A blood-based multi-pathway biomarker assay for early detection and staging of Alzheimer's disease across ethnic groups.

INTRODUCTION: Existing blood-based biomarkers for Alzheimer's disease (AD) mainly focus on its pathological features. However, studies on blood-based biomarkers associated with other biological processes for a comprehensive evaluation of AD status are limited. METHODS: We developed a blood-based, multiplex biomarker assay for AD that measures the levels of 21 proteins involved in multiple biological pathways. We evaluated the assay's performance for classifying AD and indicating AD-related endophenotypes in three independent cohorts from Chinese or European-descent populations. RESULTS: The 21-protein assay accurately classified AD (area under the receiver operating characteristic curve [AUC] = 0.9407 to 0.9867) and mild cognitive impairment (MCI; AUC = 0.8434 to 0.8945) while also indicating brain amyloid pathology. Moreover, the assay simultaneously evaluated the changes of five biological processes in individuals and revealed the ethnic-specific dysregulations of biological processes upon AD progression. DISCUSSION: This study demonstrated the utility of a blood-based, multi-pathway biomarker assay for early screening and staging of AD, providing insights for patient stratification and precision medicine. HIGHLIGHTS: The authors developed a blood-based biomarker assay for Alzheimer's disease. The 21-protein assay classifies AD/MCI and indicates brain amyloid pathology. The 21-protein assay can simultaneously assess activities of five biological processes. Ethnic-specific dysregulations of biological processes in AD were revealed.

Clinical characteristics and outcomes of PTLD following intestinal transplantation.

Post-transplant lymphoproliferative disease (PTLD) has the highest incidence following intestinal transplantation (ITx). Our center has seen a recent increase in PTLD. Our aim was to review a single-center PTLD experience with a focus on clinical characteristics and outcomes. We completed a retrospective review of biopsy-proven PTLD cases using a prospectively maintained database of 115 ITx recipients transplanted between 1991 and 2014. Nineteen (17%) ITx recipients developed 25 PTLD cases during a median follow-up time of 6.4 (1.6-14.6) years. The incidence of early PTLD was 6% (n = 7). There was a trend toward increased risk of PTLD in children compared with adults (P = .11) and a significantly increased risk of PTLD in re-ITx compared with primary ITx recipients (P = .03). Most PTLD cases were diagnosed between 2010 and 2014 (n = 14). All early PTLD cases were EBV+ on in situ hybridization. Overall graft and patient survival are 68% and 74%, respectively. Second episodes of PTLD were diagnosed in 43% of surviving pediatric patients. Our program has a low incidence of early PTLD with overall excellent graft and patient survival following diagnosis. However, we have also seen a rising incidence of late PTLD. The cause of the increase is unknown as no major changes in immunosuppression protocols have occurred since 1999.

Obliterative portal venopathy: A histopathologic finding associated with chronic antibody-mediated rejection in pediatric liver allografts.

The significance of post-transplant HLA DSA and chronic AMR in LT is an emerging field of study. Although OPV has previously been described as a histopathologic finding in DSA-positive adult LT recipients, it was not included in the recent Banff criteria for chronic AMR. Our aim was to describe the association between OPV and chronic AMR in pediatric LT recipients. A retrospective review of 67 liver biopsies performed between November 2014 and April 2016 in 45 pediatric LT recipients identified four patients with OPV. Clinical status, liver biochemistry, the presence of DSA, and available non-HLA antibody testing, as well as histopathologic features of chronic AMR, were assessed. All four patients with OPV had class II DSA and histopathologic features of chronic AMR based on the Banff criteria. Two patients were noted to have non-HLA antibodies. Three patients are undergoing treatment with IVIG but have persistent DSA. Two patients have graft failure and are awaiting retransplantation. In conclusion, OPV is a histopathologic finding associated with chronic AMR in pediatric LT recipients. Further studies are needed to elucidate whether OPV is reversible and/or amenable to medical therapy.

Blockade of EphA4 signaling ameliorates hippocampal synaptic dysfunctions in mouse models of Alzheimer's disease.

Alzheimer's disease (AD), characterized by cognitive decline, has emerged as a disease of synaptic failure. The present study reveals an unanticipated role of erythropoietin-producing hepatocellular A4 (EphA4) in mediating hippocampal synaptic dysfunctions in AD and demonstrates that blockade of the ligand-binding domain of EphA4 reverses synaptic impairment in AD mouse models. Enhanced EphA4 signaling was observed in the hippocampus of amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic mouse model of AD, whereas soluble amyloid-ß oligomers (Aß), which contribute to synaptic loss in AD, induced EphA4 activation in rat hippocampal slices. EphA4 depletion in the CA1 region or interference with EphA4 function reversed the suppression of hippocampal long-term potentiation in APP/PS1 transgenic mice, suggesting that the postsynaptic EphA4 is responsible for mediating synaptic plasticity impairment in AD. Importantly, we identified a small-molecule rhynchophylline as a novel EphA4 inhibitor based on molecular docking studies. Rhynchophylline effectively blocked the EphA4-dependent signaling in hippocampal neurons, and oral administration of rhynchophylline reduced the EphA4 activity effectively in the hippocampus of APP/PS1 transgenic mice. More importantly, rhynchophylline administration restored the impaired long-term potentiation in transgenic mouse models of AD. These findings reveal a previously unidentified role of EphA4 in mediating AD-associated synaptic dysfunctions, suggesting that it is a new therapeutic target for this disease.

The impact of antibodies and virtual crossmatching on intestinal transplant outcomes.

PURPOSE OF REVIEW: Sensitization to human leukocyte antigens (HLAs) limits access to potential donors and contributes to inferior graft survival after transplantation. In this article, we will review the effects of HLA-specific antibodies on intestinal transplant outcomes, and discuss considerations in the monitoring and treatment of anti-HLA antibodies. RECENT FINDINGS: Only a handful of studies has investigated the effects of donor-specific anti-HLA antibodies (DSAs) on intestinal allograft outcomes. Most have reported associations between DSA presence and rejection-related graft failure. The evolution of antibody detection methods and improvements in crossmatch testing have allowed for a systematic approach to the broadly sensitized transplant candidate, and facilitated the identification of compatible organ donors. The virtual crossmatch can be used to aid in organ allocation and avoid transplantation across preformed DSA. However, much remains unknown about the mechanisms of antibody-mediated injury in the intestinal graft, and the effectiveness of current therapies against DSA has yet to be established. SUMMARY: On the basis of available data, we will provide recommendations for the testing and management of DSA among intestinal transplant recipients. The precise management protocol should be tailored to each individual based on immunologic risk as well as clinical status.

Melanocortin-4 receptor regulates hippocampal synaptic plasticity through a protein kinase A-dependent mechanism.

Learning and memory require orchestrated regulation of both structural and functional synaptic plasticity in the hippocampus. While a neuropeptide alpha-melanocyte-stimulating hormone, α-MSH, has been implicated in memory acquisition and retention, the functional role of its cognate receptor, melanocortin-4 receptor (MC4R), in hippocampal-dependent synaptic plasticity has not been explored. In this study, we report that activation of MC4R enhances synaptic plasticity through the regulation of dendritic spine morphology and abundance of AMPA receptors. We show that activation of postsynaptic MC4R increases the number of mature dendritic spines and enhances surface expression of AMPA receptor subunit GluA1, resulting in synaptic accumulation of GluA1-containing AMPA receptors. Moreover, MC4R stimulates surface GluA1 trafficking through phosphorylation of GluA1 at Ser845 in a Gα(s)-cAMP/PKA-dependent manner. Blockade of protein kinase A (PKA) signaling abolishes the MC4R-mediated enhancement of neurotransmission and hippocampal long-term potentiation. Importantly, in vivo application of MC4R agonists increases LTP in the mouse hippocampal CA1 region. These findings reveal that MC4R in the hippocampus plays a critical role in the regulation of structural and functional plasticity.

Outcomes of laparoscopic donor nephrectomy without intraoperative systemic heparinization.

PURPOSE: Intravenous heparin has traditionally been given during living donor laparoscopic nephrectomy despite the paucity of evidence supporting its use. We present the results of our experience with laparoscopic donor nephrectomy done without intraoperative systemic heparinization. MATERIALS AND METHODS: We retrospectively reviewed the records of 167 consecutive laparoscopic donor nephrectomies done without intravenous heparin from July 2005 to October 2007 at our institution. We evaluated preoperative donor characteristics, intraoperative and postoperative complications, recipient renal function and graft outcomes. RESULTS: All 138 left nephrectomies were done using a conventional laparoscopic approach while 25 of 29 right nephrectomies were done using the hand assisted technique. Warm ischemia time was approximately 3.0 minutes in each group. Mean +/- SE estimated blood loss was 183 +/- 29 ml for left and 115 +/- 16 ml for right nephrectomy. Postoperatively hematocrit decreased an average of 4.5%. There were no intraoperative complications or open conversion requirements. The postoperative complication rate was 4.8%, including 2 patients (1.2%) in whom retroperitoneal hematoma developed. Only 1 of these patients (0.6%) required blood transfusion. Two grafts (1.2%) were lost due to vascular thrombosis in the immediate postoperative period and another 2 recipients experienced delayed graft function. Average 6, 12 and 24-month serum creatinine was 1.5, 1.5 and 1.6 mg/dl, respectively. Renal allograft survival was 97% 2 years after transplantation. CONCLUSIONS: Results indicate that laparoscopic donor nephrectomy can be successfully done without systemic heparinization with few donor complications, and excellent recipient graft survival and renal function up to 2 years after transplantation.

A Pentacyclic Triterpene from Ligustrum lucidum Targets γ-Secretase.

Amyloid-beta peptides generated by ß-secretase- and γ-secretase-mediated successive cleavage of amyloid precursor protein are believed to play a causative role in Alzheimer's disease. Thus, reducing amyloid-beta generation by modulating γ-secretase remains a promising approach for Alzheimer's disease therapeutic development. Here, we screened fruit extracts of Ligustrum lucidum Ait. (Oleaceae) and identified active fractions that increase the C-terminal fragment of amyloid precursor protein and reduce amyloid-beta production in a neuronal cell line. These fractions contain a mixture of two isomeric pentacyclic triterpene natural products, 3-O-cis- or 3-O-trans-p-coumaroyl maslinic acid (OCMA), in different ratios. We further demonstrated that trans-OCMA specifically inhibits γ-secretase and decreases amyloid-beta levels without influencing cleavage of Notch. By using photoactivatable probes targeting the subsites residing in the γ-secretase active site, we demonstrated that trans-OCMA selectively affects the S1 subsite of the active site in this protease. Treatment of Alzheimer's disease transgenic model mice with trans-OCMA or an analogous carbamate derivative of a related pentacyclic triterpene natural product, oleanolic acid, rescued the impairment of synaptic plasticity. This work indicates that the naturally occurring compound trans-OCMA and its analogues could become a promising class of small molecules for Alzheimer's disease treatment.

The Role of Humoral Alloreactivity in Liver Transplantation: Lessons Learned and New Perspectives.

More than ten years after the initial description of the humoral theory of transplantation by Dr. Paul I. Terasaki, the significance of humoral alloimmunity in liver transplantation has yet to be clearly defined. The liver allograft has an inherent tolerogenic capacity which confers its resistance to cell-mediated as well as antibody-mediated rejection. Nevertheless, the protection against alloimmunity is not complete, and antibody-mediated tissue injury can occur in the liver graft under specific circumstances. In this article the evidence on the clinicopathologic effects of donor-specific alloantibodies in liver transplantation will be examined and interpreted in parallel with lessons learned from renal transplantation. The unique anatomic and immunologic features of the liver will be reviewed to gain new insights into the complex interactions between humoral immune system and the liver allograft.

Evaluation of Patients With Hepatocellular Carcinomas That Do Not Produce α-Fetoprotein.

Importance: Serum α-fetoprotein (AFP) is a biomarker for hepatocellular carcinomas (HCCs) associated with a more aggressive tumor phenotype and inferior outcomes after a liver transplant (LT). Data on the outcomes for patients with HCCs that do not produce AFP are limited. Objective: To compare characteristics and outcomes among LT recipients with radiographically apparent HCC lesions with AFP-producing tumors or with tumors that do not produce AFP (hereafter referred to as non-AFP-producing tumors), and to identify factors influencing recurrence in LT recipients with non-AFP-producing tumors. Design, Setting, and Participants: Retrospective analysis at a university transplant center of 665 adults with HCC who underwent an LT during the period from 1989 to 2013. Of the 665 LT recipients, 457 (68.7%) had AFP-producing tumors, and 208 (31.3%) had non-AFP-producing tumors (the maximum AFP level before an LT was ≤10 ng/mL). Dates of study analysis were from August 2015 to June 2016. Intervention: Liver transplant. Main Outcomes and Measures: Recurrence-free survival and recurrence rates. Results: Patients with non-AFP-producing tumors had radiographic tumor characteristics similar to those of patients with AFP-producing tumors, but, pathologically, they had fewer lesions (25% vs 35% with >2 lesions; P = .03), smaller cumulative tumor diameters (4.2 vs 5.0 cm; P = .02), fewer microvascular (17% vs 22%) and macrovascular (2% vs 9%) invasions (P < .001), and fewer poorly differentiated tumors (15% vs 28%; P < .001). Patients with non-AFP-producing tumors also had significantly superior recurrence-free survival at 1, 3, and 5 years (88%, 74%, and 67% vs 76%, 59%, and 51%, respectively; P = .002) and lower 5-year recurrence rates (8.8% vs 22%; P < .001) than patients with AFP-producing tumors. When stratified by radiologic Milan criteria, 5-year survival was better, and recurrence lowest, among patients with non-AFP-producing tumors within the Milan criteria (71% survival and 6% recurrence), and survival was worse, and recurrence highest, for patients with AFP-producing tumors outside the Milan criteria (40% survival and 42% recurrence; P < .001). Significant predictors of recurrence among patients with non-AFP-producing tumors include radiologic (>2 tumors [HR, 4.98; 95% CI, 1.72-14.4; P = .003]; cumulative diameter [1.70 per log SD; 1.12-2.59; P < .001]; outside the Milan criteria [10.0; 3.7-33.3; P < .001) and pathologic factors (>2 tumors [4.39; 1.32-14.6; P = .02]; cumulative diameter [2.32 per log SD; 1.43-3.77; P = .001]; microvascular [3.07; 1.02-9.24; P = .05] and macrovascular invasion [8.75; 2.15-35.6; P = .002]). Conclusions and Relevance: Nearly one-third of patients with radiographically apparent HCC have non-AFP-producing tumors that have more favorable pathologic characteristics, lower posttransplant recurrence, and superior survival compared with patients with AFP-producing tumors. Posttransplant HCC recurrence for patients with non-AFP-producing tumors is predicted by important radiologic and pathologic factors, and is negligible for patients within the Milan criteria. Stratifying patients by AFP status in addition to radiological criteria may improve the selection process for and the prioritization of transplant candidates.

Prevalence and Clinical Impact of Donor-Specific Alloantibody Among Intestinal Transplant Recipients.

BACKGROUND: Rejection remains the leading cause of allograft loss, and a major barrier to improving long-term outcomes after intestinal transplantation. Our aim is to define the prevalence and investigate the role of donor-specific antibody (DSA) on intestinal graft outcomes. METHODS: The study includes 109 transplants performed in 95 recipients at a single center. Patients were screened for DSA pretransplant, monitored regularly posttransplant and when clinically indicated using the single-antigen bead Luminex assay. Standard induction immunosuppression was with interleukin-2 receptor antagonists, and antithymocyte globulin in high-risk recipients. Maintenance regimens were tacrolimus-based. RESULTS: Pretransplant DSA was detected in 12 (11%) recipients with 50% continuing to have circulating antibodies posttransplant. An additional 24 (25%) patients developed de novo DSA, and of these, 71% had persistent antibodies. Recipients with preformed DSA demonstrated elevated risks of early graft failure, whereas those with de novo DSA experienced accelerated graft loss once DSA was detected, reaching a 28% failure rate within 2 years. HLA-DQ mismatch is a significant risk factor for de novo DSA emergence, whereas the persistence of antibodies is predicted by DSA strength and specificity. Although inclusion of the liver in the intestinal allograft imparts an immunological advantage against rejection-related graft loss, this protective effect was lost among recipients with persistent DSA. CONCLUSIONS: The presence of DSA is associated with inferior graft outcomes among intestinal transplant recipients. An enhanced understanding of the mechanisms by which DSA causes allograft injury, and effective strategies targeting humoral immune reactivity are needed to improve long-term intestinal graft outcomes.

MELD Exceptions for Hepatocellular Carcinoma: Regional Variations in the Impact of the Share 35 Liver Allocation Policy.

Historically, the OPTN liver allocation policies have favored candidates listed with MELD exception scores, and the use of exceptions has increased each year since the inception of the MELD era. The implementation of Share 35 and other recent changes in OPTN liver allocation policies have reduced the preference for MELD exception candidates to some extent, but the nature and degree of the impact appears to vary widely from one region to another. This report emphasizes the geographic inequities and regional variations in transplant practices, with a focus on liver transplant candidates with hepatocellular carcinoma exceptions, and highlights the need for strategies to promote equitable organ distribution across geographical regions and patient conditions.

Paritaprevir/ritonavir/ombitasvir and dasabuvir for the treatment of chronic hepatitis C virus infection.

INTRODUCTION: The use of direct-acting antiviral (DAA) agents against chronic hepatitis C virus (HCV) infections can result in the successful treatment of nearly all patients. Effective antiviral treatments can prevent the progression to cirrhosis and hepatocellular malignancy, and decrease liver-related morbidity and mortality. AREAS COVERED: Paritaprevir-ritonavir-ombitasvir and dasabuvir (PrOD), with or without ribavirin, is an all-oral regimen approved for the treatment of HCV genotype 1 infections, including patients with compensated cirrhosis. Phase 2 and 3 clinical trials demonstrated the safety and efficacy of this regimen in HCV genotype 1-infected patients who are treatment-naïve and those who have failed peginterferon/ribavirin therapy. Additional studies evaluated the use of PrOD with or without ribavirin among special populations, including patients co-infected with human immunodeficiency virus-1 and HCV, liver transplant recipients with HCV recurrence, and patients with severe renal impairment. Additionally, the combination of paritaprevir-ritonavir-ombitasvir plus ribavirin is found to be highly efficacious, and is now approved in the US, for the treatment of HCV genotype 4 infections. EXPERT OPINION: The availability and use of interferon-free DAA combination regimens has resulted in a major paradigm shift in the treatment of HCV. PrOD, with or without ribavirin, is an effective, safe and tolerable treatment option.

Anemoside A3 Enhances Cognition through the Regulation of Synaptic Function and Neuroprotection.

Compounds that have the ability to both strengthen synaptic function and facilitate neuroprotection are valuable cognitive enhancers that may improve health and quality of life, as well as retard age-related cognitive deterioration. Medicinal plants are an abundant source of potential cognitive enhancers. Here we report that anemoside A3 (AA3) isolated from Pulsatilla chinensis modulates synaptic connectivity in circuits central to memory enhancement. AA3 specifically modulates the function of AMPA-type glutamate receptors (AMPARs) by increasing serine phosphorylation within the GluA1 subunit, which is a modification required for the trafficking of GluA1-containing AMPARs to synapses. Furthermore, AA3 administration activates several synaptic signaling molecules and increases protein expressions of the neurotrophin brain-derived neurotrophic factor and monoamine neurotransmitters in the mouse hippocampus. In addition to acting through AMPARs, AA3 also acts as a non-competitive NMDA receptor (NMDAR) modulator with a neuroprotective capacity against ischemic brain injury and overexcitation in rats. These findings collectively suggest that AA3 possesses a unique ability to modulate the functions of both AMPARs and NMDARs. Concordantly, behavioral studies indicate that AA3 not only facilitates hippocampal long-term potentiation but also enhances spatial reference memory formation in mice. These multifaceted roles suggest that AA3 is an attractive candidate for further development as a cognitive enhancer capable of alleviating memory dysfunctions associated with aging and neurodegenerative diseases.

Trends of Immunosuppression and Outcomes Following Liver Transplantation: An Analysis of the United Network for Organ Sharing Registry.

Advances in immunosuppression (IS) agents and strategies have resulted in reduced rejection rates and improved survival outcomes after liver transplantation. The use of induction and maintenance IS agents is both associated with reductions in acute rejection (AR) risk within the first 6 to 12 months posttransplant and with superior failure-free survival. With the lowered incidence of allograft losses attributable to rejection, the long-term sequelae of IS have become the major therapeutic challenge. The long-term use of calcineurin inhibitors and corticosteroids in maintenance immunotherapy regimens has been implicated in the development of renal dysfunction, infections, metabolic derangements, de novo and recurrent malignancies, and the propagation of hepatitis C virus reinfection. Our analysis of the United Network for Organ Sharing registry shows the use of induction and maintenance therapy is each associated with reductions in AR risk, thereby improving post-transplant survival. The administration of intensive induction regimens appears to be safe and exhibits an additive beneficial effect. Therefore, the use of intensive induction regimens may be warranted to allow for reductions in long-term maintenance IS to minimize drug toxicities while preserving graft outcomes.

The Role of Donor-Specific Antibodies in Intestinal Transplantation: Experience at the University of California Los Angeles and Literature Review.

Intestinal transplantation is a viable treatment strategy for patients with irreversible intestinal failure for whom parenteral nutrition is no longer an option. Although improvements have been made in short-term post-transplant survival outcomes, long-term allograft loss, mainly to acute or chronic rejection, remains a major obstacle to successful transplantation. In all types of solid organ transplants, there is increasing evidence that antibodies directed against human leukocyte antigens, and in particular donor-specific antibodies (DSA), contribute to acute and chronic rejection as well as allograft loss. In this single-center review of intestinal transplant recipients, we report that the presence of pretransplant circulating DSA and the de novo induction of DSA posttransplant are both associated with increased risks of allograft loss. Although the cumulative incidence of acute rejection was not significantly affected by the presence of DSA, the power of this single-center study may be limited. Prospective, multicenter studies are needed to further elucidate the role of DSA in intestinal transplant recipients. In the published literature, there is a clear link between the presence of pre-formed DSA and early injury to the mucosal vasculature of the allograft. Two groups have reported an association between pretransplant DSA and the frequency of acute rejection episodes and subsequent graft loss. Similarly, studies investigating the effects of de novo DSA have demonstrated a relationship between the presence of post-transplant circulating antibodies and the occurrence of acute rejection and the risk of allograft failure. The use of a liver-containing graft appears to facilitate the clearance of pre-formed antibodies and prevents the de novo induction of post-transplant antibodies. The most recent report stated that the de novo induction of DSA is concurrently accompanied by signs or rejection, such that the detection of circulating antibodies may signify impending graft injury, and supports the potential utility of DSA as a non-invasive biomarker for rejection in intestinal transplantation.

Dendritic cells with TGF-ß1 and IL-2 differentiate naive CD4+ T cells into alloantigen-specific and allograft protective Foxp3+ regulatory T cells.

BACKGROUND: Naturally occurring, thymic-derived Foxp3+CD25+CD4+ regulatory T cells (nTregs) are pivotal for the maintenance of self-tolerance. nTregs, however, are sparse and lack alloantigen specificity, and these properties pose challenges for their use in clinical transplantation. METHODS: We established mixed leukocyte reaction (MLR) with dendritic cells (DCs) as stimulators and CD4+ T cells as responders and supplemented the MLR with IL-2 and TGF-ß1 and investigated whether DCs+IL-2+TGF-ß1 differentiate the polyclonal CD4+ cells into alloantigen-specific and allograft protective Tregs. RESULTS: We found a greater than a 10-fold increase in Foxp3+CD25+ subpopulation (P<0.01) following stimulation of BALB/c CD4+ cells with C57BL/6 (B6) CD11c+ DCs+IL-2+TGF-ß1 in the MLR. Levels of TGF-ß1 messenger RNA (mRNA) (P=0.01) and the ratios of TGF-ß1 mRNA to granzyme B mRNA (P=0.0003) and Foxp3 mRNA to granzyme B mRNA (P<0.01) were higher in alloantigen-induced Tregs (alloTregs) compared with nTregs. alloTregs suppressed MLR at a 16:1 responder to suppressor ratio, whereas nTregs suppressed at 4:1. Suppression by alloTregs was alloantigen specific and was observed at the level of responder cells and at the level of stimulator cells. In a fully H-2-mismatched, nonlymphopenic, immunocompetent mouse islet transplantation model, alloTregs but not nTregs prolonged survival of islet allografts without any other immunosuppressive therapy (P=0.0003), and the protection was alloantigen specific. CONCLUSIONS: A combination of CD11c+ DCs, IL-2, and TGF-ß1 may help differentiate naive, high abundant CD4+ T into alloantigen-specific and allograft protective Foxp3+Tregs.

Diannexin decreases inflammatory cell infiltration into the islet graft, reduces ß-cell apoptosis, and improves early graft function.

BACKGROUND: A major unmet challenge is to reduce the islet mass needed for insulin independence in type 1 diabetic recipients after islet transplantation. The recombinant homodimer of human annexin V, diannexin, has completed a Phase II Clinical Trial in Kidney Transplantation (NCT00615966). METHODS: We developed a marginal islet mass transplantation model (10-12 islets per gram of recipient body weight) and investigated whether diannexin prevents ß-cell apoptosis and improves islet graft function. Diannexin was administered to islet cell donors shortly before pancreas harvest, added to isolation reagents, and infused into recipients at the time of transplantation and repeated daily until day 4. RESULTS: In the syngeneic marginal islet mass transplantation model, the median time needed to achieve normoglycemia was reduced from 17.0 days among untreated controls to 3.5 days among diannexin-treated recipients (P=0.004). Histologic analysis of islet grafts harvested on day 3 posttransplantation revealed decreased macrophage (44.7%±9.8% vs. 19.2%±3.2%, P=0.007) and T-cell infiltration (25.9%±5.5% vs. 9.1%±1.1%, P=0.004), and a lower rate of islet cell apoptosis (20.5%±2.8% vs. 7.6%±2.3%, P=0.01) with diannexin treatment. Expression profiling of the islet grafts showed significantly lower levels of mRNA for the proapoptotic molecule Bid, but higher levels of interleukin-6, interferon-γ, and immunosuppressive cytokine interleukin-10. CONCLUSIONS: Our findings demonstrate that diannexin improves the early function of marginal mass islet grafts, and its effects are associated with reductions in inflammatory cell infiltration and ß-cell death by apoptosis after islet transplantation.