Severity Of Cellular Rejection Research Articles

Impact of the graft cold ischemia time on severity of cellular rejection and the outcome of heart transplantation

Impact of the graft cold ischemia time on severity of cellular rejection and the outcome of heart transplantation

Role of PD-L1 in heart transplant rejection

Abstract Background Acute cellular rejection remains a major cause of morbidity after heart transplantation with up to 30% of patients experiencing at least one rejection episode during the first year. Unfortunately, the mechanism underling rejection remains poorly understood and the gold standard for diagnosing rejection remains frequent cardiac biopsy for rejection surveillance – a process that is both invasive and costly. Purpose PD-L1 is a co-inhibitory transmembrane protein that interacts with PD-1 on T cells to inhibit T cell activation. Endothelial PD-L1 expression in the heart has been shown in mouse models to play a key role in attenuating immune-mediated cardiac disease like myocarditis. Recent data that anti-PD-1 and anti-PD-L1 therapy can lead to myocarditis further supports a role for PD-1/PD-L1 signaling in cardiovascular homeostasis. We hypothesize that PD-L1 expression correlates with rejection severity. Methods Endomyocardial biopsy from a cohort of 19 heart transplant patients were analyzed for PD-L1 expression using immunohistochemistry and image analysis with HALO software. Each patient had biopsies corresponding to 0R, 1R, and 2R grades of rejection (n=57) and thus each patient served as their own internal control. Detailed clinical data was also collected on these patients from the electronic medical record. Results Average PD-L1 levels associated with 0R (n=19), 1R (n=21), and 2R (n=17) rejection were 1.54, 9.15, and 18.90 respectively (P<0.001). In patients who were treated for 2R rejection with increased immunosuppression (n=9), PD-L1 levels decreased from an average of 21.72 before treatment to an average of 5.64 after treatment (P<0.05). A multiple regression was run to see if PD-L1 level was associated with right heart pressures, EKG intervals, echo data, or common lab values. Accounting for age, race, and sex, it was found that PD-L1 was significantly associated with PA pressure (P<0.01, beta = 0.45), PCW pressure (P<0.01, beta = 0.42), and BNP (P<0.01, beta = 0.55). Conclusions Upregulation of PD-L1 in the heart is strongly associated with severity of cellular rejection after heart transplantation. Successful treatment of rejection with immunosuppression decreases PD-L1 levels. These data suggest that PD-L1 is a potential biomarker for heart transplant rejection. Further correlation of PD-L1 levels with signs of right heart strain (increased PA and PCW pressure) and systolic dysfunction (BNP) supports a clinical picture of PD-L1 as a useful biomarker for detecting both cellular rejection and reversal of rejection after treatment. Cohort identification and results Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health grants R56 HL141466 and R01 HL141466

Abstract 18729: Serum Heat Shock Protein-70 is Associated With Decreased Frequency and Severity of Cellular Rejection in Cardiac Transplant Patients

Background: Heat Shock Protein-70 (HSP70) is a highly conserved intracellular protein that is up-regulated in cells undergoing stressful stimuli. A recent study demonstrated an inverse relationship between HSP70 expression and cellular rejection grade in endomyocardial biopsies (EBx)from cardiac transplant patients. Peripheral blood based HSP70 levels have not been studied in such individuals. We hypothesized that serum HSP70 levels will be associated with severity of cellular rejection in cardiac transplant patients. Methods: 177 cardiac transplant patients (56 ± 13 years; 8.5 ± 5 years mean time from transplant) were recruited from the Emory Cardiovascular Biobank from 2004-2012. Cellular rejection was defined based on revised International Society of Heart and Lung Transplant (ISHLT) grade of 1R or higher seen on EBx. Frequency of rejection was collected from time of transplant to enrollment date. Serum HSP70 was measured using ELISA and analyzed as detectable vs non-detectable. Nonparametric correlations and ANOVA were used to study univariate relationships while linear and ordinal logistic regression (adjusted for age, gender, race, length of time since transplant, and immunosuppressant medications) were performed to analyze the relationship between HSP70 levels and frequency and severity of cellular rejection respectively. Results: HSP70 was detectable in 35% of patients with grade 0R ISHLT class, 33% for grade 1R, 16% for Grade 2R, 0% for Grade 3R (p for group=0.005). There was an inverse correlation between HSP70 and frequency of rejection (r= -0.2, p= 0.03) with 34% of those with detectable HSP70 in the lowest quintile based on frequency of rejection whereas 9% was detected in the highest quintile (p=0.019). In adjusted regression models, HSP70 remained a significant independent predictor of a) ISHLT class with an OR of 0.43 (p=0.02) and b) frequency of rejection (β=-1.5, p=0.05). Conclusion: Detectable serum HSP70 is associated with decreased frequency and severity of cellular rejection in post cardiac transplant patients. The utility of HSP70 as a marker of graft function needs further study.

The Presence of HLA-Directed Antibodies after Heart Transplantation Is Associated with Poor Allograft Outcome

The clinical significance of HLA-directed antibodies newly detected after transplantation (HT) is controversial. Seventy-one HT recipients consented to enroll. Mean follow-up time was 28 months (range 6-48). Panel reactive antibody (PRA) analysis was performed on posttransplant sera (2 weeks, 1, 2, 3, 6, and 12 months and annually thereafter) using Flow-PRA. A mean of 6.9+/-1.2 serum samples per patient were obtained. Severity of cellular rejection was measured using the ISHLT grading system. Coronary angiography and intravascular ultrasound (IVUS) studies were performed annually to evaluate severity of allograft vasculopathy. Twenty-five recipients had newly detected HLA-directed antibodies during the first year postHT. HLA class I antibodies were detected in 18 patients (25.4%), and class II in 11 patients (15.5%). The majority of donor recipient pairs were HLA mismatched (4.6+/-1.2 of the six major HLA antigens). Only mismatches at HLA-A locus had significant association with de novo posttransplant antibody formation. Length of ischemia time was correlated with early and sustained presence of de novo HLA-directed antibodies postheart transplant. Importantly, an association between de novo HLA-directed antibodies and cellular rejection was notes (P=0.0002). De novo HLA class II directed antibodies are also associated with IVUS documented vasculopathy (P<0.002). Finally, death due to allograft failure is associated with the presence of de novo formed HLA class II directed antibodies (P=0.008). Identifying the formation of de novo HLA-directed antibodies following heart transplantation may predict allograft outcome. This, in turn, may serve as a tool for individualization of immunosuppression protocols in heart transplant recipients.

Comparison of Cyclosporine Concentrations 2 Hours Post-Dose Determined Using 3 Different Methods and Trough Level in Pediatric Renal Transplantation

Immunosuppression has been one of the great challenges in pediatric recipients of kidney allografts. Cyclosporine (CsA) has evolved during the past 25 years of transplantation. It requires frequent blood level monitoring because of its narrow therapeutic window and interpatient and intrapatient variability. Neoral (Novartis) is no exception. Ideally, monitoring of blood levels should also include determination of the area under the time-concentration curve (AUC) to better target the therapeutic window, thus avoiding underdosing or overdosing, especially in pediatric patients. A single blood concentration measurement 2 hours after Neoral administration (C2) has been shown to be a more for accurate predictor of drug exposure than trough levels (C0). Therefore, its use may lead to reduction in the incidence and severity of cellular rejection and of CsA toxicity. Some studies have shown that the metabolites/CsA ratio is substantially lower using C2 than C0, however, the between-assay differences for C2 monitoring have not been considered. The purpose of this study was to evaluate CsA C0 and C2 levels, determined using monoclonal fluorescence polarization immunoassay (FPIA)/TDx and enzyme multiplied immunoassay (EMIT). CsA levels were determined using a radioimmunoassay (RIA) in 30 pediatric transplant recipients with stable renal function within 42.7 mean months follow-up. Mean age was 13.4 years; 15 children were girls; 23 patients were recipients of cadaveric kidneys. The mean CsA microemulsion dose was 5.7 mg/kg/d. The 3 methods showed a high correlation between C0 and C2 ( r ≥ 0.97). A linear regression slope was significantly higher for C0 than C2 ( P < .001). The CsA concentrations both at C0 and C2 were significantly higher with FPIA than with RIA ( P < .009) but no differences were found for EMITT ( P = .2). The mean C0 level for FPIA was 22% and 26% higher than RIA and EMIT, respectively. The mean C2, for FPIA was 7% and 12% higher than RIA and EMIT, respectively. In conclusion, CsA levels determined using RIA or EMIT are better than using FPIA/Tx; also, C2 CsA levels are more accurate than C0 in pediatric transplantation patients.

Ultrasound score is more predictive than serum creatinine in assessment of cellular rejection in cynomolgus monkey renal allografts.

To investigate whether ultrasound (US), in particular the use of an ultrasound scoring system, can provide more diagnostic information than clinical parameters, such as serum creatinine, for the diagnosis and determination of the degree of cellular rejection in renal allografts in the cynomolgus monkey (Macaca fascicularis). Sixty-eight cynomolgus monkeys with life-supporting renal allografts were examined with a 7.5MHz linear ultrasound transducer. One-hundred fifty two-dimensional, spectral, and power Doppler examinations were performed and four ultrasound parameters, percentage increase in graft volume, cortical thickness, resistive index (RI) of the renal arcuate artery, and power Doppler (PD) scores were recorded from serial examinations. An ultrasound score was assigned to each graft based on the number of those parameters that were abnormal; a score of 1 indicated that all four were normal, and a score of 5 that all four were abnormal. Each parameter and the combined score were compared with serum creatinine values and histology and evaluated statistically using Spearman rank correlation. In animals with dysfunctioning allografts (serum creatinine elevations >200 micromol/L), Spearman rank correlation showed a significant correlation between the US score and the histology score: between 200 and 500 micromol/L, r = 0.309, P = 0.046, n = 31 and if > 500 micromol/L, r = 0.486, P = 0.005, n = 30. In those same animals, no correlation could be shown between serum creatinine values and the US score or between the serum creatinine values and the histologic diagnosis. In contrast to the US score, single ultrasound parameters were not found to correlate to histologic findings. The application of ultrasound imaging in nonhuman primate renal transplant models provides valuable information concerning the presence and severity of cellular rejection in cases of graft dysfunction and the US score has a better predictive value of histology than serum creatinine values alone.

The role of vitronectin receptor (αvβ3) and tissue factor in the pathogenesis of transplant coronary vasculopathy

ObjectivesThis study was undertaken to test the hypothesis that transplant coronary vasculopathy (CV) is associated with increased myocardial protein expression of both tissue factor (TF) and integrin αvβ3. BackgroundThe vitronectin receptor (integrin αvβ3) and TF have recently been found to play a key role in apoptotic cell death and vascular endothelial cell injury. MethodsA total of 77 heart transplant recipients underwent simultaneous endomyocardial biopsy and intravascular ultrasound (IVUS) at one year of transplant. Patients with pre-existing donor coronary atherosclerosis (n = 35) or with acute rejection (grade >1A, n = 10) at the time of the IVUS were excluded from the analysis. The remaining 32 patients constitute the cohort of the present study. A computerized biopsy score was derived based on the duration and severity of cellular rejection. Both TF and αvβ3 expression in the heart biopsy specimens were evaluated by immunoperoxidase histochemistry and Western blot analysis. ResultsPatients with CV (n = 24) had increased expression of αvβ3 (2.7-fold, p = 0.003) and TF (7.9-fold, p = 0.04) compared with patients without evidence of vasculopathy (n = 8). In the absence of myocardial fibrosis, αvβ3 expression correlated significantly with the cellular rejection score (r = 0.58, p = 0.02). ConclusionsTransplant vasculopathy is associated with increased expression of both TF and αvβ3. The significant correlation of αvβ3 with cellular rejection suggests an important role for this integrin in serving as a mechanistic link between cellular rejection and vasculopathy.

C2 monitoring strategy for optimising cyclosporin immunosuppression from the Neoral formulation.

Profiling of absorption of cyclosporin microemulsion (Neoral) is a concept in therapeutic drug monitoring (TDM) designed to further optimise the clinical benefits of this formulation in transplant recipients. A single blood concentration measurement 2 hours after Neoral administration (C2) has been shown in both liver and kidney transplant recipients to be a significantly more accurate predictor of drug exposure than trough concentrations (C0), and its use results in a reduction in the incidence and severity of cellular rejection. In a prospective trial in de novo renal transplant recipients, patients who achieved target concentrations for area under the concentration-time curve over the first 4 hours postdose (AUC(0-4h)) of 4500 to 5500 ng. h/ml within 5 days of transplantation had a 7% incidence of histological acute rejection, compared with 37% rejection in those patients who did not achieve this target level. Of the single sampling points, C2 correlates best with AUC(0-4h) (r2 = 0.86); C(0) had the poorest correlation. In an international study in 21 centres examining the absorption profiling, C2 samples were the most accurate predictors of AUC(0-4h) and freedom from rejection. In liver transplant recipients receiving Neoral -based maintenance immunosuppression, adoption of Neoral C2 monitoring identifies patients who are both over- and under-dosed, which is not distinguished by C0 measurements. Further adjustment of C2 to recommended targets, even at 5 and 10 years after transplantation, results in reduction in nephrotoxicity without exposing the patient to the risk of rejection. In summary, despite a level of simplicity comparable to C0 measurement, Neoral absorption profiling, and specifically C2 measurement, is a much more sensitive approach to assessing the pharmacokinetics and predicting the clinical effect of this formulation in the individual patient, with a consequent marked reduction in the incidence of acute cellular rejection and improved long term graft function.

Primary immunosuppression with FK506 versus cyclosporin A (CyA) in liver transplant recipients: Incidence and severity of cellular rejection The NIDDK Liver Transplant Database(LTD) Introduced by , Mayo Clinic, Rochester, MN

Primary immunosuppression with FK506 versus cyclosporin A (CyA) in liver transplant recipients: Incidence and severity of cellular rejection The NIDDK Liver Transplant Database(LTD) Introduced by , Mayo Clinic, Rochester, MN

4 direct measurement of CEA in serum by one step enzyme immunoassay

Immunosuppression has been one of the great challenges in pediatric recipients of kidney allografts. Cyclosporine (CsA) has evolved during the past 25 years of transplantation. It requires frequent blood level monitoring because of its narrow therapeutic window and interpatient and intrapatient variability. Neoral (Novartis) is no exception. Ideally, monitoring of blood levels should also include determination of the area under the time-concentration curve (AUC) to better target the therapeutic window, thus avoiding underdosing or overdosing, especially in pediatric patients. A single blood concentration measurement 2 hours after Neoral administration (C2) has been shown to be a more for accurate predictor of drug exposure than trough levels (C0). Therefore, its use may lead to reduction in the incidence and severity of cellular rejection and of CsA toxicity. Some studies have shown that the metabolites/CsA ratio is substantially lower using C2 than C0, however, the between-assay differences for C2 monitoring have not been considered.The purpose of this study was to evaluate CsA C0 and C2 levels, determined using monoclonal fluorescence polarization immunoassay (FPIA)/TDx and enzyme multiplied immunoassay (EMIT). CsA levels were determined using a radioimmunoassay (RIA) in 30 pediatric transplant recipients with stable renal function within 42.7 mean months follow-up. Mean age was 13.4 years; 15 children were girls; 23 patients were recipients of cadaveric kidneys. The mean CsA microemulsion dose was 5.7 mg/kg/d. The 3 methods showed a high correlation between C0 and C2 (r ≥ 0.97). A linear regression slope was significantly higher for C0 than C2 (P < .001). The CsA concentrations both at C0 and C2 were significantly higher with FPIA than with RIA (P < .009) but no differences were found for EMITT (P = .2). The mean C0 level for FPIA was 22% and 26% higher than RIA and EMIT, respectively. The mean C2, for FPIA was 7% and 12% higher than RIA and EMIT, respectively. In conclusion, CsA levels determined using RIA or EMIT are better than using FPIA/Tx; also, C2 CsA levels are more accurate than C0 in pediatric transplantation patients.

1 Saliva levels of 17-OH progesterone during the menstrual cycle in women

Immunosuppression has been one of the great challenges in pediatric recipients of kidney allografts. Cyclosporine (CsA) has evolved during the past 25 years of transplantation. It requires frequent blood level monitoring because of its narrow therapeutic window and interpatient and intrapatient variability. Neoral (Novartis) is no exception. Ideally, monitoring of blood levels should also include determination of the area under the time-concentration curve (AUC) to better target the therapeutic window, thus avoiding underdosing or overdosing, especially in pediatric patients. A single blood concentration measurement 2 hours after Neoral administration (C2) has been shown to be a more for accurate predictor of drug exposure than trough levels (C0). Therefore, its use may lead to reduction in the incidence and severity of cellular rejection and of CsA toxicity. Some studies have shown that the metabolites/CsA ratio is substantially lower using C2 than C0, however, the between-assay differences for C2 monitoring have not been considered.The purpose of this study was to evaluate CsA C0 and C2 levels, determined using monoclonal fluorescence polarization immunoassay (FPIA)/TDx and enzyme multiplied immunoassay (EMIT). CsA levels were determined using a radioimmunoassay (RIA) in 30 pediatric transplant recipients with stable renal function within 42.7 mean months follow-up. Mean age was 13.4 years; 15 children were girls; 23 patients were recipients of cadaveric kidneys. The mean CsA microemulsion dose was 5.7 mg/kg/d. The 3 methods showed a high correlation between C0 and C2 (r ≥ 0.97). A linear regression slope was significantly higher for C0 than C2 (P < .001). The CsA concentrations both at C0 and C2 were significantly higher with FPIA than with RIA (P < .009) but no differences were found for EMITT (P = .2). The mean C0 level for FPIA was 22% and 26% higher than RIA and EMIT, respectively. The mean C2, for FPIA was 7% and 12% higher than RIA and EMIT, respectively. In conclusion, CsA levels determined using RIA or EMIT are better than using FPIA/Tx; also, C2 CsA levels are more accurate than C0 in pediatric transplantation patients.