Pretransplant Antibodies Research Articles

Antibodies to Self-Antigens Predispose to Primary Lung Allograft Dysfunction and Chronic Rejection

Primary graft dysfunction (PGD) is a known risk factor for bronchiolitis obliterans syndrome (BOS) after lung transplantation. Here, we report that preformed antibodies to self-antigens increase PGD risk and promote BOS. Adult lung transplant recipients (n = 142) were included in the study. Primary graft dysfunction and BOS were diagnosed based on International Society for Heart and Lung Transplantation guidelines. Antibodies to self-antigens k-alpha-1 tubulin, collagen type V, and collagen I were quantitated using standardized enzyme-linked immunosorbent assays, and cytokines were analyzed using Luminex immunoassays (Biosource International, Camirillo, CA). Human leukocyte antigen (HLA) antibodies were measured using Flow-PRA (One Lambda, Canoga Park, CA). Lung transplant recipients with pretransplant antibodies to self-antigens had increased risk of PGD (odds ratio 3.09, 95% confidence interval: 1.2 to 8.1, p = 0.02) compared with recipients without. Conversely, in patients with PGD, 34.7% were positive for pretransplant antibodies whereas in the PGD negative group, only 14.6% had antibodies (p = 0.03). Antibody positive patients demonstrated high levels of proinflammatory cytokines interleukin (IL)-1β (2.1-fold increase), IL-2 (3.0), IL-12 (2.5), IL-15 (3.0), and chemokines interferon-inducible protein-10 (3.9) and monocyte chemotactic protein-1 (3.1; p < 0.01 for all). On 5-year follow-up, patients without antibodies showed greater freedom from development of HLA antibodies compared with patients who had antibodies (class I: 67% versus 38%, p = 0.001; class II: 71% versus 41%, p < 0.001). Patients with pretransplant antibodies were found to have an independent relative risk of 2.3 (95% confidence interval: 1.7 to 4.5, p = 0.009) for developing BOS. Presence of antibodies to self-antigens pretransplant increases the risk of PGD immediately after transplant period and BOS on long-term follow-up. Primary graft dysfunction is associated with an inflammatory cascade that augments the alloimmune (anti-HLA) response that predisposes to BOS.

Hepatocyte growth factor and antibodies to HLA and MICA antigens in heart transplant recipients

Recent unconfirmed literature data suggest that elevated concentrations of the multifunctional cytokine hepatocyte growth factor (HGF) might be a marker of increased incidence of acute rejection after organ transplantation. The aim of this study was to test the hypothesis that HGF levels may correlate with the rejection and/or with the production of HLA and MHC Class I chain-related antigens A (MICA) specific antibodies. Sixty-three heart transplant recipients were included into the study. Hundred and eighty-five endomyocardial biopsies (EMB) obtained up to 6 months after transplantation were retrospectively analyzed for signs of cellular (CR) and antibody-mediated rejection (AMR). Pre- and post-transplant sera were tested for HGF concentrations and antibodies to HLA class I, class II and MICA antigens by xMap technology (Luminex). Pre-transplant HGF did not correlate with the incidence of CR or AMR. However, higher HGF concentrations correlated significantly with HLA antibody production before and after transplantation (P = 0.006 and P < 0.0001 respectively). Patients with both HLA class I and class II antibodies before transplantation had significantly lower AMR-free survival. Furthermore, recipients with pre-transplant donor-specific antibodies (DSA) had significantly lower AMR-free survival (50%) than recipients without pre-transplant HLA antibodies (90%) and patients with antibodies not specific to donor antigens (92%) (P = 0.005). Post-transplant MICA antibodies tended to be more frequent in patients with AMR (P = 0.063). In conclusion, elevated HGF concentrations in our study were not associated with the incidence of CR and/or AMR but with the presence of HLA-specific antibodies. Testing for DSA before heart transplantation by Luminex may be helpful for the identification of patients with increased risk of AMR.

Mechanism of Acute Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation: Which Anti-A/Anti-B Antibodies are Responsible, Natural or de Novo?

Mechanism of Acute Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation: Which Anti-A/Anti-B Antibodies are Responsible, Natural or de Novo?

454: Lack of Association between Pre-Transplant MICA Antibodies and Cardiac Allograft Dysfunction

454: Lack of Association between Pre-Transplant MICA Antibodies and Cardiac Allograft Dysfunction

25: Donor Specific Antibody (DSA) as a Time Dependent Predictor Shows a Significant Negative Impact on Survival in Lung Recipients (Recips) Regardless of Pretransplant (Pretx) Antibody (Ab) Status

25: Donor Specific Antibody (DSA) as a Time Dependent Predictor Shows a Significant Negative Impact on Survival in Lung Recipients (Recips) Regardless of Pretransplant (Pretx) Antibody (Ab) Status

76-P: Pre-transplant MICA antibodies

76-P: Pre-transplant MICA antibodies

Pretransplant IgG antibodies to polyoma BK virus in pediatric renal transplants

We retrospectively measured IgG antibody levels to BKV in pretransplant sera and compared levels in children who developed BK viremia to a control group who remained free of infection after transplantation. Sera from 45 renal transplant patients were available for analysis (BK viremia = 23, controls = 22). Serum BKV PCR levels ranged from 3400 to 6.5 million DNA copies/mL (mean +/- s.d.: 978K +/- 1.77 million) and were highest in patients with BK nephritis (p = 0.007). Overall, 35% of children with BK viremia were BKV-seronegative vs. 9% of children in control group (p = 0.04), but mean antibody levels were similar between viremic and control patients (p = 0.15). However, children who developed viremia later than six months post-transplantation had significantly lower antibody levels compared with controls (p = 0.004) and patients with early viremia (p = 0.007), and may represent de novo infection or reinfection, rather than recurrence of latent infection. Pretransplant antibody status was significantly associated with subsequent development of BK viremia. Although our findings identified possible factors for developing BK viremia, there was sufficient overlap of both seropositive status and antibody levels among viremic patients and the control group to question the clinical utility of pretransplant IgG antibodies.

HLA Antibodies and the Occurrence of Early Adverse Events in the Modern Era of Transplantation: A Collaborative Transplant Study Report

Adverse events occurring early after kidney transplantation were reported to influence graft outcome. In a prospective multicenter study initiated in 2001, we investigated the relationship between human leukocyte antigen (HLA) alloantibodies, early adverse events, and graft outcome. Pretransplant presence of HLA class I antibodies was associated with a higher rate of no immediate function (NIF) of the graft (odds ratio [OR] 1.78, P=0.023) and acute rejection episodes (ARE) during the first 3 months after transplantation (OR 2.53, P<0.001). NIF and ARE during posttransplant days 15 to 90 were associated with increased risk of graft loss to year 3 (OR 2.06 and 3.75, P=0.006 and P<0.001, respectively). ARE within the first 2 posttransplant weeks did not increase the risk significantly, especially if they occurred in nonsensitized patients without antibodies. Graft survival at 3 years in patients with both NIF and ARE during the first 3 months was significantly lower (81.3%+/-6.2%) than in patients who did not experience NIF or ARE (95.1%+/-1.0%, P<0.001). Importantly, neither NIF nor ARE had an impact on subsequent graft survival if good graft function (serum creatinine <130 mumol/L) was observed at the end of the third month. Our results show that NIF and ARE associated with pretransplant antibodies against HLA class I, and they suggest that early diagnosis and treatment of adverse events with the aim of obtaining normal 3-month graft function should be pursued rigorously. Good 3-month graft function is associated with excellent long-term survival, even in patients with pretransplant HLA antibodies and posttransplant adverse events.

Hemolytic anemia after ABO nonidentical living donor kidney transplantation

ABO compatible non-identical kidney transplants are used frequently. Acquired hemolytic anemia has been reported after ABO mismatched transplantation. Patients of A, B or AB blood groups may receive organs from ABO-compatible, but non-identical donors, mostly from O blood group donors. It may also occur in patients of the AB blood group who receive a kidney from a donor of the A or B blood groups. ABO non-identical living donor kidney transplantation was done in 214 cases. All studied patients received kidneys from one haplotype HLA mismatched living donors and had pretransplant non-specific blood transfusions. There were 164 males and 50 females with a mean age of 30 years. Ten patients with cyclosporine (CsA)-based therapy developed hemolysis. CsA was stopped in patients maintained on triple immunosuppression (pred, CsA, AZA) and shifted to azathioprine in patients maintained on pred CsA therapy. In all patients pretransplant antibody screen, direct antiglobulin test (DAT) and cytotoxic cross match were all negative. The prognosis was excellent in nine patients, and one died from severe hemolysis. Hemolytic anemia was more frequent among blood group A recipients (60% of our cases) and more severe among recipient blood group B. Six patients received antigen-negative packed RBCs. Univariate analysis demonstrated significant impact for recipient age, donor sex, number of pretransplant blood transfusions, primary immunosuppression, time to onset of diuresis, recipient and donor blood groups. Multivariate analysis restricted the significance to blood group of donor and recipient, time to onset of diuresis and primary immunosuppression. Post transplant hemolysis is infrequent after renal transplantation; however, it may occur with compatible, non-identical ABO blood group donors. Blood group of donor and recipient, time to onset of diuresis and primary immunosuppression (mainly CsA) were significant risk factors in hemolytic anemia in patients after ABO non-identical living donor kidney transplantation. The condition is usually mild and self limited, and change of immunosuppression (stop CsA) can treat the condition.

C4d Fixing, Luminex Binding Antibodies—A New Tool for Prediction of Graft Failure After Heart Transplantation

The standard method to detect pretransplant antibodies has been the complement dependent cytotoxicity (CDC) test of donor leukocytes. Solid phase assays to detect HLA antibodies in pretransplant serum reveal a greater number of sensitized patients, but their clinical impact is less certain. Here we have developed a method of detecting C4d fixing HLA antibodies on Luminex beads. Pretransplant serum from 565 cardiac transplant patients was retrospectively tested for the presence of HLA antibodies using CDC, HLA coated Luminex beads and C4d deposition on Luminex beads, and the results correlated with graft survival. Whereas 5/565 patients had CDC positive donor specific antibodies (DSA) before their transplant, this number was increased by 19 using Luminex beads. The 1-year survival of CDC -ve/Luminex +ve patients with DSA (n = 19) was 42% compared with 77% for CDC -ve/Luminex +ve without DSA (n = 39, p = 0.0039). Fixation of C4d (22/67 Luminex positive sera) had a negative effect on graft outcome; 1-year graft survival was, C4d +ve/DSA +ve (n = 11) 20%, C4d +ve/DSA -ve (n = 11) 91%, C4d -ve DSA +ve (n = 13) 54%, C4d -ve DSA -ve (n = 32) 75%, compared with 75% for antibody-negative patients (p = 0.0002). In conclusion, detection of Luminex +ve DSA in pretransplant serum provides a powerful negative predictor of graft survival, especially if they bind C4d.

Hematopoietic Stem Cells Encoding Porcine Factor VIII Induce Pro-coagulant Activity in Hemophilia A Mice with Pre-existing Factor VIII Immunity

The development of inhibitory antibodies directed against factor VIII (fVIII) remains the most significant clinical complication associated with the treatment of hemophilia A. Recently, we demonstrated that transplantation of genetically modified hematopoietic stem cells containing a high-expression porcine fVIII transgene promoted sustained high-level fVIII expression in naïve hemophilia A mice. In the current study, a similar gene transfer strategy was tested in hemophilia A mice harboring clinically significant anti-human factor VIII (anti-hfVIII) inhibitory antibody titers. Although the majority of mice contained circulating antibodies that cross-reacted with and inhibited porcine fVIII activity, transplantation of genetically modified hematopoietic stem cells containing a porcine fVIII transgene into myeloablated hemophilia A mice induced high-level fVIII activity. Furthermore, anti-hfVIII antibody titers steadily declined throughout the course of the study. However, non-myeloablative transplantation conditioning resulted in only partial success. No correlation between pre-transplantation antibody titers and post-transplantation fVIII activity levels or donor cell engraftment was observed. These data suggest that hematopoietic stem cell transplantation-based gene therapy incorporating a high-expression porcine fVIII transgene can be utilized successfully to treat hemophilia A patients harboring anti-hfVIII inhibitors.

Low incidence of anti-Gal α 1-3Gal and anti-porcine antigens antibodies in xenotransplanted type-1 diabetic patients after 6 years of follow-up (B160)

Abstract We have reported the clinical follow-up of diabetic patients xenotransplanted with islet cells. Here, we report the antibody response elicited against the xenograft after 6 years. Samples were screened by ELISA for anti-Gal IgM, IgG and IgG subclasses. Anti-pig antigen antibodies were tittered by means hemolytic antibody assay. Anti-Gal IgM and IgG titers of pretransplant sera were 90 and 115 respectively with no statistical differences in comparison with sera titers from healthy subjects. After first transplant the mean for anti-Gal IgG was 918 and increased with second and third transplants. After that the levels diminished to basal line. IgM titers were no different. IgG subclasses titers were not different, except for IgG2. Hemolytic anti-pig pretransplant antibodies mean was 320 however at this time the mean is 190. There is a classical humoral response against Gal antigen after each transplant with high levels of IgG but with very lower levels of IgM. However, these levels go backward 6 weeks after each transplant. During this assay we have observed an upsurge of IgG2 over the other subclasses. Low anti-pig levels elicited suggest an immune accommodation induced by this procedure.

Long‐term surveillance of haematopoietic stem cell recipients with resolved hepatitis B: high risk of viral reactivation even in a recipient with a vaccinated donor

Reactivation of resolved hepatitis B virus (HBV) infection is increasingly recognized in patients with severe immunosuppression. We monitored seven patients with pretransplant antibodies to hepatitis B surface antigen (anti-HBs) and hepatitis B core antigen (anti-HBc) for HBV reactivation after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Reverse seroconversion (from anti-HBs to HBsAg) was observed in six recipients occurring 12, 14, 16, 22, 31 and 39 months after allo-HSCT, respectively. The only patient without HBV reactivation had the highest pretransplant anti-HBs titre and died after the shortest follow-up period (25 months). A novel HBV surface mutant (D144G/G145E) was isolated from one recipient of stem cells from a donor vaccinated against HBV. Another surface mutant (P142L/G145R) was detected in a recipient from a non-immune donor. Serum ALT elevation was measured in only two of the six patients with viral reactivation, followed by spontaneous clearance of HBsAg in one of them. Antiviral treatment reduced viral load in five patients, but the emergence of YMDD motif polymerase mutations resulted in lamivudine resistance in two patients. In conclusion, the risk of reactivation of a resolved HBV infection is close to 100% in allogeneic stem cell recipients and vaccination of the donor does not always warrant reliable protection.

Pre-transplant IgM non-HLA antibodies are an independent risk factor for graft survival following cardiac transplantation

Pre-transplant IgM non-HLA antibodies are an independent risk factor for graft survival following cardiac transplantation

The CARI guidelines. CMV disease and kidney transplant: prophylaxis for cytomegalovirus infection in patients following renal transplantation.

The CARI guidelines. CMV disease and kidney transplant: prophylaxis for cytomegalovirus infection in patients following renal transplantation.

Detection of weak pre-transplant antibodies associated with hyperacute rejection of a renal allograft

Detection of weak pre-transplant antibodies associated with hyperacute rejection of a renal allograft

Study 3: outcome of ABO-incompatible kidney transplantation immunosuppression with tacrolimus, mycophenolate mofetil, and steroids

T o help decrease the shortage of donors, ABOincompatible living kidney transplantation is being performed. Because these patients have a higher risk of acute rejection, we have been using 1-week pretransplant immunosuppression with tacrolimus, mycophenolate mofetil, and methylprednisolone (TAC-MMF-MP), which has resulted in a marked reduction in acute humoral-vascular rejection without any serious complications. Forty-five patients with end-stage renal failure underwent ABO-incompatible living kidney transplantation at our institute between January 2000 and March 2003. There were 25 men and 19 women with a mean age of 33 years. Plasmapheresis was carried out to remove anti-AB antibodies before the kidney transplantation. In 2000, 13 patients were treated with TAC-MMF-MP without 1-week pretransplant immunosuppression (group 1). Since January 2001, we have been administering TAC (0.1 mg/kg/d)– MMF (1-2 g/d)–MP (125 mg/d) concomitantly with plasmapheresis starting from 1 week before transplantation. One week pretransplant immunosuppression with TAC-MMF-MP was given in 32 patients (group 2). In the induction phase, TACMMF-MP was used for posttransplant immunosuppression without any antibody administration, such as OKT-3 and antithymocyte globulin. Splenectomy was done at the time of kidney transplantation in all patients. Pretransplant anti-ABO antibody titer was 32 dilution or less in all cases. Patient survival was 100% in both treatment groups. Graft survival rates were 92% and 97 % in groups 1 and 2, respectively, which were almost the same as those of ABO-compatible patients. One patient in group 1 lost the graft because of severe pancreatitis, and 1 patient in group 2 lost the graft because of severe humoral rejection. The incidence rates of acute rejection were 56% (7/13) and 19% (6/32) in groups 1 and 2, respectively. Most episodes of acute rejection (about 80%) were vascular-humoral rejections in both groups. No patient experienced any severe infectious complication. Conclusion: Pretransplant immunosuppression for 1 week with TAC-MMF-MP in ABOincompatible living kidney transplantation offers an excellent outcome without any severe infectious complication. From the Department of Urology, Tokyo Women’s Medical University, Shinjuku, Tokyo, Japan. © 2003 Elsevier Inc. All rights reserved. 0955-470X/03/1704-0000$30.00/0 doi:10.1016/j.trre.2003.10.004

Relationship between CDC cross-match in liver recipients and antibody screening by flow cytometry

Several authors have shown that anti-donor antibodies before liver transplantation are associated with decreased graft survival. The aim of this study was to investigate the relationship between anti-donor antibodies detected by the CDC technique or by FlowPRA, and acute or chronic rejection as well as graft survival. Furthermore, we sought to determine whether anti-donor antibodies, detected by the CDC technique, correlated with those discovered by cytometric screening. The acute rejection incidence among patients with complement-dependent cytotoxicity positive CDC cross-match was similar to that for patients with a negative cross-match. None of the patients with a positive cross-match developed chronic rejection. Allograft survival was significantly lower among recipients with a positive T-lymphocyte cross-match. Indeed, the majority of recipients with positive CDC cross-matches displayed graft failures before first postransplant year. The results of a positive FlowPRA determination were concordant with a positive CDC cross-match in 85.71% of cases. Our data demonstrate that pretransplant FlowPRA correlates with the final CDC cross-match results. This finding suggests that in the future prospective pretransplant antibody screening with FlowPRA or CDC techniques may be useful to identify high-risk recipients.

Factors affecting antibody levels after allogeneic hematopoietic cell transplantation

AbstractTo obtain insight into the mechanism(s) of posttransplantation humoral immunodeficiency, we evaluated factors affecting serum antibody levels against polio, tetanus,Haemophilus influenzae,andStreptococcus pneumoniaein 87 patients. Patients with hematologic malignancies were randomized to receive marrow versus blood stem cells, which contain approximately 10 times more lymphocytes than marrow. Blood stem cell recipients did not have higher antibody levels than marrow recipients. Recipient pretransplantation antibody levels were correlated with the posttransplantation levels, especially in the first 6 months after transplantation when the correlation coefficients typically exceeded 0.6. Donor pretransplantation antibody levels had less of a correlation with posttransplantation levels in the recipient. Patient or donor age, total body irradiation, and graft-versus-host disease or its treatment appeared to have no effect. In conclusion, antibody levels in the first year after transplantation are affected primarily by pretransplantation antibody levels in the recipient and, to a lesser degree, in the donor. These findings suggest that immunization of the recipient and the donor before transplantation may be more effective in improving antibody immunity after transplantation than manipulating graft-versus-host disease, changing conditioning, or increasing the number of lymphocytes in the graft.

Modulation of the pathology of late xenograft rejection by PAF-antagonist UR-12670 in the hamster-to-rat liver xenotransplant model.

PAF antagonists have been used in xenotransplantation to alleviate the pathogenesis of hyperacute rejection. This study evaluated the ability of the PAF antagonist UR-12670 to improve graft function in late xenograft rejection (LXR) in an orthotopic liver xenotransplantation model, and the involvement of PAF (platelet activating factor) in this type of rejection. The recipients of a hamster xenograft received standard immunosuppression (tacrolimus 0.2 mg/kg/30 days, MMF 25 mg/kg/8 days). Study groups: group A, without UR-12670, group B, UR-12670 (20 mg/kg/8 d) and group C, continuous administration of UR-12670 (20 mg/kg/d). Serum levels of xenoantibodies were evaluated by flow cytometry and tissue deposits by immunofluorescence. Immunoblot and indirect immunofluorescence assessed specificity of xenoantibodies. Conventional histology was performed. Continuous administration of UR-12670 improved the histological pattern of liver xenografts, especially necrosis, loss of hepatocytes, hemorrhage, sinusoidal congestion and lymphocyte infiltration. There was not a shift in specificity of xenoantibodies at different times posttransplantation, as demonstrated by immunoblotting and indirect immunofluorescence. UR-12670 administration had a beneficial effect on graft function and considerably improved the histopathological pattern, but it failed to induce tolerance after withdrawal of immunosuppression. UR-12670 had an immunomodulatory effect on cellular response but not on antibody production. There was not a change in the specificity of xenoantibodies produced at LXR compared with pretransplant antibodies.