Islet infiltration, cytokine expression and beta cell death in the NOD mouse, BB rat, Komeda rat, LEW.1AR1-iddm rat and humans with type 1 diabetes.

AIMS/HYPOTHESIS: Research on the pathogenesis of type 1 diabetes relies heavily on good animal models. The aim of this work was to study the translational value of animal models of type 1 diabetes to the human situation. METHODS: We compared the four major animal models of spontaneous type 1 diabetes, namely the NOD mouse, BioBreeding (BB) rat, Komeda rat and LEW.1AR1-iddm rat, by examining the immunohistochemistry and in situ RT-PCR of immune cell infiltrate and cytokine pattern in pancreatic islets, and by comparing findings with human data. RESULTS: After type 1 diabetes manifestation CD8(+) T cells, CD68(+) macrophages and CD4(+) T cells were observed as the main immune cell types with declining frequency, in infiltrated islets of all diabetic pancreases. IL-1ß and TNF-α were the main proinflammatory cytokines in the immune cell infiltrate in NOD mice, BB rats and LEW.1AR1-iddm rats, as well as in humans. The Komeda rat was the exception, with IFN-γ and TNF-α being the main cytokines. In addition, IL-17 and IL-6 and the anti-inflammatory cytokines IL-4, IL-10 and IL-13 were found in some infiltrating immune cells. Apoptotic as well as proliferating beta cells were observed in infiltrated islets. In healthy pancreases no proinflammatory cytokine expression was observed. CONCLUSIONS/INTERPRETATION: With the exception of the Komeda rat, the animal models mirror very well the situation in humans with type 1 diabetes. Thus animal models of type 1 diabetes can provide meaningful information on the disease processes in the pancreas of patients with type 1 diabetes.

Deletion of IKK2 in hepatocytes does not sensitize these cells to TNF-induced apoptosis but protects from ischemia/reperfusion injury.

The inhibitor of NF-kappaB (I-kappaB) kinase (IKK) complex consists of 3 subunits, IKK1, IKK2, and NF-kappaB essential modulator (NEMO), and is involved in the activation of NF-kappaB by various stimuli. IKK2 or NEMO constitutive knockout mice die during embryogenesis as a result of massive hepatic apoptosis. Therefore, we examined the role of IKK2 in TNF-induced apoptosis and ischemia/reperfusion (I/R) injury in the liver by using conditional knockout mice. Hepatocyte-specific ablation of IKK2 did not lead to impaired activation of NF-kappaB or increased apoptosis after TNF-alpha stimulation whereas conditional NEMO knockout resulted in complete block of NF-kappaB activation and massive hepatocyte apoptosis. In a model of partial hepatic I/R injury, mice lacking IKK2 in hepatocytes displayed significantly reduced liver necrosis and inflammation than wild-type mice. AS602868, a novel chemical inhibitor of IKK2, protected mice from liver injury due to I/R without sensitizing them toward TNF-induced apoptosis and could therefore emerge as a new pharmacological therapy for liver resection, hemorrhagic shock, or transplantation surgery.

Pancreas transplantation with histidine-tryptophan-ketoglutarate (HTK) solution and University of Wisconsin (UW) solution: is there a difference?

CONTEXT: In clinical pancreas transplantation the choice of preservation solution may have an impact on graft pancreatitis. Experience with histidine-tryptophan-ketoglutarate (HTK) is still limited whereas University of Wisconsin (UW) solution is currently the preferred perfusate worldwide. OBJECTIVE: The aim of this study was to analyze our experience with HTK in pancreas transplantation. PARTICIPANTS: In a retrospective analysis, data from 95 primary simultaneous pancreas-kidney transplantations were reviewed. The use of HTK (n=48) and UW (n=47) solution was stratified into two groups. MAIN OUTCOME MEASURES: Patient/graft survival and early graft function were compared. RESULTS: No significant differences between 1, 3 and 12 month patient survival (HTK: 97.9%, 97.9%, and 95.7% vs. UW: 95.7%, 89.4%, and 89.4%, respectively), and pancreas graft survival (HTK: 87.5%, 87.5%, and 85.4% vs. UW: 87.0%, 82.6%, and 82.6%, respectively) were detected. Higher values for peak lipase were observed on day 1 in the HTK group (not reaching significance: P=0.131) whereas no differences were noted for amylase and C-reactive protein. CONCLUSIONS: HTK is clinically comparable to UW. Both solutions have been shown to be safe for pancreas preservation. Successful pancreas transplantation depends on many factors such as donor and recipient factors, but skilled organ procurement techniques, organ preservation, and transplant experience in this field is mandatory. The choice of organ preservation solution is only one point in this context.

Quality of life in adult transplant recipients more than 15 years after kidney transplantation.

BACKGROUND: With continuously rising survival rates following renal transplantation, health-related quality of life (HQOL) of long-term transplant survivors becomes increasingly important. METHODS: Recipients more than 15 years after successful renal transplantation were studied retrospectively. HQOL in 139 long-term transplant recipients was assessed using the SF-36 and the disease-specific kidney transplant questionnaire (KTQ-25). RESULTS: Long-term transplant recipients revealed satisfactory HQOL that was comparable to the healthy population in four of eight SF-36 categories (role physical, social functioning, role emotional and mental health). Other SF-36 categories such as physical functioning, physical pain, general health, and vitality were reduced. Among the study population, disease-specific HQOL was comparable or even improved to that of patients awaiting transplantation. In contrast to retired or unemployed patients, employed recipients revealed a highly significant improved HQOL in numerous SF-36 categories such as physical functioning (P<0.001), physical pain (P<0.001), general health (P<0.001), vitality (P<0.001), social functioning (P<0.005), and mental health (P<0.001), as well as for the KTQ-dimensions physical symptoms (P<0.001), fatigue (P>0.001), uncertainty/fear (P<0.01), and emotions (P<0.05). Other factors positively correlating with improved HQOL in certain dimensions were living situation, systolic blood pressure, and recipient age. CONCLUSIONS: More than 15 years after renal transplantation, recipients present satisfactory HQOL comparable to the general healthy population or at least to pretransplant patients. Vocational rehabilitation following renal transplantation is of highest importance among long-term survivors and is associated with improved HQOL.

Lack of influence of omega-3 fatty acid-enriched lipids on apoptosis and secondary necrosis of cultured human lymphocytes.

OBJECTIVE: The anti-inflammatory properties of parenteral nutrition might be improved by enrichment with omega-3 polyunsaturated fatty acids (PUFAs), which are responsible for the enhanced release of metabolites derived from eicosapentaenoic acid. Under physiologic conditions, lymphocyte populations are regulated by cellular mechanisms such as apoptosis. In contrast to cell death by necrosis, apoptosis does not induce an inflammatory response that might injure the host. METHODS: Apoptosis and necrosis of cultured human blood lymphocytes were investigated in vitro after incubation for 48 and 72 h with three lipid emulsions containing 50% medium-chain triacylglycerols. The lipid emulsions differed in the percentage of long-chain triacylglycerols, which were replaced in part by different amounts of omega-3 PUFA (8%, 20%, or 40%). Rates of apoptosis and necrosis of lymphocyte subpopulations were analyzed with a sensitive annexin V flow cytometric assay. RESULTS: After 48 and 72 h of incubation, time- and dose-dependent increases of apoptosis and necrosis, respectively, were found in all lymphocyte subsets regardless of the percentage of omega-3 PUFAs. CONCLUSIONS: Our results suggested that enrichment with omega-3 PUFAs in the tested lipid emulsions does not alter apoptosis and secondary necrosis of lymphocyte populations. Thus PUFAs may exert their functional effects through other mechanisms.

Diabetes prevention by immunomodulatory FTY720 treatment in the LEW.1AR1-iddm rat despite immune cell activation.

The prevention of diabetes by the immunomodulatory agent FTY720 (fingolimod) was studied in the LEW.1AR1-iddm (IDDM) rat, an animal model of human type 1 diabetes. Immune cell subtypes and cytokine profiles in pancreatic islets, secondary lymphoid tissue, and serum were analyzed for signs of immune cell activation. Animals were treated with FTY720 (1 mg/kg body weight) for 40 d starting on d 50 of life. Changes in gene and protein expression of cytokines, CD8 markers, monocyte chemoattractant protein-1, inducible NO synthase, and caspase 3 were evaluated. Treatment with FTY720 prevented diabetes manifestation and islet infiltration around d 60 of life, the usual time of spontaneous diabetes development. On d 120, 30 d after the end of FTY720 therapy, diabetes prevention persisted. However, six of 12 treated animals showed increased gene expression of IL-1beta, TNF-alpha, and CD8 markers in pancreas-draining lymph nodes, indicating immune cell activation. In parallel, serum concentrations of these proinflammatory cytokines were increased. These six animals also showed macrophage infiltration without proinflammatory cytokine expression in a small minority (2-3%) of islets. Interestingly, regulatory T lymphocytes were significantly increased in the efferent vessels of the pancreas-draining lymph nodes only in animals without signs of immune cell activation but not in the rats with immune cell activation. This provides an indication for a lack of protective capacity in the animals with activated immune cells. Thus, FTY720 treatment prevented the manifestation of diabetes by promoting the retention of activated immune cells in the lymph nodes, thereby avoiding islet infiltration and beta-cell destruction by proinflammatory cytokines.

Adult Kasabach-Merritt Syndrome due to Hepatic Giant Hemangioma.

Cavernous hemangiomas are the most common benign tumors of the liver. They can reach enormous sizes and cause various complications. Kasabach-Merritt syndrome is a rare but serious complication characterized by consumptive coagulopathy caused by the hemangioma; mortality rate ranges between 10 and 37%. More than 80% of cases occur within the first year of life. Goals of the treatment are to control the coagulopathyand thrombocytopenia as well as to eradicate the hemangioma. Different nonsurgical treatment regimens are performed, includingsystemic corticosteroids, irradiation and various chemicals. Surgery should be limited to symptomatic or complicated cases. Although difficult, resection of the tumor is usually curative. Here we present a 44-year-old woman with giant hepatic hemangioma causing Kasabach-Merritt syndrome managed by enucleation.

Platelet P-selectin and GPIIb/IIIa expression after liver transplantation and resection.

Platelet dysfunction contributes to haemostatic defects, possibly leading to bleeding complications. We hypothesised that liver transplantation and liver resection, together with portal clamping time, might be a potential stimulus for platelet activation. Therefore, we determined the expression of platelet GPIIb/IIIa and P-selectin, representing important platelet activation markers, and the thrombopoietin (TPO) serum level after transplantation and resection. Twenty patients [ten that had undergone orthotopic liver transplantation (OLT), ten with liver resection (LRX)] were included in the study. From sequential venous blood samples, surface expression of GPIIb/IIIa and P-selectin was quantified by flow cytometry, and TPO serum levels were determined by ELISA. Baseline GPIIb/IIIa receptor expression on circulating platelets was significantly reduced in the OLT group compared to the LRX group and healthy volunteers. GPIIb/IIIa expression after activation with TRAP-6 increased significantly ( P<0.001) in the LRX group but not in the OLT group. P-selectin expression after TRAP-6 stimulation increased significantly ( P<0.001) in the LRX group, being comparable to that in healthy volunteers, whereas only a very low increase in the OLT group was found. In the OLT group, TPO serum levels were in the lower normal range and rose above the upper limit of normal values 24 h after reperfusion. These data indicate that neither liver transplantation nor liver resection influences GPIIb/IIIa and P-selectin expression on circulating platelets. There was a lack of expression in cirrhotic patients and unimpaired baseline expression and functional reserve in non-cirrhotic liver-resection patients. After liver transplantation, increasing serum TPO levels, which indicated a recovering graft function, resulted in rising peripheral platelet counts.