肾移植术后特异性HLA抗体对急性排斥的影响

目的评价肾移植术后特异性HLA抗体对移植肾急性排斥的影响.方法采用前瞻性队列研究,通过酶联免疫吸附(ELISA)法检测136例肾移植患者围手术期特异性HLA抗体水平,随访观察HLA抗体对急性排斥的影响.结果术后HLA抗体阳性组急性排斥发生率高于阴性组(32.65%vs13.79%,P=0.000).按照HLA-Ⅰ类和Ⅱ类抗体水平分组后,移植肾无排斥存活率依次为HLA-Ⅰ-/Ⅱ-组＞HLA-Ⅰ-/Ⅱ+组＞HLA-Ⅰ+/Ⅱ-组＞HLA-Ⅰ+/Ⅱ+组(P=0.03).结论术后特异性HLA抗体可能是引起移植肾急性排斥的原因之一,HLA-Ⅰ类抗体与急性排斥关系较为密切.     

Posttransplant antidonor antibodies and graft rejection. Evaluation by two-color flow cytometry

The posttransplant production of antibodies against cryopreserved donor cells was studied in 50 consecutive cadaveric kidney graft recipients and in 23 additional patients selected for acute rejection. Serum was obtained twice weekly during the first 3 weeks posttransplant and then monthly for 6 months. IgM and IgG anti-T cell Abs were measured by 2-color flow cytometry. Results were analyzed in conjunction with the patients' demographics, previous sensitization, HLA-matching, posttransplant blood transfusions, incidence of delayed function, rejection episodes, and biopsy results. Antidonor antibodies, predominantly IgG, were detected in 19/48 (40%) of the patients proximate to the time of rejection. In contrast, antibodies were seen in only 2/22 (9%) of nonrejecting patients, and these antibodies were exclusively IgM. Younger patients were more likely to have antibody-mediated rejections. Cytotoxic antibody reactivity against panel cells developed or increased posttransplant in some patients, but it did not correlate with rejection. Previous sensitization and posttransplant transfusions favored the development of posttransplant panel reactivity but not of antidonor antibodies. Most rejections, including those associated with antidonor antibodies, were reversed by antirejection therapy. We conclude that antidonor antibodies are involved in a significant proportion of rejection episodes and that the damage induced does not necessarily culminate with loss of the graft.     

Anti-perlecan antibodies and acute humoral rejection in hypersensitized patients without forbidden HLA specificities after kidney transplantation

BackgroundThe improvement in the definition of serum anti-HLA antibodies (HLA-Abs) profiles after Luminex-assay implementation in transplant patients follow-up is clear. This success has permitted the development of hypersensitized-recipient allocation and donor-paired exchange programs improving the access to transplantation. However, non-HLA Abs have been described in transplanted patients but their effect in hypersensitized transplanted recipients is unclear.MethodsTwenty-seven HLA hypersensitized patients awaiting for kidney transplantation (KT) were studied and 11 of them were followed after KT. The HLA Abs profile was confirmed in serum by Single Antigen Luminex assay and panel reactive of antigens >98% was achieved in all patients. Subsequently, the ability to fix complement by C1q test was also assessed. Serum non-HLA Abs before and 1 month after transplantation were measured in the 11 hypersensitized recipients.Results95.2% of the hypersensitized on waiting list had concomitant serum anti-HLA and non-HLA Abs. The more frequent specificity in non-HLA Abs were found against Glutathione S-transferase theta-1 (GSST-1) (in 62%) and C-terminal fragment of perlecan (LG3) (in 52%). Four out of 11 transplanted patients presented early antibody-mediated rejection (ABMR) confirmed by biopsy and had serum anti-LG3 antibodies, two of them with concomitant anti-anti-angiotensin II type I receptor. Only one patient developed de novo-donor specific HLA antibodies.ConclusionsThe incidence of non-HLA antibodies in patients in the waiting list is largely underestimated. The concomitance anti-HLA and non-HLA Abs in hypersensitized patients is very common and the detection of non-HLA Abs in this population could allow to identify patients with an increased risk of humoral rejection.     

Hypercholesterolemia is associated with increased kidney graft loss caused by chronic rejection in male patients with previous acute rejection

BACKGROUND: Whereas acute rejection is the main risk factor for the occurrence of chronic rejection, mechanisms in addition to the donor-specific immune response probably contribute to late allograft failure. In this study, we investigated the possible role of hypercholesterolemia in the incidence of chronic kidney graft loss. METHODS: By using the actuarial method, we retrospectively analyzed the long-term loss of cadaveric kidney grafts in patients who had a functioning graft at 1 year and had received a transplant and undergone cyclosporin A therapy in our center between 1983 and 1997. RESULTS: As observed previously, patients with acute rejection during the 1st posttransplant year (n=198) had significantly higher actuarial graft loss at 10 years compared with those free of acute rejection (n=244). In patients free of acute rejection at 1 year, hypercholesterolemia (> or =250 mg/dl) had no impact on graft loss at 10 years. On the contrary, in patients with previous acute rejection, those with hypercholesterolemia (n=59) had a higher immunological (36.0% vs. 19.2%; P<0.01) and overall (50.0% vs. 25.3%; P<0.01) graft loss at 10 years compared with patients with serum cholesterol <250 mg/dl (n=139). Among patients with 1st year acute rejection, hypercholesterolemia was associated with a significant increase in graft loss in male but not in female recipients. Multivariate analysis confirmed that hypercholesterolemia was an independent risk factor for chronic graft loss in male patients (P<0.05). CONCLUSION: Hypercholesterolemia is an independent risk factor for kidney graft loss from chronic rejection in male patients with previous acute rejection. Correction of hypercholesterolemia could help to reduce kidney graft loss caused by chronic rejection in this category of patients.     

Pre-transplant donor specific anti-HLA antibody is associated with antibody-mediated rejection,progressive graft dysfunction and patient death

BackgroundThe long term effect of donor specific antibodies (DSA) detected by Luminex Single Antigen Bead (SAB) assay in the absence of a positive complement-dependant cytotoxicity (CDC) crossmatch is unclear.DSA at the time of transplant were determined retrospectively in 258 renal transplant recipients from 2003 to 2007 and their relationship with rejection and graft function prospectively evaluated.After a median of 5.6 years follow-up 9% of patients had antibody mediated rejection (AMR) (DSA 11/37 (30%), DSA-Neg 13/221 (6%), HR 6.6, p < 0.001). Patients with anti-HLA class II (HR 6.1) or both class I + II (HR 10.1) DSA had the greatest risk for AMR. The Mean Fluorescent Intensity (MFI) of the DSA was significantly higher in patients with AMR than those with no rejection (p = 0.006). Moreover, the strength of the antibody was shown to be important, with the risk of AMR significantly greater in those with DSA > 8000 MFI than those with DSA < 8000 MFI (HR 23, p < 0.001).eGFR progressively declined in patients with DSA but was stable in those without DSA (35.7 ± 20.4 mls/min vs 48.5 ± 22.7) and composite patient and graft survival was significantly worse in those with class II (HR 2.9) or both class I + II (HR 3.7) but not class I DSA. Class II DSA alone, or in combination with class I DSA had the strongest association with graft loss and patient death.Patients with DSA not only have increased rates of acute AMR, but also chronic graft dysfunction, graft loss and death. Antibody burden quantified by SAB assay may identify patients at highest immunological risk and therefore influence patient management and improve long-term patient outcome.     

Pretransplant soluble CD30 is a better predictor of posttransplant development of donor-specific antibodies and acute vascular rejection than panel reactive antibodies

BACKGROUND: This study tests a hypothesis that pretransplant concentration of soluble CD30 (sCD30) is a better predictor of posttransplant development of donor-specific HLA antibodies (DSA) and acute vascular rejection (AVR) than panel reactive HLA antibodies (PRA). METHODS: Pretransplant sera from 115 patients were evaluated for their PRA and sCD30 concentrations. All patients received calcineurin-inhibitor based immunosuppressive therapy. Objective measurements for rejection were biopsy-proven AVR episodes within first 6 months of the transplant. Posttransplant sera of patients with or without AVR were tested for the presence of DSA. RESULTS: AVR rate was 16% (18/115). Patients positive for PRA and sCD30 tests were at significantly higher risk for AVR compared to those patients negative for both tests (36% versus 5%, p = 0.01). Among negative PRA patients risk for AR was significantly elevated if they were also tested positive for sCD30 concentrations (21% versus 5%, p = 0.04). Of the 18 patients with AVR, 14 were positive for sCD30, and 13 of them (93%) developed DSA posttransplant (p = 0.001) Nineteen patients without AVR were tested for DSA and sCD30 concentrations. Only two of these 19 patients were positive for sCD30 and DSA. AVR was strongly associated with the patients tested positive for both the tests: DSA and sCD30 (p = 0.00007). Furthermore, patients with AVR are more likely to produce DSA than those without AVR (p = 0.02). CONCLUSION: These data support our hypothesis that patients positive for sCD30 contents are at high risk the development of DSA and AVR posttransplant regardless of their pretransplant PRA.     

Methotrexate in acute persistent humoral rejection: an option for graft rescue

Humoral response emerges as an important component in acute graft rejection and a new challenge to clinicians in posttransplant care. Management of recurrent episodes and persistent activation of the humoral component of the immune system, despite the usual therapeutic approach to rejection, remains unknown. This article describes the successful use of methotrexate as an option for rescuing a graft in this worrisome situation.     

Relevance of MICA antibodies in acute humoral rejection in renal transplant patients

The presence of MICA antibodies was examined in eleven patients diagnosed with AHR. MICA typing was performed in both recipients and donors. Sera were collected sequentially: pre-transplant, at the AHR episode and at follow-up. Sera from 30 patients with functioning graft were also analysed. A stable MICA()008 transfected cell line was used as target to identify MICA antibodies. MICA antibodies were not detected pre-transplant nor post-transplant in patients receiving a compatible graft. MICA antibodies were detected post-transplant AHR in patients receiving an incompatible graft. The persistence of MICA antibodies was associated with chronic graft dysfunction in 3 of 4 patients in this series; although it was not always associated with the graft loss in treated AHR. None of the 30 patients in the control group with long-term functioning grafts showed antibodies to MICA()008. This report provides some insights of the relevance of MICA antibodies in AHR.     

Acute transplant glomerulopathy is associated with antibody-mediated rejection and poor graft outcome

Transplant glomerulopathy (TG) is traditionally considered to be a chronic entity. However, in our practice we observed patients who presented with features of TG as early as 14 days posttransplantation. We investigated the clinicopathological features of these cases. During a 4-year period, all patients with acute rejection were identified. Charts were reviewed to identify patients with antibody-mediated rejection and biopsy features of TG within 6 months posttransplantation. Three patients met the above- mentioned criteria. All of them had diffuse margination of inflammatory cells in peritubular capillaries in the setting of acute renal failure or delayed graft function. Monocyte (CD68-positive) margination in peritubular capillaries was a common feature. All 3 patients had donor-specific antibodies and features suggestive of antibody-mediated rejection. C4d stain in peritubular capillaries was focal and mild or absent in serial biopsies. Occlusive endothelial swelling of glomerular capillary loops (endotheliosis) preceded TG. None of the patients had evidence for other causes of similar glomerular changes in a transplant, such as calcineurin inhibitor toxicity, ischemia, hepatitis C, or immune complex glomerulonephritis. They did not have other biopsy features of chronicity when TG appeared and as it progressed. TG can occur as an acute phenomenon. We propose that endotheliosis is a more accurate and specific precursor of TG than mere glomerulitis. These cases of acute TG may represent a form of antibody-mediated rejection associated with proteinuria and poor response to treatment.     

Delirium is associated with early postoperative cognitive dysfunction

The purpose of this analysis was to determine if postoperative delirium was associated with early postoperative cognitive dysfunction (at 7 days) and long-term postoperative cognitive dysfunction (at 3 months). The International Study of Postoperative Cognitive Dysfunction recruited 1218 subjects ≥ 60 years old undergoing elective, non-cardiac surgery. Postoperatively, subjects were evaluated for delirium using the criteria of the Diagnostic and Statistical Manual. Subjects underwent neuropsychological testing pre-operatively and postoperatively at 7 days ( n  = 1018) and 3 months ( n  = 946). Postoperative cognitive dysfunction was defined as a composite Z -score > 2 across tests or at least two individual test Z -scores > 2. Subjects with delirium were significantly less likely to participate in postoperative testing. Delirium was associated with an increased incidence of early postoperative cognitive dysfunction (adjusted risk ratio 1.6, 95% CI 1.1–2.1), but not long-term postoperative cognitive dysfunction (adjusted risk ratio 1.3, 95% CI 0.6–2.4). Delirium was associated with early postoperative cognitive dysfunction, but the relationship of delirium to long-term postoperative cognitive dysfunction remains unclear.     

The early posttransplant prognosis of acute renal allograft rejection as determined by detection of cytotoxic antibodies to lymphoid B cell lines

We have studied serial samples of pretransplant and posttransplant sera for cytotoxic antibodies to lymphoid B cell lines (LCL) in 45 renal allograft recipients. A total of 48 rejection reactions occurred in 31 patients. A comparison of each patient's most reactive posttransplant serum showed a significantly higher reactivity in the ten patients with early allograft failure when compared with the 21 patients with reversible rejections and the 14 patients who had no rejections. Rejection reactions were easily differentiated by comparing the change in cytotoxic reactivity to LCL of recipients' sera drawn at the time of a rejection episode with the reactivity of their pretransplant sera. In 32 rejections considered non-antibody-associated cytotoxic reactivity of recipients' sera to LCL either decreased or remained essentially unchanged during the rejection. In 16 rejections considered antibody-associated the recipients' sera drawn during the rejection episode showed an increase in cytotoxic reactivity ranging from 40% to 100%. Response to antirejection therapy and three month graft survival had a significant correlation with changes in LCL antibody reactivity during a rejection. Only two of the 32 rejections considered non-antibody-associated failed to reverse compared with eight of the 16 antibody-associated rejections (P less than .001). Graft survival at three months in patients with non-antibody-associated rejections was 90% compared with 27% in the 11 patients who had antibody-associated rejections (P less than .001) Other parameters possibly related to the severity of a rejection reaction or to early allograft prognosis did not differ appreciably between the two types of rejections. This included the time posttransplant to the first rejection episode, the number of patients with multiple rejections in the first three months, and rejections requiring dialysis therapy. Determination of a change in cytotoxic reactivity to LCL during a rejection reaction enables one to predict the response to antirejection therapy and early allograft prognosis. This may ultimately be useful in selecting different types of antirejection therapy for individual patients.     

Pretransplant donor-specific and non-specific immune parameters associated with early acute rejection

BACKGROUND: New immunosuppression protocols have resulted in decreased rates of biopsy-proven acute rejection; however, it is unclear whether recipients without biopsy-proven acute rejection are still at risk for immune complication and chronic allograft dysfunction. The aim of our studies was to determine whether pretransplant immune parameters were associated with posttransplant early acute rejection, unstable creatinine courses, and poor graft outcome. METHODS: Immune parameters, including human leukocyte antigen (HLA) mismatch, HLA-specific antibodies, global CD4+ cellular response as measured by intracellular adenosine triphosphate (iATP) synthesis, and IFN-gamma precursor frequencies to donor or third-party cells as measured by ELISPOT were determined for a total of 126 kidney recipients treated with a protocol, including rapid discontinuation of prednisone. RESULTS: The donor specific pretransplant parameters of HLA class I mismatches (P=0.04) and total HLA mismatches (P=0.04) with the donor as well as the pretransplant HLA-donor specific antibodies (P=0.002) were associated with biopsy-proven acute rejection. Higher pretransplant iATP levels, a donor nonspecific parameter, were found associated with biopsy proven acute rejection (P=0.04). Pretransplant iATP levels were significantly greater for recipients with early unstable creatinine levels (P=0.01). Recipients with a pretransplant iATP value greater than 375 ng/ml were 3.67 times more likely to experience acute rejection (P=0.03). CONCLUSIONS: Pretransplant assessment of donor specific and nonspecific immune parameters may identify recipients who can benefit from closer clinical and immunological surveillance to allow for tailored immunsuppression and selective intervention aimed at optimizing both short and long-term graft outcome.