自身免疫性甲状腺疾病相关肾损害研究概况

本文从发病机制、病理特点及诊断、治疗等方面介绍自身免疫性甲状腺疾病相关肾损害的研究现况.     

Acute Rejection After Rat Renal Transplantation Leads to Downregulation of Na+ and Water Channels in the Collecting Duct

Renal transplantation is associated with alterations of tubular functions and of the renin-angiotensin-aldosterone system. The underlying cellular and molecular mechanisms are unclear. We used an allogeneic rat renal transplantation model of acute rejection with and without immunosuppression by cyclosporine A (CsA) and a syngeneic model as control. Uninephrectomized Lewis or Lewis-Brown-Norway (LBN) rats received a kidney from LBN-rats. Renal transporters and receptors were analyzed by immunohistochemistry, semiquantitative RT-PCR and Western-blot analysis. Intracellular Na(+) was analyzed microfluorimetrically in isolated cortical collecting ducts. mRNA expression and function of the epithelial Na(+)-channel (ENaC) and mRNA and protein expression of the water-channel AQP2 were downregulated in transplanted kidneys undergoing rejection. Expression of the serum- and glucocorticoid-kinase (Sgk1) was decreased and that of the ubiquitin-protein ligase Nedd4-2 was increased. These changes were absent under CsA-therapy and in syngeneic model. Expression and function of the Na(+)-K(+)-ATPase, expression of the secretory K(+)-channel and of the mineralocorticoid receptor remained unchanged. Reduced ENaC function is likely due to decreased Sgk1- and increased Nedd4-2 mRNA expression leading to reduced ENaC expression in the membrane. These acute downregulations of ENaC and AQP2 may be triggered to reduce energy consumption in the distal nephron to protect the kidney immediately after transplantation.     

STARR with Contour® Transtar™: prospective multicentre European study

Objective  The stapled transanal rectal resection (STARR) in patients with defecation disorders is limited by the shape and capacity of the circular stapler. A new device has been recently developed, the Contour^® Transtar^™ stapler, in order to improve the safety and effectiveness of the STARR technique. The study has been designed to confirm this declaration.
Method  From January to June 2007 a prospective European multicentre study of consecutive patients with defecation disorder caused by internal rectal prolapse underwent the new STARR technique. The assessment of perioperative morbidity and functional outcome after 6 weeks, 3 and 12 months was documented by different scores.
Results  In all 75 patients, median age 64, the Transtar procedure was performed with 9% intraoperative difficulties, 7% postoperative complications and no mortality. The mean reduction of the ODS score was −15.6 (95%−CI: −17.3 to −13.8, P  < 0.0001), mean reduction of SSS was −12.6 (95%−CI: −14.2 to −11.2; P  < 0.0001). 41% stated improvement of their continence status by CCF score, only 4 patients (5%) had deterioration.
Conclusion  The Transtar procedure is technically demanding, with good functional results similar to the conventional STARR.     

Air emboli with Haemaccel®

We report two cases of venous air embolism which occurred in association with infusion of Haemaccel(R) using a pressure bag. As a result of these incidents, we performed a study that showed that up to 45 ml of air can be infused into a patient from a pressurised Haemaccel(R) plastic bottle using a standard administration set. We also demonstrated that the volume of air infused was influenced by the type and size of the pressure bag and the warming of the Haemaccel(R) plastic container.     

A new supraglottic airway device: LMA-Supreme™, comparison with LMA-Proseal™

Background and objective: The LMA‐Supreme^? (S‐LMA^?) is a new supraglottic airway device that presents combined features of flexibility, curved structure and single use and a different cuff structure. The purpose of this study was to compare the oropharyngeal leak pressures (OLP) of LMA‐Proseal^? (P‐LMA^?) and S‐LMA^?. Methods: Sixty adult patients were prospectively and randomly allocated to undergo insertion of P‐LMA^? (n=30) or S‐LMA^? (n=30). The cuffs were inflated until the intracuff pressure (ICP) reached 60 cm H₂O. Orogastric leak pressures, insertion times, first attempt success rates, fiberoptical assessment of position, cuff pressures, orogastric tube (OGT) placement and OGT insertion times were compared. Unblinded observers collected intraoperative data and blinded observers collected post‐operative data. Results: The first insertion attempts and time taken to provide an effective airway were similar between the groups. Two patients (P‐LMA^?, n=1; S‐LMA^?, n=1) were intubated due to excessive oropharyngeal leak and in one patient (P‐LMA^?, n=1) due to failed OGT placement. OLPs were similar (P‐LMA^?; 26.9±6.6 S‐LMA^?; 26.1±5.2). ICP increased significantly in the P‐LMA^? at the 30 and 60 min during anesthesia (P‐LMA^?; 80.1±12.8, 92.9±14.4, S‐LMA^?; 68.3±10.9, 73.7±15.6). OGT placement was successful in all patients in the S‐LMA^?, but failed in five patients in the P‐LMA^? (P=0.02). Fiberoptically determined anatomic position was better with the P‐LMA^? (P=0.03). Conclusion: Our findings suggest that S‐LMA^? had leak pressures similar to the P‐LMA^?, and this new airway device proved to be successful during both spontaneous and positive pressure ventilation.     

CD4+25+ Regulatory T Cells Limit Th1-Autoimmunity by Inducing IL-10 Producing T Cells Following Human Lung Transplantation

Chronic human lung allograft rejection is manifested by bronchiolitis obliterans syndrome (BOS). BOS has a multifactorial etiology. Previous studies have indicated that both cellular and humoral alloimmunity play a significant role in the pathogenesis of BOS. Recently, autoimmunity has also been demonstrated to contribute to lung allograft rejection in animal models. However, the significance of autoimmunity in BOS remains unknown. In this report, we investigated the role of naturally occurring CD4(+)CD25(+) regulatory T cells (T-regs) in modulating cellular autoimmunity to collagen type V (col-V), a 'sequestered' yet immunogenic self-protein present in the lung tissue, following lung transplantation (LT). We demonstrated that col-V reactive CD4(+) T cells could be detected in the peripheral blood of lung transplant recipients. There was a predominance of IL-10 producing T cells (T(IL-10)) reactive to col-V with significantly lower levels of IFN-gamma and IL-2 producing T cells (Th1 cells). The col-V specific T(IL-10) cells suppressed the proliferation and expansion of col-V specific Th1 cells by IL-10-dependent and contact-independent pathways. The T(IL-10) cells were distinct but their development was dependent on the presence of T-regs. Furthermore, during chronic lung allograft rejection there was a significant decline of T(IL-10) cells with concomitant expansion of col-V-specific IFN-gammaproducing Th1 cells.     

CD4+CD25+FOXP3+ Regulatory T Cells Increase De Novo in Kidney Transplant Patients After Immunodepletion with Campath-1H

Campath-1H (Alemtuzumab) is an effective immunodepletion agent used in renal transplantation. To evaluate its influence on T lymphocytes during repletion, we analyzed peripheral blood from Campath-1H-treated renal allograft recipients for the presence of FOXP3⁺ regulatory T (Treg) cells. Flow cytometry demonstrated that CD4⁺CD25⁺FOXP3⁺ lymphocytes increased significantly within the CD4⁺ T-cell population, skewing Treg/Teff (T effector) ratios for up to several years. In contrast, Treg levels in patients treated with anti-CD25 (Basiliximab) and maintained on CsA demonstrated a sustained decrease. The increase in Tregs in Campath-1H treated patients developed independent of maintenance immunosuppression. Importantly, the increase in Tregs was not fully explained by their homeostatic proliferation, increased thymic output, or Treg sparing, suggesting de novo generation/expansion. Consistent with this, in vitro stimulation of PBMCs with Campath-1H, with or without anti-CD3, activation led to an increase in CD4⁺CD25⁺FOXP3⁺ cells that had suppressive capabilities. Together, these data suggest that Campath-1H promotes an increase in peripheral Tregs and may act as an intrinsic generator of Tregs in vivo .     

The TEG® vs the ROTEM® thromboelastography/thromboelastometry systems

We have evaluated the TEG^® thromboelastograph and the ROTEM^® thromboelastometer, two point-of-care devices that measure blood coagulation. During a one-week period, seven consultant anaesthetists, one consultant haematologist, one associate specialist anaesthetist and two senior trainee anaesthetists were trained by the manufacturers and set up, calibrated and used both systems, after which their views were obtained and specific technical/support information was sought from the manufacturers using a questionnaire. Although the devices shared common features, they differed in complexity and aspects of ease of use, and in their purchase and running costs.     

Cyclosporine Microemulsion (Neoral®) Absorption Profiling and Sparse-sample Predictors During the First 3 Months after Renal Transplantation

Recent data suggest that optimal cyclosporine (CsA) exposure early post‐transplant significantly reduces the risk of acute graft rejection. They indicate that trough level monitoring is inadequate for precise concentration‐controlled therapy, and suggest that absorption profiling may offer a superior approach for guiding clinical immunosuppression with Neoral. An international, prospective, multicenter study examined the feasibility, accuracy, precision and clinical utility of cyclosporine microemulsion (Neoral^®) absorption profiling in de novo renal transplant recipients receiving basiliximab immunoprophylaxis and cyclosporine microemulsion maintenance immunosuppression. The nested pharmacokinetic study reported here was conducted in 4 study centers in which full (11‐point) pharmacokinetic profiles were performed on days 3, 7, 14 and 84 post‐transplant to examine absorption profile and absorption efficiency, and to determine optimal sparse‐sampling pharmacokinetic methods to predict Neoral exposure. Twenty‐four patients had complete 12‐h pharmacokinetic (PK) data on all 4 sampling days. Area under the time‐concentration curve (AUC) over the first 4 h of the 12‐h dosage interval (AUC[0–4]) and AUC over the entire 12‐h dosage interval (AUC[0–12]) reached 3803 ± 1033 and 7462 ± 2120 μg.h/L, respectively, by day 3, remained stable throughout the first 2 weeks, and declined to 2310 ± 698 and 4062 ± 1158 μg.h/L by day 84 (p < 0.001). AUC[0–4], capturing the drug absorption phase, represented 52% of the AUC[0–12] values across the four PK study days (mean R² > 0.90). Between‐patient variability was highest for C0 and C1 (mean coefficient of variation [c.v.] 36–47%), and lower for C2 (mean c.v. 28%) and subsequent time‐points during the dosing interval. Mean relative CsA absorption, measured by dose‐ and weight‐adjusted AUC[0–4] and AUC[0–12], increased significantly over time. The dose‐ and weight‐corrected AUC[0–4h] (DWC.AUC[0–4]) rose by over 100% (p < 0.001) from 753 ± 202 at day 3 to 905 ± 232 at day 7, 1080 ± 330 at day 14 and 1521 ± 316 by day 84, while the dose‐ and weight‐corrected AUC[0–12h] (DWC.AUC[0–12]) rose by over 80% (p < 0.001) from 1477 ± 390 μg.h/L/mg/kg on day 3, to 1721 ± 426 on day 7, 2086 ± 478 on day 14 and 2690 ± 602 on day 84 (p < 0.001). Relative CsA absorption varied over 5‐fold between patients at day 3, but patients tended to remain within the same quartiles over time. Sparse‐sample modeling identified optimum 3‐point, 2‐point and 1‐point predictors for AUC[0–4] and AUC[0–12]. C2 was the most accurate and robust 1‐point predictor for AUC[0–4] (mean R²: 0.80), while C3 was superior for AUC[0–12] (mean R²: 0.75). C0 was not a good predictor of either AUC[0–4] or AUC[0–12] (mean R²: 0.13 and 0.24, respectively). Conclusion: Absorption profiling defines the heterogeneity in CsA exposure and relative absorption post‐transplant. A 2‐h post‐dose blood sample is the most consistent, accurate and robust single‐point predictor of the absorption phase measured by AUC[0–4] and should replace trough level monitoring for accurate concentration‐control of Neoral therapy in the clinical setting. The use of additional samples at 1 and 3 h is more complex and costly, but increases prediction accuracy and may be valuable in selected patients with erratic absorption.     

Monitoring of Human Cytomegalovirus-Specific CD4+ and CD8+ T-Cell Immunity in Patients Receiving Solid Organ Transplantation

Absolute and human cytomegalovirus (HCMV)-specific CD4+ and CD8+ T-cell counts were monitored in 38 solid organ (20 heart, 9 lung and 9 kidney) transplant recipients during the first year after transplantation by a novel assay based on T-cell stimulation with HCMV-infected autologous dendritic cells. According to the pattern of T-cell restoration occurring either within the first month after transplantation or later, patients were classified as either early (n = 21) or late responders (n = 17). HCMV-specific CD4+ and CD8+ T-cell counts were consistently lower in late compared to early responders from baseline through 6 months after transplantation. In addition, in late responders, while HCMV infection preceded immune restoration, HCMV-specific CD4+ restoration was significantly delayed with respect to CD8+ T-cell restoration. The number of HCMV-specific CD4+ and CD8+ T-cells detected prior to transplantation significantly correlated with time to T-cell immunity restoration, in that higher HCMV-specific T-cell counts predicted earlier immune restoration. Clinically, the great majority of early responders (18/21, 85.7%) underwent self-resolving HCMV infections (p = 0.004), whereas the great majority of late responders (13/17, 76.5%) were affected by HCMV infections requiring antiviral treatment (p = <0.0001). Simultaneous monitoring of HCMV infection and HCMV-specific T-cell immunity predicts T-cell-mediated control of HCMV infection.     

Living Donor Renal Transplantation Using Alemtuzumab Induction and Tacrolimus Monotherapy

Alemtuzumab was used as an induction agent in 205 renal transplant recipients undergoing 207 living donor renal transplants. All donor kidneys were recovered laparoscopically. Postoperatively, patients were treated with tacrolimus monotherapy, and immunosuppression was weaned when possible. Forty-seven recipients of living donor renal transplants prior to the induction era who received conventional triple drug immunosuppression without antibody induction served as historic controls. The mean follow-up was 493 days in the alemtuzumab group and 2101 days in the historic control group. Actuarial 1-year patient and graft survival were 98.6% and 98.1% in the alemtuzumab group, compared to 93.6% and 91.5% in the control group, respectively. The incidence of acute cellular rejection (ACR) at 1 year was 6.8% in the alemtuzumab group and 17.0% (p < 0.05) in the historic control group. Most (81.3%) episodes of ACR in the alemtuzumab group were Banff 1 (a or b) and were sensitive to steroid pulses for the treatment of rejection. There was no cytomegalovirus disease or infection. The incidence of delayed graft function was 0%, and the incidence of posttransplant insulin-dependent diabetes mellitus was 0.5%. This study represents the largest series to date of live donor renal transplant recipients undergoing alemtuzumab induction, and confirms the short-term safety and efficacy of this approach.     

Factors Associated with Hyperhomocysteinemia After Renal Transplantation

Recent studies show that clinically stable renal transplant recipients have an increased prevalence of hyperhomocysteinemia (hyperHcy), but the mechanism of this disorder has not yet been elucidated. The aim of the present study was to evaluate the factors associated with hyperHcy after a successful renal transplantation. In 106 stable renal transplant recipients, total serum Hcy level (tHcy), folate, total protein, serum creatinine concentration, creatinine clearance, lipid status, body weight (BW), body mass index (BMI), and body fat (BF) were determined. The mean doses of cyclosporine, prednisolone, and azathioprine (mg/kg/day) were recorded. The mean serum tHcy level was significantly higher in renal transplant patients than in healthy controls (22.02 ± 8.02 versus 13.0 ± 3.3 μmol/L; p < 0.001), and the incidence of patients with hyperHcy was 82%. Comparison of the group of 20 patients with tHcy level <15 μmol/L and the group of 86 patients with tHcy level >15 μmol/L revealed that the latter was significantly older, heavier, had been longer on dialysis before renal transplantation, and had older donors and poorer renal graft function. Significant correlation was found between tHcy level and recipient age, dialysis duration, BW, creatinine clearance, serum creatinine, and folate concentration. However, multivariate analysis indicated that creatinine clearance (p = 0.025) and BW (p = 0.03) were the only determinants of elevated total Hcy level in renal transplant recipients. HyperHcy persists after successful kidney transplantation in the majority of renal transplant recipients, and its appearance is primarily associated with creatinine clearance and body weight.     

End-Stage Renal Disease After Orthotopic Heart Transplantation: A Single-Institute Experience

Orthotopic heart transplantation is the treatment of choice for end-stage heart failure, and calcineurin inhibitor agents allow for better allograft survival. However, pretransplantation low cardiac output status and posttransplantation immunosuppressants contribute toward deterioration of renal function. From 1987 to 2008, 350 patients underwent orthotopic heart transplantation in our hospital. Most of them received anti-thymocyte globulin (ATG) as the induction immunosuppressant. The introduction of mycophenolate mofetil (MMF) reduced the maintenance level of cyclosporine. The 26 patients who developed end-stage renal disease required dialysis. We reviewed the patient characteristics, including pretransplantation status, immunosuppressant regimens and drug levels, time and type of dialysis, and mortality rate. The mean age of these 26 patients was 53 years. Three patients underwent peritoneal dialysis. The overall 1-year survival rate was 96%, and the 5-year survival rate was 80%. The duration from heart transplantation to chronic dialysis correlated with the presence of a pretransplantation diagnosis of diabetes (P < .05) and an elevated pretransplantation blood creatinine level (P = .01), but there was no significant effect of the initial level of cyclosporine. In addition, the pretransplantation blood creatinine level was also related to the necessity of immediate postoperative hemodialysis (P = .01). There was no significant risk factor in relation to mortality. Regardless of modification of immunosuppressant regimens and initial drug levels, pretransplantation kidney function played an important inverse role in the duration from transplantation to dialysis: the higher the pretransplantation blood creatinine, the shorter the duration. While awaiting a heart transplant, more effort should be spent on protecting renal function to avoid early chronic dialysis.     

T cell receptor beta chain (TCR-Vβ) repertoire of circulating CD4+ CD25−, CD4+ CD25low and CD4+ CD25high T cells in patients with long-term renal allograft survival

The mechanisms underlying maintenance of renal allografts in humans under minimal or conventional immunosuppression are poorly understood. There is evidence that CD4⁺ CD25⁺ regulatory T cells and clonal deletion, among other mechanisms of tolerance, could play a key role in clinical allograft survival. Twenty‐four TCR‐Vβ families were assessed in CD4⁺ CD25^?, CD4⁺ CD25^low and CD4⁺ CD25^high T cells from patients with long‐term renal allograft survival (LTS), patients exhibiting chronic rejection (ChrRx), patients on dialysis (Dial) and healthy controls (HC) by flow cytometry. LTS patients presented a higher variability in their TCR‐Vβ repertoire, such decreased percentage of Vβ2⁺, Vβ8a⁺ and Vβ13⁺ in CD4⁺ CD25^low and ^high compared with CD4⁺ CD25^? subset and increased Vβ4 and Vβ7 families in CD4⁺ CD25^high T cells exclusively. Additionally, LTS patients, particularly those that were not receiving calcineurin inhibitors (CNI), had increased percentages of CD4⁺ CD25^high T cells when compared with Dial (P < 0.05) and ChrRx (P < 0.05) patients. Our results suggest that a differential expression of particular TCR‐Vβ families and high levels of circulating CD4⁺ CD25^high T cells in long‐term surviving renal transplant patients could contribute to an active and specific state of immunologic suppression. However, the increase in this T cell subset with regulatory phenotype can be affected by CNI.     

Expression of cyclin-dependent kinase inhibitors, p21cip1 and p27kip1, during wound healing in rats

Wound healing is a physiological process in which growth of cells is stringently regulated. Cell growth is controlled by cell cycle-related proteins in which the cyclin kinase inhibitors cause cell cycle arrest and inhibit proliferation. However, little is known about the expression and the role of cyclin kinase inhibitors during wound healing in vivo. This study was mainly designed to examine the expression of p21cip1 and p27kip1 in excisional wounds of full-thickness skin in rats. Concomitant expression of proliferation marker Ki67 was also examined. Proliferation predominantly occurred in the first week after injury, peaking at postwounding day 5. Expression of both p21cip1 and p27kip1 at the gene and protein levels did occur during wound healing and showed an inverse gradient to that of Ki67. Constitutive p27kip1 was expressed throughout wound healing with low levels during the proliferating period of days 3 and 5 and increased levels during post-mitotic and remodeling stages. In contrast, p21cip1 was expressed transiently with detectable levels only between days 7 and 14 by Western blot analysis. Immunohistochemically, epithelial cells, endothelial cells and fibroblasts all could express both p21cip1 and p27kip1. In conclusion, the overall results suggested that p21cip1 and p27kip1 may play a key role in supervising the growth resulting from cell proliferation in tissue repair.     

CD4+CD25+ Regulatory T Cells in Transplantation: Progress, Challenges and Prospects

The involvement of CD4(+)CD25(+) regulatory T cells (Treg) in general immune homeostasis and protection from autoimmune syndromes is now well established. Similarly, there has been increasing evidence for Treg involvement in allograft rejection and current immunotherapies. However, despite significant advances in understanding the development, function, and therapeutic efficacy of Treg in certain well-defined rodent models, the relevance of Treg to clinical transplantation remains unclear. In this review, we summarize our current understanding of the role of Treg in immunity and organ transplantation in experimental and clinical settings. In addition, we review advances in using Treg as a form of immune therapy. The goal is to highlight the complexities and opportunities in the field and to provide evidence to support the use of antigen-specific Tregs in the context of transplantation to facilitate a robust and selective state of immune tolerance.     

CD4+ CD25+ CD62+ T-Regulatory Cell Subset Has Optimal Suppressive and Proliferative Potential

CD4+ CD25+ regulatory T cells (Treg) are potent suppressors, and play important roles in autoimmunity and transplantation. Recent reports suggest that CD4+ CD25+ Treg are not a homogeneous cell population, but the differences in phenotype, function, and mechanisms among different subsets are unknown. Here, we demonstrate CD4+ CD25+ Treg cells can be divided into subsets according to cell-surface expression of CD62L. While both subsets express foxp3 and are anergic, the CD62L+ population is more potent on a per cell basis, and proliferates and maintains suppressive function far better than the CD62L- population and unseparated CD4+ CD25+ Treg. The CD62L+ population preferentially migrates to CCL19, MCP-1 and FTY720. Both CD62L+ and CD62L- subsets prevent the development of autoimmune gastritis and colitis induced by CD4+ CD25-CD45RBhigh cells in severe combined immunodeficiency (SCID) mice. Overall, these results suggest CD4+ CD25+ Treg are not a homogenous cell population, but can be divided into at least two subsets according to CD62L expression. The CD62L+ subset is a more potent suppressor than the CD62L- population or unfractionated CD4+ CD25+ Treg cells, can be expanded far more easily in culture, and is more responsive to chemokine-driven migration to secondary lymphoid organs. These properties may have significant implications for the clinical manipulation of the CD4+ CD25+ CD62L+ cells.