摘要:

Background.The Duffy antigen-receptor for chemokines (DARC) is a chemokine-binding protein that is up-regulated on peritubular capillaries (PTC) during cellular renal allograft rejection. C4d deposition and accumulation of inflammatory cells in PTC are indicators of humoral renal allograft rejection. Because DARC is expressed at the site of C4d deposition and might be involved in inflammatory cell recruitment, the authors evaluated the expression of DARC in different forms of human renal allograft rejection.Methods.Deposition of C4d and DARC expression were evaluated by immunohistochemistry in 42 renal transplant biopsy specimens. Biopsy specimens were subdivided according to histologic and immunohistochemical results, that is, C4d-negative biopsy specimens with (Banff 1, n=8) or without signs of cellular rejection (n=16), and C4d-positive biopsies (humoral rejection) with (Banff 1 rejection, n=7) or without cellular rejection (n=11).Results.DARC expression was found on a small number of PTC and veins in patients without rejection. Cellular and humoral rejection led to a comparable increase in the number of DARC-positive PTC (9.7 and 8.7 vs. 2.6 vessels per high-power field [HPF], respectively). The highest numbers were found in biopsy specimens with signs of both humoral and cellular rejection (17.5 vessels per HPF).Conclusions.This is the first study that demonstrates an induction of a chemokine-binding protein at the site of C4d deposition in humoral allograft rejection. The additive effect of humoral and cellular rejection on DARC expression might imply different pathways of DARC induction for different forms of allograft rejection.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.This study aimed to determine whether the production, in renal transplant recipients, of antibodies directed against donor HLA mismatches is predictive of transplant failure.Methods.The failure study group comprised 112 adult recipients of primary renal transplants who had re-entered the transplant waiting list after failure of the first graft. A control group of 123 recipients with functioning transplants was selected from transplantations performed during the same time period, in which patients had equivalent HLA matching and immunosuppression and a minimum of 5 years of follow-up. Sera taken before transplantation and at 1, 3, and 6 months and annually after transplantation were tested by enzyme-linked immunoabsorbent assay (ELISA) for the presence of HLA class I- and class II-specific antibodies. Antibody specificity was defined by a combination of cytotoxicity, ELISA, and flow cytometry techniques to determine whether the antibodies were directed against donor mismatches.Results.All recipients were negative for donor HLA-specific antibodies before transplantation. After transplantation, 57 (50.9%) of the 112 patients in the failure group produced donor HLA-specific antibodies compared with 2 (1.6%) of the 123 controls (P<0.0001; odds ratio [OR]=64.98; confidence interval [CI], 14.78–399.51). For 60% of the donor-specific antibody-positive patients, antibodies were detected before transplant failure. In 17 cases, these were class I specific; in 14 cases, class II specific; and in 3 cases, specific for both class I and II.Conclusions.This study has demonstrated that the production of posttransplantation antibodies directed against donor HLA-A, -B, -Cw, -DR, and -DQ mismatches are all strongly predictive of transplant failure.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.It has been shown that the transcription factors activator protein (AP)-1 and nuclear factor (NF)-&kgr;B play a pivotal role in various renal diseases. We aimed to study their activations in chronic cyclosporine A (CsA) nephrotoxicity and evaluate the effect of magnesium (Mg) supplementation and blockade of the renin-angiotensin system (RAS), which are known to ameliorate CsA nephrotoxicity, on these transcription factors.Methods.CsA (15 mg/kg/day) was administered subcutaneously daily to rats maintained on a low-sodium diet for 7, 14, and 28 days. DNA-binding activities of AP-1 and NF-&kgr;B in renal cortex were determined by electrophoretic mobility shift assay.Results.DNA-binding activity of AP-1 and NF-&kgr;B started to increase at day 14 and further elevated at day 28 by CsA treatment. These activations were markedly attenuated when rats were maintained on a high-Mg diet. In contrast, angiotensin-converting enzyme inhibitor (ACEI) had no effect on CsA-induced AP-1 activation. CsA-induced activation of NF-&kgr;B was suppressed by ACEI at day 14, whereas such effect could not be observed at day 28.Conclusions.Renal cortical AP-1 and NF-&kgr;B DNA binding were activated in chronic CsA nephrotoxicity. These activations were induced largely by means of RAS-independent mechanisms. It is suggested that prevention of CsA-induced DNA-binding activation of these transcription factors is at least in part responsible for the beneficial effects of Mg supplementation on CsA nephrotoxicity.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Human liver allografts sometimes show self-induced permanent tolerance without immunosuppression. It has recently been proposed that the replacement of liver donor endothelial cells by recipient cells could confer a survival advantage. The aim of this study was to analyze liver endothelial cell replacement in relation to the response (tolerance or rejection) after withdrawal of immunosuppression in liver transplant patients.Methods.Nine liver recipient patients were entered into a program of immunosuppressive drug withdrawal. The authors studied liver endothelial cell chimerism in five of these patients who received a liver from a donor of the opposite sex by in situ hybridization for X and Y chromosomes.Results.Three patients (33%) achieved complete withdrawal of immunosuppression. The authors’ data show similar endothelial cell chimerism in both the tolerant and nontolerant patients analyzed.Conclusions.Endothelial cell chimerism has nothing to do with the induction of clinical tolerance in liver transplant patients after withdrawal of immunosuppression.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Axillofemoral bypass grafts are used in the treatment of aortoiliac occlusive disease caused by atherosclerosis. There have been no previous reports on renal transplantation used as treatment for chronic renal failure after an axillofemoral bypass graft being placed because of atypical coarctation of the aorta.Methods.The patient was a 47-year-old woman who had received regular hemodialysis for 15 years. Axillofemoral bypass surgery was performed because of atypical coarctation of the aorta in October 1999. Three years after surgery, she underwent renal transplantation.Results.Renal transplantation was successful, and helical computed tomography demonstrated patent graft bypass and good nephrographic effects of the renal artery.Conclusions.Even though dialysis patients with atypical coarctation of the aorta are treated with an axillofemoral bypass, it is possible for them to undergo regular renal transplantation, if part of the external or internal iliac artery is intact.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Invasive aspergillosis (IA) is rare among renal transplant recipients (RTRs). We investigated a cluster of IA among RTRs at a California hospital from January to February 2001, when construction was ongoing. We conducted a cohort study among RTRs who were hospitalized between January 1 and February 5, 2001, to determine risk factors for IA. IA was defined using established guidelines. Four IA cases occurred among 40 RTRs hospitalized during the study period. Factors associated with an increased risk of IA included prolonged hemodialysis, lengthy corticosteroid treatment posttransplant, and use of sirolimus alone or with mycophenolate (P<0.05). After the study period, three additional RTRs developed IA; twoAspergillusisolates recovered from these patients had indistinguishable profiles by DNA fingerprinting, suggesting common-source exposure. This study suggests that immunosuppressed RTRs can be at an increased risk for IA. Measures to prevent IA in these patients should be taken during hospital construction.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Transmission of bacterial infections from donor to recipient may occur with donor bacteremia. We describe a novel mechanism for transmission ofPseudomonasto multiple recipients through direct contamination of a donor innominate artery graft. Patient data were collected by chart review from the donor and the kidney, kidney-pancreas, heart, lung, and liver recipients. The donor was not bacteremic but hadP. aeruginosaisolated from routine tracheal cultures. Spillage of tracheal contents onto the innominate artery and subsequent contamination of intra-abdominal organs likely occurred. Vascular anastomotic infections with graft loss caused byPseudomonasoccurred in three patients (liver, kidney, and kidney-pancreas), and the lung patient developed severe pneumonia. AllPseudomonasisolates were identical by molecular typing. Donors may transmit bacterial infections to multiple recipients by mechanisms other than donor bacteremia. Although donor tracheal cultures are commonly positive, in certain settings antimicrobial treatment of recipients may be needed.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Tacrolimus, an immunosuppressive agent, is widely used in patients after transplantation to prevent allograft rejection. Because tacrolimus has a narrow therapeutic range, it is essential to carefully control the blood level. It has been demonstrated that tacrolimus is metabolized mainly by cytochrome P-450 (CYP) 3A4, and that tacrolimus is a substrate of P-glycoprotein.Methods.This article reports a case of considerable increase in the blood level of tacrolimus after the intake of pomelo in a renal transplant recipient.Results.Pomelo may increase the blood concentration of tacrolimus by inhibiting CYP 3A4, P-glycoprotein, or both.Conclusions.Patients taking drugs such as tacrolimus or cyclosporine, which have their kinetics affected by grapefruit juice, should avoid pomelo and other grapefruit-related citrus fruits.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Background.Muromonab-CD3 (OKT3), a mouse monoclonal antibody directed against human T lymphocytes, is a potent immunosuppressive agent used to reverse and more recently to prevent allograft rejection, mostly in cardiac transplant recipients. Neurotoxicity from OKT3 usually manifests itself as a transient aseptic meningitis and remains uncommon.Methods.The authors describe a dramatic neurologic syndrome after orthotopic heart transplant characterized by akinetic mutism, blepharospasm, anomic aphasia, and delirium.Results.Magnetic resonance imaging (MRI) showed meningeal enhancement and single-photon emission computed tomography (SPECT) showed markedly reduced tracer uptake. Discontinuation of OKT3 resulted in resolution of this neuropsychiatric syndrome and reversal of abnormalities on neuroimaging that coincided with normalization of CD3+lymphocyte count.Conclusions.In the initial posttransplant period, it remains difficult to attribute encephalopathic signs to toxicity of immunosuppressive drugs. However, MRI and cerebral perfusion studies may help support the diagnosis. More precise characterization of the prevalence of OKT3-associated encephalopathy could come from prospective SPECT studies.

ISSN:0041-1337    

出版商:OVID    

年代:2003

数据来源: OVID