Positive Panel Reactive Antibody Research Articles

#1390 Differences in the detection of anti-HLA antibodies between two single antigen bead methods in kidney transplantation patients

Abstract Background and Aims Two semiquantitative single-antigen bead (SAB) methods are currently available for the detection of anti-HLA antibodies and the estimation of their activity, depending on complement binding. However, data on accordance of the two methods on specificities detection and their reactivity evaluation are scarce. The purpose of this study is to compare the two methods in terms of anti-HLA antibodies specificities detection and of their complement binding capacity Method Sera from 97 patients with a positive Panel Reactive Antibody Test (>5%) was tested by two SAB methods, Immucor (IC) and One-lambda (OL), for class I and II anti-HLA antibody specificities and their ability to bind complement. The patients were either on a waiting list for kidney transplantation or transplanted patients tested routinely or after a clinical event. Statistical analysis of the results and comparison of the two methods followed. Results OL detected more class I positive specificities per patient [25 (9-34) vs. 18 (7-28) with IC, p < 0.001], while the two methods showed no difference in class II anti-HLA antibodies. IC detected 1608 out of 8148 and 1136 out of 7275 totally examined, positive anti-HLA class I and II antibody specificities respectively, with a median mean fluorescence intensity (MFI) of 4195 (1995-11272) and 6706 (2647-13184) respectively. Similarly, OL detected 1942/8148 and 1247/7275 positive specificities of anti-HLA class I and II antibodies respectively, with MFI 6185 (2855-12099) and 9498 (3630-17702)] respectively. In the IC method, 428/1608 [MFI 13900 (9540-17999)] and 409/1136 [MFI 11832 (7128-16531)] positive class I and II specificities, respectively, bound the C3d fraction of complement. Similarly, OL detected 485/1942 [MFI 15452 (9369-23095)] and 298/1247 [MFI 18852 (14415-24707)] class I and II specificities respectively that bound the C1q fraction of complement. In the analysis of the specificities that were positive by both methods, MFI showed a strong positive linear correlation between the two methods (r = 0.61, p < 0.001 and r = 0.54, p = 0.001 for classes I and II respectively). Accordingly, data were analyzed with Principal Components Analysis, in which negative results were also included. In the projection of the plane defined by the first two principal components the vector corresponding to the IC method for class I antibodies was congruent with the vectors of the complement binding detection methods, C3d and C1q. In contrast, the OL vector was nearly perpendicular to the other vectors, indicating the existence of non-complement-binding specificities that are not detected by IC. A similar picture was found for antibodies against HLA class II (Figure). Conclusion OL was more sensitive for detecting class I and II anti-HLA antibodies despite the fact that there was no difference in the number of class II specificities per patient. However, the additional specificities detected by OL, potentially do not bind complement. The MFI of the complement binding specificities were higher in both methods. The two methods were equivalent in detecting complement-binding class I specificities, however the C3d IC method was more sensitive in detecting complement-binding class II anti-HLA antibodies.

The Challenge of Preoperative Panel Reactive Antibody Positivity in Parathyroid Transplantation.

Identifying suitable recipient criteria and matching recipients with appropriate donors are required to increase survival for parathyroid transplant. This study was undertaken to evaluate transplant survival rates while comparing preoperative panel reactive antibody positivity. The study included 14 hypoparathyroidism patients who presented to our clinic for parathyroid transplant. Preoperative ABO compatibility and negative cross-match tests were prioritized for recipient-donor matching, and panel reactive antibody screening tests were performed. During the 24-month follow-up, we evaluated medication use and serum calcium, phosphorus, and parathormone levels of patients. Preoperative panel reactive antibody positivity was assessed in 3 groups. The HLA class I-positive group (mean fluorescence intensity range, 179-1770) showed decreased medication use and stability in serum calcium levels. The HLA class IIpositive (mean fluorescence intensity range, 85-3959) showed decreased medication use by 25% to 50% and returned to their former prescription doses after 12 months. An opposite pattern was observed in 2 patients with panel reactive antibody positivity for both HLA classes (mean fluorescence intensity range, 462-2289), with 1 patient requiring medication for continuing symptoms and the other patient occasionally taking additional magnesium supplementation, despite decreased medication doses after 12 months. Serum calcium levels remained normal, and parathormone and phosphorus levels were elevated. Improving patient symptoms and having no requirement for intravenous calcium replacement are priorities, and monitoring serum levels is the next important step. Varied panel reactive antibody positivities and survival rates indicate a requirement, and each HLA class could require a proper limitation for the mean fluorescence intensity. Preoperative mean fluorescence intensity cut-off value should be <900. Higher mean fluorescence intensity values in panel reactive antibody screenings could increase risk of short-term graft survival after parathyroid transplant. Further studies should include immunological risk assessments by individualizing the outcome with donor-specific antibodies.

Complement and Non-Complement Binding Anti-HLA Antibodies Are Differentially Detected with Different Antigen Bead Assays in Renal Transplant Recipients.

Two semi-quantitative, Luminex-based, single-antigen bead (SAB) assays are available to detect anti-HLA antibodies and evaluate their reactivity with complement binding. Sera from 97 patients with positive panel reactive antibody tests (>5%) were analyzed with two SAB tests, Immucor (IC) and One-Lambda (OL), for anti-HLA antibody detection and the evaluation of their complement-binding capacity. IC detected 1608/8148 (mean fluorescent intensity (MFI) 4195 (1995-11,272)) and 1136/7275 (MFI 6706 (2647-13,184)) positive anti-HLA class I and II specificities, respectively. Accordingly, OL detected 1942/8148 (MFI 6185 (2855-12,099)) and 1247/7275 (MFI 9498 (3630-17,702)) positive anti-HLA class I and II specificities, respectively. For the IC assay, 428/1608 (MFI 13,900 (9540-17,999)) and 409/1136 (MFI 11,832 (7128-16,531)) positive class I and II specificities bound C3d, respectively. Similarly, OL detected 485/1942 (MFI 15,452 (9369-23,095)) and 298/1247 (MFI18,852 (14,415-24,707)) C1q-binding class I and II specificities. OL was more sensitive in detecting class I and II anti-HLA antibodies than IC was, although there was no significant difference in the number of class II specificities per case. MFI was higher for complement vs. non-complement-binding anti-HLA antibodies in both assays. Both methods were equal in detecting complement-binding anti-HLA class I antibodies, whereas the C3d assay was more sensitive in detecting complement-binding anti-HLA class II antibodies.

The correlation of results of panel reactive antibody, identification, and single antigen beads in detection of anti-HLA antibodies: Istanbul Faculty of Medicine, tissue typing laboratory experience

BackgroundWe have performed a retrospective analysis of anti-HLA class I MHC and class II MHC antibodies measured using a single antigen bead (SAB) assay and a panel reactive antibody (PRA) assay. Material and methodsA group of 256 patients with end-stage renal disease (ESRD) was tested for anti-HLA antibodies in the tissue typing laboratory between 2017 and 2020. In the cohort, the serum samples of patients waiting for transplantation were tested. Both the PRA and SAB tests of these patients were analyzed using the Luminex (Immucor) method. The threshold of positivity was accepted as median fluorescence intensities (MFI) ≥1000 for PRA screening and MFI ≥750 for SAB screening. ResultsOverall, antibodies to HLA antigens were detected in 202 (78.9%) out of 256 patients in the PRA study. Antibodies against both class I/II antigens were detected only in 15.6% of these patients, whereas antibodies against only against class I HLA in 31.3% and only against class II HLA in 32.0%. By comparison, the SAB study found that 66.8% of patients were positive for HLA antigens. Furthermore, donor-specific antibodies (DSA) were detected in 52.0% of PRA-positive patients and 52.6% of SAB-positive patients. It was shown that 168 patients (83.2%) out of 202 PRA-positive patients were found to be SAB-positive. In addition, 51 patients negative in the SAB assay (94.4%) were also negative in the PRA assay. Statistical analysis established a significant correlation between the PRA and SAB positivity (p > 0.001).It was also shown that MFI ≥3000 PRA positivity for class I HLA antigens (p = 0.049) and MFI ≥5000 PRA positivity for class II antigens (p < 0.001) correlated with the SAB positivity in patients. ConclusionOur results showed the importance of both PRA and SAB assays to define the status of sensitization in patients.

Anti-human leukocyte antigen and anti-ABO antibodies after SARS-CoV-2 mRNA vaccination in kidney transplant recipients.

In this study, we evaluated whether SARS-CoV-2 mRNA vaccines induce anti-human leukocyte antigen (HLA) antibodies and anti- ABO blood type antibodies (ABOAb) in kidney transplant recipients (KTRs). Sixty-three adult KTRs with functioning grafts who received two doses of the SARS-CoV-2 mRNA vaccine were enrolled in this cohort. Changes in anti-ABO blood type immunoglobulin IgM and IgG antibody titers, flow panel reactive antibody (PRA), de novo donor-specific anti-human leukocyte antigen antibodies (DSA), and kidney allograft function before and after vaccination were evaluated. Only one patient experienced conversion from negative to positive flow PRA after vaccination. However, there was no DSA in single antigen flow-bead assays. The mean fluorescence intensity (MFI) in the eight DSA-positive recipients did not significantly change before and after vaccination (p=.383), and no additional DSA was produced after vaccination in those patients. No significant elevation of ABOAb titer was observed for either IgM (p=.438) or IgG (p=.526) after vaccination. There was no significant deterioration in estimated glomerular filtration rate (eGFR) after vaccination (p=.877) or elevation of the urine protein-to-creatinine ratio (p=.209) after vaccination. One episode of AMR was observed in addition to a preexisting acute cellular rejection. The SARS-CoV-2 mRNA vaccine did not induce anti-HLA antibody or ABOAb production in KTRs.

DETERMINATION OF THE PRA POSITIVITY PERCENTAGE IN MALE PATIENTS WITH CHRONIC KIDNEY DISEASE BY USING FLOW CYTOMETRY TECHNIQUE.

The antibodies directed against human leukocyte antigen (HLA) molecules, which play a crucial role in allograft histocompatibility, are called anti-HLA antibodies. Anti-HLA antibodies against foreign HLA molecules may be present in patients with chronic kidney disease even before transplantation. The panel reactive antibody (PRA) test is used to measure the renal transplant candidate's immune sensitivity to HLA molecules other than their own HLA molecules by assessing the diversity of anti-HLA antibodies in the blood of these patients. This study aimed to determine the PRA values and the percentage of PRA positivity of Turkish male patients with chronic kidney disease (CKD), who had not been sensitized by the major known causes (those with no history of organ or tissue transplantation, those with no history of blood transfusion), who had not been diagnosed with any autoimmune diseases, and who had not been under immunosuppressive treatment. The study included 60 male patients aged over 18 years. All of the patients were followed up with a diagnosis of CKD at the Nephrology Clinic, Internal Medicine Department, Akdeniz University Medical Faculty Hospital. None of the patients included in the study was sensitized by a known mechanism previously (they did not have blood transfusion or organ transplantation). Glomerular filtration rate (GFR) levels of all patients were below the level of 60 mL/min/1.73 m2. Patient data including their age information, etiology of CKD, accompanying diseases, and information about dialysis modalities were recorded. HLA antibody percentage was determined by the flow cytometry technique. Statistical data analysis was performed by using SPSS 22.0 (Statistical Package for Social Sciences, Version 22.0). The values of p less than 0.05 were considered statistically significant. Twenty patients were receiving dialysis treatment due to end-stage renal disease. Of the 60 patients included in the study, 25% showed PRA positivity; 28.3% of all study patients were found to be positive for anti-HLA class I antibodies and 26.7% of all study patients were found to be positive for anti-HLA class II antibodies on separate analysis for anti-HLA class I and anti-HLA class II antibody positivity. When the patients were categorized as PRA negative and PRA positive in two groups, there were no differences between the groups according to mean age, percentage of hemodialysis patients, percentage of peritoneal dialysis patients and presence of accompanying chronic diseases (such as hypertension, type 2 diabetes mellitus, hyperlipidemia, nephrolithiasis, coronary artery disease). In addition to this, evaluation of the GFR levels showed that the PRA positive group contained a significantly higher percentage of end-stage renal disease patients (GFR <15 mL/min/1.73 m2) as compared with the PRA negative group. Detailed analysis of the percentages of PRA levels in the PRA positive patients, which was carried out to determine the degree of sensitization, showed that the PRA values were over 80% in 11.77% of the patients positive for anti-HLA class I antibodies. On the other hand, PRA values were within the range of 15%-80% in 88.23% of the patients who had anti-HLA class II antibodies. The PRA values were below 80% in all of the patients positive for anti-HLA class II antibodies and those positive for both anti-HLA class I and class II antibodies. In conclusion, PRA levels of the candidates for kidney transplantation should always be measured to assess their state of sensitization before transplantation, even though they have no risk factors known to cause anti-HLA antibody development.

Effect of panel reactive antibodies on T cell immunity reinstatement following renal transplantation.

BACKGROUNDChronic kidney disease is associated with immunological disorders, presented as phenotypic alterations of T lymphocytes. These changes are expected to be restored after a successful renal transplantation; however, additional parameters may contribute to this process.AIMTo evaluate the impact of positive panel reactive antibodies (PRAs) on the restoration of T cell phenotype, after renal transplantation.METHODSCD4CD28null, CD8CD28null, natural killer cells (NKs), and regulatory T cells (Tregs) were estimated by flow cytometry at T0, T3, and T6 which were the time of transplantation, and 3- and 6-mo follow-up, respectively. Changes were esti mated regarding the presence or absence of PRAs.RESULTSPatients were classified in two groups: PRA(-) (n = 43) and PRA(+) (n = 28) groups. Lymphocyte and their subtypes were similar between the two groups at T0, whereas their percentage was increased at T3 in PRA(-) compared to PRA(+) [23 (10.9-47.9) vs 16.4 (7.5-36.8 μ/L, respectively; P = 0.03]. Lymphocyte changes in PRA(-) patients included a significant increase in CD4 cells (P < 0.0001), CD8 cells (P < 0.0001), and Tregs (P < 0.0001), and a reduction of NKs (P < 0.0001). PRA(+) patients showed an increase in CD4 (P = 0.008) and CD8 (P = 0.0001), and a reduction in NKs (P = 0.07). CD4CD28null and CD8CD28null cells, although initially reduced in both groups, were stabilized thereafter.CONCLUSIONOur study described important differences in the immune response between PRA(+) and PRA(-) patients with changes in lymphocytes and lymphocyte subpopulations. PRA(+) patients seemed to have a worse immune profile after 6 mo follow-up, regardless of renal function.

Association of end-stage renal disease with HLA phenotypes and panel reactive antibodies in patients awaiting renal transplantation in Hunan Province.

ObjectivesTo explore the immune‐related genetic susceptibility of human leukocyte antigen (HLA) alleles and their correlation with panel reactive antibody (PRA) generation during end‐stage renal disease (ESRD) progression.Materials and methodsData of the expression patterns of HLA‐A, ‐B, and ‐DR alleles and PRAs of 347 ESRD patients awaiting renal transplantation in Hunan Province from 2015 to 2019 were retrospectively studied. The polymerase chain reaction with sequence‐specific primers was used for HLA genotyping and the enzyme‐linked immunosorbent assay for PRA detection. SPSS 21.0 software was used for all allele frequency and statistical analyses.ResultsThirteen HLA‐A, 25 HLA‐B, and 13 HLA‐DR alleles were expressed. The allele frequencies of HLA‐A2, ‐B48, ‐B52, and ‐B55 were significantly higher in the case group than in the control group (p < 0.05), whereas that of HLA‐B60 was significantly higher in the control group (p < 0.05). The frequency of HLA alleles in the PRA‐positive group was significantly higher in females than in males (p < 0.05). The allele frequencies of HLA‐A2, ‐B38, and ‐B46 were significantly higher in the PRA‐positive group than in the PRA‐negative one (p < 0.05), whereas that of HLA‐60 was significantly higher in the PRA‐negative group (p < 0.05).ConclusionHLA‐A2, ‐B48, ‐B52, and ‐B55 may be the ESRD susceptibility alleles in Han Chinese patients in Hunan Province, whereas HLA‐B60 may be the protective allele. Patients carrying HLA‐A2, ‐B38, and ‐B46 are more likely to develop PRA positivity, whereas the opposite is true for those with HLA‐B60.

Long-term Persistence of Allosensitization After Islet Allograft Failure.

Allosensitization has been reported after discontinuation of immunosuppression following graft failure in islet transplantation (ITx) recipients, though duration of its persistence is unknown. We evaluated 35 patients with type 1 diabetes who received ITx, including 17 who developed graft failure (ITx alone, n = 13; ITx plus bone marrow-derived hematopoietic stem cells, n = 4) and 18 with persistent graft function. Panel-reactive antibody (PRA) was measured yearly for the duration of graft function within 1 y after graft failure at enrollment and yearly thereafter. In ITx alone graft failure patients, 61% (8/13) were PRA-positive at 6 y postgraft failure, and 46% (6/13) developed donor-specific anti-HLA antibodies (DSA to 2 ± 1 donors) during follow-up. The degree of sensitization was variable (cPRA ranging between 22% and 100% after graft failure). Allosensitization persisted for 7-15 y. Three subjects (3/13) were not allosensitized. In ITx plus bone marrow-derived hematopoietic stem cell recipients, cPRA-positivity (88%-98%) and DSA positivity persisted for 15 y in 75% (3/4) of subjects. Allosensitization was minimal while subjects remained on immunosuppression, but after discontinuation of immunosuppressive therapy, the majority of subjects (77%) became allosensitized with persistence of PRA positivity for up to 15 y. Persistence of allosensitization in this patient population is of clinical importance as it may result in longer transplant waiting list times for identification of a suitable donor in the case of requiring a subsequent transplant.

Underlying Causes and Risk Factors of Chronic Renal Allograft Dysfunction Among Renal Transplant Recipients

Objective: Dialysis or renal transplantation are the two treatment options for end-stage renal disease patients. Renal transplantation from an appropriate donor increases survival and quality of life compared to treatment with dialysis. Recent advances in immunosuppressive therapy have significantly improved the success in 1-year graft survival. However, the long-term graft survival remains the same. Therefore, we aimed to determine the underlying causes and risk factors of chronic allograft dysfunction in renal transplant recipients.&#x0D; Materials and Methods: From 2000 to 2012, all consecutive renal transplant recipients followed in our tertiary referral center who underwent renal biopsy due to an increase in serum creatinine level were enrolled. Etiologies of chronic allograft dysfunction were assessed according to pathologic results of renal biopsy specimens and laboratory findings. The immunological and non-immunological risk factors of chronic allograft dysfunction were screened and recorded retrospectively.&#x0D; Results: Eighty (80) renal transplant recipients with a mean age of 38±10 years were included in the study. Delayed graft function (p=0.007), history of acute rejection (p&lt;0.001), positive panel reactive antibody (p=0.033) (Class I (p=0.013), Class II (p=0.006)), positive donor specific antibodies (p=0.001), number of recurrent acute rejections (p&lt;0.001), number of human leukocyte antigens mismatches (p=0.051), cold ischemia time (p=0.001) were found to be risk factors for chronic allograft dysfunction. The donor specific antibodies positivity (p&lt;0.001) and the panel reactive antibody positivity (Class I (p=0.003), Class II (p=0.001)) were significantly higher in patients with antibody mediated rejection than patients without antibody mediated rejection (p=0.002).&#x0D; Conclusion: Delayed graft function, presence and the number of acute rejections, increased cold ischemia time, panel reactive antibody positivity, donor specific antibodies positivity, and the number of human leukocyte antigens mismatches were risk factors for chronic allograft dysfunction.

Long Hemodialysis Duration Predicts Delayed Graft Function in Renal Transplant Recipients From Living Donor: A Single-Center Study

This study aims to determine the ratio of delayed graft function in renal transplant recipients from living donors and the predictive value of hemodialysis time before transplant for delayed graft function. We conducted a study on 116 adult patients who were diagnosed with end-stage kidney disease and were treated with hemodialysis and transplanted kidneys from living donors for 2 years (from June 2018 to June 2020). Delayed graft function event was collected for each patient. The recipients had a median age of 36.5 years old, in which 55.2% of them were men, 4.3% of them had the diabetic mellitus, and the median hemodialysis duration was 6 months. The ratio of positive panel-reactive antibody was 33.6% and vascular reconstruction of the donor's kidney was 16.4%. The ratio of delayed graft function was 12.2% (14 of 116 patients). Delayed graft function significantly related to positive panel-reactive antibody, long duration of hemodialysis before transplant, and vascular reconstruction of donor's kidney with P < .001. Duration of hemodialysis before kidney transplant had a predictive value for delayed graft function (area under the curve, 0.83; P < .001). Delayed graft function was not rare in renal transplant recipients from living donors. Duration of hemodialysis before kidney transplant was a good predictor for delayed graft function.

Use of panel reactive antibodies for immunological risk stratification and its correlation with antecedent events in live donor kidney transplant: A prospective single-center study

Background: Panel reactive antibody (PRA) is a screening test to identify the immunological sensitization of the transplant recipients. The current study focuses on the role of PRA in immunological risk stratification in live donor kidney transplant and its correlation with antecedent events and posttransplant outcomes. Methods: This was a prospective, single-center, observational study. All patients with end-stage renal disease between January 1, 2016, and October 1, 2016, were included. The patient's sensitization history and other immunological workup were recorded. Patients were followed up for 6 months. Results: PRA positivity was seen in 29/185 (15.7%) patients. Female sex (P = 0.004), longer duration renal replacement therapy (P = 0.037), and hepatitis C virus infection positivity (P = 0.047) were significantly associated with PRA positivity. Only 3/87 (3.4%) patients who had no history of sensitizing events had high PRA. Less number of patients in PRA-positive group received transplant as compared to PRA-negative group (12/29; [41.4%] vs. 143/156 [91.7%, P

Böbrek Transplant Alıcılarında HLA Hassasiyetinin Greft Fonksiyonuna ve Hayatta Kalmaya Etkisi

Objective: Anti-human leukocyte antibodies (HLA) play an important role in graft survival, particularly in kidney transplantation. Preformed anti-HLA antibodies, especially donor specific antibodies can cause acute and chronic rejections. In this study, it was aimed to assess the effects of anti-HLA antibodies in kidney patients before transplant on graft function, failure, and patient survival. Methods: PRA (Panel Reactive Antibody) levels were monitored using bead based methods such as Luminex and flow cytometry. Post-transplant estimated glomerular filtration ratios (eGFR) among first, third, and fifth year patient survivals and graft failures were statistically analyzed. Results: In this study, it was observed that related transplants had low levels of PRAs, and their eGFRs were at normal reference range. The patients without acute rejection episode (ARE) had higher eGFR values than those with ARE. When five year-graft survival terms were evaluated, it was found that 65.6±9.8% and 86.5±3.2% graft survival terms were detected in anti-HLA Class I/II positive and negative patients, whereas 74.8±6.4% and 84.3 ±2.6% graft survival terms were observed in ARE positive and negative patients, respectively. eGFR value is a predictor of graft failure and patient survival. Our Cox regression analyses (HR=0.843, p=0.00) also supported this information. Conclusion: The study concluded that although the correlation between PRA positivity and graft survival were not significant, the shortest graft survival was observed in PRA positive patients in the whole cohort and ARE positive patients. The importance and requirement of pre- and post-transplant PRA tests continue.

Delayed Graft Function and Acute Rejection in Kidney Transplant Patients with Positive Panel-Reactive Antibody and Negative Donor-Specific Antibodies

Background: Delayed graft function (DGF) and acute rejection (AR) are common complications in kidney transplant patients. Objectives: The study evaluated DGF and AR in highly sensitized patients and their effects on kidney function for six months post-transplantation. Methods: We enrolled 95 patients with kidney transplants from living donors who were divided into two groups. Group 1 included 47 highly sensitized patients with panel reactive antibody (PRA) &lt; 20.0% and negative donor-specific antigen, and group 2 included 48 patients with negative PRA. All patients were followed for the state of DGF, AR, and kidney function for six months. Results: Group 1 showed a significantly higher proportion of DGF and AR than group 2 (27.7% versus 2.1%, P &lt; 0.001 and 14.9% versus 2.1%, P = 0.031, respectively). The rates of positive PRA in DGF and AR patients were significantly higher than those in non-DGF and non-AR patients (92.9% versus 42.0%, P &lt; 0.001 and 87.5% versus 46.0%, P = 0.031, respectively). Transplanted kidney function was significantly worse in patients with PRA and DGF and/or AR than in patients with negative PRA and non-DGF and non-AR only in the seventh-day post-transplantation. Conclusions: Kidney transplant in highly sensitized patients with positive PRA was related to the increased ratio of DGF and AR.

Phase I Trial of Allogeneic Umbilical Cord Tissue-Derived Mesenchymal Stromal Cells in Neonates with Hypoxic-Ischemic Encephalopathy

Background & Aim Background In neonatal animal models of hypoxic-ischemic brain injury administration of mesenchymal stromal cells (MSCs) improves anatomic and functional outcomes. A prior study suggests potential benefit of autologous cord blood-derived cells for infants with hypoxic-ischemic encephalopathy (HIE) but cord blood collection in this population is challenging. A safe, effective off-the-shelf allogeneic cell product could be a useful alternative. Our aim was to conduct a phase I open-label study of umbilical cord tissue-derived MSCs in infants treated with hypothermia for HIE. Methods, Results & Conclusion Methods Infants >35 weeks gestation treated with hypothermia for HIE based on NICHD hypothermia trial criteria were eligible. Goal enrollment was 6 infants. Allogeneic umbilical cord tissue-derived mesenchymal stromal cells (hCT-MSC) were manufactured in the Robertson GMP Cell Manufacturing Laboratory from a single cord tissue donated to the Carolinas Cord Blood Bank. Cells were expanded to passage 2 and cryopreserved. A representative cryobag was quality-tested for cell count, viability, phenotype, functional assays, gram stain and sterility. For administration cells were thawed and diluted 1:1 and delivered in syringes containing plasmalyte-A, 5% HSA, and residual DMSO. Post thaw samples were tested for cell count, viability (required ≥70%) and sterility. The first 3 infants (cohort 1) received 2 × 106 cells/kg i.v. in the first 48 postnatal hours, the second 3 (cohort 2) received a 2nd dose at 2 months. Primary safety outcomes were occurrence of infusion reactions or infections within 2 weeks of infusion. Results Of 18 eligible infants, 6 were enrolled (Table 1). All cultures obtained from subjects were negative, and no subject had an infusion reaction. Subject #5, had a positive panel reactive antibody (PRA) screen at 6 months. Broth culture from thawed hCT-MSC for subject # 1 grew coagulase-negative staphylococci. The infant remained asymptomatic after re-warming and the infant's blood cultures were sterile. The broth culture was assessed as contaminant via handling post-thaw rather than cell product contamination. There was one protocol deviation (One infant received a study dose at 71 hours. (Table 2)). Conclusions Our results suggest that hCT-MSC, an umbilical cord tissue-derived MSC product, can be prepared and infused safely in infants treated with hypothermia for moderate - severe HIE. Further safety and efficacy studies are warranted.

Early graft survival after renal transplantation, single center experience

Aim: The best treatment for patient with end stage kidney disease is kidney transplantation which improve their quality of life and survival rate. The aim of our study is to determine the factors that affect the results of early outcomes of graft function. Method: Twenty-eight adult patients who underwent renal transplantation from 2016 to 2017 were included in our university. Results: The median age of the recipients was 38.5 (range: 19-65) and 68% (19 patients) were male. Acute rejection was detected in 8 patients. Patients who developed rejection were found to have higher panel reactive antibody positivity and higher parathyroid hormone levels. Panel reactive antibody positivity was found to be 25% in patients who developed rejection and 0% in patients who did not develop rejection (p = 0.02). The parathyroid hormone level was calculated as 963.2 ± 587 in the rejection group and 378 ± 227 in the rejection group (p = 0.003). It was observed that 37.5% of DM patients had rejection and 10% in non-diabetic patients. The difference was statistically significant (p = 0.08). Conclusion: Panel reactive antibody positivity and parathyroid hormone levels increased the likelihood of rejection. The effect of the presence of diabetes mellitus in the patient on the development of rejection was observed to be limited. Our findings were consistent with the literature. Because of the number of patients and the short follow-up period, further studies are needed.

Prevalence and risk factors of having antibodies to class I and II human leukocyte antigens in older haploidentical allograft candidates

The effect of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) has been recognized as a factor in graft failure (GF) in patients who underwent umbilical cord blood transplantation (UBT), matched unrelated donor transplantation (MUDT), or haploidentical stem cell transplantation (haplo-SCT). Presently, we know little about the prevalence of and risk factors for having anti-HLA antibodies among older transplant candidates. Therefore, we analyzed 273 older patients with hematologic disease who were waiting for haplo-SCT. Among all patients, 73 (26.7%) patients had a positive panel-reactive antibody (PRA) result for class I, 38 (13.9%) for class II, and 32 (11.7%) for both. Multivariate analysis showed that females were at a higher risk for having a PRA result for class II (P = 0.001) and for having antibodies against HLA-C and HLA-DQ. Prior pregnancy was a risk factor for having a PRA result for class I (P < 0.001) and for having antibodies against HLA-A, HLA-B and HLA-DQ. Platelet transfusions were risk factors for the following: having a positive PRA result for class I (P = 0.014) and class II (P < 0.001); having antibodies against HLA-A, HLA-B, HLA-C, HLA-DP, HLA-DQ, and HLA-DR; and having higher mean fluorescence intensity (MFI) of PRA for class I (P = 0.042). In addition, previous total transfusions were at high risk for having higher numbers of antibodies to specific HLA loci (P = 0.005), and disease course (7.5 months or more) (P = 0.020) were related to higher MFI of PRAs for class I. Our findings indicated that female sex, prior pregnancy, platelet transfusions and disease courses are independent risk factors for older patients with hematologic disease for having anti-HLA antibodies, which could guide anti-HLA antibody monitoring and be helpful for donor selection.

Clinical Prognosis of Renal Retransplant Patients: A Single-Center Experience

BackgroundRetransplantation is a treatment option in patients with end-stage renal failure due to graft loss. Outcomes of these patients due to high immunologic risk remain unclear. The aim of this study was to evaluate outcomes of renal retransplantation patients retrospectively. MethodsRenal retransplant patients in our unit were evaluated retrospectively between 2010 and 2018. Patients’ demographic characteristics, primary diseases, the causes of prior graft loss, immunologic status, desensitization protocols, the induction and maintenance treatments, the complications during the follow-up period, numbers of acute rejections, and the clinical prognosis were all detected from the patients’ files. ResultsWe retrospectively evaluated 17 patients who underwent a second or third renal allograft. Of these, 16 received a second and the remaining 1 patient received a third renal allograft. Immunologically, all of the 17 patients had negative flow cytometry crossmatch, 1 patient had a positive complement-dependent cytotoxicity crossmatch (Auto 12%), 16 patients had positive panel reactive antibody, the median HLA-mismatch was 3.5, and the score of donor-specific antibody relative intensity score (RIS) was 6.4 ± 6.3. Ten pretransplant patients had desensitization treatment. While scores for HLA-MM and HLA-RIS in the patients who had a desensitization therapy were determined higher, no statistical difference was observed (respectively, P = .28 and .55). No acute rejection episode developed. BK virus DNA viremia was detected in 4 patients during the posttransplant 6th month. We observed no patient death or no graft loss during the follow-up period. ConclusionAlthough the retransplant patients who had a graft loss previously have high immunologic risks, retransplantation is reliable in these patients, but they should be followed up carefully in terms of BKV nephropathy.

Renal Transplantation in High Immunological Risk Patients: A Single-Center Experience

BackgroundRenal transplantation (RT) in high-risk patients is increasingly performed due to an inadequate organ pool and increased rate of RT after a failed transplantation. Safety and prognosis of RT in such patients with high risk is an ongoing debate. Herein we aimed to present our single-center experience on RT of high-risk patients. MethodsA total of 89 consecutive RT patients were included into this study in a 10-month period. Patients were divided into 3 groups: the low-risk group (n = 47) with negative panel reactive antibody (PRA), medium-risk group (n = 18) with positive PRA but mean fluorescence intensity (MFI) < 2000, and high-risk group (n = 24) with positive PRA and MFI >2000 or donor specific antibody (DSA) positivity. Groups were compared in terms of demographic features, serum creatinine levels, acute rejection rates, delayed graft function (DGF), and patient or graft loss. ResultsAge of the recipients were similar between the groups. Desensitization (7% vs 11% vs 42%, respectively, in low-, medium-, and high-risk groups; P = .001), plasmapheresis (6% vs 11% vs 46%, respectively, P < .001), and rituximab treatments (0% vs 0% vs 25%, respectively, P < .001) were significantly more frequently performed in high-risk patients. Serum creatinine levels at 1 month and 6 months after RT were similar between the groups (P = .43 and P = .71, respectively). Rates of acute rejection (6% vs 6% vs 16%, respectively, P = .52) and DGF (9% vs 11% vs 29%, respectively, P = .15) were similar between the groups. Frequencies of loss of patient or graft were also similar (0% vs 6% vs 4%, P = .15). ConclusionRT may be successfully performed in high-risk patients without an increase in the risk of acute rejection, DGF, or patient/graft loss.

Outcome of Desensitization Therapy in Immunologically High-Risk Kidney Transplantation: Single-Center Experience

AimSensitization to HLA antigens creates an immunologic barrier, linked to an increased risk of antibody-mediated rejection and poorer graft survival, that remains a persistent and often impenetrable deterrent to transplantation. Desensitization can improve transplantation rates in broadly sensitized kidney transplant recipients. We aimed to compare the clinical outcomes of immunologic high-risk kidney recipients who had desensitization treatment with the outcomes of those who did not. Materials And MethodsWe retrospectively evaluated patients who underwent desensitization protocol due to immunologic risk between 2010 and 2018. Living-donor transplantation patients with panel reactive antibody positivity, retransplantation, donor specific antibody, and/or single antigen bead positivity were included in the study. We excluded deceased-donor transplantation recipients. Demographic data (age, sex, etiology of end-stage renal disease, blood transfusions, pregnancy, etc), immunologic status (HLA-mismatch [HLA-MM], panel reactive antibody, donor specific antibody, etc), induction and maintenance of immunosuppressive medications, and complications (all-cause hospitalizations, episodes of acute rejections, etc) were noted. We compared data and clinical outcomes of patients who had desensitization (Group 1) with data and clinical outcomes of patients who had not had desensitization (Group 2). FindingsThere were 124 living-kidney donors (49 female, mean age 43.7 ± 12.2 years, mean body mass index [BMI] 25.8 ± 5.8 kg/m2, mean follow-up time 20.9 ± 14.6 months). Thirty-four of these patients (25 female, mean age 43.7 ± 12.5 years, mean follow-up time 26.1 ± 17.7 months, mean BMI 27 ± 6.5 kg/m2) had desensitization treatment (rituximab+plasmapheresis for 19 patients, rituximab for 11 patients, rituximab+plasmapheresis+intravenous immunoglobulin for 4 patients). Ninety patients (24 female, mean age 43.7 ± 12.2 years, mean follow-up time 18.9 ± 12.9 months, mean BMI 25.3 ± 5.4 kg/m2) had not had desensitization. There was no statistical difference between groups for age, sex, hepatitis serology, history of blood transfusion, history of pregnancy, or history of dialysis (P < .05 for all parameters). While scores for HLA-MM and HLA-relative intensity scale (RIS) were 2.7 ± 1.6 and 7.86 ± 6.2, respectively, in Group 1, in Group 2 the same scores were 2.1 ± 1.1 and 3.6 ± 2.5, respectively (P: .053 and .03). Delayed graft function, acute rejection episodes, and hospitalizations were similar between groups (P: .47, .29, and .34, respectively). Follow-up time and length of hospitalization were longer in Group 1 (P: .013 and .001, respectively). Total doses of ATG were higher in Group 1 patients (P: .007). ConclusionDespite the higher HLA-MM and RIS scores, clinical outcomes in desensitized patients were found to be similar to those in nondesensitized patients for acute rejection episodes and hospitalizations. Desensitization with rituximab in patients with high HLA-RIS scores can prevent acute rejection and hospitalization.