MFI Values Research Articles

Clinical significance of low pre-transplant donor specific antibodies (DSA) in living donor kidney recipients with negative complement-dependent cytotoxicity crossmatches (CDCXM), and negative flow cytometry crossmatches (FLXM) – A single-center experience

BackgroundIt is controversial whether all donor-specific antibodies (DSA) detected by the solid-phase single antigen bead (SAB) assay negatively affect kidney transplantation outcomes. The study aimed to evaluate the possible clinical significance of low pre-transplant DSA in living donor kidney recipients. We analyzed a group of patients with HLA-A, B, and -DR DSA reactivities below a virtual crossmatch (VXM) value of 5000 MFI but with all VXM DSA reactivities at HLA-DQ, -DP, and -Cw, which were not typed routinely for donors prior to transplantation. We also investigated the incidence of persistent and de novo DSAs in available posttransplant SAB assays. MethodsFrom the historical cohort of living donor recipients transplanted between 2014 and 2018 at our center (n = 82), 55 patients met the inclusion criteria, namely: these patients were > 18 years old with non-HLA identical sibling donors, who were not desensitized, who had available pre-transplant SAB results, and who had negative both complement-dependent cytotoxicity crossmatch (CDCXM) and flow cytometry crossmatch (FLXM) results. An additional donor HLA typing, performed for all 55 recipients, identified donor additional HLA-DQ, -DP, and -Cw DSA reactivities. These patients were then divided by SAB reactivity into three groups: 1) those with DSA-positive reactivities; 2) those with non-donor-specific anti-HLA reactivities (NDSA); and, 3) those who were anti-HLA-negative. All these recipients were followed for three years and checked for their de novo or persistent DSA. ResultsIn the studied cohort, DSA-positive, NDSA reactive, and anti-HLA negative recipients constituted 33%, 36%, and 31% of 55 patients, respectively. Non-routinely considered pre-transplant HLA-DQ, -DP, and -Cw DSA-positive reactivities were shown in as many as 78% of DSA-positive cases (group 1) with the lowest MFI value of 319 to DP4 and the highest MFI of 5767 to DQ2. Of the pre-transplant HLA-A, B, and -DR DSA reactivities, only -DR52 DSA reactivity reached the highest MFI value of 2191. These detected DSAs did not reduce the mean estimated glomerular filtration rate (eGFR) values and did not increase the incidence of proteinuria in recipients. While the 3-year graft survival was lower in the DSA-positive group (94.4%) with one recipient who lost kidney transplant, the difference was not significantly different (p = 0.7) from the NDSA (100%) and negative (100%) groups. In terms of the incidence of de novo acute antibody-mediated rejection (AMR) at three years after transplantation, no case has been reported in the cohort. This may suggest that low DSA-positive recipients do not experience higher rejection rate. However, DSA-positive recipients had a tendency for a higher frequency of C4d deposits in peritubular capillaries (PTC) and de novo DSA. ConclusionOur 3-year follow-up of patients with low pre-transplant DSA found no association with a deterioration in graft function and worse graft survival. Furthermore, we did not observe an increase in AMR in our patients with low DSA. A larger cohort and a longer follow-up period may be needed to evaluate the tendency of low DSA-positive recipients towards the higher incidence of C4d deposits in PTC and/or de novo DSA.

Noncontrast T1ρ dispersion imaging is sensitive to diffuse fibrosis: A cardiovascular magnetic resonance study at 3T in hypertrophic cardiomyopathy

PurposeTo determine the sensitivity of a noncontrast T1 dispersion cardiovascular magnetic resonance technique for detecting diffuse fibrosis in hypertrophic cardiomyopathy (HCM). MethodsThirty-two adult HCM patients and ten age- and gender-matched healthy volunteers were prospectively included in this study. Patients and controls underwent cine, T1ρ-mapping, and pre- and post-contrast T1-mapping imaging using a 3-T magnetic resonance system. Myocardial extracellular volume fraction (ECV) maps were obtained using pre- and post-contrast T1 maps to determine reference values for diffuse fibrosis. Myocardial T1ρ and T1ρ dispersion maps called myocardial fibrosis index (mFI) maps provided 570 myocardial segments for Pearson or Spearman correlation analysis. The left ventricle myocardia of the HCM patients were divided into 16 segments that were further classified as either normal-thickness myocardium (<15 mm) (HCM-N) or hypertrophic myocardium (≥15 mm) (HCM-H). ResultsECV and mFI values increased progressively on a per-segment basis from healthy controls to the HCM-N group and then to the HCM-H group (ECV: 27.4 ± 2.8% vs. 31.1 ± 4.2% vs. 37.6 ± 6.9%, respectively [P < 0.0001]; mFI: 6.1 ± 0.9 ms vs. 8 ± 1.9 ms vs. 11 ± 3.3 ms, respectively [P < 0.0001]). There was a strong positive correlation between the segmented ECV and the mFI (r = 0.878). The mFI was equally or significantly better than the ECV for differentiating fibrosis content in HCM-N and HCM-H according to their receiver operating characteristic curves. ConclusionA T1ρ dispersion imaging mFI can sensitively detect diffuse myocardial fibrosis in HCM, even in HCM-N.

The Effect of Bentonite Using Edible Oil as a Dispersed Medium on the Rheological, Thermal and Water Absorption Properties of PBS/Bentonite Composites

Polybutylene succinate (PBS) with bentonite was investigated for its rheological, thermal and water absorption properties. The bentonite (BTN) was modified with soybean oil (SBO) and lard oil (LO) (2:98 clay: oil % by weight) by mechanical stirring and ultrasonication. The composites were prepared using an internal mixer and processed by compression molding. Under the bentonite modification conditions, XRD showed that the bentonite layers were penetrated with edible oils into the small layers and the enhancement of d-spacing between the BTN-layers in the composites. A small platelet-like structure of the modified bentonite composites was observed by SEM micrographs. The increase in MFI of untreated bentonite displayed the viscosity of PBS involving the moisture and water molecules decreased the frictional force. In addition, the viscosity of composites between PBS and treated bentonite with LO represented in an increase of the MFI value. Regarding the thermal properties, the presence of bentonite could act as a nucleating agent for PBS at low content (1-2%). Moreover, the treated with edible oils of bentonite could increase the percentage crystallinity of PBS at higher bentonite content. The presence of bentonite tends to increase the water absorption behavior of PBS/bentonite composites.

The effect of kenaf loading on kenaf/ABS composites structure and thermal properties

Many manufacturers have recently become interested in using fiber-reinforced polymer composites (FRPs) in structural applications. Synthetic fibres, such as carbon and glass fibres, have been commercialised internationally for decades, but they cause environmental issues because synthetic fibres are non-biodegradable and difficult to recycle once they have served their purpose, potentially polluting the environment. Thus, natural fibre composites like kenaf is a possible replacement for synthetic fibre due to their superior physical and mechanical properties. Kenaf appears to be the best candidate for replacing synthetic fibres in order to accomplish the goal of environmental preservation while also displaying excellent properties such as equivalent specific strength, low density, and renewable resources. The kenaf fiber was treated in KOH and added to ABS matrix to produce new composites at different loading (10, 15, 20 and 25 wt.%) by using Two Roll Mill machine. The influence of the fiber on the composites properties was evaluated. The produced material was subjected to SEM, MFI, TGA and DSC analysis. The incorporation of the treated kenaf fiber has an influence on the properties of kenaf/ABS composites. The addition of 10 wt.% kenaf was found to be the best loading with MFI value, initial degradation temperature and glass transition temperature at 0.8208 g/10 min, 322.63°C and 130°C respectively. The fiber was well dispersed in the matrix and shown good adhesion to the ABS. The addition of treated fiber contribute to a reduction in the MFI, improved the thermal stability of the composites and typical effects of Tg of the composite compare to pure ABS. The results suggest the need to continue the study in order to further analyse higher kenaf loading and shed more light on the properties of the composites to improve understanding of kenaf/ABS composites. Obtained results are a solution to alternative of synthetic fibers, which may contribute to the sustainable development of composites materials industry through the utilization of kenaf fiber with ABS matrix.

First Report of Daratumumab in Clinical Lung Transplantation

<h3>Purpose</h3> Antibody mediated rejection (AMR) after lung transplantation is difficult to treat and often results in death or graft loss. Therapies targeting antibodies or B cells are in many cases inadequate for decreasing donor specific antibodies (DSA), particularly when they are directed against MHC class II. Daratumumab (DAR) is a humanized anti-CD38 monoclonal antibody, which induces plasma cell death through multiple mechanisms including complement- dependent cytotoxicity, antibody-dependent phagocytosis, and apoptosis. Based on these properties it may have the potential to reduce the amount of DSAs and therefore improve outcome after AMR. <h3>Methods</h3> Retrospective analysis of all patients who received daratumumab as an add on rescue therapy for AMR or for desensitization pre/post-transplant at our center. <h3>Results</h3> Six patients received daratumumab due to the following reasons: 5 patients with de novo DSAs and AMR, 1 patient with pre-transplant DSAs and post-transplant immunadsorption without clinical AMR. Daratumumab was safely administered with just mild infusion reactions and no severe adverse event. Of not, none of the patients developed and infectious complication. Five of the 6 patients showed a significant decrease of their DSAs with a reduction of MFI values after 6-8 weeks to <50% of the baseline . Despite this early success, four patients developed CLAD (,two of which required retransplantation. The remaining two patients stabilized with their lung function and did not develop CLAD. <h3>Conclusion</h3> Treatment for AMR remains challenging, especially in the presence of class II HLA antibodies. Daratumumab might be a promising addition to the AMR treatment panel, prospective clinical studies are needed.

Variances in Humoral Responses to Different Spike Protein Domains After SARS-CoV-2 Vaccination in Lung and Heart Transplant Recipients

PurposeSolid organ transplant recipients are lacking an adequate immune response to SARS-CoV-2 vaccination. Therefore, these patients are still at risk and potentially in need of booster vaccinations. Furthermore, it is important to differentiate between the recipients of distinct organs. The efficacy of SARS-CoV-2 vaccination is usually examined via antibodies specific for the spike protein with assays containing the S1 and receptor-binding-domains (RBD) and rather rarely the S2 domain. To gain information about the humoral response in Tx recipients, it is feasible to compare the immunogenicity of these three domains. To address this, we compared the IgG antibody levels specific for the three spike protein domains in heart (HTx) vs lung (LTx) transplant recipients.MethodsBlood plasma 4-6 weeks after the second dose of SARS-CoV-2 vaccination (85% mRNA) of n=100 LTx and n=40 HTx patients was analysed for S1, S2 and RBD-specific IgG antibodies by Luminex-based multiplex assays. The threshold for positive antibody responses was set separately for each spike domain based on the median MFI + 2σ in an unexposed pre-pandemic control group.ResultsFor all three spike protein domains, HTx patients showed a significantly higher rate of positive IgG responses than the LTx patients (73% vs 43%). The comparison of MFI values for S1-, S2- and RBD-specific IgG further underlines the superior antibody response by HTx patients with higher MFI values for S1 (p = 0.0001, S2 p = 0.008, RBD p < 0.0001). In the LTx cohort, MFI values for S2- (p < 0.0001) as well as for RBD-specific IgG (p < 0.0001) were higher than for S1. The same applies for S2 vs S1 (p < 0.0001) and RBD vs S1 (p = 0.0018) in the HTx cohort. Comparing the MFI of S2 vs RBD, the levels of domain-specific IgG were higher for S2 than RBD in both LTx (p < 0.0001) and HTx patients (p = 0.0914).ConclusionHTx patients exhibit a moderately good IgG response to vaccination while LTx recipients show lower antibody responses. Based on the more efficient antibody production against S2 as opposed to the RBD and especially S1-domain, the S2-specific IgG response should be taken into consideration when evaluating the general immune response and the resulting protection after SARS-CoV-2 vaccination in transplant recipients. Both groups of patients might benefit from booster vaccinations.

The Pre-Transplant Non-HLA Antibody Burden Associates With the Development of Histology of Antibody-Mediated Rejection After Kidney Transplantation

BackgroundMany kidney allografts fail due to the occurrence of antibody-mediated rejection (ABMR), related to donor-specific anti-HLA antibodies (HLA-DSA). However, the histology of ABMR can also be observed in patients without HLA-DSA. While some non-HLA antibodies have been related to the histology of ABMR, it is not well known to what extent they contribute to kidney allograft injury. Here we aimed to investigate the role of 82 different non-HLA antibodies in the occurrence of histology of ABMR after kidney transplantation.MethodsWe included all patients who underwent kidney transplantation between 2004-2013 in a single center and had biobanked serum. Pre- and post-transplant sera (n=2870) were retrospectively tested for the presence of 82 different non-HLA antibodies using a prototype bead assay on Luminex (Immucor, Inc). A ratio was calculated between the measured MFI value and the cut-off MFI defined by the vendor for each non-HLA target.Results874 patients had available pretransplant sera and were included in this analysis. Of them, 133 (15.2%) received a repeat kidney allograft, and 100 (11.4%) had pretransplant HLA-DSA. In total, 204 (23.3%) patients developed histology of ABMR after kidney transplantation. In 79 patients (38.7%) the histology of ABMR was explained by pretransplant or de novo HLA-DSA. The multivariable Cox analysis revealed that only the broadly non-HLA sensitized (number of positive non-HLA antibodies) patients and those with the highest total strength of the non-HLA antibodies (total ratios of the positive non-HLA antibodies) were independently associated with increased rates of histology of ABMR after transplantation. Additionally, independent associations were found for antibodies against TUBB (HR=2.40; 95% CI 1.37 – 4.21, p=0.002), Collagen III (HR=1.67; 95% CI 1.08 – 2.58, p=0.02), VCL (HR=2.04; 95% CI 1.12 – 3.71, p=0.02) and STAT6 (HR=1.47; 95% CI 1.01 – 2.15, p=0.04). The overall posttransplant non-HLA autoreactivity was not associated with increased rates of ABMRh.ConclusionsThis study shows that patients highly and broadly sensitized against non-HLA targets are associated with an increased risk of ABMR histology after kidney transplantations in the absence of HLA-DSA. Also, some pretransplant non‐HLA autoantibodies are individually associated with increased rates of ABMR histology. However, whether these associations are clinically relevant and represent causality, warrants further studies.

207.5: Impact of HLA Donor Specific Antibodies in the Era of Cell Therapy: Clinical Trajectories in Islet Allotransplantation Illustrate a Challenging Model

Introduction: Islet transplantation is a unique paradigm in the case of organ transplantation, since multiple injections and donors are required to achieve complete insulin-independence. Preformed or de novo DSAs may target one or several donor islets, which complexifies the analysis of their impact. Our objective is to discriminate illustrative clinical trajectories which can occur after transplantation. Methods: Adult type 1 diabetic pancreatic islet recipients transplanted between January 2005 and December 2018, were included in a monocentric observational study. Only patients with available sera tested by Luminex for Class I and II anti-HLA antibodies during their whole follow-up were analyzed. Results: 32 patients had a complete HLA antibodies screening during follow-up. Among them, 7 patients presented with DSA. Five clinical trajectories were identified according to the MFI-value, and the presence of preformed DSA, de novo DSA, or both. To simplify, we provide specific clinical-based trajectories considering an islet transplantation with 1- high MFI preformed DSA, 2- high MFI de novo DSA, 3- low-MFI preformed DSA, 4-low de novo DSA, and 5- a de novo DSA which becomes a preformed DSA because of multiple islet infusions. We analyzed also the specific case of islet-after-kidney transplantation. Recipients transplanted with preformed DSA had all favorable islet transplantation outcomes. The prognosis of de novo DSA was associated with unfavorable outcomes when following markers of unsteady glycemic control. Conclusion: Clinical-based trajectories and evidence from the literature reveal that islet transplantation with preformed DSA, even with high MFI values, can be associated with favorable outcomes. The fate of recipient presenting with de novo DSA is more questionable as both clinical data and preclinical studies show separate outcomes. Clinical phenotype and unsteady glycemic control before the emergence of DSA may lead the clinician to detect rejection.I-SITE ULNE.

PA6/PA66/talc composite: Effect of reprocessing on the structure and properties

AbstractIn this study the effect of repeated injection molding cycles on the structure and properties of polyamide 6/polyamide 66/talc (PA6/PA66/talc ‐ 35/35/30) composite was investigated for samples subjected to one, four, and seven processing cycles. Their morphology (scanning electron microscopy), structure (Fourier transform infrared spectroscopy), melt viscosity (melt flow index [MFI]), mechanical (tensile, flexural, impact, and fatigue tests), and thermal properties (differential scanning calorimetry and thermogravimetric analysis tests) were analyzed. The increase in MFI value and the decrease in the maximum decomposition temperature of PA6, observed by TG analysis, for samples subjected to seven processing cycles, indicated a possible reduction in molar mass of the PA6/PA66 matrix. These samples presented a decrease in degree of crystallinity of PA6 and PA66, which was more pronounced for PA6. The reprocessing of the composite did not present changes in the mechanical properties up to the fourth processing cycle, except for fatigue life which presented a 59% reduction. Samples subjected to seven processing cycles presented a decrease in tensile and flexural strength as well as in tensile and flexural modulus. Charpy impact strength of the samples did not significantly change upon reprocessing. The micrographs of the fatigue fractured surfaces indicated that the weak talc‐matrix interaction and talc‐matrix debonding became more evident with increasing processing cycles.

Diagnostic, Prognostic, Predictive, and Monitoring Role of Neutrophil CD11b and Monocyte CD14 in Neonatal Sepsis.

Background Sepsis is a critical medical condition that requires additional diagnostic considerations. Recently, focus has shifted to the diagnosis of sepsis using new markers to overcome the limitations of traditional laboratory diagnostic modalities. Neutrophil CD11b (nCD11b) and monocyteCD14 (mCD14) cell surface antigens have been shown to be useful in such diagnostic consideration. Aim To investigate the diagnostic, monitoring, prognostic, and predictive roles of nCD11b and mCD14 as sepsis biomarkers in comparison to each other and to traditional laboratory sepsis parameters in order to select the best fit for routine daily use in neonatal intensive care units (NICUs). Subject The study included 188 neonates from Ain Shams University Hospitals' NICUs, who were divided into two groups: the control group (n = 100) and the sepsis group (n = 88). Highly sensitive CRP (hs-CRP), complete blood count (CBC), blood culture, and nCD11b and mCD14 evaluations were all part of the laboratory sepsis evaluation (done by flow cytometry technology). Positive blood culture results (BACT/ALERT system) confirmed the sepsis diagnosis. Twenty-four enrolled sepsis neonates were subjected to follow-up assessments, and they were divided into two groups based on clinical improvement: improved sepsis and sepsis without improvement. In order to predict performance evaluation, the subjected neonates were reclassified according to their outcome into survivors' and nonsurvivors' group. Results Sepsis patients had a significant increase in mCD14 MFI values when compared to controls. With sensitivity 75.4 percent, specificity 71.9 percent, efficacy 73.3 percent, and AUC 0.703, mCD14 MFI at cutoff 9.36 could distinguish the presence of septicemia. Significant increases in both mCD14 MFI and nCD11b MFI (P = 0.001) were observed in the severe sepsis/septic shock group compared to the nonsevere sepsis group. The combined measurement of CD14 MFI at cutoff 9.97 and CD14 percent at cutoff 44.7 percent yielded the best predictive performance. Conclusion Sepsis patients had a significant increase in mCD14 MFI comparable to the controls. mCD14 MFI demonstrated better diagnostic, prognostic, and predictive results than nCD11b. hs-CRP outperformed mCD14 and nCD11b in terms of diagnostic efficacy and AUC. In the monitoring of sepsis patients, both mCD14 and nCD11b produced unsatisfactory results. Currently, the routine use of mCD14 or nCD11b as sepsis biomarkers in neonatal ICUs is not justified.

Modification of asphalt binder by the blend of chemically grafted thermoplastics and SBS: Influence of blend composition, chemical grafting, sulphur content, and MFI value

Modification of asphalt binder by the blend of chemically grafted thermoplastics and SBS: Influence of blend composition, chemical grafting, sulphur content, and MFI value

Overexpression of KMT2E Is Associated with Higher Granulocytic Differentiation Rate in Response to ATRA-Based Treatment in Acute Promyelocytic Leukemia Cell Lines

Introduction: In the clinical setting, low KMT2E expression has been associated with poor prognosis in both acute myeloid leukemia (Damm et al. J Clin Oncol. 2011 Feb 20;29(6):682-9) and acute promyelocytic leukemia (APL) (Lucena-Araujo et al. Br J Haematol. 2014 Aug;166(4):540-9). Member of the Trithorax-group, the KMT2E is implicated in the positive transcriptional control of a specific set of genes related to hematopoiesis and differentiation processes in many cell types. Functional analyses showed that the encoded protein is involved in terminal myeloid differentiation and facilitate retinoic-acid induced granulopoiesis in human promyelocytes. Using lentiviral gene transfer, we hypothesized that the forced expression of KMT2E is implicated in the ATRA-induced granulocytic differentiation in APL. Aims: To investigate the effects of overexpression of KMT2E gene in cell viability and signaling in response to ATRA plus anthracycline or arsenic trioxide (ATO) treatment in APL cell lines. Methods: NB4 and NB4-R2 (resistant to ATRA treatment) cell lines were transduced with pMEG or pMEG- KMT2E lentiviral vectors and cultured with stable selection using puromycin. Before all functional experiments, cells were tested for KMT2E gene and protein expression by qPCR and confocal microscopy, respectively. The cells transduced with KMT2E and control cells were evaluated for cell viability (MTT assay), proliferation (Ki-67 staining), cell cycle (flow cytometry), mitochondrial reactive oxygen species (ROS) production (flow cytometry) in basal conditions and under treatment with ATRA (1 μM), ATO (0.187, 0.375, 0.75, 1.5 and 3 μM), and the association of ATO (1 μM) plus ATRA (1 μM) or cytarabine (150 nM). The granulocytic differentiation in response to ATRA treatment was evaluated based on the CD11b expression (flow cytometry) plus morphological analysis (Leishman staining). The expression of the main target genes (p21, MDM2, and BMI1) encoding for proteins known to be involved in KMT2E function were evaluated by qPCR. Results: Overexpression of KMT2E was significantly associated with higher cell proliferation rates in basal or ATO and cytarabine treatment compared to vehicle treated cells (all P<.001). KMT2E overexpression significantly increase cell proliferation in NB4, but not in NB4-R2 cells (Ki-67 mean intensity of fluorescence (MFI) value - pMEG: 489±10 vs KMT2E : 1432±25; P<.001). The distribution of cells in the phases of the cell cycle was similar between groups. Using a nonlinear regression analysis, IC50 for ATO was of 2.96 and 6 μM for NB4 pMEG and KMT2E transduced cells, respectively. NB4- KMT2E cells showed lower levels of ROS generation upon ATO treatment (1.5 μM) compared to controls (ROS - MFI value - pMEG: 270.6±6 vs KMT2E : 84±11; P <.001). In the attempt to assess the role of KMT2E in granulocytic differentiation, NB4- KMT2E cells were treated with ATRA 1 μM. The cells containing an extra copy of KMT2E gene showed more differentiation rate in 72, 96 and 120 hours compared to empty vector transduced cells (all p<.05). Considering the expression of target genes of KMT2E, only p21 showed an increase in KMT2E cells treated with ATRA. Conclusion: In summary, the overexpression of KMT2E is associated with higher proliferation capacity and increased resistance to ATO treatment, associated with less ROS generation. DisclosuresNo relevant conflicts of interest to declare.

The association between preoperative modified frailty index and postoperative complications in Chinese elderly patients with hip fractures

ObjectivesTo investigate the role of a preoperative modified frailty index (mFI) based on data from medical records in predicting postoperative complications among older Chinese patients with hip fractures.MethodsThis retrospective cohort study included consecutive older patients with hip fracture admitted to the Department of Orthopaedics, West China Hospital, Sichuan University, from December 2010 to June 2017 who underwent surgical repair. We selected 33 variables, including characteristics of hip fracture, to construct a mFI. Each variable was coded with a value of 0 when a deficit was absent or 1 when it was present. We calculated the mFI as the proportion of positive items and defined frailty as mFI value greater than or equal to 0.21 according to threshold proposed by Hoover et al. We examined the relationship between mFI and severity of postoperative complications and the occurrence of in-hospital pneumonia including statistical adjustment for several demographics (e.g. age, gender, and marital status) and habits (smoking and alcohol intake), time from fracture to surgery in the multivariable model.ResultsWe included 965 patients (34% male; mean age: 76.77 years; range: 60 to 100 years) with a prevalence of frailty of 13.06%. The presence of frailty was associated with a higher severity of complications (OR: 2.07; 95% CI: 1.40 to 3.05). Frail patients were more likely to develop in-hospital pneumonia than non-frail patients (OR: 2.08; 95% CI: 1.28 to 3.39).ConclusionThe preoperative modified frailty index based on data from medical records proved significantly associated with postoperative complications among older patients with hip fractures undergoing hip surgery.

Impact of C1q fixing donor-specific antibodies on renal transplant outcome.

Not all anti-HLA donor-specific antibodies (HLA-DSAs) are detrimental to renal allograft. In this context, the C1q complement activating ability of antibodies appears to be an important parameter to distinguish clinically inert versus detrimental DSAs. We evaluated sera of 206 consecutive primary live donor renal transplant recipients before transplant and at post-operative day 7, 30, 90, 180 and at the time of graft dysfunction for quantifying HLA-DSAs using single antigen bead assay on a Luminex platform. Patients positive for these antibodies with an MFI >500 were further screened for C1q fixing nature of DSA. Fourteen of the 18 antibody-positive patients had C1q fixing DSA with MFI value >5000. Only 4 antibody-positive patients did not have C1q fixing DSA. The MFI values of DSA detected by C1q assay were generally higher at least by 25% than those detected by the conventional IgG-SAB assay. Twelve of the 14 patients (85.71%) with C1q+ DSA developed antibody-mediated rejection during the mean follow-up period of 21.43±8.03months as compared to none of the four C1q-negative DSA (85.71% vs 0%; P=.001). These results suggest deleterious effect of C1q+ DSA vis-à-vis C1q-negative DSA on renal allograft.

Abstract PO048: CD40/anti-PD-1 sequential immunotherapy outperforms multiple immunotherapy combinations in an oral cancer prevention mouse model

Abstract PD-1 checkpoint inhibitors pembrolizumab and nivolumab are approved for the treatment of recurrent or metastatic oral squamous cell carcinoma (OSCC). Previously we have demonstrated that PD-1/PD-L1 pathway blockade can reduce the progression of oral premalignant lesions (OPL) to carcinoma in the 4-NQO carcinogen-induced murine model of OSCC. Furthermore, pembrolizumab is currently being evaluated for prevention of OSCC in patients with high risk OPLs in the Immune Prevention of Oral Cancer clinical trial (NCT02882282). Building on these earlier studies, here we have conducted pre-clinical evaluation of other possible targets including CD40, OX40, and 4-1BB for the immunoprevention of OSCC, and determined the impact of combined or sequential treatment with PD-1/PD-L1 pathway blockade. We treated C57BL/6 mice with the carcinogen 4-nitroquinoline 1-oxide for 8 weeks in drinking water. Eight weeks after discontinuing 4-NQO, mice were treated with either IgG (n: 20), used as control group, anti-PD-1 monotherapy, concomitant anti-PD-1+OX4, anti-PD-1+CD40, anti-PD-1+4-1BB, or OX40, CD40, and 4-1BB followed by anti-PD-1 therapy (n:10 treatment groups). Mice were sacrificed 8 weeks after treatment. We assessed serial H&amp;E-stained cross sections of tongues harvested at the same time point for total OSCC area. Tumor draining lymph nodes (TDLN) lymphocytes were analyzed by flow cytometry. Anova and Mann-Whitney test were used for statistical comparison. Treatment of mice harboring OPLs with CD40 followed by anti-PD-1 immunotherapy resulted in a decrease in the median total OSCC area when compared with our IgG control group (p= 0.034). Treatment with anti-PD-1 monotherapy showed a trend towards reducing progression of OPL to OSCC. Concomitant therapy with CD40 and anti-PD-1 along with the other combination immunotherapy regimens did not demonstrate any significant reduction in the progression of OPL to OSCC. Treatment with sequential CD40+anti-PD-1 increased both the CD8+PD-1+ lymphocyte population and the MFI values for PD-1 in the CD4+Foxp3- population in TDLN. When the TDLN of both concomitant and sequential 4-1BB+anti-PD-1 treatment groups were analyzed, a decrease in the CD4+PD-L1+ population, and an increase in both CD8+PD-1+ population and CD8/CD4+PD-L1+ ratio was found, although this change in the immune milieu was not associated to a reduction of OPL progression to OSCC. Targeting CD40 and PD-1 pathways sequentially, but not concomitantly, during the OPL stage led to a reduction in the progression of OPL to OSCC. The TDLN analysis of this treatment group revealed an increase in both CD8+PD-1+ lymphocytes and MFI values for PD-1 in CD4+Foxp3- lymphocytes. No other treatment group was able to significantly reduce progression of OPL to OSCC or showed a similar modulation of the lymphocyte population. These results support further investigation on how sequential CD40+anti-PD-1 immunotherapy hinder tumor immune evasion, making it a potential regimen for prevention of OSCC. Citation Format: Jose A. Monteiro de Oliveira Novaes, Alissa Poteete, Marlese Pisegna, William N. William, John V. Heymach. CD40/anti-PD-1 sequential immunotherapy outperforms multiple immunotherapy combinations in an oral cancer prevention mouse model [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO048.

Perioperative Management for Liver Transplantation with DSA Positive Patients

Background: Liver transplantation is an accepted treatment for end-stage liver disease. Despite improvements of the surgical techniques, organ preservation methods, and immunosuppressive therapy, antibody mediated rejection is still big problem. It has been reported that the existence of donor-specific antibodies (DSA) is correlated with rejection and with an increased risk of early mortality. We described our treatment and prognosis about the patient who has undergone liver transplantation with DSA. Methods: 16 patients among 87 patients of recipient who has undergone liver transplantation in our department from September 2011 to December 2018. In each patient, the type of DSA and the MFI were measured before liver transplantation. A high DSA titer was defined as a normalized, trimmed MFI value ≥10000. Patients received the standard immunosuppressive protocol for liver transplantation, including steroids, tacrolimus, and mycophenolate mofetil, with addition of rituximab more than two weeks before transplantation and took medication such as tacrolimus and mycophenolate mofetil one week before the transplantation. During operation, each patient underwent splenectomy. Results: 7 patients have high titer DSA, and each patient has a desensitization method that described before. Only one patient was dead because of other disease. 9 patients are still arrived without severe rejection. Conclusion: If the patients who has DSA was undergone right desensitization methods, we can get good survival rate.

HLA Class II Positivity by Lysate Crossmatch in Renal Transplant Scenario-Dangerous if Ignored!!!

The detection of antibodies before transplantation is an important step in assessment of patient immunological risk and exclusion of incompatible donors. Many centers have now implemented donor-specific antibody (DSA) along with complement-dependent cytotoxicity crossmatch (CDC XM) for renal transplant cases. A 34-year-old male with end-stage kidney disease was referred for an ABO-compatible transplant from his mother. The CDC XM done 30 days before transplant was negative. DSA XM was negative for Class I (median fluorescence intensity [MFI] 189) and positive for Class II (MFI 1671). Since CDC and DSA Class I were negative, the nephrologists went ahead with the transplantation. On day 6 posttransplant, serum creatinine showed a rising trend (up to 2.13 mg/dl), and therefore, renal biopsy was done which showed mild acute tubular necrosis with positive C4d staining. DSA XM performed on day 15 posttransplant showed negative Class I (MFI 148) and positive Class II (MFI 9987) confirming antibody-mediated rejection (AMR). The patient was started on steroids, and intravenous immunoglobulin and serial plasma exchanges were performed. Then, DSA Class II levels came down to 1602. DSA levels have been monitored periodically and Class II MFI values have been ranging from 2000 to 4000. The patient is maintained on routine immunosuppression, and a graft is intact with serum creatinine level between 1.7 and 1.8 mg/dl 8 months posttransplant. DSA-isolated Class II positivity in renal transplant recipients correlates strongly with AMR and should be considered clinically significant.

Comparative analysis of complement-dependent lymphocytotoxicity crossmatch and flow cytometry crossmatch results versus Luminex single-antigen bead-based donor-specific IgG class I antibody MFI values in live related renal transplant cases; a retrospective observation in 102 cases

ABSTRACT The aim of this study was to compare the results of solid phase assay and cell-based assay, and explore the near-accurate DSA-MFI-cutoff value detected on solid phase assay above which the cell-based assay would show a positive result. In this retrospective study, 102 prospective renal transplant recipients were tested for the presence of donor-specific antibodies (DSAs) by cell-based assay (T-cell-CDC-AHG-XM and T-cell-IgG-FC-XM) and solid phase assay (class-I-IgG-L-SAB) with their corresponding donor. Among the 40 patients in the group first (L-SAB-DSA-MFI<1000), one case was positive in IgG-T-cell-FC-XM while T-cell-CDC-AHG-XM was negative in all the cases. In the second group having L-SAB-DSA-MFI values between 1000 and 3000, 19 cases were positive and the remaining 11 cases were negative in IgG-T-cell-FC-XM. T-cell-CDC-AHG-XM showed a negative reaction in all 30 cases. In the third group having L-SAB-DSA-MFI values between 3000 and 5000, IgG-T-cell-FC-XM was positive in 18 cases while, two were negative. T-cell-CDC-AHG-XM demonstrated a negative result in 14 cases while reaming six cases demonstrated a positive result. In the fourth group having L-SAB-DSA-MFI values >5000, all 12 cases showed a positive result in both IgG-T-cell FC-XM and T-cell-CDC-AHG-XM. Our results indicated that the L-SAB-DSA-MFI values >2215 were significantly (P < .001) correlated with positive IgG-T-cell-FC-XM while L-SAB-DSA-MFI values >4689 were significantly (P < .001) correlated with positive CDC-XM.

LRP1/CD91 is highly expressed in monocytes from patients with vitiligo - even after repigmentation.

Vitiligo pathophysiology is mediated by antigen-specific cytotoxic T cells. Environmental stressors cause susceptible melanocytes to secrete damage-associated molecular patterns (DAMPs). DAMPs are recognized by receptors such as the endocytic low-density lipoprotein receptor-related protein (LRP1/CD91), expressed in antigen-presenting cells, which activate self-reactive CD8+ T cells, leading to melanocyte destruction. Within this response, interferon gamma triggers production of cytokine CXCL10, recruiting more activated T cells causing further melanocytic damage. We hypothesized that expression of LRP1/CD91 was higher in vitiligo patients compared to non-vitiligo individuals. And further that levels/expression of CXCL10 in plasma were linked to disease severity. We enrolled forty individuals in this study: 18 patients with vitiligo and 22 healthy volunteers. We assessed LRP1/CD91 expression and plasma CXCL10 in patients with vitiligo and healthy volunteers. Additionally, vitiligo patients received combined treatment for 16weeks following which the said parameters were reassessed. Vitiligo Area Scoring Index was calculated before and after treatment for these patients. Analysis of LRP1/CD91 MFI values in monocytes from vitiligo patients showed high surface levels of LRP1/CD91 than from healthy volunteers (10.50±0.77 vs. 6.55±0.77 MFI units, p<0.001). This expression did not change after treatment. Plasma levels of CXCL10 were higher in vitiligo patients than healthy volunteers (93.78±7.73 vs. 40.17±6.25pg/ml). The patients with a good clinical response to treatment had a parallel reduction in plasma CXCL10 levels (105.8±18.44 vs. 66.13±4.87pg/ml) before and after treatment. LRP1/CD91 expression may reflect susceptibility to vitiligo. Plasma levels of CXCL10 can represent a biomarker for monitoring treatment response. LRP1 and CXCL10 may represent therapeutic targets.

Hybrid nanocomposites of elastomeric polyurethane containing halloysite nanotubes and POSS nanoparticles: tensile, hardness, damping and abrasion performance

AbstractThermoplastic polyurethane (TPU) matrix was reinforced with polyhedral oligomeric silsesquioxane (POSS) and halloysite nanotubes (HNT), both separately and combined. Composite samples were fabricated using a melt-compounding method. Characterization of the composites obtained was performed via tensile and hardness tests, melt-flow index measurements (MFI), abrasion tests, dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM) to investigate the mechanical performance, flow behaviour, tribological characteristics, thermo-mechanical response and morphological properties. The greatest tensile strength value was obtained for the smallest HNT content. Further addition of HNT resulted in agglomerations for both POSS and HNT particles. The shore hardness of TPU was enhanced by filler inclusions. The TPU/POSS composites displayed significant improvement in terms of abrasion resistance compared to TPU at lower loading levels. The DMA study showed that composites containing 0.5% POSS and 1.0% HNT displayed the greatest storage modulus. The glass-transition temperature of TPU shifted to smaller values with the addition of both nanoparticles. The HNT inclusions increased the MFI value of TPU because of their large aspect ratio. Homogeneous mixing of nanoparticles in the TPU matrix was confirmed by a SEM study of the composites. Their dispersion decreased as the concentrations of POSS and HNT increased. An adjuvant effect of POSS with HNT was achieved in their hybrid composites.