Clinical relevance of Luminex donor-specific crossmatches: data from 165 renal transplants

The clinical significance of the presence of donor-specific anti-human leucocyte antigen (HLA) antibodies (DSA) prior to renal transplantation detected solely by solid-phase techniques remains unclear. This study was designed to determine the clinical relevance of the recently introduced bead-based Luminex donor-specific crossmatch (LumXm). A group of 165 patients transplanted between 1997 and 2001 were tested. Of 165 recipients transplanted with a negative complement-dependent cytotoxicity crossmatch, 32 proved to have a positive Luminex crossmatch. Sixteen were positive for class I, 15 were positive for class II, 1 was both class I and II positive and 133 recipients were negative. Acute rejection (AR)-free survival for all recipients was 77%, and there was no difference in AR-free survival between LumXm-positive and LumXm-negative recipients. Overall graft survival after a median follow-up time of 8 years was 56%. Recipients with a positive class I LumXm had worse long-term graft survival ( P  = 0.006). In recipients with a positive class I LumXm, 5-year graft survival was 41% vs 70% in negative patients and 10-year graft survival was 27% vs 56%. Positivity for class II LumXm was not a significant risk factor for graft failure ( P  = 0.7). In conclusion, pretransplant DSA detected by the LumXm had no impact on AR episodes. Class II LumXm positivity proved no significant risk factor for graft failure, but the value of the class II LumXm is questionable. A positive class I LumXm resulted in worse long-term graft survival compared with a negative one.     

Urinary C-X-C Motif Chemokines 13:a Noninvasive Biomarker of Antibody-Mediated Renal Allograft Rejection

Objective: Since acute rejection remains one of the major complications which necessitate periodic surveillance, noninvasive diagnostic/prognostic methods are preferred by renal transplant recipients. Here, we explored whether urinary C-X-C motif chemokines 13(CXCL13) could be a potential candidate to reflect ongoing immune processes within the renal graft. Methods: We investigated urinary CXCL13 levels by a cross-sectional analysis of 146 renal allograft recipients and 40 healthy controls. Besides, a subset of patients(n=57) were followed-up for kinetic monitoring of immune status.Results: Urinary CXCL13/Cr was lower in normal transplants compared to those with acute tubular necrosis(ATN, P=0.001), chronic allograft nephropathy(CAN, P=0.01) and acute rejection(AR, P0.0001), which yielded a good diagnosis performance of urinary CXCL13 for AR(AUC=0.818, P0.0001). Interestingly, urinary CXCL13 further distinguished acute antibody mediated rejection(ABMR) from acute cellular rejection,with an AUC of 0.856. Besides, patients with steroid-resistant acute rejection had distinctly greater urinary CXCL13/Cr levels than patients with reversible acute rejection,P=0.001. Follow-up data revealed that urinary CXCL13/Cr varied in line with the occurrence of ABMR. Furthermore, elevated levels of urinary CXCL13/Cr within the first month was predictive of graft function at 3, 6 months, P=0.044 and 0.4. Conclusion: This study demonstrates that monitoring of urinary CXCL13/Cr might be a valuable noninvasive approach for the detection of AR, especially ABMR. Additionally, high urinary CXCL13/Cr levels related to the poor response to steroid treatment and predicted a compromised graft function after AR.     

前群体反应性抗体对肾移植长期存活的影响

目的：分析术前PRA水平与肾移植长期存活之间的关系 。方法：收集我中心2001年1月至2014年6月间,接受首次肾移植术的1 162例受者临床资料,根据受者术前PRA水平分组,将PRA≤10%分为阴性组,PRA>10%为阳性组,并对其进行回顾性分析。结果：术前PRA阴性者1、5、10年人存活率为96.8%、89.4%、78.6%,阳性者为93.5%、81.6%、65.4%,而术前PRA阴性者1、5、10年肾存活率为95.9%、84.8%、63.1%,阳性者为92.3%、74.1%、51.9%,两组移植人/肾间生存曲线均有统计学差异（人/肾log-rank检验χ²=9.623/11.019,P=0.002/0.001）。Cox多因素回归分析显示PRA水平是影响人/肾存活的重要因素（P<0.001）,PRA与术后急性排斥反应发生相关（OR=8.25,95% CI=2.86-5.72, P）。术前PRA阴性受者术后5年、10年血肌酐均较术前PRA阳性者低,具有统计学差异（P<0.05）,而两者术后1年血肌酐无统计学差异。此外,PRA与术后抗供体特异性抗体（DSA）出现相关（OR=6.89,95% CI=4.52-9.17, P）。结论：PRA是肾脏移植术前筛选致敏受者的重要指标,术后更应注重PRA阳性受者急性排斥反应及DSA的监测和诊断。<0.05<0.001     

A clinicopathologic study of isolated intestinal allografts with preformed IgG lymphocytotoxic antibodies

Humoral rejection of human small bowel allografts has not been well documented. The aim of this study was to determine the significance of preformed IgG lymphocytotoxic antibodies, as determined by the modified Amos crossmatch technique, in 6 of 28 (21.4%) adult isolated intestinal allograft recipients treated with tacrolimus basal immunosuppression. The crossmatch with dithiothreitol (DTT) was strongly positive in 5 grafts and weakly positive in the remaining one. The strongly positive crossmatch grafts (n=5) developed severe mucosal injuries immediately after reperfusion. Within the first 10 days after transplantation, 3 of the 5 strongly positive crossmatch grafts developed clinically and endoscopically documented severe mucosal congestion, cyanotic discoloration, and focal hemorrhage within the allograft. Simultaneous mucosal biopsy specimens demonstrated severe congestion, neutrophilic margination, and fibrin-platelet thrombi within the lamina propria microvasculature, along with focal hemorrhage, but with no histological neutrophilic or necrotizing arteritis, and the immunofluorescent findings were unremarkable. The other 2 strongly positive crossmatch allograft recipients developed macroscopic congestion of mucosa with microscopic foci of congestion and hemorrhage. In contrast, the recipient with a weakly positive crossmatch, as well as the 22 crossmatch negative recipients, exhibited none of these characteristic clinical, endoscopic, or microscopic findings (P <.05). With prompt augmentation of the immunosuppression therapy, the 3 grafts with the characteristic clinicopathologic syndrome were successfully reversed with the monoclonal antilymphocyte preparation OKT3. Thus there was no statistical difference (P >.05) in early graft survival and the frequency of acute rejection episodes between the crossmatch-positive and the crossmatch-negative groups within the first 6 months after transplantation. We conclude that preformed IgG lymphocytotoxic antibodies in isolated intestinal recipients can be associated with a characteristic clinicopathologic syndrome during the early postoperative course, similar to that observed in experimental animal models and in other solid organ transplantation. If recognized and treated aggressively, early graft failure can be avoided. The long-term significance of these preformed antibodies has yet to be determined.     

Pre- and posttransplantation allosensitization in heart allograft recipients: major impact of de novo alloantibody production on allograft survival

The involvement of humoral response in allograft rejection has been suggested by both immunologic and histochemistry studies. In the present study, we explored the role of alloantibodies in a large cohort of heart allograft recipients followed for 15 years. Sequential samples of sera were obtained from 950 recipients of heart allografts before and after transplantation at the time when protocol endomyocardial biopsies were performed. The presence of anti-human leukocyte antigen (HLA) antibodies was investigated using complement mediated cytotoxicity and solid phase assay (SPA). Our data reveal an inverse correlation between the development of alloantibodies after transplantation and heart allograft survival. The 15-year graft survival was highest in patients who never developed alloantibodies (70%) or who displayed them only before transplantation (71%); graft survival in recipients who showed antibodies both before and after transplantation (56%), or only after transplantation (47%), was lower. The deleterious effect of antibodies on graft survival started 8 years after transplantation, suggesting that the production of de novo antibodies may have been triggered by some later event. We found that patients with de novo antibodies appearing more than 1 year after transplantation had the poorest survival. Furthermore, the development of de novo antibodies was preceded in 76% of these patients by cellular rejection grade 3 or higher, according to the International Society for Heart Transplantation (ISHT) grading criteria. Development of antibody-mediated rejection (AMR) had a significant negative impact on graft survival (16% in AMR(+) vs 63% in AMR(-) patients, p = 0.0008). Of the 23 patients with AMR, 21 displayed cytotoxic donor-specific antibodies (DSA) at the time of diagnosis, and in 18 of these cases SPA showed that they were directed against the donors' HLA. The data demonstrate that the detection of alloantibodies permits a better definition of AMR in heart allograft recipients. Identification of patients at risk for developing AMR is of great importance for early treatment of rejection episodes.     

肾移植后急性体液排斥反应：5年同一机构296例随访*

背景：肾移植后急性体液排斥反应虽然发生率不高,但对移植物功能恢复可造成严重影响,是移植物早期丢失的主要原因。 目的：分析肾移植后急性体液排斥反应早期诊断和防治的意义。 方法：选择接受肾移植后规律随访的受者296例,其中移植前群体反应性抗体阳性受者26例,阴性受者270例。酶联免疫吸附试验动态监测肾移植受后外周血中的群体反应性抗体和供者特异性抗体,免疫组织化学染色观察穿刺活检组织中C4d的沉积及浸润淋巴细胞表面分子标记,按Banff 2005标准结合临床相关指标诊断急性体液排斥反应。 结果与结论：26例移植前群体反应性抗体阳性受者中6例(23%)移植后发生了急性体液排斥反应,270例阴性受者中19例(7%)发生了急性体液排斥反应,差异有显著性意义(P < 0.01)。发生急性体液排斥反应的患者中22例(88%)外周血清中检测到供者特异性抗体,271例无急性体液排斥反应的患者中仅1例检出供者特异性抗体,差异具有显著性意义(P < 0.01)。急性体液排斥反应受者中C4d阳性率为80%,未发生急性体液排斥反应的患者C4d阳性率仅为6.7%,差异具有显著性意义(P < 0.001)。肾移植后早期监测群体反应性抗体和供者特异性抗体水平,通过穿刺活检观察移植肾组织中的C4d沉积情况,可及时诊断急性体液排斥反应,有效改善移植物功能并提高移植物存活率。关键词：肾移植;供者特异性抗体;急性体液排斥反应;C4d;利妥昔单抗  doi:10.3969/j.issn.1673-8225.2012.18.005 中图分类号: R617  文献标识码: A   文章编号: 1673-8225(2012)18-03249-06     

Peritubular capillary C4d deposition in chronic allograft dysfunction

Peritubular capillary (PTC) C4d staining represents a marker for acute humoral rejection, however, the impact of positive staining on chronic allograft dysfunction has received little attention. Ninety-three renal allograft biopsies from 93 patients were selected from a total of 174 renal allograft biopsies, which were obtained 6 months or more after transplantation (median: 89 months). Fresh frozen renal tissue was stained with monoclonal antibody against C4d. Sixteen of 93 biopsies showed C4d staining in PTC. C4d staining was positive in 40% of acute rejection cases (n=15) and 21% of chronic rejection cases (n=24). When the samples were divided according to C4d positivity, the C4d (+) group had a higher proportion of acute rejection than the C4d (-) group. However, no significant difference was observed between the two groups in terms of the prevalence of chronic rejection. Degrees of histological injury including tubulitis, interstitial inflammation and interstitial fibrosis were not significantly different between C4d (+) and C4d (-) groups. However, the 2-year graft survival rate after biopsy was lower in the C4d (+) group than in the C4d (-) group (24.8% versus 59.0%, p=0.1255). C4d staining in PTC is associated with late acute rejection, but not with chronic rejection based on conventional morphologic criteria in patients with chronic allograft dysfunction.     

肾移植受者HLA体液免疫致敏状态的监测及其临床意义

为探讨肾移植受者同种异体HLA抗原致敏后体液免疫状态与术后排斥反应及移植物存活率的相关性及其临床意义,应用One Lambda混合抗原板(LATM)通过ELISA筛查受者术前血清中的HLA-IgG抗体,对阳性血清进一步用抗原板(LAT1240和LAT1HDS)检测抗体阳性率及其特异性;并采用序列特异性引物聚合酶链反应(PCR-SSP)技术进行HLA基因分型。在1 297例肾移植受者中,HLA-IgG抗体阳性者165例,其中I类抗体阳性126例,II类抗体阳性90例,51例同时存在I类和II类HLA-IgG抗体,抗体阳性率>50%的高致敏受者94例。所有受者术后未发生超急性排斥反应,抗体阳性组受者的急性排斥发生率与阴性组受者比较,没有统计学差异。然而抗体阳性组受者移植物功能延迟恢复(DGF)的发生率显著高于阴性组受者(P<0.001)。抗体阳性组受者的1年、3年和5年移植肾存活率分别为95%、88%和80%;与抗体阴性组受者组比较无统计学差异。女性受者中抗体阳性率明显高于男性受者(P<0.001);再次移植受者中抗体阳性率显著高于初次移植受者(P<0.001)。抗体阳性组受者的供受者配型明显优于抗体阴性组受者。HLA-IgG抗体是反映受者体液免疫致敏状态的敏感指标,供受者间良好的HLA配型能显著降低排斥反应发生率和改善移植物存活。     

Comparative and Prospective Analysis of Three Different Approaches for Live-Donor Nephrectomy

PURPOSE:

Living donor nephrectomy is usually performed by a retroperitoneal flank incision. Due to the significant morbidity and long recovery time for a flank incision, anterior extra peritoneal sub-costal and transperitoneal video-laparoscopic methods have been described for donor nephrectomy. We prospectively compare the long-term results of donors as well as functional recipients submitted to these three approaches.

MATERIALS AND METHODS:

A total of 107 live donor renal transplantations were prospectively evaluated from May 2001 to January 2004. Donors were compared with regard to operative and warm ischemia time, postoperative pain, analgesic requirements, and complications. Recipients were compared with regard to graft function, acute cellular rejection, surgical complications, and graft and recipient survival.

RESULTS:

The mean operative and warm ischemia times were longer in the video-laparoscopic group (p<0.001), whereas patients of the flank incision group presented more postoperative pain (p=0.035), required more analgesics (p<0.001), had longer hospital stays (p<0.001), and suffered more pain on the 90th day after surgery (p=0.006). In the sub-costal and flank incision groups, there was a larger number of paraesthesias and abdominal wall asymmetries (p<0.001). Recipient groups were demographically comparable and presented similar acute tubular necrosis incidence and delayed graft function. The incidence of acute cellular rejection was higher in the video-laparoscopic and flank incision groups (p=0.013). There was no difference in serum creatinine levels, surgical complications, or recipient or graft survival between groups.

CONCLUSIONS:

The video-laparoscopic and sub-costal approaches proved to be safe, and to provide donor advantages relative to the flank incision approach. Among recipients, the complication rate, graft survival, and recipient survival were similar in all groups.     

Association of MCP-1 and CCR2 polymorphisms with the risk of late acute rejection after renal transplantation in Korean patients

Among the factors modulating transplant rejection, chemokines and their respective receptors deserve special attention. Increased expression of monocyte chemoattractant protein-1 (MCP-1) and its corresponding receptor (chemokine receptor-2, CCR2) has been implicated in renal transplant rejection. To determine the impact of the MCP-1-2518G and CCR2-64I genotypes on renal allograft function, 167 Korean patients who underwent transplantation over a 25-year period were evaluated. Genomic DNA was genotyped using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Fifty-five (32.9%) patients were homozygous for the MCP-1-2518G polymorphism. Nine (5.4%) patients were homozygous for the CCR2-64I polymorphism. None of the investigated polymorphism showed a significant shift in long-term allograft survival. However, a significant increase was noted for the risk of late acute rejection in recipients who were homozygous for the MCP-1-2518G polymorphism (OR, 2.600; 95% CI, 1.125-6.012; P = 0.022). There was also an association between the MCP-1-2518G/G genotype and the number of late acute rejection episodes (P = 0.024). Although there was no difference in the incidence of rejection among recipients stratified by the CCR2-V64I genotype, recipients with the CCR2-V64I GG genotype in combination with the MCP-1-2518G/G genotype had a significantly higher risk of acute or late acute rejection among the receptor-ligand combinations (P = 0.006, P = 0.008, respectively). The MCP-1 variant may be a marker for risk of late acute rejection in Korean patients.     

Association of viral genome with graft loss in children after cardiac transplantation

BACKGROUND: The survival of recipients of cardiac allografts is limited by rejection, lymphoproliferative disease, and coronary vasculopathy. The purpose of this study in children who had received heart transplants was to evaluate the cardiac allografts for myocardial viral infections and to determine whether the presence of viral genome in the myocardium correlates with rejection, coronary vasculopathy, or graft loss. METHODS: We enrolled heart-transplant recipients 1 day to 18 years old who were undergoing evaluation for possible rejection and coronary vasculopathy. Endomyocardial-biopsy specimens were evaluated for evidence of rejection with the use of standard criteria and were analyzed for the presence of virus by the polymerase chain reaction (PCR). RESULTS: PCR analyses were performed on 553 consecutive biopsy samples from 149 transplant recipients. Viral genome was amplified from 48 samples (8.7 percent) from 34 patients (23 percent); adenovirus was found in 30 samples, enterovirus in 9 samples, parvovirus in 5 samples, cytomegalovirus in 2 samples, herpes simplex virus in 1 sample, and Epstein-Barr virus in 1 sample. In 29 of the 34 patients with positive results on PCR (85 percent), an adverse cardiac event occurred within three months after the positive biopsy, and 9 of the 34 patients had graft loss due to coronary vasculopathy, chronic graft failure, or acute rejection. In 39 of the 115 patients with negative results on PCR (34 percent), an adverse cardiac event occurred within three months of the negative PCR finding; graft loss did not occur in any of the patients in this group. The odds of graft loss were 6.5 times as great among those with positive results on PCR (P=0.006). The detection of adenovirus was associated with considerably reduced graft survival (P=0.002). CONCLUSIONS: Identification of viral genome, particularly adenovirus, in the myocardium of pediatric transplant recipients is predictive of adverse clinical events, including coronary vasculopathy and graft loss.     

Renal medullary changes in renal allograft recipients with raised serum creatinine

OBJECTIVE: To test the hypothesis that the renal medulla may reflect rejection related changes and thus have a predictive value in the assessment of acute renal allograft rejection or chronic graft damage. METHODS: 75 post-transplant biopsies from 57 patients were scored according to the Banff 1997 scheme. The biopsies with adequate cortical and medullary tissue (n = 23) were selected and medullary tissues were reviewed for rejection related lesions except intimal arteritis. Chronic damage was determined by image analysis depending on periodic acid-methenamine silver (PAMS)-Masson trichrome (MT) staining. Medullary and cortical changes were compared. RESULTS: Interstitial inflammation and tubulitis were more frequent and severe in the cortex (p<0.001). Medullary tubulitis was associated with intimal arteritis (p = 0.003, r = 0.598). Medullary interstitial inflammation (n = 8) and tubulitis (n = 4) were associated with cortical borderline changes (n = 5) or allograft rejection (n = 3). The sensitivity, specificity, and positive and negative predictive values of medullary inflammatory changes in predicting cortical allograft rejection were 43%, 69%, 37%, and 73%, respectively. A significant association was observed between medullary MT-SAP and cortical PAMS-SAP values (p = 0.02, R(2) = 0.23). CONCLUSIONS: Acute rejection related lesions are more common and severe in the cortex, and the renal medulla does not sufficiently reflect cortical rejection. The positive and negative predictive values of medullary changes for allograft rejection are low, and medullary inflammation is not a reliable indicator of allograft rejection. Increased medullary fibrosis is correlated with chronic cortical damage.     

Effect of the use or nonuse of long-term dialysis on the subsequent survival of renal transplants from living donors

BACKGROUND: The effect on allograft survival of the transplantation of kidneys from living donors without the previous initiation of long-term dialysis is controversial. METHODS: Using data from the U.S. Renal Data System, we performed a retrospective cohort study of 8481 patients who were or who were not treated by long-term dialysis before receiving a kidney transplant from a living donor. The relative rate of allograft failure for patients who received a transplant without previously undergoing long-term dialysis, as compared with patients who underwent long-term dialysis before transplantation, was assessed by proportional-hazards analysis, with adjustment for potential confounding variables, including the transplantation center and median household income. The association between the receipt of a kidney transplant from a living donor without previous dialysis ("preemptive transplantation") and the risk of biopsy-confirmed acute rejection within six months after transplantation was evaluated by conditional logistic-regression analysis, with adjustment for the transplantation center. RESULTS: Transplantation of a kidney from a living donor without previous long-term dialysis was associated with a 52 percent reduction in the risk of allograft failure during the first year after transplantation (rate ratio, 0.48; P=0.002), an 82 percent reduction during the second year (rate ratio, 0.18; P=0.001), and an 86 percent reduction during subsequent years (rate ratio, 0.14; P=0.001), as compared with transplantation after dialysis. The reduction in the rate of allograft failure during the first year was attenuated when adjustment was made for the timing of acute rejection within the first year (rate ratio, 0.69; 95 percent confidence interval, 0.44 to 1.10; P=0.10). Increasing duration of dialysis was associated with increasing odds of rejection within six months after transplantation (P=0.001). CONCLUSIONS: Preemptive transplantation of kidneys from living donors without the previous initiation of dialysis is associated with longer allograft survival than transplantation performed after the initiation of dialysis.     

Maintenance of cytomegalovirus (CMV) latency and host immune responses of long term renal allograft survivors. II. Secondary CMV infections associated with impaired in vitro proliferative responses to mitogens, allogeneic lymphocytes and CMV infected cells.

The relationship between secondary cytomegalovirus (CMV) infections and host general cellular immunocompetence was investigated in 16 renal allograft recipients with minimal immunosuppressive treatment and excellent renal function. Results were compared with 19 CMV seropositive healthy controls. Significantly impaired immune responses were detected in the subgroup of nine recipients who experience at least 2 years before a secondary CMV infection. Their in vitro lymphocyte reactivity (LR) tests to phytohaemagglutinin (PHA, P = 0.01), pokeweed mitogen (PWM, P less than 0.05), microbial antigens (P less than 0.001) and to pooled allogeneic stimulator lymphocytes in the MLC test (P = 0.02) were lower than the controls. The MLC responses, however, increased with graft survival time (r = 0.8810, P = 0.01). This was positively correlated with the virus specific cellular immunity measurable by the LR responses to CMV infected target cells (r = 0.8333, P = 0.02). In contrast, long term renal allograft survivors who maintained their CMV infection in latency after transplantation (n = 7) showed normal responses to PWM, pooled lymphocytes and CMV infected target cells, whereas the responses to PHA and to bacterial antigens were less severely impaired (P less than 0.05 and P less than 0.001, respectively). This study of long term renal allograft survivors shows that a secondary CMV infection has a long lasting negative effect on immunity especially against alloantigens and CMV infected targets. However, in the data presented here it would be as acceptable to suggest that the patients are consistently relapsing with CMV because they initially had poor immune response and not vice versa.     

Significance of C4d staining in ABO-identical/compatible liver transplantation.

Complement degradation product C4d has become an important marker of humoral or antibody-mediated rejection in renal and heart allograft biopsies. Although there have been several reports on the detection of C4d in liver allografts, the significance of C4d in liver transplantation and its relationship with humoral rejection are still not clear. We investigated the frequency and pattern of C4d staining in liver allograft biopsies with reference to preoperative lymphocyte crossmatch tests, which detect donor-reactive lymphocyte antibody. Survival rates at 5 years were 77% for crossmatch-negative patients and 53% for crossmatch-positive patients (P=0.009). In crossmatch-negative patients, reproducible positive staining was obtained in 28 of 86 (33%) biopsies taken within 90 days after transplantation and 33 of 96 (34%) biopsies 90 days or after transplantation. Most C4d staining was observed in the portal areas, and no clear correlation was observed between C4d positivity and histological diagnosis. In crossmatch-positive patients, 9 of 11 (82%) biopsies showed positivity for C4d. C4d stained perivenular areas as well as portal areas. Histology of crossmatch-positive patients included acute rejection and cholangitis, but did not include periportal changes that were seen in humoral rejection in ABO-incompatible liver transplantation. In summary, focal C4d deposition was seen in various types of liver allograft injury and had little clinical impact on crossmatch-negative patients, but extensive C4d staining in crossmatch-positive patients may be associated with humoral rejection and poor graft survival.     

Transcriptional Profiles in Urine During Acute Rejection, Bacteriuria, CMV Infection and Stable Graft Function After Renal Transplantation

Acute rejection remains an important cause of renal allograft dysfunction and the need for accurate diagnosis is essential to treat transplant recipients successfully. Molecular markers in urine may serve as a diagnostic tool in acute rejection, but controversy still exists regarding the uniqueness of these biomarkers. We measured mRNA of perforin (PRF), granzyme B (GZMB) and granulysin (GNLY) normalized to cyclophilin B in urine specimens from 24 renal allograft recipients with acute rejection, 12 with bacteriuria, 11 with cytomegalovirus (CMV) infections and 17 controls with stable graft function. Measurements were performed using a real-time polymerase chain reaction assay. mRNA levels (means [95% CI]) for all three markers were significantly higher in recipients with acute rejection compared with controls: PRF (0.23 [0.12–0.42] versus 0.04 [0.02–0.07] P  < 0.001), GZMB (0.14 [0.09–0.23] versus 0.05 [0.03–0.08] P  = 0.003), GNLY (0.24 [0.14–0.41] versus 0.06 [0.03–0.11] P  = 0.001). GZMB and GNLY levels during acute rejection were significantly higher when compared with bacteriuria ( P  = 0.011 and P  = 0.005 respectively), and PRF level during acute rejection was significantly elevated compared with CMV infection ( P  = 0.015). No significant difference was found when comparing marker levels during bacteriuria and CMV infection to controls. Urinary mRNA levels of PRF, GZMB and GNLY are significantly elevated during acute rejection but not during bacteriuria or CMV infections when compared with recipients with stable graft function. The ability to differentiate acute rejection from bacteriuria and CMV infections was only present for some of the markers, that is why careful consideration should be given before applying this technique to clinical practice.     

Decreased humoral antibody episodes of acute renal allograft rejection in recipients expressing the HLA-DQβ1*0202 allele

The present investigation was designed to show the effect of human leukocyte antigen (HLA) class II molecular allelic specificities in the recipient on the induction of humoral antibody rejection, identified by C4d peritubular capillary staining, as well as specific antibody identified by Luminex technology. Major histocompatibility complex (MHC) class II molecules are expressed on dendritic cells, macrophages, and B lymphocytes and they present antigenic peptides to CD4 positive T lymphocytes. Human renal peritubular and glomerular capillaries express class II MHC molecules upon activation. Expression of class II molecules on renal microvascular endothelial cells exposes them to possible interaction with specific circulating antibodies. We hypothesize that HLA-DQβ1*0202 expression in recipients decreases the likelihood of antibody-mediated renal allograft rejection. We found that 80% (=25) of DQ2 positive haplotype recipients failed to induce humoral antibody renal allograft rejection and 20% (n=25) of DQ2 positive haplotype recipients induced humoral antibody renal allograft rejection (p=0.008). By contrast, 48% (n=46) of DQ2 negative haplotype recipients failed to induce a humoral antibody component of renal allograft rejection and 52% (n=46) of DQ2 negative haplotype recipients induced humoral antibody-mediated renal allograft rejection. Our results suggest that recipients who express the DQβ1*0202 allele are less likely to induce a humoral antibody component of acute renal allograft rejection than are those expressing DQ1, DQ3, or DQ4 alleles. DQβ1*0202 allele expression in recipients could possibly be protective against acute humoral allograft rejection and might serve as a future criterion in recipient selection and in appropriate therapy for acute renal rejection episodes.     

Kidney graft recipients with pretransplantation HLA CLASS I antibodies and high soluble CD30 are at high risk for graft loss

In the present study, we investigated whether pretransplantation HLA class I and class II antibodies and pretransplantation levels of soluble CD30 (sCD30) and IgA anti-Fab autoantibodies are predictive of kidney allograft survival. Pretransplantation sera of 504 deceased-donor kidney recipients were tested for IgG HLA class I and class II antibodies, sCD30, and IgA anti-Fab levels using the CTS 4 ELISA kit. Kidney graft survival was estimated by Kaplan-Meier method and multivariate Cox regression. Regardless of the presence of HLA class II antibodies, recipients with high HLA class I reactivity had lower 1-year graft survival than recipients with low reactivity (p < 0.01). Recipients with high sCD30 had lower 5-year graft survival rate than those with low sCD30 (p < 0.01). The sCD30 effect was observed in presensitized and nonsensitized recipients, demonstrated a synergistic effect with HLA class I antibodies (p < 0.001), and appeared to be neutralized in recipients with no HLA class II mismatches. IgA anti-Fab did not influence kidney graft survival. Our results indicate that high pretransplantation sCD30 levels and HLA class I positivity increase the risk of kidney graft loss regardless of other factors. Consequently, such determinations should be routinely performed to estimate recipients' risks of graft rejection before transplantation.     

Analysis of gene polymorphisms in the regulatory region of MCP-1, RANTES,and CCR5 in liver transplant recipients

Chemokines and their receptors play a major role in the inflammatory and immune responses that mediate allograft outcome. The production of some chemokines varies among individuals and these variations may be determined by genetic polymorphisms, most commonly within the regulatory region of the gene. We investigated whether the functional polymorphisms of the chemokines RANTES, MCP-1 and chemokine receptor CCR5 are associated with the incidence of acute rejection and long-term liver graft survival. Two hundred nine liver transplant recipients were genotyped using polymerase chain reaction sequence-specific primers for the following polymorphisms: RANTES-28, MCP-1 -2518, and CCR5-59029. There was no association with any of the three genotypes and the incidence of acute rejection episodes. In addition, no association of RANTES-28, MCP-1 -2518, or CCR5 -59029 variants with long-term liver graft survival was found. In conclusion, variants of RANTES-28, MCP-1 -2518, and CCR5-59029 neither influenced the incidence of acute rejection nor affected long-term allograft survival upon liver transplantation in the context of this analysis.