PRA Values Research Articles

Measuring copeptin, a surrogate for vasopressin in patients with hypertension – Can it identify those who are volume Responsive?

BackgroundAmong hypertensive patients, plasma renin activity is lower and the response to diuretic monotherapy greater in volume responsive hypertensive patients. We hypothesized that hormones influencing extracellular volume such as vasopressin / antidiuretic hormone (ADH) might permit the development of a simple test to identify those with volume-related hypertension. Such a test might be of particular benefit to the Black population which is purported to have a higher incidence of volume-related and responsive hypertension. Thus, using copeptin, a surrogate marker for ADH, we studied if there were differences in this hormone between those with and without volume responsive hypertension. MethodsSerum copeptin was measured in biobanked blood samples from the Genetic Epidemiology of Responses to Antihypertensives (GERA) I study and analyzed with other variables from the study dataset. ResultsThere was no relationship between PRA and copeptin values nor could the response in blood pressure be predicted by the copeptin values. However, baseline copeptin levels were higher in Black than in White subjects (7.5 pmol/L vs 5.4 pmol/L, P < 0.001) while plasma sodium and calculated plasma osmolality were slightly lower in keeping with the concept that Black subjects have more volume-related hypertension. In addition, after hydrochlorothiazide (HCTZ), copeptin was significantly lower in Black (6.2 pmol/L, P = 0.004) but unchanged in White subjects (5.2 pmol/L, P = 0.901) and there were also changes in sodium. ConclusionThe current study suggests differences in ADH physiology between hypertensive Black and White patients. However, the use of copeptin to identify volume responsive patients could not be confirmed.

Selective Loss of Donor Specific HLA Antibodies in a Highly Sensitized Patient After Lung Transplantation

<h3>Introduction</h3> Lung transplantation in the presence of donor specific antibodies (DSA) is safe with peri-operative desensitization, although persistence of DSA is common. Herein, we present a unique case of a highly sensitized lung transplant recipient with selective loss of DSA post-transplantation. <h3>Case Report</h3> A 65-year-old female with a calculated PRA (cPRA) value of of 17% (class I) and 100% (class II), underwent bilateral lung transplantation for chronic obstructive pulmonary disease. Virtual crossmatch (VCM) was positive, involving DPB1*04:01, DR17, and DR52. The subsequent flow cytometry B-cell crossmatch was strongly positive (median channel shift 296). She received peri-operative desensitization protocol for VCM positive patients, which includes intra-operative and post-operative plasmapheresis, intravenous immune globulin, and anti-thymocyte globulin. Maintenance immunosuppression included cyclosporine (target trough 250-350 umol/L), mycophenolic acid 900mg BID and prednisone 20 mg OD. An increase in DSA reactivity was observed one month after transplant (DPB1*04:01 (MFI=17639), DR17 (MFI=17812), and DR52 (MFI=19414). Repeat HLA testing at 3, 4, and 6 months post-transplant showed sequential reduction of DSAs to below the laboratory cut-off for positivity point despite persistence of non-DSA alloantibodies. The patient continues to maintain good lung function with an FEV1 of 2L (86% of predicted) at 6 months post-transplant. Surveillance transbronchial biopsies at 3 and 6 months were free of cellular rejection. <h3>Summary</h3> Despite initial rebound of pre-formed DSA following peri-operative desensitization, sustained selective clearance of the DSA subsequently occurred in this case, which likely benefited graft function. Similar cases have been reported after combined kidney-liver transplant. Robust laboratory research and prospective studies are required to understand the mechanism of selective DSA elimination in organ transplantation.

89 Pooled Safety Analysis Evaluating Bioengineered Allogeneic Cellularized Construct in Patients with Deep Partial-thickness Thermal Burns

IntroductionAutograft (AG) is the standard of care treatment for deep burns but requires creation of a donor site wound prone to pain and scarring. Treatment with a bioengineered allogeneic cellularized construct (BACC) is an alternative approach that can reduce or eliminate the need for autografting. The BACC is a bilayer construct that was recently approved in the US for the treatment of adult deep partial-thickness (DPT) burns. Here, we report the analysis of pooled safety data from two open-label, randomized, controlled trials (STRATA2011 [NCT01437852] and STRATA2016 [NCT03005106]) that evaluated efficacy and safety of BACC versus autografting in patients with DPT burns.MethodsThe trials enrolled 101 patients aged ≥18 years with 3–49% total body surface area (TBSA) thermal burns. In each patient, two DPT areas on the torso or extremities were randomized to receive BACC or AG, where the mean total BACC dosage was 234.8 cm2 (range: 12.0–960.0 cm2). The safety endpoints assessed at each visit included: 1) treatment-emergent adverse events (TEAEs), treatment-related AEs (TRAEs), and serious AEs (SAEs); 2) changes in immunologic responses (panel reactive antibodies [PRA], anti-bovine serum albumin [BSA] antibody response [STRATA2016 only]); 3) persistence of allogeneic DNA; and 4) laboratory exam and vital signs.ResultsEighty-seven patients (86.1%) experienced TEAEs, 30 patients (29.7%) experienced TRAEs, and 16 patients (15.8%) experienced SAEs. The most frequent TEAEs reported by ≥10% of patients in the pooled analysis were pruritus (n=31, 30.7%) and blister, hypertension, and hypertrophic scar (n=11, 10.9% each). The most frequent TRAEs (≥5% of patients) were pruritus (n=13, 12.9%) and blister (n=5, 5%). The most common SAEs were transplant (BACC or AG) failure, pneumonia, and deep vein thrombosis (n=2, 2% each), where only one SAE (impaired healing of moderate severity) was possibly related to BACC. One patient (1%) discontinued the trial due to a TEAE (traumatic brain injury). Two patients (2%) experienced SAEs that led to death, neither related to BACC. The number of patients with positive PRA values that were negative at baseline were 36 (38.7%) at Day 28 and 20 (22%) at Month 3. The number of patients with reactivity to HLA I class alleles found in the BACC increased from 4 (4%) at baseline to 39 (40.9%) at Day 28, then decreased to 22 (24.2%) at Month 3. No persistence of allogeneic DNA from the BACC was detected.ConclusionsBACC is well tolerated and is not associated with any unexpected SAEs or TEAEs. The safety profile at BACC treatment sites is similar to that at AG treatment sites. Thus, BACC may offer a safe alternative to autografting for the treatment of DPT burns.

P1743IMPORTANCE OF KIDNEY ALLOGRAFT REJECTİON IN BK VIRUS NEPHROPATHY

Abstract Background and Aims Allograft rejection following BK virus nephropathy (BKVN) is an important cause of allograft loss in kidney transplant recipients. However, the effect of rejection type on allograft survival in patients with BKVN has not been described previously. This study aimed to investigate the relationship between allograft rejection type and graft survival in patients with BKVN. Method We retrospectively analyzed the data of 159 kidney transplant recipients diagnosed BKVN and followed-up in our center between January 2009 and December 2019. BKVN was diagnosed by persistent viremia of more than 10000 copies/mL for four weeks or allograft biopsy. Vascular, obstructive or other non-parenchymal etiologies for allograft dysfunction were excluded. All patients were investigated for the presence of anti-HLA antibody at 6 and 12 months after BKVN diagnosis. Luminex solid-phase assay was used to investigate Class I and Class II PRA and MFI values greater than 1000 were accepted as positive. Allograft biopsy was performed in patients with progressive graft dysfunction or the presence of donor-specific antibodies (DSA) and analyzed according to the Banff Classification. The primary outcomes were defined as allograft loss or the allograft dysfunction which defined as was doubling serum creatinine levels. Results Patients were followed-up median 70 (IQR 13-198) months after kidney transplantation. Demographic data and clinical characteristics are provided in the table. 28 kidney transplant recipients suffered from allograft rejection after BKVN. Median rejection time to rejection after BKVN was 9 (IQR 5-164) months. 3 patients (18,8%) in the AMR group and 1 patient (8,3%) in the TCMR group experienced graft loss during follow-up. The mean serum creatinine levels at the last clinical visit were significantly higher in the AMR group compared to the TCMR group (1,9±0,8 vs 1,3±1,2 mg/dl; p=0,002). In multivariate analysis, AMR was an independent risk factor for allograft dysfunction (HR, 1,735; 95% CI 1,060 to 2,839; p=0,028). Conclusion The occurrence of AMR after BKVN is an important indicator of allograft dysfunction compared to TCMR. DSA screening should be routinely used in this group for early diagnosis and treatment of AMR.

Comparing head impact kinematics simultaneously measured using 6 different sensors in a human cadaver model

ObjectiveTo compare head kinematics measurements obtained from 6 different head impact sensors utilizing different methods of sensor-to-head fixation.DesignFree-drop impacts (total n = 54) were performed at 3.5 and 5.5 m/s onto to the front, back, side, and top of 2 elderly human cadaveric head-neck specimens: a helmeted (Riddell Revolution Speed) male specimen was dropped onto a NOCSAE testing pad; an un-helmeted female specimen was dropped onto a framed sample of field turf. The specimens were instrumented with an intracranial reference sensor surgically mounted at the approximate head center-of-mass by a rigidly-fixed custom standoff pad, an intra-oral test sensor rigidly fixed to the upper teeth/hard palate by a custom orthodontic appliance, and 4 commercially available head impact sensing systems: X-Patch, Vector mouth guard, HITS (helmeted condition only), and G-Force Tracker (affixed to helmet interior or head band depending on helmet status). Peak linear and rotational head accelerations (PLA and PRA) were compared between each sensor and the intracranial reference sensor using intraclass correlation coefficients (ICC [2, 1]).ResultsAgreement with reference PLA and PRA values differed between sensors, with the greatest agreement observed for the rigidly affixed intraoral sensor (ICC = 0.921, PLA; ICC = 0.810, PRA). Agreement for PLA and PRA, respectively, was: for X-Patch, ICC = 0.638, ICC = 0.155; for Vector mouth guard, ICC = 0.775, ICC = 0.480; for HITS, ICC = 0.662 (PLA only); for G-Force Tracker, ICC = 0.364 (PLA only).DiscussionHead kinematics measurements during free-drop testing differed among sensors using different approaches of fixation to the head. There was greater agreement with intracranial reference PLA and PRA values for a rigidly affixed intraoral sensor utilizing an orthodontic appliance than for commercially available sensors incorporated into athletic equipment or otherwise non-rigidly affixed to the head. Measurement error attributable to non-rigid sensor-head coupling could potentially be reduced by incorporating an impact sensor into an orthodontic appliance in future research.

HLA Class I Alloimmunization and Platelet Transfusion Support in HLA-Identical Bone Marrow Transplant for Sickle Cell Disease: A Sickle Transplant Alliance for Research Study

Introduction: HLA alloimmunziation has been described in patients, including pediatric patients with sickle cell disease (SCD), who received only leukocyte-reduced red blood cell (RBC) transfusions. While HLA alloimmunization has significant implications in bone marrow transplant (BMT) with an HLA-disparate donor (donor-specific HLA antibodies increase the risk of graft rejection), the clinical significance of this alloimmunization in HLA-identical BMT is unclear. In particular, it is unknown whether HLA class I alloimmunization affects platelet transfusion support during BMT. Platelet transfusions are especially important in BMT for SCD because of the historic high incidence of intracranial bleeding and the subsequent adoption of a relatively high platelet transfusion threshold.Methods: We tested for HLA class I alloimmunization using pre-BMT serum or plasma from 32 pediatric patients with SCD undergoing BMT with an HLA-identical sibling donor. HLA class I alloimmunization was evaluated using the FlowPRA® (panel reactive antibody) screening test which detects IgG antibodies to the majority of HLA class I antigens. Pre-BMT, patients had received leukocyte-reduced RBC transfusions. All patients undergoing BMT received leukocyte-reduced, irradiated, apheresis platelet transfusions to maintain a platelet count greater than 50 x 109/L. The number of platelet transfusions received in the first 45 days post-BMT was compared between those with a positive PRA versus those with a negative PRA using a two-sample t-test.Results: Among the 32 patients studied, the mean age at BMT was 9.4 years (range 1-21 years). Pre-BMT, 40% had received greater than 10 RBC transfusions and 32% of the entire cohort was receiving chronic RBC transfusions. BMT conditioning regimens included: traditional myeloablative busulfan, cyclophosphamide, antithymocyte globulin (BU-CY-ATG) (n=10); dose-reduced BU-CY-ATG + fludarabine (flu) (n=16); reduced intensity conditioning (RIC) alemtuzumab, flu, melphalan +/- thiotepa (n=5); and RIC BU-flu-ATG (n=1). All patients received HLA-identical sibling donor bone marrow, with 3 patients receiving a combined bone marrow and cord blood graft. All patients engrafted with 100% survival at day +45. Six patients developed acute graft-versus-host disease (GVHD): 1 grade I, 3 grade II, 1 grade 3, 1 grade 4. No patient had an intracranial bleed or other serious bleeding.From testing of the pre-BMT sample, 11/32 (34%) of patients had a positive HLA class I antibody screen. HLA class I alloimmunized patients received significantly more platelet transfusions than non-alloimmunized patients: mean 19.2 (SD 13.9) vs. 11.2 (SD 8.0) transfusions, p=0.049 (Figure). On univariate analysis, age, sex, conditioning regimen, and GVHD were each not significantly associated with the number of platelet transfusions (p>0.1). Only two patients developed hepatic sinusoidal obstruction syndrome (one HLA alloimmunized patient, one non-alloimmunized patient). Mean day of platelet engraftment was not significantly different between alloimmunized compared to non-alloimmunized patients: day +34.6 (SD 10.6) vs. day +30.2 (SD 11.3), p=0.28. Among HLA class I alloimmunized patients, the mean positive PRA was 19.7% (range 4-55%); there was no association with this PRA value and the number of platelet transfusions (r2=0.0064, p=0.81).Conclusion: In pediatric HLA-identical sibling BMT for SCD, pre-BMT HLA class I alloimmunization (but not the absolute PRA value) appears to be associated with more platelet transfusions. It is unclear if this increased platelet transfusion requirement is due directly to HLA antibody immune-mediated clearance of transfused platelets or other inherent differences of HLA class I alloimmunized patients. [Display omitted] DisclosuresQayed:Novartis: Consultancy.

The dynamics of pre-existing anti-HLA antibodies and the results of kidney transplantation

Aim. To analyze the relationship between the peak panel-reactive antibodies (peak-PRA), the value at the time of transplantation (Tx-PRA) and the results of kidney transplantation.Materials and methods. The study included 287 patients from the waiting list with anti-HLA antibodies of I and/or II classes. 142 patients underwent transplantation of a cadaveric kidney. All patients received standard immunosuppression: a calcineurin inhibitor, mycophenolate and steroids. Desensitization in the preoperative period was carried out in 11 patients. Screening and identification of antibodies was performed using multiplex technology on Luminex platform.Results. The median PRA was 47% (interquartile range – 29%; 65%). Depending on the dynamics of PRA, we identified several groups of patients: stable PRA (83 patients), increasing (77 patients) or decreasing value (96 patients), or variable dynamics (31 patients). The change in PRA was accompanied by a change in the mean fluorescence intensity (r = 0.787, r2 = 0.59, p &lt; 0.0001). In the univariate analysis, each 5% of peak-PRA and Tx-PRA increased the relative risk (RR) of humoral graft rejection (1.09 (95%CI 1.06; 1.17), p &lt; 0.001; 1.17 (95%CI 1.09; 1.26), p &lt; 0.001 respectively), and ΔPRA decreased a RR (0.932 (95% CI 0.861; 0.967), p = 0.009). In multivariate analysis (adjusted for sex and age of recipient, duration of dialysis, number of HLA mismatches), we observed a similar scenario: peak-PRA 1.14 (95% CI 1.07; 1.19), p &lt; 0.001; Tx-PRA 1.13 (95% CI 1.09; 1.22), p &lt; 0.001; ΔPRA 0.949 (95% CI 0.871; 0.981), p = 0.017. In the univariate analysis increases in peak- PRA and Tx-PRA increased aRR of graft loss (1.1 (95% CI 1.05; 1.14), p &lt; 0.001; 1.09 (95% CI 1.05; 1.15), p &lt; 0.001 respectively), and increase in ΔPRA decreased RR (0.952 (95% CI 0.891; 0.97), p = 0.011). In the adjusted multivariate model, Tx-PRA did not increasea RR of graft loss (1.04 (95% CI, 0.95; 1.1), p = 0.098), while peak-PRA and ΔPRA remained significant factors (1.1 (95% CI, 1.17; 1.24), p &lt; 0.001; 0.931 (95% CI, 0.855; 0.954), p = 0.007, respectively). Conclusion. In the selection donor-recipient pair it is necessary to take into account the spectrum of antibodies at the point of peak values of PRA. A decrease in PRA may hide antibodies that have a specificity to donor antigens or on certain epitope.

Correlation of Salt Sensitivity, Plasma Renin Activity and Aldosterone in Hypertensive Patients

Abstract Plasma-renin values vary in normotensive and hypertensive populations. Some studies consider renin to be a key factor in the aetiology of hypertension, but other studies note that renin is an important factor in cardiovascular homeostasis and functions more as a growth factor than as a pressor hormone. The aim of this study was to assess the PRA and aldosterone values under different salt intake regimes in patients with essential hypertension. The study group consisted of 50 untreated patients (27 women and 23 men; average age 42±9,2 yrs.; average BMI 27,91±4,6 kg/m2) with essential hypertension. All patients were put on a high-sodium diet (200 mmol NaCl per day) for one week after a week on a low-sodium diet (20 mmol NaCl per day). Sodium sensitivity (SS) was defined as a 10-mmHg increase in the mean blood pressure at the end of the high- vs. the low-sodium diet. The SS group consisted of 26 patients, and the sodiuminsensitive group consisted of 24 patients. The PRA and aldosterone levels were determined in 12 patients. PRA values in the SS group during rest were significantly lower compared with the salt-resistant group during all regimes of salt intake (F=10,56, p=0,0012). Salt loading in SS patients causes a significant decrease in PRA (in rest and effort) values in comparison to values during a low salt intake regime (rest: t=4,49, p&lt;0,001; effort: t=3,45, p&lt;0,01). The PRA values in the salt-resistant group did not vary significantly under the different salt intake regimes. The aldosterone values followed the pattern of the PRA values. It is necessary to distinguish investigations on salt intake effects based on incidence and value of blood pressure and investigations on salt restriction’s effects on of blood pressure levels (i.e., non-pharmacological hypertension therapy).

P153 Utility of the virtual crossmatch for living donor evaluations

Aim Our institution performs 750–900 flow cytometric crossmatches (FCXM) annually in support of living-donor renal transplantation. The FCXM is costly, time consuming, and has interpretational conundrums (i.e., FCXM + donor specific antibody (DSA) negative or FCXM−/DSA+). By combining high resolution HLA typing with solid-phase antibody (SAB) testing, recipients should be transplantable based solely on a virtual crossmatch (vXM). Given the increased utilization of the vXM, our aim was to assess its utility in living donor evaluations. Methods We reviewed 100 living donor FCXMs and retrospectively performed a vXM for each pair. vXM was performed only on cases with available donor typing and SAB specificity testing. Additionally, ΔMESF values of the FCXM, FlowPRA results, and mean fluorescence intensity (MFI) values of DSA were analyzed. Results Initially, there was a 75% correlation between FCXM and vXM: 60 cases were negative for both FCXM and vXM; 15 cases were positive for both. However, 20 cases were FCXM+ (mostly B-cell) but vXM−, which tended to occur in non-alloimmunized recipients. 3/20 had autoimmune disease and 8/20 were transplanted without development of DSA. Although deemed compatible, the remaining 12 were not transplanted. These 20 cases were considered False Positive FCXMs. 5 cases were FCXM−/vXM+. Of these, 4 had Class I DSAs and 1 had both Class I and II DSAs; however, all 5 had low MFI values. (Table 1). Thus, reclassifying the false positive FCXMs, the final correlation was 95%. Download : Download high-res image (146KB) Download : Download full-size image Conclusions Though the initial FCXM/vXM correlation rate was only 75%, there are key characteristics such as differences in FCXM, ΔMESF, PRA values, and DSA MFI values that can help interpret discrepant result. Notably, there were 4 times more false positive FCXMs then false positive vXMs. Reclassifying the False Positive FCXM cases increased the correlation to 95%. These data support the utility of the vXM as a replacement for a physical FCXM for most living donor evaluations.

Prospective validation of an automated chemiluminescence-based assay of renin and aldosterone for the work-up of arterial hypertension.

The availability of simple and accurate assays of plasma active renin (DRC) and aldosterone concentration (PAC) can improve the detection of secondary forms of arterial hypertension. Thus, we investigated the performance of an automated chemiluminescent assay for DRC and PAC in referred hypertensive patients. We prospectively recruited 260 consecutive hypertensive patients referred to an ESH Center for Hypertension. After exclusion of six protocol violations, 254 patients were analyzed: 67.3% had primary hypertension, 17.3% an aldosterone producing adenoma (APA), 11.4% idiopathic hyperaldosteronism (IHA), 2.4% renovascular hypertension (RVH), 0.8% familial hyperaldosteronism type 1 (FH-1), 0.4% apparent mineralocorticoid excess (AME), 0.4% a renin-producing tumor, and 3.9% were adrenalectomized APA patients. Bland-Altman plots and Deming regression were used to analyze results. The diagnostic accuracy (area under the curve, AUC of the ROC) of the DRC-based aldosterone-renin ratio (ARRCL) was compared with that of the PRA-based ARR (ARRRIA) using as reference the conclusive diagnosis of APA. At Bland-Altman plot, the DRC and PAC assay showed no bias as compared to the PRA and PAC assay. A tight relation was found between the DRC and the PRA values (concordance correlation coefficient=0.92, p<0.0001) and the PAC values measured with radioimmunoassay and chemiluminescence (concordance correlation coefficient=0.93, p<0.001). For APA identification the AUC of the ARRCL was higher than that of the ARRRIA [0.974 (95% CI 0.940-0.991) vs. 0.894 (95% CI 0.841-0.933), p=0.02]. This rapid automated chemiluminescent DRC/PAC assay performed better than validated PRA/PAC radioimmunoassays for the identification of APA in referred hypertensive patients.

A 6-Year Experience of a Kidney Paired Donation Centralized Lab, Performing Crossmatches Resulting in 220 Transplants.

INTRODUCTION: Flow crossmatch (FXM) results with donor cells were compared to computer-based virtual crossmatch (VXM) results in patients stratified by their calculated PRA (cPRA) values to evaluate the accuracy of both crossmatch methods. METHODS: A total of 1949 VXM tests (with HLA-A, B, C, DR, and DQB) were performed. A single antigen bead assay was used for patients with 1-100% cPRA to create a list of unacceptable HLA antigens; VXM results were used to perform daily match runs. Selected donor/recipient pairs were tested by FXM with donor cells. Weekly match runs were performed to identify compatible pairs with negative VXM results. RESULTS: Between 2007 and 2012, there was an increase in the number of sensitized (1-79% cPRA) and highly sensitized (80-100% cPRA) patients (Figure 1). The accuracy of negative VXM ranged from 70.5% in 2007 to 74% in 2012 (Figure 2). False negative VXM results ranged from 26% in 2012 to 29.5% in 2007. When all negative VXM results were divided by cPRA, patients with 0% cPRA had no false negative results, those with 1-79% cPRA had 20% positive FXM, and those with 80-100% cPRA had 45% positive FXM. Analysis of the class I and II false negative VXM results revealed that the majority were falsely negative in both class I and II HLA (47%), rather than in class II alone (40%) or in class I alone (13%).Figure: No Caption available.Figure: No Caption available.CONCLUSION: Significant (˜ 25%) false negative VXM (especially for high PRA and Class II sensitized patients) when assessed by actual FXM demonstrates that data reported to centralized repositories by multiple transplant centers results in higher false negative VXM than can be achieved by single centers.

Impact of Pre-Transplant PRA Level On Renal Graft Survival in Patients With Negative Cross-Match and No Donor Specific Antibody.

Purpose: The aim of this study was to investigate the impact of pre-transplant PRA level on rejection and graft survival after kidney transplantation in patients with negative cross-match(CXM(-)) and no donor specific antibody(DSA(-)). Method: We analyzed retrospectively 513 kidney recipients transplanted at our center. And among them, those who identified positive test on cross-match, those who had donor specific antibodies, ABO incompatible, and those who had no information of PRA were excluded(n=130). The factors included peak PRA, age, gender, HLA mismatch number, transplant number, donor source, rejection were reviewed. Peak PRA was stratified into 3 groups according to their PRA levels group I, PRA=0; group II, PRA 0< ≤50%, and group III, PRA 50%<. Graft failure was defined as return to dialysis, transplant nephrectomy, or death with functioning kidney. Results: The mean follow up duration was 29.4±14.6month(0-59). The rejection rate was 20.1%(group I 18.5%(n=58) vs. group II 23.8%(n=10) vs. group III 33.3%(n=9) (p=0.053)). The graft failure rate was 21.7%(group I 6.4%(n=20) vs. group II 7.1%(n=3) vs. group III 7.4%(n=7)(p=.792))Table: No Caption available.Univariate analysis by log-rank test, donor source and rejection were significantly associated with graft survival(p=.000 and .000, respectively), however subcatergories of PRA were not(p=.851). On multivariate Cox regression analysis, donor source and rejection were also significantly associated with graft survival(p=0.002 and 0.000, respectively), however including subcatergories of PRA(p=.552), other variables were not significant. Conclusion: The rejection rate was higher as PRA group increasing, however it was not statistically significant(p=.053). Pre-transplant PRA value was not significantly associated with graft survival, in patients with CXM(-) and DSA(-). However, donor source and presence of rejection were significantly associated with graft failure.

Improved Outcomes in Highly Sensitized Pediatric Heart Transplant Patients Using Current Management Strategies.

Background: Previous studies suggest that children with preformed anti-HLA antibodies undergoing orthotopic heart transplantation (OHT) have increased risk for cellular and humoral rejection, coronary artery vasculopathy (CAV) and death. In 2005, our program started utilizing aggressive desensitization (including plasmapheresis, IVIG, pulse cytoxan and rituximab) with the goal of improving outcomes for these patients. The purpose of this study was to compare outcomes with this new strategy in pediatric OHT recipients with pre-OHT high PRA (>10%) versus low PRA (≤ 10%). Methods: Retrospective chart review of 70 consecutive pediatric OHT patients between January 2005 and July 2013 was undertaken to identify patients with pre-OHT PRA > 10% (high PRA), or PRA ≤ 10% (low PRA). Demographic information and detailed post-OHT outcomes including rejection, 30-day, and overall mortality, freedom from significant rejection, and CAV were analyzed. Results: 14 (20%) had high PRA, while 56 (80%) had low PRA. Figure 1 shows PRA values before and after desensitization. 30-day and overall mortality, and the proportion of patients experiencing rejections and CAV were lower in the high PRA group, albeit not statistically significant. Kaplan-Meier survival analysis (Figure 2) revealed no statistically significant difference in survival between the 2 groups (log-rank P=0.98). Figure 3 compares our current outcomes (2005-2013) to our outcomes before 2005. Conclusions: Our study did not show significant differences in outcomes between patients with high or low PRA. These preliminary findings may suggest an improvement in OHT outcomes for patients with high PRA as a result of aggressive desensitization. A future larger study is warranted to confirm these findings.Figure: No Caption available.Figure: No Caption available.

Successful Interim Outcomes of Bortezomib Desensitization on Highly Sensitized Deceased Donor Kidney Transplant Waitlist Patients

Highly sensitized (HS) patients seldom have chance to receive kidney transplant. To increase transplantation rate among those population, previous IV immunoglobulin and rituximab desensitization protocol showed good transplant conversion rate, but also carried moderate rate of antibody mediated rejection. Bortezomib, a proteasome inhibitor can control the production of anti-HLA antibodies through plasma cell apoptosis. A single center waitlist desensitization program was employed to facilitate successful kidney transplantation in HS patients group. We prospectively enrolled 23 patients from Jul 2010 to Dec 2013. Desensitization protocol included two doses of IVIG (2 g/kg), single dose of rituximab (375 mg/m 2 , max 500 mg), and 4 days of bortezomib (1.3 mg/m 2 on days 1,3,7 and 9). Anti-HLA class I and II antibodies were determined by Luminex solid phase bead assay at baseline and M2, M3 and M6. We investigated the difference of transplant conversion rate between desensitized HS patients and non-desensitized HS waitlist patients. Also we analyzed the difference of PRA % values and mean fluorescence intensity (MFI) between pre- and post-desensitization serum. Mean age of treatment group was 48.7±11.2 years old. Male to female ratio was 12:11. O+ blood type patients were 34.8% of patients. Mean duration of previous renal replacement therapy were 153.5±65.5 months. Baseline mean class I and II PRA % values were 86±15.3 and 66±34. Baseline class I and II MFI values were 13,893±6,147 and 12,274±6,891. After desensitization, kidney transplant were successfully performed in 34.8% of patients, compared to 13.8% transplant conversion rate among non-desentized HS controls ( p =0.001 by Log-Rank). Among KT recipients, median duration of waiting after desensitization was 3 months with interquartile range 2-8.1 months. Class I PRA % had showed decreased values until 3 months after desensitization. After 6 months, there were no differences between the class I PRA values between pre-desensitization samples and post-desensitization samples. There were no other differences except class I PRA % values. Desensitization protocol were generally well tolerated, with the completion rate of 92% patients. There were no serious adverse events, but moderate adverse event were in 46%, most commonly fever and diarrhea. Highly sensitized waitlist patients are manageable by desensitization protocol including bortezomib.

Combination of LC–MS/MS aldosterone and automated direct renin in screening for primary aldosteronism

BackgroundAldosterone to renin ratio (ARR) is used in screening for primary aldosteronism (PA). However, there are only few studies on the influence of assay methods on ARR and its cut-off limits. MethodsPlasma direct renin immunoreactivity by chemiluminescence immunoassay (DR) was compared to renin activity assay (PRA), and a specific liquid chromatography–mass spectrometric method (LC–MS/MS) to radioimmunoassay (RIA) for plasma aldosterone. There were 75 samples for renin assays, and 42 samples of 39 patients for both renin and aldosterone assays. PA screening was considered positive if ARR by the aldosterone RIA:PRA was ≥800pmol/L:μg/L/h or by LC–MS/MS:DR≥44pmol/L:ng/L. ResultsThe correlation between the DR and PRA methods (n=75, r2=0.845) and between LC–MS/MS and RIA (n=42, r2=0.973) was high in general, but low between the renin methods (n=49, r2=0.435) at low PRA values. When ARR was used in screening for PA, there were three divergent cases (positive only by alternative methods), but when applied in combination with criteria for elevated aldosterone, the methods showed good agreement, resulting in eight positive and 31 negative screening results. ConclusionsThe automated DR assay combined with LC–MS/MS method for aldosterone provides a rapid, reliable, and specific method for screening of PA.

61-OR

Aim Complement binding donor specific HLA antibodies (DSA) detected by the C1qScreenTM assay are associated with poor post-transplant outcomes. However, in some patients with episodes of antibody mediated rejection or graft failure, C1q binding DSA are not detected by the C1qScreenTM. We have recently developed a sensitive anti-human globulin (AHG) - C1qScreenTM enhanced (ACE) assay, which detects more complement binding DSA compared to standard protocol. Here we investigate functional relevance of HLA antibodies identified using the ACE assay by correlation with CDC and CDC-AHG Lambda Cell Tray (LCT) testing. Methods Ten sera from highly sensitized post-transplant patients with well characterized HLA antibodies were tested using C1qScreenTM and the ACE assay. CDC and CDC-AHG crossmatches were performed using 1W60 LCT panels. CDC and CDC-AHG PRA were calculated (#Pos /#Valid reactions) for each serum and compared to predicted PRA values based on identified C1q positive antibody specificities. Results PRA values predicted based on ACE assay positive antibodies correlated with CDC-AHG PRA (mean difference = 2.9%, range = −1.7-8.6%) but not with CDC PRA (mean difference = 26.2%, range = 7-48%). In contrast, PRA values predicted based on C1qScreenTM positive antibodies correlated with CDC PRA (mean difference = −4.8%, range = −39.7 – 17.2%) but not with CDC-AHG PRA (mean difference = −28%, range = −62 – 5%). Importantly, 377 of 383 (98.4 %) positive CDC-AHG reactions were predicted to be positive by ACE assay. In contrast, a significant proportion of positive CDC reactions, 49 of 240 (20.4%), were not predicted positive by standard C1qScreenTM suggesting poor assay sensitivity. Conclusions Strong correlation between ACE assay positive antibodies and CDC-AHG reactivity suggests that ACE assay may be used to predict CDC-AHG crossmatches. This would be very useful in pre-transplant risk assessment especially in the context of class II HLA antibodies not easily studied with CDC/CDC-AHG methods.

Defining the Benefits of Desensitization Therapy

Defining the Benefits of Desensitization Therapy

The Influence of Single Dose Induction Therapy on Graft Function in a Developing Country

Introduction: Induction with single dose therapy is rarely practiced in renal transplantation. Hence, we did this prospective study to see the influence of single dose induction therapy on graft function. Methods: Our study cohort comprised 358 patients (253 Males, 105 females) with a mean age of 43.42±13.22. Patients were divided into 4 groups based on the choice of induction therapy used (Basiliximab, Daclizumab, Thymoglobulin or no induction). Details such as age, sex, modality of dialysis and related details prior to transplantation, induction and immunosuppressive regimen, rate of rejection, diabetic status, previous transfusions, previous pregnancies, biopsy results and mortality were collected. Analysis was done using PASW Statistics 18 with chisquare test and one way Anova with post-hoc Tukey. The PRA values in thymoglobin was 26.17% ± 8.63% (Range:12.5% to 45.5%). The cost of the drugs is as follows - Basiliximab USD 1122, Thymoglobulin USD 551 and Daclizumab USD 800. Results: Of the 358 patients, single dose-induction was initiated on 310 patients; 125 with Basiliximab, 143 with Daclizumab (2 doses) and 42 patients with Thymoglobulin. Overall, 29.9% of patients were diabetic, however this was not significantly different across the groups (p=0.25). The transfusion rate was 53.8% in patients on thymoglobulin induction while the overall rate of transfusion was only 21.1% (p < 0.001). A positive biopsy report was seen in 24.5% of all patients (20.8% no induction; 27.2% Basiliximab, 23.8% Daclizumab, 23.1% Thymoglobulin) (p=0.82). Death-censored graft survival showed a lower incidence of graft survival with no induction (87.1%) (p=0.54).[Table 1 - Demographic and renal parameters]Figure: [Death-censored graft survival]Conclusion: Our study shows that single dose induction with thymoglobulin is the most cost effective modality in preventing rejection in patients with high PRA.

Contact lenses vs spectacles in myopes: is there any difference in accommodative and binocular function?

Theoretically, the accommodative and vergence demands are different between single-vision contact lenses and spectacle lenses. The aim of the present study was to determine whether these differences exist when these two correction methods are used in clinical practice. For this, different visual parameters that characterize the accommodative (accommodation amplitude, accommodative facility, and accommodative response) and binocular function (near and distance horizontal and vertical dissociated phorias, near and vertical associated phorias, near and distance negative and positive fusional vergence, vergence facility, near point of convergence, negative and positive relative accommodation, stimulus AC:A ratio and stereoacuity) were evaluated in a student population when their myopia was corrected with either spectacles or soft contact lenses (SCL). All parameters were measured on two separate occasions in 30 myopic habitual contact lens and spectacle wearers of mean age 19 ± 2.4years. Some parameters such as accommodation amplitude, accommodative response, and stimulus AC:A ratio were measured using two measurement methods which are commonly used in clinical practice. Three measurements were taken for each parameter and averaged. For the comparative statistical analysis, we used the Student's t-test (p value < 0.05). The following statistically significant differences were found with the use of SCL in comparison to spectacles: higher accommodative lags, higher negative relative accommodation, more esophoric near horizontal dissociated phoria, and lower negative fusional vergence in near vision. The results found in this study show a definite trend towards poorer accommodative and vergence function with the use of contact lenses in comparison to glasses. This downward trend, though not statistically significant in accommodative function (lower PRA values and less lens amplitude of accommodation) might suggest that temporal insufficiency in the accommodation process could be occurring while contact lenses are used, thereby possibly creating a lag in accommodation to reduce associated overconvergence. This would be manifested in more esophoric values being found in the vergence function. The higher accommodative lags found in this study with SCL could indicate that prolonged use of SCL in near tasks may provoke a continuous hyperopic retinal defocus, a risk factor for the onset and progression of myopia, as indicated in numerous studies.

A comparative study on inter and intralaboratory reproducibility of renin measurement with a conventional enzymatic method and a new chemiluminescent assay of immunoreactive renin

The activity of the renin-angiotensin system is usually evaluated as plasma renin activity (PRA, ngAI/ml per h) but the reproducibility of this enzymatic assay is notoriously scarce. We compared the inter and intralaboratory reproducibilities of PRA with those of a new automated chemiluminescent assay, which allows the direct quantification of immunoreactive renin [chemiluminescent immunoreactive renin (CLIR), microU/ml]. Aliquots from six pool plasmas of patients with very low to very high PRA levels were measured in 12 centres with both the enzymatic and the direct assays. The same methods were applied to three control plasma preparations with known renin content. In pool plasmas, mean PRA values ranged from 0.14 +/- 0.08 to 18.9 +/- 4.1 ngAI/ml per h, whereas those of CLIR ranged from 4.2 +/- 1.7 to 436 +/- 47 microU/ml. In control plasmas, mean values of PRA and of CLIR were always within the expected range. Overall, there was a significant correlation between the two methods (r = 0.73, P < 0.01). Similar correlations were found in plasmas subdivided in those with low, intermediate and high PRA. However, the coefficients of variation among laboratories found for PRA were always higher than those of CLIR, ranging from 59.4 to 17.1% for PRA, and from 41.0 to 10.7% for CLIR (P < 0.01). Also, the mean intralaboratory variability was higher for PRA than for CLIR, being respectively, 8.5 and 4.5% (P < 0.01). The measurement of renin with the chemiluminescent method is a reliable alternative to PRA, having the advantage of a superior inter and intralaboratory reproducibility.