considered warranted once multiple skin cancers per year developed or with individual high-risk skin cancers. Moderate reduction was considered appropriate when patients experienced > 25 skin cancers per year or for skin cancers with a 10% 3-year risk of mortality. Severe reduction was considered warranted only for life-threatening skin cancers. CONCLUSIONS: Reduction of immunosuppression is considered a reasonable adjuvant management strategy for transplant recipients with numerous or life-threatening skin cancers. Proposed guidelines are presented for the graduated reduction of immunosuppression coincident with the increasing skin cancer risks.

Invariant chain retains MHC class II molecules in the endocytic pathway.

During exocytosis of MHC class II, the class II alpha beta heterodimer associates with a third polypeptide termed invariant chain (Ii). Class II and Ii are coordinately processed and transported until proteolytic cleavage of Ii in an acidic compartment immediately before class II surface expression. Although the lysosomotropic agent chloroquine (CQ) prevents dissociation of class II/Ii within the cell, the ultimate fate of these complexes has not been determined. We considered two alternative possibilities. If Ii encodes an intracellular retention signal, then persistent association of Ii with class II could lead to intracellular accumulation of class II/Ii complexes. Alternatively, if Ii does not block further transport of class II, then CQ treatment should result in aberrant expression of class II/Ii complexes at the cell surface. Ltk- and EL4 cells transfected with I-A(d) alone or I-A(d) plus Ii were treated with CQ and examined for changes in surface class II and Ii expression. Anti-Ii mAb surface staining did not increase with prolonged CQ treatment, but a dramatic decrease in surface class II staining was observed. This decrease in class II was observed both with genomic Ii and p31 cDNA transfectants and was rapidly reversed upon drug removal. Accumulation of Ii and class II within treated cells was directly observed by intracellular staining. Similar effects on MHC surface expression were observed with the lysosomotropic agents primaquine and NH4Cl and the cysteine protease inhibitor leupeptin. Ii-negative cells treated in parallel displayed no effect of the lysosomotropic agents or leupeptin on class II surface staining. These results indicate that dissociation of Ii from newly synthesized class II is required for transport of the alpha beta dimer to the cell surface, and suggest that Ii serves to retain class II molecules in a post-Golgi endocytic compartment.

Transplant therapy for type 1 diabetes mellitus.

Insulin-dependent diabetes mellitus is a devastating disease affecting more than one million patients in the United States alone. While advances have been made in exogenous insulin therapy, pancreas transplantation remains the only available treatment that restores a euglycemic state, a consistently normal glycosylated hemoglobin level, and functioning biofeedback regulatory control. New immunosuppressive regimens and improvements in surgical technique have resulted in improved patient and pancreas graft survival rates. Recent advances in islet cell purification and immunosuppressive therapies aimed at reducing rejection have renewed interest in islet cell transplantation.