A combined physicochemical approach towards human tenocyte phenotype maintenance.

During in vitro culture, bereft of their optimal tissue context, tenocytes lose their phenotype and function. Considering that tenocytes in their native tissue milieu are exposed simultaneously to manifold signals, combination approaches (e.g. growth factor supplementation and mechanical stimulation) are continuously gaining pace to control cell fate during in vitro expansion, albeit with limited success due to the literally infinite number of possible permutations. In this work, we assessed the potential of scalable and potent physicochemical approaches that control cell fate (substrate stiffness, anisotropic surface topography, collagen type I coating) and enhance extracellular matrix deposition (macromolecular crowding) in maintaining human tenocyte phenotype in culture. Cell morphology was primarily responsive to surface topography. The tissue culture plastic induced the largest nuclei area, the lowest aspect ratio, and the highest focal adhesion kinase. Collagen type I coating increased cell number and metabolic activity. Cell viability was not affected by any of the variables assessed. Macromolecular crowding intensely enhanced and accelerated native extracellular matrix deposition, albeit not in an aligned fashion, even on the grooved substrates. Gene analysis at day 14 revealed that the 130 kPa grooved substrate without collagen type I coating and under macromolecular crowding conditions positively regulated human tenocyte phenotype. Collectively, this work illustrates the beneficial effects of combined physicochemical approaches in controlling cell fate during in vitro expansion.

Allogeneic Mesenchymal Stromal Cells (MSCs) are of Comparable Efficacy to Syngeneic MSCs for Therapeutic Revascularization in C57BKSdb/db Mice Despite the Induction of Alloantibody.

Intramuscular administration of mesenchymal stromal cells (MSCs) represents a therapeutic option for diabetic critical limb ischemia. Autologous or allogeneic approaches may be used but disease-induced cell dysfunction may limit therapeutic efficacy in the former. Our aim was to compare the efficacy of allogeneic and autologous MSC transplantation in a model of hindlimb ischemia in diabetes mellitus and to determine whether allogeneic transplantation would result in the activation of an immune response. MSCs were isolated from C57BL/6 (B6) and diabetic obese C57BKSdb/db mice. Phosphate-buffered saline (control group), and MSCs (1 × 106) from B6 (allogeneic group) or C57BKSdb/db (syngeneic group) were administered intramuscularly into the ischemic thigh of C57BKSdb/db mice following the induction of hindlimb ischemia. MSCs derived from both mouse strains secrete several angiogenic factors, suggesting that the potential therapeutic effect is due to paracrine signaling. Administration of allogeneic MSCs significantly improved blood perfusion as compared with the control group on week 2 and 3, post-operatively. In comparison with the control group, syngeneic MSCs significantly improved blood perfusion at week 2 only. There was no statistical difference in blood perfusion between allogeneic and syngeneic MSC groups at any stages. There was no statistical difference in ambulatory and necrosis score among the three groups. Amputation of toes was only observed in the control group (one out of seven animals). Alloantibody was detected in three out of the eight mice that received allogeneic MSCs but was not observed in the other groups. In summary, we demonstrated comparable efficacy after transplantation of autologous and allogeneic MSCs in a diabetic animal model despite generation of an immune response.

Factors influencing health-related quality of life in patients with Type 1 diabetes.

AIMS: Generic, preference-based measures of health-related quality of life (HRQoL) are a common input to the economic evaluation of new health technologies. As such, it is important to explore what characteristics of patients with Type 1 diabetes might impact scores on such measures. METHODS: This study utilizes baseline data from a cluster-randomized trial that recruited patients with Type 1 diabetes at six centers across Ireland. Health-related quality of life was assessed using the three-level EuroQol EQ-5D (EQ-5D) measure. Patients' responses to individual dimensions of the EQ-5D were explored. To see which patient factors influenced EQ-5D scores, multivariate regression analysis was conducted with EQ-5D scores as the outcome variable. RESULTS: Data was available for 437 Type 1 diabetes patients. The median age of these patients was 40 (IQR: 31-49) years and 53.8% were female. Overall, patients reported a high HRQoL based on EQ-5D scores (0.87 (SD: 0.19). Fifty-four percent of patients reported a perfect HRQoL. For those that reported problems, the most common dimension was the anxiety/depression dimension of the EQ-5D (29.6%). In the multivariate regression analysis, self-reported mental illness (- 0.22 (95% CI: -0.34, - 0.10)) and being unemployed (- 0.07 (95% CI: -0.13, - 0.02)) were negatively associated with EQ-5D scores (p < 0.05). The influence of self-reported mental illness was persistent in sensitivity analyses. CONCLUSIONS: The study results indicate that patients with Type 1 diabetes report a high HRQoL based on responses to the EQ-5D. However, there are a substantial number of Type 1 diabetes patients that report problems in the anxiety/depression dimension, which may provide avenues to improve patients' HRQoL. TRIAL REGISTRATION: Current Controlled Trials ISRCTN79759174 .

ANCA-associated vasculitis: a comparison of cases presenting to nephrology and rheumatology services.

BACKGROUND: Anti-neutrophil cytoplasmic antibody (ANCA) -associated vasculitis (AAV) is a disease characterized by inflammation of small vessels and detectable ANCA in the circulation. Patients may develop a broad spectrum of clinical features ranging from indolent sino-nasal disease and rashes to fulminant renal failure or acute life-threatening pulmonary haemorrhage. Consequently, patients with AAV present to a variety of specialties including nephrology and rheumatology, whose training and approaches to management of such patients may differ. There is little literature comparing patients presenting to different specialties and their outcomes. METHODS: We compared two cohorts of patients with ANCA-positive AAV presenting to either the rheumatology or nephrology department at Galway University Hospitals from June 2002 to July 2011. A standardized data collection form was used to collect information regarding baseline demographics, manifestations of AAV, initial management, relapses and complications. RESULTS: Forty-five patients were included in this study (15 rheumatology/30 nephrology). The nephrology cohort was older, had a higher C-reactive protein, Birmingham Vascular Activity Score and ANCA titer at presentation compared to the rheumatology group. Induction treatment varied between the cohorts with rheumatology patients most commonly receiving a combination of oral corticosteroids (73%) and methotrexate (60%) and nephrology patients receiving a combination of intravenous corticosteroids (93%) and cyclophosphamide (90%). Fifty-three percent of the rheumatology patients who completed induction therapy relapsed compared to 30% of the nephrology patients. CONCLUSION: This study presents two different cohorts of patients with the same disease that were managed by two different disciplines. It highlights the heterogeneity of AAV and the importance of interdisciplinary communication and cooperation when managing these patients.

Culture expanded primary chondrocytes have potent immunomodulatory properties and do not induce an allogeneic immune response.

OBJECTIVE: Allogeneic cell therapies, such as mesenchymal stromal cells (MSC), which have potent regenerative and anti-inflammatory potential are being investigated as a therapy for osteoarthritis (OA) and cartilage injury. Here we describe another potential source of regenerative and anti-inflammatory allogeneic cells, culture expanded primary chondrocytes (CEPC). In direct comparison to allogeneic MSC, we extensively assess the immunological interactions of CEPC in an allogeneic setting. METHODS: Chondrocytes were isolated from rat articular cartilage and cultured in normoxic or hypoxic conditions. In vitro co-culture assays with allogeneic lymphocytes and macrophages were used to assess the immunomodulatory capacities of the chondrocytes, followed by immune response analysis by flow cytometry, ELISA and qPCR. RESULTS: CEPC showed reduced induction of proliferation, activation and cytotoxic granzyme B expression in allogeneic T cells. Importantly, exposure to pro-inflammatory cytokines did not increase CEPC immunogenicity despite increases in MHC-I. Furthermore, CEPC had a potent ability to suppress allogeneic T cell proliferation, which was dependent on nitric oxide production. This suppression was contact independent in hypoxia cultured CEPC. Finally, chondrocytes were shown to have the capacity to modulate pro-inflammatory macrophage activity by reducing MHC-II expression and TNF-α secretion. CONCLUSION: These data indicate the potential use of allogeneic chondrocytes in OA and cartilage defects. The lack of evident immunogenicity, despite exposure to a pro-inflammatory environment, coupled with the immunomodulatory ability indicates that these cells have the potential to evade the host immune system and suppress inflammation, thus potentially facilitating the resolution of OA induced inflammation and cartilage regeneration.

Mesenchymal stem cell therapy promotes corneal allograft survival in rats by local and systemic immunomodulation.

Mesenchymal stem cells (MSCs) are being investigated extensively due to their ability to dampen immune responses. Here, we tested the ability of MSCs from three distinct sources to prolong rat corneal allograft survival. A fully allogeneic rat cornea transplant model (DA to LEW) was used. Recipient rats received 1 × 10(6) MSCs (syn [LEW], allo [DA] or third-party [Wistar Furth]) intravenously 7 days before transplantation and again on the day of transplantation (day 0). A high percentage of untreated and syn-MSC treated allografts were rejected (80% and 100%, respectively). Preactivation of syn-MSCs with interferon gamma also failed to prolong allograft survival. Conversely, corneal allograft survival was significantly prolonged in allo-MSC treated (90%) and third-party MSC treated (80%) allograft recipients. Flow cytometric analysis revealed less infiltrating natural killer T cells in corneas of both allo- and third-party MSC treated animals, coupled with a higher proportion of splenic CD4+Foxp3+ regulatory T cells, compared to controls. In the case of allo- and third-party MSCs, results from a delayed-type hypersensitivity assay clearly showed that hypo-responsiveness was specific for corneal donor-associated allo-antigens. Thus, allo- and third-party MSC treatment prolongs corneal allograft survival by suppressing peripheral immune responses and promoting an intragraft immunoregulatory milieu.

Oral paricalcitol reduces the prevalence of posttransplant hyperparathyroidism: results of an open label randomized trial.

Postkidney transplant hyperparathyroidism is a significant problem. Vitamin D receptor agonists are known to suppress parathyroid hormone (PTH) secretion. We examined the effect of oral paricalcitol on posttransplant secondary hyperparathyroidism by conducting an open label randomized trial in which 100 incident kidney transplant recipients were randomized 1:1 to receive oral paricalcitol, 2 µg per day, for the first year posttransplant or no additional therapy. Serial measurements of serum PTH, calcium and bone alkaline phosphatase, 24-h urine calcium and bone density were performed. The primary endpoint was the frequency of hyperparathyroidism 1-year posttransplant. Eighty-seven patients completed the trial. One-year posttransplant, 29% of paricalcitol-treated subjects had hyperparathyroidism compared with 63% of untreated patients (p = 0.0005). Calcium supplementation was discontinued in two control and 15 treatment patients due to mild hypercalcemia or hypercalcuria. Paricalcitol was discontinued in four patients due to hypercalcuria/hypercalcemia and in one for preference. Two subjects required decreasing the dose of paricalcitol to 1 µg daily. Hypercalcemia was asymptomatic and reversible. Incidence of acute rejection, BK nephropathy and renal function at 1 year were similar between groups. Moderate renal allograft fibrosis was reduced in treated patients. Oral paricalcitol is effective in decreasing posttransplant hyperparathyroidism and may have beneficial effects on renal allograft histology.

Structural and dynamic requirements for optimal activity of the essential bacterial enzyme dihydrodipicolinate synthase.

Dihydrodipicolinate synthase (DHDPS) is an essential enzyme involved in the lysine biosynthesis pathway. DHDPS from E. coli is a homotetramer consisting of a 'dimer of dimers', with the catalytic residues found at the tight-dimer interface. Crystallographic and biophysical evidence suggest that the dimers associate to stabilise the active site configuration, and mutation of a central dimer-dimer interface residue destabilises the tetramer, thus increasing the flexibility and reducing catalytic efficiency and substrate specificity. This has led to the hypothesis that the tetramer evolved to optimise the dynamics within the tight-dimer. In order to gain insights into DHDPS flexibility and its relationship to quaternary structure and function, we performed comparative Molecular Dynamics simulation studies of native tetrameric and dimeric forms of DHDPS from E. coli and also the native dimeric form from methicillin-resistant Staphylococcus aureus (MRSA). These reveal a striking contrast between the dynamics of tetrameric and dimeric forms. Whereas the E. coli DHDPS tetramer is relatively rigid, both the E. coli and MRSA DHDPS dimers display high flexibility, resulting in monomer reorientation within the dimer and increased flexibility at the tight-dimer interface. The mutant E. coli DHDPS dimer exhibits disorder within its active site with deformation of critical catalytic residues and removal of key hydrogen bonds that render it inactive, whereas the similarly flexible MRSA DHDPS dimer maintains its catalytic geometry and is thus fully functional. Our data support the hypothesis that in both bacterial species optimal activity is achieved by fine tuning protein dynamics in different ways: E. coli DHDPS buttresses together two dimers, whereas MRSA dampens the motion using an extended tight-dimer interface.

The outcome of patients with nephrogenic systemic fibrosis after successful kidney transplantation.

Nephrogenic systemic fibrosis (NSF) is a debilitating disease in patients with severely diminished kidney function. Currently, no standard treatment exists but improvement has been reported after restoration of kidney function. We retrospectively studied 17 NSF patients with and without successful kidney transplantation (KTx) to evaluate the effects of KTx on NSF. Nine of the 11 KTx developed NSF pretransplant whereas two developed NSF immediately after KTx with delayed graft function. Two of the six dialysis patients had previous failed kidney transplants. Age and sex were well matched. All but one patient was dialysis dependent at the time of NSF. Median follow-up was 35 months for KTx patients and 9 months for dialysis patients. Kidney transplants achieved adequate renal function with median serum creatinine of 1.4 (0.9-2.8) mg/dL and a glomerular filtration rate of 42 (19-60) mL/min/1.73 m(2). NSF improved in 54.6% of the transplanted patients and 50% of the nontransplanted patients (p = 0.86). Two KTx patients had complete resolution of their symptoms whereas four had partial improvement. Improvement in the dialysis patients was all partial. Successful KTx did not insure improvement in NSF and in fact appeared to have no significant benefit over dialysis.

Effect of oxidation and mutation on the conformational dynamics and fibril assembly of amyloidogenic peptides derived from apolipoprotein C-II.

The oxidation of methionine residues in proteins can inhibit the self-assembly of proteins to form amyloid fibrils. For human apolipoprotein (apo) C-II the oxidation of methionine at position 60 inhibits fibril formation by the mature protein and by the core peptides apoC-II(56-76) and apoC-II(60-70). To investigate the molecular nature of these effects, we carried out fully solvated, all-atom molecular dynamics simulations of the structural changes in apoC-II(56-76) associated with substitutions of oxidized methionine (Met ox) at position 60. The results with apoC-II(56-76) (Met ox) showed less flexibility in structure, leading to a perturbation of the hydrophobic core. Valine substitution at position 60 showed an increased tendency to explore a wide range of conformational space, whereas the behavior of the Gln substitution mutant was similar to the wild-type peptide. These simulations are consistent with kinetic measurements which showed that a Met60Gln substitution within apoC-II(56-76) had little effect on the rate of fibril formation whereas substitution of Met ox or Val at position 60 lead to significant inhibition of peptide fibril formation. The effects of amino acid modification and substitutions on the kinetics of peptide fibril formation differ from the effects observed with full-length apoC-II inferring that additional mechanisms are involved in fibril formation by mature apoC-II.

Posttransplant lymphoproliferative disorder following pancreas transplantation.

The incidence, risk factors and impact on patient and graft survival were evaluated for posttransplant lymphoproliferative disorder (PTLD) among 212 pancreas transplant recipients. Thirteen (6.1%) developed PTLD during 71 +/- 27 months follow-up. Cumulative incidences of PTLD at 1, 3, 5 and 10 years posttransplant were 4.2%, 5.3%, 6.0% and 7.0%, respectively. Incidence of PTLD was lower for recipients of simultaneous pancreas kidney compared to pancreas after kidney transplant or pancreas transplant alone, though not significantly so. Recipient Epstein-Barr virus (EBV) seronegativity and number of doses of depleting antibody therapy administered at transplant were associated with increased risk of PTLD, while recipient age, gender, transplant type, cytomegalovirus mismatch maintenance immunosuppression type and treated acute rejection were not. All 13 cases underwent immunosuppression reduction, and 10 received anti-CD20 monoclonal antibody. During follow-up, 10/13 (77%) responded to treatment with complete remission, while 3 (23%) died as a result of PTLD. Patient and graft survivals did not differ for recipients with and without PTLD. The strong association of PTLD with EBV-seronegativity requires considering this risk factor when evaluating and monitoring pancreas transplant recipients. With reduction of immunosuppression and anti-CD20 therapy, survival for pancreas transplant recipients with PTLD was substantially better than previously reported.

Survival of patients on the kidney transplant wait list: relationship to cardiac troponin T.

Patients waiting for a kidney transplant have high mortality despite careful preselection. Herein, we assessed whether cardiac troponin T (cTnT) can help stratify risk in patients selected for kidney transplantation. cTnT levels were measured in all kidney transplant candidates but the results were not used for patient selection. Among 644 patients placed on the kidney waiting list from 9/2004 to 12/2006, 61% had elevated cTnT levels (>0.01 ng/mL). Higher levels related to diabetes, longer time on dialysis, history of cardiovascular disease and low serum albumin. High cTnT also related to cardiac anomalies, including left ventricular hypertrophy (LVH), wall motion abnormalities and stress-inducible ischemia by dobutamine echo (DSE). However, 54% of patients without these cardiac findings had elevated cTnT. Increasing cTnT levels were associated with reduced survival (HR = 1.729, CI (1.25-2.39), p = 0.01) independently of low serum albumin (0.449 (0.24-0.83), p = 0.011) and history of stroke (3.368 (1.47-7.73), p = 0.0004). The results of the DSE and/or coronary angiography did not relate significantly to survival. However, high cTnT identified patients with abnormal echo findings and poor survival. Wait listed patients with normal cTnT have excellent survival irrespective of other factors. In contrast, high cTnT levels are strongly predictive of poor survival in the kidney transplant waiting list.

Patient survival and cardiovascular risk after kidney transplantation: the challenge of diabetes.

An increasing proportion of kidney recipients have diabetes mellitus (DM). Herein, we assessed the impact of DM on morbidity and mortality. The study included 933 recipients of first transplants. DM was present in 212 (23%). Compared to non-diabetics (NoDM), DM were older, heavier and had more pretransplant cardiovascular (CV) disease (16% vs. 48%, p < 0.0001). DM had reduced survival (5 years, 93% vs. 70%, p < 0.0001) and higher incidence of CV events (9% vs. 37%, p < 0.0001). CV disease was the most common cause of death in DM (61%) but not in NoDM (26%). Mortality from infections was also higher in DM (p = 0.001). In NoDM, survival related to recipient age (hazard ratio (HR) = 1.07, p < 0.0001) and dialysis pretransplant HR = 2.21, p = 0.01, while in DM, survival related to dialysis (HR = 2.89, p = 0.01) and pretransplant CV disease (HR = 2.79, p = 0.007). In NoDM, the incidence of posttransplant CV events was related to traditional CV risk factors, while in DM only the pretransplant CV history related to this outcome. In conclusion, survival differs between NoDM and DM recipients quantitatively, by cause of death and by risk factors. In NoDM, survival is excellent, and the main threat to survival relates to immunosuppression. In DM, survival is inferior primarily due to CV disease generally present prior to transplantation.

Reduction of immunosuppression for transplant-associated skin cancer: thresholds and risks.

BACKGROUND: Although evidence supports the efficacy of reducing immunosuppression for transplant-associated skin cancer, clinical thresholds for and risks associated with reduction are not well defined. OBJECTIVES: In this study, experienced transplant physicians were surveyed regarding appropriate thresholds for consideration of reduction of immunosuppression and the likelihood of rejection and allograft compromise associated with various levels of reduction. PATIENTS AND METHODS: Fifty-two transplant physicians reviewed 13 hypothetical patient scenarios with graduated morbidity and mortality risk and provided opinions on the degree of reduction of immunosuppression that was warranted and the risks associated with various degrees of reduction. RESULTS: Renal, liver and cardiac transplant physicians generally concurred on the level of reduction of immunosuppression warranted by various degrees of skin cancer. As morbidity and mortality from skin cancer increased, physicians were more likely to accept risk to allograft function from more aggressive reduction. CONCLUSIONS: Reduction of immunosuppression is considered a reasonable adjuvant strategy in recipients of solid organ transplants who have substantial morbidity and mortality risk from skin cancer. Physicians are willing to accept an increased risk of allograft compromise when confronted by severe or extensive skin cancer. Further research is needed to define the precise correlation among levels of reduction of immunosuppression, therapeutic efficacy, and concomitant risks.

Deficiency of heme oxygenase-1 impairs renal hemodynamics and exaggerates systemic inflammatory responses to renal ischemia.

Heme oxygenase-1 may exert cytoprotective effects. In this study we examined the sensitivity of heme oxygenase-1 knockout (HO-1(-/-)) mice to renal ischemia by assessing glomerular filtration rate (GFR) and cytokine expression in the kidney, and inflammatory responses in the systemic circulation and in vital extrarenal organs. Four hours after renal ischemia, the GFR of HO-1(-/-) mice was much lower than that of wild-type mice in the absence of changes in renal blood flow or cardiac output. Eight hours after renal ischemia, there was a marked induction of interleukin-6 (IL-6) mRNA and its downstream signaling effector, phosphorylated signal transducer and activator of transcription 3 (pSTAT3), in the kidney, lung, and heart in HO-1(-/-) mice. Systemic levels of IL-6 were markedly and uniquely increased in HO-1(-/-) mice after ischemia as compared to wild-type mice. The administration of an antibody to IL-6 protected against the renal dysfunction and mortality observed in HO-1(-/-) mice following ischemia. We suggest that the exaggerated production of IL-6, occurring regionally and systemically following localized renal ischemia, in an HO-1-deficient state may underlie the heightened sensitivity observed in this setting.

Transplant glomerulopathy: subclinical incidence and association with alloantibody.

Transplant glomerulopathy (TG) usually has been described as part of a constellation of late chronic histologic abnormalities associated with proteinuria and declining function. The current study used both protocol and clinically-indicated biopsies to investigate clinical and subclinical TG, their prognosis and possible association with alloantibody. We retrospectively studied 582 renal transplants with a negative pre-transplant T-cell complement dependent cytotoxicity crossmatch. TG was diagnosed in 55 patients, 27 (49%) based on protocol biopsy in well-functioning grafts. The cumulative incidence of TG increased over time to 20% at 5 years. The prognosis of subclinical TG was equally as poor as TG diagnosed with graft dysfunction, with progressive worsening of histopathologic changes and function. Although TG was associated with both acute and chronic histologic abnormalities, 14.5% of TG biopsies showed no interstitial fibrosis or tubular atrophy, while 58% (7/12) of biopsies with severe TG showed only minimal abnormalities. TG was associated with acute rejection, pretransplant hepatitis C antibody positivity and anti-HLA antibodies (especially anti-Class II), with the risk increasing if the antibodies were donor specific. We suggest that subclinical TG is an under-recognized cause of antibody-mediated, chronic renal allograft injury which may be mechanistically distinct from other causes of nephropathy.

Polyomavirus-associated nephropathy risk in kidney transplants: the influence of recipient age and donor gender.

Polyomavirus-associated nephropathy (PVAN) is a frequent cause of kidney transplant failure. We determined the risk factors for biopsy-proven PVAN among 1027 recent kidney transplant recipients by univariate and multivariate analyses. The rate of PVAN was determined over an univariate and multivariate analysis over an average of 30 months of follow-up of patients receiving predominantly living donor grafts with antibody induction and sequential surveillance biopsies to detect subclinical graft disease. Seventy-four transplant recipients were diagnosed with PVAN with the finding made on surveillance biopsy in 40 patients. These 40 cases did not differ from the 34 non-surveillance cases with respect to baseline clinical characteristics or initial histological features. Older recipient age and female donor gender were independent risks associated with PVAN. Factors not linked to PVAN risk included the use and type of induction agent, use of tacrolimus vs sirolimus, the number of human lympocyte antigen (HLA) mismatches, or the frequency of acute rejection. We conclude that PVAN preferentially affects older age patients and allografts from female donors but is unrelated to immunological risk, choice of immunosuppression, or rejection history.

Recurrence of ANCA-associated vasculitis following renal transplantation in the modern era of immunosupression.

Progressive glomerulonephritis and attendant end-stage renal disease (ESRD) result from antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. The optimum time of kidney transplantation in patients with ESRD due to ANCA-associated vasculitis (AAV) and the risk of renal or nonrenal recurrence of vasculitis after transplantation are unknown. To answer some of these questions, we followed 35 transplant recipients with diagnoses of microscopic polyangiitis (20 patients) and Wegener's granulomatosis (15 patients). The median time from diagnosis to transplantation was 25 months with all patients being in clinical remission. Fifteen patients were ANCA-positive at time of the transplant with 13 preemptive transplants. The most common immunosuppressive strategy included antibody induction, corticosteroid, mycophenolate mofetil, and tacrolimus with acute rejection occurring in eight cases. Overall and death-censored graft survivals were 94 and 100%, respectively, 5 years post-transplantation. Nonrenal relapse occurred in three patients with a satisfactory response to treatment. No clear risk factor to relapse emerged and no detrimental effect to renal function was found. We conclude that transplantation should be considered as the treatment of choice for ESRD due to AAV. Potent antirejection regimes are well tolerated in these patients, are associated with a low risk of recurrence and an absence of AAV-related graft dysfunction.

Resident dendritic cells are the predominant TNF-secreting cell in early renal ischemia-reperfusion injury.

Renal ischemia-reperfusion injury (IRI) rapidly induces production of inflammatory mediators including, and in particular, tumor necrosis factor (TNF). Possible sources include resident parenchymal and bone marrow-derived cells as well as recruited leukocytes. Cell suspensions from kidneys subjected to IRI were examined by cell separation followed by in vitro culture and enzyme-linked immunosorbent assay (ELISA), immunoperoxidase and immunofluorescence microscopy, and multicolor flow cytometry to determine the contribution of dendritic cells (DCs) to early production of TNF and other inflammatory mediators. Secretion of TNF, interleukin (IL-6), monocyte chemoattractant protein-1 (MCP-1), and regulated on activation normal T cell expressed and secreted (RANTES) was increased in cell suspensions from IRI compared with control kidneys and was higher in DC-enriched preparations. Immunostaining identified TNF(+ve) cells that coexpressed the DC marker CD11c. Flow cytometry of bone marrow-derived (CD45(+ve)) cell populations at 24 h post-IRI demonstrated that F4/80(+ve)/CD11c(+ve) DCs remained proportionately stable and exhibit higher levels of DC maturation markers, whereas the proportion of F4/80(-ve) DCs, monocytes, neutrophils, and T cells increased. Intracellular staining for TNF confirmed that F4/80(+ve) DCs were the predominant TNF(+ve) cell and expressed higher levels than other TNF(+ve) cells. In vivo depletion of DCs from the kidney substantially attenuated TNF secretion by total and CD45(+ve) cells following IRI. The results uncover a role for resident F4/80(+ve) DCs as the predominant secretors of TNF within 24 h of IRI.