移植肾急性排斥反应新认识

急性排斥反应是影响肾移植长期预后的重要因素。在新型免疫抑制剂应用下,急性排斥反应具有表现不典型、难治性排斥反应比例高等特点。本文从发生急性排斥反应高危因素的术前筛查与处理、急性排斥反应早期诊断方法以及对急性排斥反应的干预和免疫抑制药物合理应用、移植后感染预防等方面,综合浙江大学医学院附属第一医院肾脏病中心的临床研究结果,探讨发生急性排斥反应的高危因素、诊断和防控措施,以提高肾移植后长期存活率。     

Valacyclovir for cytomegalovirus prophylaxis reduces the risk of acute renal allograft rejection

BACKGROUND: Both oral ganciclovir and valacyclovir decrease the incidence of cytomegalovirus (CMV) disease after renal transplantation. Moreover, valacyclovir has been shown to reduce the risk of acute rejection. Our study was designed to compare the efficacy and safety of oral ganciclovir and valacyclovir in the prophylaxis of CMV disease after renal transplantation. METHODS: A total of 83 patients were prospectively randomized to 3-month treatment with oral ganciclovir (3 g/day, n=36, GAN) or oral valacyclovir (8 g/day, n=35, VAL). A control group (DEF, n=12) was managed by deferred therapy. RESULTS: No differences were found in demography, immunosuppression, or donor/recipient CMV serology. The 12-month incidence of CMV disease was 67% in the DEF group compared with 6% in the GAN group and 3% in the VAL group (P<0.001 GAN or VAL vs. DEF; P=0.575 GAN vs. VAL). The biopsy-confirmed acute rejection rate at 12 months was 12% in the VAL group compared with 34% in the GAN group (P=0.030) and 58% in the DEF group (P<0.001). The difference between the GAN and DEF groups was not significant (P=0.087). The average CMV-associated costs per patient were $3,072, $2,906, and $4,906 in the GAN, VAL, and DEF groups, respectively. CONCLUSIONS: Valacyclovir and oral ganciclovir are equally effective in the prevention of CMV disease after renal transplantation. Both regimens are cost-effective. Valacyclovir is associated with a significantly reduced risk of acute rejection compared with both ganciclovir prophylaxis and deferred therapy.     

移植肾急性排斥反应的免疫表型

目的阐明移植肾急性排斥反应的发生机制。方法发生严重急性排斥反应的１６例移植肾行免疫组化染色,其中６例行免疫胶体金电镜观察。结果移植肾组织中主要免疫活性细胞为Ｔ细胞,动脉壁及肾小管细胞间的Ｔ细胞均为ＣＤ８细胞。结论移植肾急性排斥反应主要是由Ｔ淋巴细胞尤其是ＣＤ８细胞介导的一种免疫损伤。     

Elevated blood pressure predicts the risk of acute rejection in renal allograft recipients

BACKGROUND: Acute rejection (AR) is a strong predictor of renal allograft survival. Recent advances in immunosuppression have reduced considerably the incidence of AR. Still, approximately 25% of patients have AR early post-transplant, and the factors that predispose to AR have not been fully clarified. METHODS: The study includes 1641 adults, recipients of first cadaveric (CAD, N = 1195) or living related renal grafts (LRD, N = 446), transplanted in one institution. The variables associated with the occurrence of AR during the first year post-transplant were identified. RESULTS: By univariate analyses, AR was associated with the following variables: younger (P < 0.001); heavier (P = 0.003); and African American recipients (P = 0.002); CAD transplants (P = 0.001); higher number of HLA mismatches (P = 0.001); delayed graft function (DGF, P = 0.001); higher levels of serum creatinine post-transplant (P = 0.003); and higher levels of systolic and/or diastolic blood pressure (BP) post-transplant (P < 0.001). Higher BP levels were also associated with earlier AR episodes (P < 0.0001). By multivariable analysis AR was significantly associated with recipient age, number of HLA mismatches, DGF, pre-PRA and systolic BP. Analysis of BP measured weekly post-transplant indicated that elevated BP levels, even three weeks prior to the AR episode, were significantly associated with AR. For every level of BP, the use of BP medications was associated with a lower incidence of AR (P < 0.0001). Furthermore, the use of calcium channel blockers was also associated with lower incidence of AR (P = 0.001). Of note, 81% of recipients whose BP increased after the transplant had AR. In contrast, 22% of patients whose BP declined post-transplant had AR. CONCLUSIONS: Elevated BP levels post-transplant identify patients at high risk of AR independently of graft function. Treatment of BP and reduction of BP levels appears to be associated with a decreased risk of AR. We hypothesize that high BP may be an indicator of a particular type of allograft damage, perhaps ischemic, that may predispose to AR.     

Aspects of allograft rejection, ii: risk factors in renal allograft rejection

The most important risk factor for the development of chronic rejection is acute rejection either early or late posttransplantation. The more episodes of acute rejection that occur, the greater the likelihood that chronic rejection will eventually develop. In this light, a key to managing the long-term viability of the kidney transplant through reducing the incidence of chronic rejection may best be achieved by lowering the frequency of acute rejection episodes.     

Plasma cell-rich acute renal allograft rejection.

BACKGROUND: Acute renal allograft rejection is usually seen within the first 3 months posttransplant, and is characterized by an intense infiltrate of T cells. Some acute rejections, however, contain many plasma cells and/or appear late posttransplant. METHODS: We have investigated 27 cases of intensely plasma cell-rich acute rejections (PCAR) from 1987 to 1997 and have compared them to 21 control cases (CAR) of typical acute rejection. Each group was divided into early (<6 months) and late (>6 months) subgroups. PCAR and CAR cases were matched for histological features of chronic allograft nephropathy. In all four groups, most cases had Banff '97 type IB and IIA acute rejection. RESULTS: A significantly greater number of PCAR cases experienced graft failure due to chronic allograft nephropathy or complications of acute rejection (P<0.05). There was no significant difference between PCAR and CAR in HLA matching, occurrence of posttransplant acute tubular necrosis, presence versus absence of previous allografts, number of previous or subsequent acute rejection episodes, Banff '97 sum scores for acute rejection, cyclosporine A or FK506 levels, or percent change from baseline creatinine at time of biopsy. Plasma cells in PCAR cases showed IgG predominance whereas those in CAR had comparable staining for IgG and IgA. Kappa and lambda light chain immunostaining of all PCAR cases revealed polyclonality. Three of 18 PCAR cases studied for the presence of Epstein-Barr virus RNA showed scattered positivity in 2-7% of lymphoid cells, although the remainder was negative. None of the PCAR cases developed post-transpland lymphoproliferative disorder. CONCLUSIONS: We conclude that PCAR can occur from 1 month to many years posttransplant, is associated with poor graft survival, and is not a manifestation of concomitant chronic allograft nephropathy or viral infection, including posttransplant lymphoproliferative disorder.     

肾移植术后早期排斥反应的处理

目的：探讨。肾移植术后早期排斥反应(AR)的处理方法。方法：对14例。肾移植术后3周内发生AR的患者,应用甲基泼尼松龙(MP)治疗7例,改硫唑嘌呤(Aza)为霉酚酸脂(MMF?)治疗5例,抗CD3治疗6例。结果：应用MP治疗的7例中5例AR逆转,2例无效;改Aza为MMF治疗的5例3例逆转,2例无效(其中包括MP无效的2例改Aza为MMF治疗后1例逆转1例无效)。抗CD3治疗6例4例逆转,2例无效(其中MP治疗无效改Aza为MMF治疗后仍无效的1例逆转,MP治疗无效的基础免疫为CsA加MMF?加Pred的1例无效)。结论：MP可使大部分术后早期AR逆转。应用Aza的患者改用MMP后可使早期AR逆转,MP不能完全逆转的AR改用MMF后也有良好的效果。及时应用抗CD3几乎可使术后早期AR全部逆转。     

Steroid-resistant acute allograft rejection in renal transplantation

Steroid-resistant rejection after pediatric renal transplantation forms a rare but severe complication with a guarded prognosis particularly if this occurs late after transplantation. There is a paucity of data on how to manage these challenging rejection episodes, particularly in the pediatric literature. Mohan Shenoy et al. published a case series of 15 patients who were treated with anti-thymocyte globulin for steroid-resistant acute allograft rejection over a 15-year period in a single center in this issue of Pediatric Nephrology. While the results for the early rejection group were encouraging, the results in the eight patients with late rejection episodes after transplantation were unfavorable and afflicted with a high incidence of side-effects. Important diagnostic tools such as C4d staining of the renal transplant biopsy and the measurement of donor-specific antibodies were underutilized. The editorial reviews the importance of the differentiation between humoral and cellular rejection and the challenges of treating late antibody-mediated acute rejection in these patients. A multi-center approach is required to establish a registry of these events and ideally prospective randomized interventions should be designed to provide some evidence base for the management of this challenging complication after pediatric renal transplantation.     

Osteopontin expression in acute renal allograft rejection

BACKGROUND: Osteopontin (OPN) is a potent chemoattractant for mononuclear cells that is up-regulated in various inflammatory states of the kidney. The role of OPN and its expression in human renal allograft rejection are unknown. METHODS: We examined by immunohistochemistry and in situ hybridization, renal biopsies from patients with acute rejection (N= 22), protocol biopsies without rejection (N= 9), and perioperative donor biopsies (N= 35) for intrarenal expression of OPN, and its correlation with clinical, laboratory, and histopathologic parameters. In the rejection biopsies, interstitial monocyte/macrophage infiltration, tubulointerstitial cell proliferation/regeneration and apoptosis were investigated. RESULTS: In the majority of rejection biopsies, OPN expression by proximal tubular epithelium was widespread, and tended to be enhanced in the tubules surrounded by numerous inflammatory cells. Conversely, in patients that did not experience episodes of rejection and in donor biopsies, OPN expression by proximal tubules was nil or weak. OPN mRNA was colocalized with its translated protein in the renal tubular epithelium. OPN expression positively correlated with the degree of interstitial inflammation (P < 0.05), CD68+ monocyte infiltration (P < 0.01), Ki-67+ regenerating tubular and interstitial cells (P < 0.05 and P < 0.005, respectively), but not with terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL)-positive apoptotic tubular cells. CONCLUSION: These data suggest that inducible expression of OPN in the tubular epithelium may have a pathogenic role in acute renal allograft rejection by mediating interstitial monocyte infiltration and possibly tubular regeneration.     

Determinants of hypofiltration during acute renal allograft rejection

This study sought to determine the extent to which GFR is decreased during acute renal allograft rejection in human subjects and to determine the mechanism of the decrease in GFR. Eight patients with biopsy-proven acute rejection were compared with 18 recipients of optimally functioning renal allografts. GFR and renal plasma flow (RPF) were measured as the clearance of inulin and para-aminohippuric acid, respectively. Arterial BP was determined, blood was sampled, and plasma oncotic pressure (pi(A)) was measured. Glomeruli obtained by biopsy during rejection were subjected to morphometric analysis, for determination of K(f). Control morphometric values for healthy glomeruli were provided by 10 living donors from whom biopsies were obtained at the time of organ donation. The subjects in the acute rejection group exhibited a significantly reduced GFR of 17 +/- 4 ml/min per 1.73 m(2), compared with 72 +/- 4 ml/min per 1.73 m(2) for control subjects (P < 0.001). With the use of a sensitivity analysis to take into account the unknown para-aminohippuric acid extraction ratio, the RPF rate was calculated to have likely been significantly decreased, by 45 to 70%, in the acute rejection group. Neither the plasma oncotic pressure nor the mean arterial pressure differed between the two groups. Morphometric analysis revealed no difference in the single-nephron K(f) values for the acute rejection group, compared with the control group. These results indicate that acute renal allograft rejection causes a profound decrease in GFR, which is attributable to a decrease in RPF alone or in combination with a decrease in the glomerular transcapillary hydraulic pressure gradient (DeltaP).     

Adhesion molecule polymorphisms in acute renal allograft rejection

Acute rejection is the main cause of early renal allograft failure. Adhesion molecules provide signals for activation and recruitment of effector cells leading to graft infiltration by host T cells, which are key to allograft rejection. This study was undertaken to analyze the adhesion molecule gene polymorphisms in renal transplant recipients and to investigate their potential association with the development of acute allograft rejection. A total of 120 renal transplant recipients and 100 controls were retrospectively genotyped. Seven nucleotide polymorphisms in intracellular adhesion molecule (ICAM)-1, platelet endothelial cell adhesion molecule (PECAM)-1, L-selectin, and E-selectin were analyzed using allele-specific polymerase chain reaction (PCR)-SSP assay and PCR-restriction fragment length polymorphism (RFLP). Recipients were selected on the basis of the development of acute allograft rejection in the first 6 months after renal transplantation. Forty-one patients developed acute allograft rejection and 79 showed uneventful courses. There was no evidence for an association of any polymorphism with acute rejection. Thus, we concluded that these genes do not predispose to acute renal allograft rejection.     

移植肾急性排斥反应新认识（附视频）

急性排斥反应是影响肾移植长期预后的重要因素。在新型免疫抑制剂应用下,急性排斥反应具有表现不典型、难治性排斥反应比例高等特点。本文从发生急性排斥反应高危因素的术前筛查与处理、急性排斥反应早期诊断方法以及对急性排斥反应的干预和免疫抑制药物合理应用、移植后感染预防等方面,综合浙江大学医学院附属第一医院肾脏病中心的临床研究结果,探讨发生急性排斥反应的高危因素、诊断和防控措施,以提高肾移植后长期存活率。     

Study of acute antibody-mediated rejection in renal allograft biopsies

INTRODUCTION: Acute B-cell-mediated rejection (AMR) was ill-defined until the 6(th) Banff meeting establishing the criteria. We performed a retrospective analysis of renal allograft biopsies to evaluate immune injury with reference to the Ahmedabad Tolerance Induction Protocols (ATIP). METHODS: We evaluated renal allograft biopsies belonging to 3 groups: group A patients (n = 120) underwent a modified ATIP with addition of mesenchymal stem cells, anti-B-cell antibodies, and higher target-specific irradiation; group B patients (n = 351) belong to the old ATIP; and group C (n = 142) were controls who opted out of ATIP. The majority were biopsied 2 or 3 times. Biopsies were subdivided: 相似文献   

急性体液性排斥反应对移植肾预后的影响

Objective To explore the effect of acute humoral rejection on kidney graft survival.Methods 1098 patients received cadaveric renal transplant from January 2002 to December 2008 in our center. All patients were given triple immunosuppressants including tacrolimus or cyclosporine.According to patients who experienced biopsy-proved humoral rejection and cellular rejection within one year post-transplant, there were 53 cases in humoral rejection group, 109 in cellular rejection group (including 63 patients with borderline change), and 936 in normal group. Patients who experienced acute rejection received mythyl-prednisolone pulse, or received anti-CD3 antibody/plasma exchange/globulin. Clinical characteristics before operation including sex, age, HLA mismatch, panel reactive antibody, cold/warm ischemic time, graft loss rate and graft survival were compared among three groups. The effect of completely reversed cellular rejection and humoral rejection on graft survival was analyzed. Results There was no significant difference in sex, age and cold ischemic time among three groups, but there was significant difference in warm ischemic time, level of PRA and HLA mismatch between cellular rejection group or humor rejection group and normal group (P＜0. 05). During a follow-up period, the incidence of graft loss in humoral rejection group was 27.4 %, significantly higher than 7.3 % in cellular rejection group and 2.2 % in normal group, P＜0. 001. Kaplan-Meier analysis revealed the survival rate of grafts in humoral rejection group was significantly lower than in cellular rejection group and normal group (P＜0.001 ). After patients with irreversible rejection were excluded,there was no significant difference in the survival rate of grafts among the three groups.Conclusion Patients with acute humoral rejection survived with inferior graft outcome,but completely reversible rejection showed no effect on the graft survival.