Donor-specific Anti-human Leukocyte Antigen Antibodies Research Articles

A paired kidney analysis on the impact of pre-transplant anti-HLA antibodies on graft survival.

Pre-transplant donor-specific anti-human leucocyte antigen (HLA) antibodies (DSAs) are associated with impaired kidney graft survival while the clinical relevance of non-donor-specific anti-HLA antibodies (nDSAs) is more controversial. The aim of the present paired kidney graft study was to compare the clinical relevance of DSAs and nDSAs. To eliminate donor and era-dependent factors, a post hoc paired kidney graft analysis was performed as part of a Dutch multicentre study evaluating all transplantations between 1995 and 2005 with available pre-transplant serum samples. Anti-HLA antibodies were detected with a Luminex single-antigen bead assay. Among 3237 deceased donor transplantations, we identified 115 recipient pairs receiving a kidney from the same donor with one recipient being DSA positive and the other without anti-HLA antibodies. Patients with pre-transplant DSAs had a significantly lower 10-year death-censored graft survival (55% versus 82%, P=0.0001). We identified 192 pairs with one recipient as nDSA positive (against Class I and/or II) and the other without anti-HLA antibodies. For the patients with nDSAs against either Class I or II, graft survival did not significantly differ compared with patients without anti-HLA antibodies (74% versus 77%, P=0.79). Only in patients with both nDSAs Class I and II was there a trend towards a lower graft survival (58%, P=0.06). Lastly, in a small group of 42 recipient pairs, 10-year graft survival in recipients with DSAs was 49% compared with 68% in recipients with nDSAs (P=0.11). This paired kidney analysis confirms that the presence of pre-transplant DSAs in deceased donor transplantations is a risk marker for graft loss, whereas nDSAs in general are not associated with a lower graft survival. Subgroup analysis indicated that only in broadly sensitized patients with nDSAs against Class I and II, nDSAs may be a risk marker for graft loss in the long term.

Histological picture of antibody-mediated rejection without donor-specific anti-HLA antibodies: Clinical presentation and implications for outcome.

In this cohort study (n=935 transplantations), we investigated the phenotype and risk of graft failure in patients with histological criteria for antibody-mediated rejection (ABMR) in the absence of circulating donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA), and compared this to patients with definite ABMR and HLA-DSA-positivity. The histological picture did not differ between HLA-DSA-positive (n=85) and HLA-DSA-negative (n=123) cases of ABMR histology, apart from increased complement split product 4d (C4d) deposition in the peritubular capillaries in HLA-DSA-positive cases. Histology of ABMR without HLA-DSA was more transient than DSA-positive ABMR, and patients with ABMR histology without HLA-DSA had graft survival superior to that of HLA-DSA-positive patients, independent of concomitant T cell-mediated rejection (38.2%) or borderline changes (17.9%). Multivariate analysis showed that the risk of graft failure was not higher in patients with histological picture of ABMR (ABMRh ) in the absence of HLA-DSA, compared to patients without ABMRh . Despite an association between C4d deposition and HLA-DSA-positivity, using C4d deposition as alternative for the DSA criterion in the diagnosis of ABMR, as proposed in Banff 2017, did not contribute to the prognosis of graft function and graft failure. We concluded that biopsies with ABMRh but without detectable HLA-DSA represent a distinct, often transient phenotype with superior allograft survival.

Preformed C1q-binding Donor-specific Anti-HLA Antibodies and Graft Function After Kidney Transplantation

BackgroundDe novo complement-binding donor-specific anti-human leukocyte antigen antibodies (DSAs) are reportedly associated with an increased risk of kidney graft failure, but there is little information on preformed complement-binding DSAs. This study investigated the correlation between preformed C1q-binding DSAs and medium-term outcomes in kidney transplantation (KT). MethodsWe retrospectively studied 44 pretransplant DSA-positive patients, including 36 patients who underwent KT between April 2010 and October 2016. There were 17 patients with C1q-binding DSAs and 27 patients without C1q-binding DSAs. Clinical variables were examined in the 2 groups. ResultsPatients with C1q-binding DSAs had significantly higher blood transfusion history (53.0% vs 18.6%; P = .0174), complement-dependent cytotoxicity crossmatch (CDC-XM)-positivity (29.4% vs 0%; P = .0012), and DSA median fluorescence intensity (MFI) (10,974 vs 2764; P = .0009). Among patients who were not excluded for CDC-XM-positivity and underwent KT, there was no significant difference in cumulative biopsy-proven acute rejection rate (32.5% vs 33.5%; P = .8354), cumulative graft survival, and 3-month and 12-month protocol biopsy results between patients with and without C1q-binding DSAs. Although patients with C1q-binding DSAs showed a higher incidence of delayed graft function (54.6% vs 20.0%; P = .0419), multivariate logistic regression showed that DSA MFI (P = .0124), but not C1q-binding DSAs (P = .2377), was an independent risk factor for delayed graft function. ConclusionsIn patients with CDC-XM-negativity, preformed C1q-binding DSAs were not associated with incidence of antibody-mediated rejection and medium-term graft survival after KT. C1q-binding DSAs were highly correlated with DSA MFI and CDC-XM-positivity.

Role of C1q-binding anti-HLA antibodies as a predictor of lung allograft outcome.

Presence of anti-human leukocyte antigen donor-specific antibodies (DSAs) is associated with poor outcome after lung transplantation. Currently, DSAs are detected using the Luminex technique, which may be overly sensitive. The new C1q assay allows for the exclusive detection of complement (C1q)-binding antibodies, involved in antibody-mediated rejection. We investigated whether early detection of complement-binding DSAs is associated with chronic lung allograft dysfunction (CLAD) and survival.From 2009 to 2012, lung transplant recipients from three transplantation centres were screened for the presence of DSA and their complement-binding capacity during the 6-12 months post-transplantation in a stable condition.The analysis included 168 patients. The 3-year rates of freedom from CLAD and graft survival were lower for patients with complement-binding DSAs (33.6% and 53.7%, respectively), as compared with patients with non-complement-binding DSAs (61.9% and 77.4%, respectively) and patients without DSA (70% and 84.9%, respectively) (p<0.001 and p=0.001, respectively). Detection of complement-binding DSA was associated with a risk of graft loss that was nearly tripled after adjustment for clinical, functional, histological and immunological factors (hazard ratio 2.98, 95% CI 1.33-6.66; p=0.008).Assessment of the C1q-binding capacity of DSA appears to be useful in identifying stable lung transplant recipients at high risk of lung allograft loss.

B-Cell Depletion with Rituximab Exacerbates Anti-Donor CD4+ T-Cell Responses in Patients with Donor-Specific Anti-Human Leukocyte Antigen Antibodies

B-Cell Depletion with Rituximab Exacerbates Anti-Donor CD4+ T-Cell Responses in Patients with Donor-Specific Anti-Human Leukocyte Antigen Antibodies

The disappointing contribution of anti-human leukocyte antigen donor-specific antibodies characteristics for predicting allograft loss.

The disappointing contribution of anti-human leukocyte antigen donor-specific antibodies characteristics for predicting allograft loss.

Complement-activating donor-specific anti-HLA antibodies and solid organ transplant survival: A systematic review and meta-analysis.

BackgroundAnti-human leukocyte antigen donor-specific antibodies (anti-HLA DSAs) are recognized as a major barrier to patients’ access to organ transplantation and the major cause of graft failure. The capacity of circulating anti-HLA DSAs to activate complement has been suggested as a potential biomarker for optimizing graft allocation and improving the rate of successful transplantations.Methods and findingsTo address the clinical relevance of complement-activating anti-HLA DSAs across all solid organ transplant patients, we performed a meta-analysis of their association with transplant outcome through a systematic review, from inception to January 31, 2018. The primary outcome was allograft loss, and the secondary outcome was allograft rejection. A comprehensive search strategy was conducted through several databases (Medline, Embase, Cochrane, and Scopus).A total of 5,861 eligible citations were identified. A total of 37 studies were included in the meta-analysis. Studies reported on 7,936 patients, including kidney (n = 5,991), liver (n = 1,459), heart (n = 370), and lung recipients (n = 116). Solid organ transplant recipients with circulating complement-activating anti-HLA DSAs experienced an increased risk of allograft loss (pooled HR 3.09; 95% CI 2.55–3.74, P = 0.001; I2 = 29.3%), and allograft rejection (pooled HR 3.75; 95% CI: 2.05–6.87, P = 0.001; I2 = 69.8%) compared to patients without complement-activating anti-HLA DSAs. The association between circulating complement-activating anti-HLA DSAs and allograft failure was consistent across all subgroups and sensitivity analyses. Limitations of the study are the observational and retrospective design of almost all included studies, the higher proportion of kidney recipients compared to other solid organ transplant recipients, and the inclusion of fewer studies investigating allograft rejection.ConclusionsIn this study, we found that circulating complement-activating anti-HLA DSAs had a significant deleterious impact on solid organ transplant survival and risk of rejection. The detection of complement-activating anti-HLA DSAs may add value at an individual patient level for noninvasive biomarker-guided risk stratification.Trial registrationNational Clinical Trial protocol ID: NCT03438058.

Comparison of Sensitivity of Immunocomplex Capture Fluorescence Analysis for Detecting Donor-specific Anti-HLA Class II Antibodies in Kidney Transplant Patients

BackgroundImmunocomplex capture fluorescence analysis (ICFA) detects donor-specific antihuman leukocyte antigen (HLA) antibodies (DSA), but the detection sensitivity of HLA class II antibodies using conventional ICFA is as low as 57%. The aim of the study was to improve the detection sensitivity of HLA class II antibodies by ICFA, and compare the ICFA results with the Luminex single-antigen bead test. MethodsSix DSA-negative kidney transplant donors and recipient pairs and 10 HLA class II DSA-positive pairs were included in the study. The detection sensitivity of modified ICFA was compared with conventional ICFA, and the ICFA results were compared with the Luminex single-antigen bead test. ResultsThe index value of modified ICFA was higher than that of conventional ICFA. The cutoff value of conventional ICFA was 30,686 (MFI), which was improved to 19,405 using modified ICFA. Regarding the HLA-DQ antibody, 5 samples found to be positive by Luminex single-antigen bead testing were all negative using modified ICFA. The reason for this discrepancy could be related to: (1) the difference in detection sensitivity; (2) the difference in HLA antigen surface expression between naive lymphocytes and synthetic beads; or (3) the structure of synthetic HLA DQ antigen on the Luminex single-antigen beads. ConclusionThe index value of the modified ICFA was higher than that of conventional ICFA, and the detection sensitivity of HLA class II antibodies was improved by modified ICFA. Further assessment is necessary to clarify the reasons for divergence between ICFA and Luminex single-antigen bead test results.

Clinical and histological evolution after de novo donor-specific anti-human leukocyte antigen antibodies: a single centre retrospective study

BackgroundDonor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) can be preformed or de novo (dn). Strategies to manage preformed DSA are well described, but data on the management and outcomes of dnDSA are lacking.MethodsWe performed a retrospective analysis of data from a single centre of the management and outcomes of 22 patients in whom a dnDSA was identified with contemporary and follow up biopsies.ResultsEvolution from baseline to follow up revealed a statistically significant loss of kidney function (estimated glomerular filtration rate: 45.9 ± 16.7 versus 37.4 ± 13.8 ml/min/1.73 m2; p = 0.005) and increase in the proportion of patients with transplant glomerulopathy (percentage with cg lesion ≥1: 27.2% vs. 45.4%; p = 0.04). Nine patients were not treated at the time of dnDSA identification, and 13 patients received various drug combinations (e.g., corticosteroids, plasmapheresis, thymoglobulins and/or rituximab). No significant pathological changes were observed for the various treatment combinations.ConclusionOur retrospective analysis of a small sample suggests that dnDSA should be considered a risk factor for the loss of kidney function independent of the baseline biopsy, and multidisciplinary evaluations of the transplant patient are a necessary requirement. Further confirmation in a multicentre prospective trial is required.

Renal transplant outcomes and de novo donor-specific anti-human leukocyte antigen antibodies: a systematic review.

Pre-transplant donor-specific anti-human leukocyte antigen antibodies (DSAs) are known risk factors for acute rejection and reduced graft survival after kidney transplantation. DSAs may also develop de novo DSAs (dnDSAs) after transplantation but the clinical implications of these antibodies remain uncertain. We undertook a systematic review of observational studies that examined the association between dnDSAs and graft and patient outcomes (through August 2017) with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system of reporting used to assess the quality of evidence available. Thirty-six studies involving 10535 transplant recipients were eligible. There was moderate quality evidence that transplant recipients who developed dnDSAs had increased risks of acute antibody-mediated rejection (AMR) [relative risk (RR) 9.66; 95% confidence interval (CI) 6.79-13.73, 16 studies, n = 4174]. For all other outcomes, the evidence was low to very low due to moderate-high heterogeneity and low study quality (acute cellular rejection, RR 2.92; 95% CI 2.16-3.94, 22 studies, n = 4991, low-quality evidence; chronic AMR and transplant glomerulopathy RR 6.78; 95% CI 4.31-10.66, 3 studies, n = 1617, very low-quality evidence; and graft loss RR 4.95; 95% CI 3.81-6.43, 19 studies, n = 5473, low-quality evidence). Meta-regression indicated that deceased kidney donation (R2 = 1.00, P < 0.001) and region of study conduction (R2 = 0.50, P = 0.005) modified associations between dnDSAs and outcomes. dnDSAs are associated with increased risks of adverse graft and patient outcomes after kidney transplantation, but estimation uncertainty of the augmented risks exist due to limitations such as heterogeneity within the existing literature. Therapeutic interventions targeted to eliminate or prevent these antibodies evaluated in randomized controlled trials are needed to establish whether dnDSAs are causal to transplantation outcomes.

Clinical utility of C3d binding donor-specific anti-human leukocyte antigen antibody detection by single antigen beads after kidney transplantation-a retrospective study.

Development of donor-specific antibodies (DSA) after renal transplantation is known to be associated with worse graft survival, yet determining which specificities in which recipients are the most deleterious remains under investigation. This study evaluated the relationship of the complement binding capacity of post-transplant de novo anti-human leukocyte antigen (HLA) antibodies with subsequent clinical outcome. Stored sera from 265 recipients previously identified as having de novo DSA were retested for DSA and their C3d binding capacity using Luminex-based solid-phase assays. Most recipients had anti-HLA class II-reactive DSA (class I = 12.5%, class II = 68.7%, class I and class II = 18.9%). The recipients that had C3d binding DSA (67.5%) had a significantly higher incidence of antibody-mediated rejection and any rejection. They also had significantly lower kidney survival, with the lowest survival in those that had both anti-HLA class I and class II C3d binding DSA. Concurrent biopsy comparison revealed a 96.2% positive predictive value and 47.4% negative predictive value for C4d peritubular capillary (Ptc) deposition. Anti-HLA class I and class II C3d binding DSA carried a twofold and 1.5-fold increased risk of kidney loss, respectively, in multivariate analysis.

Impact of Preformed Donor-Specific Anti-Human Leukocyte Antigen Antibody C1q-Binding Ability on Kidney Allograft Outcome.

The consolidation of single antigen beads (SAB-panIgG) assay in the detection of preformed anti-human leukocyte antigen (HLA) antibodies has improved transplantation success. However, its high sensitivity has limited the allograft allocation for sensitized patients, increasing their waiting time. A modification of the standard SAB-panIgG assay allows the detection of that subset of antibodies capable of binding C1q (SAB-C1q assay). However, the clinical usefulness of SAB-C1q assay for determining the unacceptable mismatches is under discussion. We retrospectively analyzed the impact of preformed donor-specific anti-HLA antibodies (DSA) according to the C1q-binding ability on allograft outcome, examining 389 single-kidney transplanted patients from deceased donors. Recipients with preformed C1q-binding DSA showed the lowest allograft survival up to 7 years (40.7%) compared to patients with preformed non-C1q-binding DSA (73.4%; p = 0.001) and without DSA (79.1%; p < 0.001). Allograft survival rate was similar between patients with preformed non-C1q-binding DSA and patients without preformed DSA (p = 0.403). Interestingly, among the high-mean fluorescence intensity DSA (≥10,000) population (n = 46), those patients whose DSA were further capable of binding C1q showed a poorer allograft outcome (38.4 vs. 68.9%; p = 0.041). Moreover, in our multivariate predictive model for assessing the risk of allograft loss, the presence of C1q-binding DSA (HR 4.012; CI 95% 2.326–6.919; p < 0.001) but not of non-C1q-binding DSA (HR 1.389; CI 95% 0.784–2.461; p = 0.260) remained an independent predictor after stratifying the DSA population according to the C1q-binding ability and adjusting the model for other pre-transplantation predictive factors including donor age, cold-ischemia time, and HLA-DR mismatches. In conclusion, the unacceptable mismatch definition according to the SAB-C1q assay would improve the risk stratification of allograft loss and increase the limited allograft allocation of highly sensitized patients, shortening their waiting time.

Characteristics of Donor-Specific Antibodies Associated With Antibody-Mediated Rejection in Lung Transplantation.

Although donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) are frequently found in recipients after lung transplantation (LT), the characteristics of DSA which influence antibody-mediated rejection (AMR) in LT are not fully defined. We retrospectively analyzed 206 consecutive LT patients of our center (2010–2013). DSAs were detected by using luminex single antigen beads assay and mean fluorescence intensity was assessed. Within the study population, 105 patients had positive DSA. Patients with and without AMR (AMRPos, n = 22, and AMRNeg, n = 83, respectively) were compared. AMRPos patients had significantly greater frequencies of anti-HLA DQ DSA (DQ DSA) than AMRNeg patients (95 vs 58%, respectively, p < 0.0001). Compared to AMRNeg patients, AMRPos patients had higher DQ DSA sum MFI [7,332 (2,067–10,213) vs 681 (0–1,887), p < 0.0001]. DQ DSA when associated with AMR, had more frequent graft loss and chronic lung allograft dysfunction (CLAD). These data suggest (i) that DSA characteristics clearly differ between AMRPos and AMRNeg patients and (ii) the deleterious impact of DQ DSA on clinical outcome.

Role of de novo donor-specific anti-HLA antibodies in kidney graft failure: A case-control study.

The role of de novo donor-specific anti-human leukocyte antigen (anti-HLA) antibodies (dnDSA) within the pathways leading to graft failure remains not fully understood. We investigated 56 patients who were transplanted between 2002 and 2014 with kidney graft failure (cases), for a possible association of development of dnDSA with graft failure. The 56 patients with failed transplants were matched with 56 patients with a functioning graft at present for the variables deceased or living donor, transplant number, transplant year, recipient age and gender, donor age and gender, dialysis vintage time, transplant induction therapy. All patients had at least one serum collected 1 year before failure (in cases) or end of follow-up (in controls). Cases and controls were very well-matched in several baseline characteristics. Post-transplant anti-HLA antibodies were found in 84% of cases and only 36% of controls (P < .001), with 54% of cases and 16% of controls (P < .001) having dnDSA at time of detection. Chronic active antibody-mediated rejection was significantly more common (P < .001) in patients with dnDSA (61% vs 12%), in 53 (47%) patients that had at least one graft biopsy performed during follow-up. dnDSA was a significant risk factor (odds ratio [OR] = 6.06; P = .003) for graft failure in a multivariable conditional logistic regression model. dnDSA as a time-dependent variable, was also an independent predictor [hazard ratio (HR) = 2.46; P = .002] of graft failure in a multivariable Cox regression analysis. In both statistical approaches, only dnDSA-II (OR = 11.90; P = .006) (HR = 2.30; P = .014) was significantly associated with graft failure. Post-transplant dnDSA was clearly associated with graft loss, particularly if against HLA class II antigens. dnDSA detection should be a tool for post-transplant monitoring of kidney graft recipients, allowing for the identification of those with a higher risk of graft failure.

The Impact of Donor-Specific Anti-Human Leukocyte Antigen (HLA) Antibody Rebound on the Risk of Antibody Mediated Rejection in Sensitized Kidney Transplant Recipients.

BACKGROUND Donor-specific anti-HLA antibody (DSA) detected on Luminex-based single antigen assay (LSA) has become the subject of desensitization based upon the results of previous studies. We retrospectively investigated the impact of preoperative DSA on the incidence of antibody mediated rejection (AMR) in patients desensitized using a protocol based on rituximab and rabbit antithymocyte globulin (rATG). MATERIAL AND METHODS Nine patients (Group 1, 9/327, 2.8%) were complement dependent cytotoxicity crossmatch (CDC-XM) positive and underwent desensitization with rituximab (375 mg/m²), intravenous immunoglobulin (IVIG; 400 mg/kg), plasmapheresis, and rATG. Twenty-two patients (Group 2, 22/327, 6.7%) were CDC-XM negative but DSA positive on LSA and had received desensitization with rituximab and rATG, while 55 patients (Group 3, 55/327, 16.8%) were CDC-XM and DSA negative with a calculated panel reactive antibody (cPRA) ≥50%. Another 241 patients (Group 4, 241/327, 73.7%) were CDC-XM and DSA negative with a cPRA <50%. RESULTS Recipients with DSA (Group 2) experienced more AMR than other groups (p<0.01). More de novo DSAs also developed in Group 2 (p<0.001). The mean fluorescence intensity (MFI) of DSA of patients with AMR tended to rebound (p=0.01). CONCLUSIONS Patients who were CDC-XM negative but DSA positive status were at a higher risk of developing AMR even though they had received desensitization with rATG and rituximab. A more intense desensitization protocol is needed for these recipients. Patients with MFI rebound of DSA should be carefully monitored for the risk of AMR.

Characteristics of donor-specific anti-HLA antibodies and outcome in renal transplant patients treated with a standardized induction regimen.

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. Pre-transplant sera from 174 patients receiving a crossmatch-negative kidney transplant were retrospectively analysed for DSA using Luminex technology. DSA with mean-fluorescence intensity (MFI) values above 500 were considered positive. All recipients received basiliximab induction and tacrolimus-based 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. 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 post-transplant predicted excellent long-term outcome. . The favourable outcome in the majority of DSA-positive 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.

Impact of Antibodies That React With Liver Tissue and Donor-Specific Anti-HLA Antibodies in Pediatric Idiopathic Posttransplantation Hepatitis.

BackgroundThe cause of late graft dysfunction has not been elucidated. Although an antibody-mediated reaction is suspected as a potential mechanism, the target antigens have not been clarified.MethodsTo clarify the etiology of idiopathic posttransplantation hepatitis (IPTH), we simultaneously examined the presence of antibodies that react with liver tissue (ARLT) by means of indirect immunofluorescence staining, as well as the presence of donor-specific anti-human leukocyte antigen antibodies (HLA-DSA). A subanalysis of the IPTH group was also performed. Within the IPTH group, the correlation between ARLT titer and clinical data were analyzed.ResultsIn the sera of patients with IPTH (30 patients), ARLT were found at a significantly higher frequency than in patients without IPTH (42 patients; P < 0.001). Moreover, the ARLT titer appeared to be correlated with the severity of hepatitis or hepatic injury. In contrast, the frequency of HLA-DSA was significantly lower in patients with IPTH than in patients without IPTH (P = 0.001).ConclusionOur findings indicate that ARLT, and not HLA-DSA, profoundly influence the etiology of IPTH.

De Novo Donor-Specific Anti–Human Leukocyte Antigen Antibody Detection in Long-Term Adult Liver Transplantation

IntroductionInformation about the consequences of de novo donor-specific anti-human leukocyte antigen (DSA) antibody development in the long term after adult liver transplantation (LT) is scarce. We conducted a cross-sectional study in LT patients with a follow-up of at least 6 years. MethodsA total of 28 adult LT patients were included, with a median follow-up of 77 months (range, 63 to 96) and without preformed anti- human leukocyte antigen (HLA) antibodies prior to LT. The anti-HLA identification was performed with LABScreen Single Antigen, whereas the ability to fix the complement was demonstrated with C1q test (One Lambda). In both assays, a value >3.500 mean fluorescence intensity (MFI) was considered positive. The anti-HLA antibody specificities were compared with donor HLA antigens to confirm them as DSA. Hepatic fibrosis was assessed by transient elastography. ResultsIn 5 patients (17.8%), de novo DSA were detected, all them against DQ locus. In all of these cases (100%) the complement fixation was confirmed by C1q binding. The grade of hepatic fibrosis in de novo DSA patients was significantly higher compared with No-DSA patients (13.2 ± 9.2 KPa vs 7.3 ± 3.7 KPa; P = .02). It is noteworthy that in both groups of patients the levels of liver function tests (LFT) at the time of the study were normal or near the normal range with no difference between patients with or without de novo DSA. ConclusionsOur preliminary results are consistent with those previously demonstrated in pediatric LT, where de novo DSA production and humoral response could contribute to the liver fibrosis observed in the long term after LT in pediatric patients with normal or near-normal LFT.

Lung intragraft donor-specific antibodies as a risk factor for graft loss

The effect of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) on graft survival is recognized in lung transplantation, but not all serum DSAs appear to be harmful. We wondered whether in situ DSA detection from graft biopsy specimens could help in identifying lung transplant recipients (LTRs) at higher risk for graft loss. Class I and II HLA antibody single-antigen flow bead assays were performed in 53 LTRs to identify immunoglobulin G DSA in biopsy specimen eluates and in sera and to evaluate C1q binding ability of DSA in sera. Intragraft DSAs (gDSAs) were correlated with serum DSAs (sDSAs), clinical and histologic data, and graft survival. Twenty-eight (52.8%) LTRs had sDSAs, 12 (22.6%) had C1q-positive sDSAs, and 11 (20.8%) had gDSAs. Fifty sDSAs were found, among which 15 (30%) were C1q-positive and 14 (28%) were found in biopsy specimen eluates. One DSA was detected in the biopsy specimen only. Serum mean fluorescence intensity and biopsy fragment size were higher for sDSAs detected in biopsy specimens (p = 0.003 and p = 0.02, respectively). One-year post-biopsy graft survival was lower for LTRs with gDSAs (p = 0.008 by log-rank test). Presence of gDSA at the time of biopsy constituted a risk factor for graft loss in univariate (odds ratio, 6.67; 95% confidence interval [CI] 1.51-29.47; p = 0.008; hazard risk, 3.44; 95% CI, 1.47-8.01, p = 0.005) and multivariate (odds ratio, 5.85; 95% CI, 1.23-27.68; p = 0.03; hazard risk, 4.51; 95% CI, 1.83-11.13; p = 0001) analyses using logistic regression and a Cox proportional hazard model, respectively. In lung transplantation, gDSA appears to be a valuable biomarker to identify pathogenic DSA and LTRs with a higher risk for graft loss.

Donor-specific anti-human leukocyte antigen antibodies were associated with primary graft failure after unmanipulated haploidentical blood and marrow transplantation: a prospective study with randomly assigned training and validation sets.

BackgroundSmall studies suggest an association of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) with primary graft failure (GF) following haploidentical stem cell transplantation, but primary graft rejection (GR) was not discriminated from primary poor graft function (PGF). In this study, we aimed to determine the association of DSAs with primary GF, including GR and PGF, in patients who underwent unmanipulated haploidentical blood and marrow transplantation.MethodsA total of 345 subjects were prospectively recruited and randomly selected as training group (n = 173) and validation group (n = 172). Patient plasma/serum was screened. For HLA antibody positive samples with a median fluorescent intensity (MFI) >500, DSAs were further tested using a LABScreen Single Antigen Kit (One Lambda).ResultsA total of 342 patients (99.1 %) achieved sustained myeloid engraftment. The median times to neutrophil engraftment and platelet engraftment were 13 days (range, 8–28 days) and 18 days (range, 6–330 days), respectively. The cumulative incidence of primary GF was 6.4 ± 1.3 % and included GR (0.9 ± 0.5 %) and PGF (5.5 ± 1.2 %). Of the 345 cases tested, 39 (11.3 %) were DSA positive. Multivariate models showed that DSAs (MFI ≥ 10,000) were correlated to primary GR (P < 0.001) and that DSAs (MFI ≥ 2000) were strongly associated with primary PGF (P = 0.005). All patients were classified into three groups for analysis. Group A included cases that were DSA negative and those with a DSA MFI <2000 (n = 316), group B included cases with a 2000 ≤ MFI < 10,000 (n = 19), and group C included cases with a MFI ≥10,000 (n = 10). The DSAs were associated with an increased incidence of the primary GF (3.2 vs. 31.6 vs. 60 %, for groups A, B, and C, respectively, P < 0.001), transplant-related mortality (TRM) rate (17.2 vs. 14.7 vs. 33.3 %, for groups A, B, and C, respectively, P = 0.022), and inferior overall survival (OS, 77.3 vs. 85.3 vs. 44.4 %, for groups A, B, and C, respectively, P = 0.015). The primary GF was independently associated with a higher incidence of TRM (P < 0.001), inferior disease-free survival (P < 0.001), and OS (P < 0.001).ConclusionsThe findings confirmed the effect of DSAs on primary GF, including GR and PGF, and survival. Our results suggest incorporating DSAs in the algorithm for haploidentical donor selection.