Donor-reactive HLA antibodies in renal allograft recipients: Considerations, complications, and conundrums (original) (raw)
Related papers
American Journal of Transplantation, 2003
In renal transplantation, a positive cytotoxic crossmatch between donor cells and recipient serum is associated with early rejection or graft loss and was the driving force behind the establishment of HLA laboratories. Initially, crossmatches were performed by relatively insensitive techniques [e.g. leukoagglutination and direct complement-dependent cytotoxicity (CDC) of target cells]. A negative result justified proceeding, while a positive crossmatch was considered a contraindication to renal transplantation. However, the underlying premises driving this practice, namely that (i) all positive reactions were the result of relevant (i.e. HLA) antibodies that could lead to allograft rejection; and (ii) all negative reactions predicted long-term graft survival were known to be incorrect. From its first clinical description, the simple complementdependent assay was recognized as neither sufficiently specific nor sensitive to identify all relevant antibodies. Over time, more sensitive and specific lymphocyte crossmatch assays were developed that effectively decreased the incidence of early antibody-mediated rejection.
Journal of the American Society of Nephrology, 2005
The involvement of immunologic and nonimmunologic events in long-term kidney allograft failure is difficult to assess. The development of HLA antibodies after transplantation is the witness of ongoing reactivity against the transplant, and several studies have suggested that the presence of HLA antibodies correlates with poor graft survival. However, they have not discriminated between donor-specific (DS) and non-specific (NDS) antibodies. A total of 1229 recipients of a kidney graft, transplanted between 1972 and 2002, who had over a 5-yr period a prospective annual screening for HLA antibodies with a combination of ELISA, complement-dependent cytotoxicity, and flow cytometry tests were investigated; in 543 of them, the screening was complete from transplantation to the fifth year postgrafting. Correlations were established between the presence and the specificity of the antibodies and clinical parameters. A total of 5.5% of the patients had DS, 11.3% had NDS, and 83% had no HLA antibodies after transplantation. NDS antibodies appeared earlier (1 to 5 yr posttransplantation) than DS antibodies (5 to 10 yr). In multivariate analysis, HLA-DR matching, pretransplantation immunization, and acute rejection were significantly associated with the development of both DS and NDS antibodies and also of DS versus NDS antibodies. The presence of either DS or NDS antibodies significantly correlated with lower graft survival, poor transplant function, and proteinuria. Screening of HLA antibodies posttransplantation could be a good tool for the follow-up of patients who receive a kidney transplant and allow immunosuppression to be tailored.
portuguese journal of nephrology and hypertension, 2022
Contributorship Statement: n DA: Literature researching, writing original draft-review and editing. n ST, IT and ATN: Review and editing of the manuscript. n AR, MB and SS: Supervision and review of the manuscript. n All authors approved the final version of this manuscript. n INTRODUCTION A growing problem in the field of kidney transplantation is the accumulation of highly sensitized patients on the transplant waiting list, 1,2 which is associated with high mortality rates on dialysis. 3,4 Therefore, extra effort needs to be taken to transplant this group of patients. These patients develop antibodies against nearly all common human leucocyte antigen (HLA) types, present in the donor population, making transplantation of cross-match-negative organs very difficult. Sensitization toward HLA can occur through pregnancies, blood transfusions, and prior transplants. Since the presence of pretransplant donor-specific antibodies (DSAs) is associated with highest risk of immune-mediated rejection, potential donors with HLA antigens that induce a reaction with antibodies produced by the patient (unacceptable mismatches), are usually excluded. Commonly, patients are regarded as highly sensitized when having an HLA antibody profile n ABSTRACT For patients with end stage renal disease, kidney transplant offers significant survival and quality-of-life advantages compared with dialysis. But for patients seeking transplant who are highly sensitized, waiting times have traditionally been long and options limited. We present the case of a 34-year-old hypersensitized female who underwent renal retransplantation. Histocompatibility tests revealed a calculated panel-reactive antibody of 99.53% with multiple antibodies against class I and II human leucocyte antigens and an eplet analysis was performed. The donor's potential unacceptable antigens were redefined and the calculated panel-reactive antibody decreased to 88.38%. After one month the patient received a deceased-donor kidney transplant. Complement dependent cytotoxicity crossmatch was negative; virtual crossmatch and flow cytometry crossmatch with historical serum were positive. High-dose intravenous immunoglobulin and rituximab were added to the thymoglobulin-based induction immunosuppression. Three donor-specific antibodies were detected and plasmapheresis was performed. Renal allograft biopsy revealed no manifestations of rejection. Repeated testing observed a decrease in donor-specific antibodies median fluorescence intensity values. Four months post-transplant, the patient remained with normal graft function without proteinuria. She is receiving a standard maintenance immunosuppression regime with prednisolone, mycophenolate mofetil and tacrolimus. The careful discussion among the transplantation center and histocompatibility laboratory in association with intense immunosuppression and close laboratory monitoring allowed a successful human leukocyte antigen-incompatible deceased donor kidney transplantation in the most critical phase for the occurrence of humoral rejection. It is noteworthy that the new histocompatibility and immunogenetics methodologies provide a more affirmative and comprehensive assessment of mismatch acceptability.
Preexisting Donor-Specific HLA Antibodies Predict Outcome in Kidney Transplantation
Journal of the American Society of Nephrology, 2010
The clinical importance of preexisting HLA antibodies at the time of transplantation, identified by contemporary techniques, is not well understood. We conducted an observational study analyzing the association between preexisting donor-specific HLA antibodies (HLA-DSA) and incidence of acute antibody-mediated rejection (AMR) and survival of patients and grafts among 402 consecutive deceaseddonor kidney transplant recipients. We detected HLA-DSA using Luminex single-antigen assays on the peak reactive and current sera. All patients had a negative lymphocytotoxic cross-match test on the day of transplantation. We found that 8-year graft survival was significantly worse (61%) among patients with preexisting HLA-DSA compared with both sensitized patients without HLA-DSA (93%) and nonsensitized patients (84%). Peak HLA-DSA Luminex mean fluorescence intensity (MFI) predicted AMR better than current HLA-DSA MFI (P ϭ 0.028). As MFI of the highest ranked HLA-DSA detected on peak serum increased, graft survival decreased and the relative risk for AMR increased: Patients with MFI Ͼ6000 had Ͼ100-fold higher risk for AMR than patients with MFI Ͻ465 (relative risk 113; 95% confidence interval 31 to 414). The presence of HLA-DSA did not associate with patient survival. In conclusion, the risk for both AMR and graft loss directly correlates with peak HLA-DSA strength. Quantification of HLA antibodies allows stratification of immunologic risk, which should help guide selection of acceptable grafts for sensitized patients.
Clinical implications of anti-HLA antibodies testing in kidney transplantation
portuguese journal of nephrology and hypertension, 2018
Alloantibodies against donor human leukocyte antigens (HLA), termed as donor -specific antibodies (DSA), are one of the most important factors for both early and late kidney allograft dysfunction. In the past, these antibodies were mainly detected through cell -based crossmatch tests. Recently, new techniques such as solid phase immunoassays (SPI) have revealed these antibodies in patient sera with a high degree of detail, previously unimaginable. They have allowed us to accurately determine recipients’ allosensitization status, improve pre-transplant risk assessment with a potential donor and post -transplant alloimmune monitoring. However, the high sensitivity of these new assays has also created areas of uncertainty about their clinical impact. In the pre -transplant setting, the presence of preformed DSA has been associated with an increased risk of antibody -mediated rejection (AMR) and subsequent allograft loss. Nevertheless, several studies have shown that not all DSA are del...
HLA class I donor-specific triplet antibodies detected after renal transplantation
Transplantation Proceedings, 2004
The purpose of this study was to investigate whether IgG, non-donor-specific anti-HLA class I antibodies (HLAabI) detected after renal transplantation recognize immunogenic amino acid triplets expressed on the foreign graft. In addition, we sought to evaluate the effect of these antibodies as well as other posttransplant HLAabI on graft outcome. Posttransplant sera from 264 renal recipients were tested for the presence of IgG HLAabI and HLA class II-specific alloantibodies (HLAabII) by ELISA. The HLAMatchmaker computer algorithm was used to define the HLA class I non-donor-specific antibodies, which seem to recognize immunogenic amino acid triplets. Donor-specific triplet antibodies (DSTRab) were detected in 16 of 22 (72.7%) recipients based on at least one HLA-A orB mismatched antigen with the donor. DSTRab were found either without (n ϭ 7) or with (n ϭ 9) HLA donor-specific antibodies (HLA-DSA). The presence of DSTRab alone in the periphery was associated with acute rejection, whereas the presence of both DSTRab and HLA-DSA was associated with chronic rejection and graft failure.
Nephrology Dialysis Transplantation, 2017
Background. Pre-transplant donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) have been associated with antibody-mediated rejection (AMR) and early kidney allograft loss. Uncertainties remain regarding the general applicability of these findings and the optimal induction therapy in DSA-positive patients. Methods. Pre-transplant sera from 174 patients receiving a crossmatch-negative kidney transplant were retrospectively analysed for DSA using Luminex technology. DSA with meanfluorescence intensity (MFI) values above 500 were considered positive. All recipients received basiliximab induction and tacrolimusbased maintenance immunosuppression. DSA were monitored post-transplantation in patients with pre-transplant DSA. Antibody results were correlated with the incidence of rejection and graft loss. Results. In total, 61/174 patients had pre-transplant DSA. We found a strong correlation between the presence of DSA against class I and II HLA and DSA MFI greater than 10 000. Both DSA patterns independently predicted an increased risk of early AMR (odds ratio 4.24 and 4.75, respectively, P < 0.05). The risk for AMR in patients with intermediate MFI (3000-10 000) gradually increased with increasing MFI but group sizes were too small to allow for final conclusions. The risk for AMR was comparable to nonsensitized patients in patients with only class I or II HLA-DSA or MFI below 3000. 5-year allograft survival was lowest in patients with simultaneous presence of class I and II HLA-DSA and MFI above 10 000 (45%) but was comparable between patients with only HLA class I or II or no DSA (90.0, 90.0 and 88.1%, respectively). AMR was the only independent predictor of graft loss. Undetectable DSA 14 days posttransplant predicted excellent long-term outcome. Conclusion. The favourable outcome in the majority of DSApositive patients despite non-depleting antibody induction and the poor outcome in patients with class I and II HLA-DSA and high DSA strength call for a differentiated therapeutic approach in this patient population.