Donor-specific Antibodies Group Research Articles

Effect of donor-specific antibodies and panel reactive antibodies in living donor liver transplant recipients.

PurposePreformed circulating donor-specific antibodies (DSAs) immunologically challenge vascular endothelium and the bile duct. However, the liver is an immune-tolerant organ and can avoid immunological challenges. This study was undertaken to analyze the effects of DSAs after adult living donor liver transplantation (LDLT).MethodsWe retrospectively reviewed 219 LDLT patients' records treated at our center.ResultsOf the 219 patients, 32 (14.6%) were DSA (+) and 187 (85.4%) were DSA (-). Class I DSAs were present in 18 patients, class II in seven patients, and both in seven patients. Seven patients (3.2%) showed DSA to HLA-A, four (1.8%) to HLA-B, seven (3.2%) to HLA-DR, and 14 (6.4%) to two or more HLAs. More DSAs were observed in female recipients than male recipients in the DSA (+) group. The DSA (+) group showed significantly higher levels of class I and II panel reactive antibody (PRA) than did the DSA (-) group. No significant intergroup differences were found between incidences of primary nonfunction, acute rejection, vascular complication, or biliary complication. There were no significant differences in graft survival rates between the two groups. However, the recipients with multiple DSAs tended to have more acute rejection episodes and events of biliary stricture and lower graft survival rates than did patients in the DSA (-) group.ConclusionIn LDLT, the presence of multiple DSAs and high PRA seemed to be associated with poor graft outcomes, although our results did not reach statistical significance. Large cohort studies are necessary to clarify the impact of DSA and PRA in LDLT.

Donor Specific Anti-HLA Antibodies Towards HLA Cw and HLA DP Should Be Considered as Pathogenic in Kidney Transplantation.

It is widely accepted that HLA donor-specific antibodies (DSA) have a deleterious impact in kidney transplantation. However, non-classical preformed anti-HLA Cw and anti-HLA DP DSA are not considered in organ allocation policies and their clinical relevance is uncertain. Here we wondered whether anti-Cw/DP DSA should be considered as pathogenic through a retrospective study, comparing 48 patients transplanted with isolated preformed anti-Cw/DP DSA (Anti-Cw/DP DSA group) with (i) 104 matched HLA-sensitized kidney transplant recipients (KTR) with no DSA at D0 (No DSA group)and with (ii) 58 KTR with at least one identified preformed DSA other than anti HLA-Cw or HLA-DP antibodies (anti-A, -B, -DR, -DQ group or Classical DSA group). A positive flow cytometry XM in the anti Cw/DP DSA group was more frequent than in the No DSA group and as frequent as in the Classical DSA group. Two years after transplantation, graft survival and renal function were significantly lower in the anti-Cw/DP group than in the No DSA group, but not different from the Classical DSA group. Similarly, the biopsy-proven acute rejection-free survival was worse in the anti-Cw/DP and Classical DSA groups (with more inflammatory microcirculations lesions g+ptc) compared to No DSA group. Taken together, our results suggest that preformed anti-Cw and anti-DP DSA can exert the same deleterious effects that classical anti-A, -B, -DR, -DQ DSA. This might justify the systematic typing of HLA Cw and DP donor antigens and the detection of anti-Cw and anti-DP recipient antibodies as well as their inclusion in the kidney allocation algorithms.

High Prevalence of Post Transplant Donor Specific HLA-DQ Antibody in Live Related Renal Transplantation. Is It Time To Extend Typing To HLA-DQ in Renal Transplantation.

PURPOSE: The aim of this study was to determine the HLA classes of post transplant donor specific antibody (DSA) in live related renal transplant recipient. PATIENT AND METHODS: HLA antibodies were analyzed in 212 renal transplant recipient 1-24 month post transplant. Samples were collected in routine follow-up in out patient. All recipients were HLA antibody negative by flow cross match and Luminex pre-transplant. All rejections were confirmed by biopsy. Antibody screen and single antigen screen was undertaken by Luminex. Outcomes were compared between recipient with DSA and No DSA for rejection, HLA match, Serum Creatinine and Graft Survival. RESULTS: of the 212 recipient screened for HLA antibodies 20 (9.4%) were positive for Class I and 34 (16%) for Class II. DSA were found in 31 (14.6%). DSA developed in 2 (7%) of the recipient within 3 months, in 4 (14%) within 6 and 25 (79%) after 6 months. DSA against Class I in 10 (4.7%) and Class II in 27 (13%). Within Class I, against HLA A in 9 (90%) and HLA B 1 (10%), while within Class II, HLA-DR in 11 (41%), HLA-DQ in 15 (55%) and HLA-DR + HLA-DQ in 1 (3.7%). Rejections were diagnosed in 16 (52%) of DSA group vs 48 (26%) in No DSA group (p< 0.05). The mean HLA match was 3.39 ± 0.9 in DSA vs 3.67 ± 1.2 in Non DSA (p 0.231). The mean S. Creatinine was 2.42 ± 1.4 mg/dl in DSA vs 1.6 ± 0.8 in Non DSA (p 0.001). Graft survival in DSA group at 1, 3, 5 years was 97%, 90% and 57% vs 93%, 92% and 78% in the No DSA group. CONCLUSION: In OPD follow-up 14.6% of the recipient had DSA mainly against Class II HLA-DQ antigens. Although rejection episode were higher in patients with DSA but the short term survival at 1, 3 years was similar to non DSA group. High frequency of HLA-DQ antibodies warrant typing for HLA-DQ as routine specially in live related transplant to determine the long term consequences of DSA against HLA-DQ antigens.

Excellent Results of Immunocomplex Capture Fluorescence Analysis-I for Cross-Match Test in Renal Transplantation

A flow cytometry cross-match (FCXM) test is the gold standard for detection of human leukocyte antigen (HLA) antibodies in renal transplantation because of its high sensitivity. However, this technique can produce false-positive results when non-HLA antibodies or low-titer donor-specific antibodies (DSA) are detected. To determine the clinical relevance of the recently introduced novel cross-match test termed immunocomplex capture fluorescence analysis (ICFA), we retrospectively compared the results of ICFA and FCXM, including a single-antigen bead test for detection of DSA in renal transplant recipients. We found a correlation of 71.4% (235/329) between the results of ICFA-I and FCXM-T, whereas that between ICFA-II and FCXM-B was 41.1% (134/326). Ninety-four patients were ICFA-I negative and FCXM-T positive, and 188 were ICFA-II negative and FCXM-B positive, whereas 46.8% (44/94) and 61.7% (116/188) were found to be DSA-I and DSA-II negative, respectively, which classified them into the non-HLA antibody and low-titer DSA groups, respectively. The mean value of molecules of equivalent soluble fluorochrome for DSA-I was 22,994 in the ICFA-I–positive group, which was significantly higher than 2117 in the negative group (P < .0001), whereas there was no significant difference for DSA-II between the ICFA-II–positive and ICFA-II–negative groups. Graft survival in the ICFA-I–negative group was significantly higher than that in the ICFA-I–positive group (P = .0058). Our results indicate that ICFA-I does not respond to non-HLA antibodies or low-titer DSA, which have influence on graft survival. Therefore, this novel hybrid test, which combines cross-match testing and HLA antibody detection functions, may be useful for clinical pretransplantation evaluation of renal transplantation patients.

Clinical outcomes among renal transplant recipients with pre‐transplant weakly reactive donor‐specific antibodies

Alloantibody can lead to antibody-mediated rejection and graft loss in renal transplantation, necessitating an assessment of cross-match compatibility. Within the past decade, more specific solid phase assays of alloantibody have been widely adopted, allowing virtual cross-matching based on unacceptable antigens, the threshold of which is determined by individual centers. We examined the clinical outcomes of 482 patients transplanted 2007-2009 in a single center, focusing on 30 patients with weakly reactive donor-specific antibody (DSA) determined prospectively prior to renal transplant. Compared with patients without DSA, patients with weakly reactive DSA do not have increased rates of antibody-mediated rejection, cellular rejection, or graft loss despite conventional immunosuppression utilization. Using the screening methodology and immunosuppression regimen, we have applied to the patients with weak DSA allows them to be transplanted with equivalent outcomes as those without DSA, despite the overall higher risk characteristics of the patients in the weak DSA group.

Outcomes of Living Donor Renal Transplants With a Negative Cross-Match and Pretransplant Donor-Specific Antibody

IntroductionManagement of renal transplant recipients with a negative complement-dependent cytotoxicity-antihuman globulin (CDC-AHG) cross-match and pretransplant donor-specific antibody (DSA) is controversial. We sought to compare outcomes of immunologically high-risk living donor (LD) renal transplant recipients with and without DSA. MethodsWe conducted a single-center, retrospective review of all high immune-risk LD renal transplant recipients with a negative CDC-AHG cross-match performed between January 2008 and December 2010. Pretransplant desensitization for DSA was not utilized. Immunosuppression consisted of thymoglobulin induction, followed by tacrolimus, myeophenolate mofetil, and prednisone. DSA was assessed pretransplant and at 1, 3, 6, 9, and 12 months, and every 6 months thereafter. ResultsBetween January 2008 and December 2010, 44 LD renal transplants were performed in high immune-risk recipients with a negative CDC-AHG cross-match. Outcomes of 14 recipients with pretransplant DSA were compared with 30 recipients with no DSA. After a median follow-up of 26 months (range, 12–40), overall death-censored graft survival was 100%, with no acute rejection episodes in the DSA group and 1 antibody-mediated rejection in the non-DSA cohort. Mean serum creatinines of the DSA and non-DSA groups at 1 year post-transplant were 1.0 ± 0.4 and 1.2 ± 0.6 mg/dL (P = NS), respectively. Among the pretransplant DSA cohort, 5 of the 14 (36%) developed persistent post-transplant DSA at a median of 9 months (range, 3–24) versus 2 of 30 (7%; P = .025) at a median of 12 months post-transplant in the non-DSA cohort. All recipients in the pretransplant DSA group underwent renal biopsy for persistent post-transplant DSA. Three of 5 biopsies showed C4D deposition in peritubular capillaries without glomerulopathy or arteriopathy. ConclusionsEarly post-transplant outcomes for LD recipients with a negative cross-match and pretransplant DSA were excellent. In recipients with good and stable renal function, the significance of persistent post-transplant DSA in combination with C4D deposition on biopsy is unclear at this time.

The Development and Impact of De Novo Circulating Antibodies in Non-Sensitized Patients after Heart Transplantation

Purpose According to the 2012 ISHLT Registry, two-thirds of patients at the time of transplant do not have circulating antibodies. For these non-sensitized patients, the incidence of post-transplant de novo antibody production has not been firmly established. Its impact on outcome in patients on routine triple drug immunosuppression has also not been determined. Methods and Materials Between 2006 and 2011, we evaluated 133 non-sensitized heart transplant patients for the development of de novo circulating antibodies [both non-specific and donor-specific antibodies (DSA)] in the first year after transplant. Blood for detection of circulating antibodies are routinely drawn at 1,3,6,12 months after heart transplant. Post-transplant outcomes assessed included 3-year survival, freedom from cardiac allograft vasculopathy (CAV), 1-year treated cellular rejection (CR) and antibody-mediated rejection (AMR). Results Of the 133 non-sensitized heart transplant patients, the development of non-specific antibodies was detected in 29 (22%) patients, DSA in 10 (7.5%) patients and no antibodies in 94 (70.5%) patients. Patients with first-year DSA had significantly lower survival and a trend for less freedom from CAV. The DSA and non-specific antibody groups had less freedom from first-year treated AMR (see table). Conclusions Non-sensitized pre-transplant patients who developed first year DSA after transplant have poor outcome. Treatment of these patients with anti-humoral therapies appears warranted, but merits a randomized trial. Outcomes No Ab (n=94) Non-Specific Ab (n=29) DSA (n=10) Log-Rank p-value 3-Year Actuarial Survival 93% 93% 50% 3-Year Freedom from CAV 84% 96% 70% 0.076 1-Year Freedom from Any-Treated CR 92% 90% 90% 0.970 1-Year Freedom from Any-Treated AMR 100% 90% 90% 0.007

Donor-specific antibodies are associated with antibody-mediated rejection, acute cellular rejection, bronchiolitis obliterans syndrome, and cystic fibrosis after lung transplantation

Lung transplantation is limited by chronic lung allograft dysfunction. Acute cellular rejection (ACR) is a risk factor for allograft dysfunction; however, the role of antibody-mediated rejection (AMR) is not well characterized. This was a retrospective review from 2007 to 2011 of lung transplant recipients with human leukocyte antigen (HLA) antibody testing using Luminex (Luminex Corp, Austin, TX) single-antigen beads. Statistics included Fisher's exact test for significance. Donor-specific antibodies (DSA) developed in 13 of 44 patients. Of the 13 with DSA, 12 had cystic fibrosis compared with 18 of 31 in the non-DSA group (p = 0.035). Of those with DSAs, 23.1% occurred within the first year, and 69.2% occurred between 1 and 3 years. Twelve of 13 DSA patients had anti-HLA DQ specificity compared with 2 of 31 non-DSA patients (p = 0.0007). AMR developed in 10 of the 13 DSA patients compared with 1 of 31 non-DSA patients (p = 0.0001). The DSA group experienced 2.6 episodes/patient of cellular rejection vs 1.7 episodes/patient in the non-DSA group (p = 0.059). Bronchiolitis obliterans syndrome developed in 11 of 13 in the DSA group vs 10 of 31 in the non-DSA group (p = 0.0024). In the DSA group, 11.5% HLAs matched compared with 20.4% in the non-DSA group (p = 0.093). AMR developed in 11 of 22 patients in the non-DSA HLA group compared with 0 of 22 in the group without non-DSA HLA antibodies (p = 0.002). Survival at 1 and 3 years was 92% and 36% in the DSA group, respectively, and 97% and 65% in the non-DSA group. DSAs and non-DSAs occur frequently after lung transplantation. DSAs are prevalent in the cystic fibrosis population and are associated with AMR, bronchiolitis obliterans syndrome, and possibly, ACR.

16-P

Aim To examine the relationship of flow crossmatch reactivity with antibodies to split antigens and allelic variants. Methods Records of donors from 2008-12 with A23, A24, B57 or B58 were reviewed for crossmatches with sera with a single CI donor specific antibody(DSA) to one of the above. The Luminex SA kit contains 1 A23, 2 A24, 1 B58 and 2 B57 beads. MFIs of the most recent SA were compared to T-cell flow crossmatch (FCXM) as follows: max MFI, sum MFI(A24 and B57 only) and sum split MFI (ex.A24(1)+A24(2)+A23). Correlation coefficients (r) were calculated between MFI and T cell shifts(TCS). Results 33 FCXMs met our criteria:5 with A23 DSA, 23 with A24, 4 with B57 and 1 with B58. Of 28 FCXMs with DSA to A23 or A24, 1 was pos. Of 5 FCXMs with DSA to B57 or B58, 1 was pos, and 1 weak pos. In the A23 DSA group, r of 0.7 was obtained when comparing A23 MFI to TCS (p = 0.12). Sum MFI of A23+A24 beads reduced r to −0.5 (p = 0.31). In the B57 group, r between TCS and MFI for both max B57 DSA and sum DSA was 0.6 (p = 0.33). Including B58 MFI increased r to 0.8 (p = 0.14). When B58 MFI was evaluated against TCS for B57, r increased to 0.9 (p = 0.02) [Figs. 1 and 2]. Download : Download full-size image Download : Download full-size image Conclusions Our results suggest that combining the MFIs of antigen splits does not necessarily increase the predictive value of SA testing, despite the conventional view that HLA alloimmunization primarily results in antibodies to public epitopes.

Evidence for Antibody-Mediated Injury as a Major Determinant of Late Kidney Allograft Failure

Late graft failure (LGF) is believed to be the consequence of immunologic and nonimmunologic insults leading to progressive deterioration in kidney function. We studied recipients with new onset late kidney graft dysfunction (n=173) to determine the importance of C4d staining and circulating donor-specific antibody (DSA) in subsequent LGF. One hundred seventy-three subjects transplanted before October 1, 2005 (mean time after transplant 7.3+/-6.0 years) had a baseline serum creatinine level of 1.4+/-0.3 mg/dL before January 1, 2006 and underwent biopsy for new onset graft dysfunction after that date (mean creatinine at biopsy 2.7+/-1.6 mg/dL). Statistical analysis was based on central DSA and blinded pathology determinations. Subjects were divided into four groups based on C4d and DSA: no C4d, no DSA (group A; n=74); only DSA (group B; n=31); only C4d (group C; n=28); and both C4d and DSA (group D; n=40). Among DSA+ recipients (groups B and D), group D had broader reactivity and a stronger DSA response. After 2 years, groups C and D (C4d+) were at significantly greater risk for LGF than groups A and B. Adjusting for inflammation (Banff i, t, g, and ptc scores) did not change the outcome. Local diagnosis of calcineurin inhibitor nephrotoxicity was spread across all four subgroups and did not impact risk of LGF. Evidence of antibody-mediated injury (DSA or C4d) is common (57%) in patients with new onset late kidney allograft dysfunction. The risk of subsequent graft failure is significantly worse in the presence of C4d+ staining.

Living donor renal transplantation in the presence of donor-specific human leukocyte antigen antibody detected by solid-phase assay

Presensitization of donor human leukocyte antigens (HLA) demonstrated through a positive crossmatch is detrimental to allograft function and best avoided through donor exclusion. The clinical significance of alloantibody detectable by sensitive solid-phase assay is not completely defined and is the focus of this study. Pretransplant sera from 64 consecutive living-donor renal transplant recipients were screened by enzyme-linked immunosorbent assay (ELISA) and Luminex assays. Results were analyzed for correlation with clinical outcome. Luminex proved more sensitive than ELISA for alloantibody detection, with three identifiable patterns. Twenty-eight patients were antibody negative, 24 had non-donor-specific antibody (non-DSA), and 12 had donor-specific antibody (DSA). The highest number of rejections ( n = 4) and graft losses ( n = 6) occurred in the antibody-negative group. The non-DSA group had two graft losses, as did the DSA group. The two graft losses in the DSA group were caused by recurrent focal segmental glomerulosclerosis (FSGS) at 35 months and death with a functioning graft at 32 months. Overall, there were no cases of antibody-mediated rejection and allograft function to 4 years was comparable among all three groups. Under our standard immunosuppression protocol and crossmatch criteria for histocompatibility, alloantibody detectable by Luminex was not detrimental to successful living-donor transplantation.