Lung Recipients Research Articles

(1423) - Pretransplant Left Ventricular Ejection Fraction Did Not Impact Short-Term Survival in Lung Recipients

(1423) - Pretransplant Left Ventricular Ejection Fraction Did Not Impact Short-Term Survival in Lung Recipients

Association Between FEV₁ Decline Rate and Mortality in Long-Term Follow-Up of a 21-Patient Pilot Clinical Trial of Inhaled Liposomal Cyclosporine Plus Standard-of-Care Versus Standard-of-Care Alone for Bronchiolitis Obliterans Syndrome After Lung Transplantation.

BACKGROUND The association between forced expiratory volume in 1 second (FEV1) trajectory and mortality in bronchiolitis obliterans syndrome (BOS) is not well defined. Using long-term data from a prior clinical trial of inhaled liposomal cyclosporine A (L-CsA-I) for lung transplant patients with BOS, this study examined the association between longitudinal FEV₁ change and mortality. MATERIAL AND METHODS We analyzed long-term data from a clinical trial which randomized 21 patients with BOS (³20% decrease in FEV1 from personal maximum) to receive L-CsA-I plus standard-of-care (n=11) or standard-of-care (SOC) alone (n=10) for 24 weeks. A joint statistical model, combining a linear mixed model for FEV₁ change and Cox regression for mortality, was utilized to examine the overall association between FEV₁ trajectory and mortality during follow-up. RESULTS The 21 trial participants (10 single, 11 double lung recipients) had a mean FEV₁ of 1.7±0.6 Liters at randomization. Median follow-up post-randomization was 35 months. In joint model analysis, 1 percent FEV₁ decline predicted 1.076-fold increased mortality risk (95% confidence interval: -0.998 to 1.160, p=0.058). FEV₁ decline was reduced by 2.6% per year in L-CsA-I patients compared to SOC (p=0.210), and overall survival at 1/3/5 years was 91%/64%/27% vs 90%/20%/0% for L-CsA-I versus SOC, respectively (p=0.164). CONCLUSIONS In BOS patients, greater longitudinal FEV₁ decline predicts increased mortality. Trends towards prolonged stabilization of FEV₁ and improved survival were observed with L-CsA-I receipt. Further analyses will aid in evaluating the utility of FEV₁ change as a survival predictor, having implications in BOS management and future trial design.

Validation of a novel donor lung scoring system based on the updated lung Composite Allocation Score

Lung transplantation (LTx) continues to have lower rates of long-term graft survival compared with other organs. Additionally, lung utilization rates from brain-dead donors remain substantially lower compared with other solid organs, despite a growing need for LTx and the significant risk of waitlist mortality. This study aims to examine the effects of using a combination of the recently described novel lung donor (LUNDON) acceptability score and the newly adopted recipient lung Composite Allocation Score (CAS) to guide transplantation. We performed a review of nearly 18 000 adult primary lung transplants from 2015-2022 across the US with retroactive calculations of the CAS value. The medium-CAS group (29.6-34.5) had superior 1-year posttransplant survival. Importantly, the combination of high-CAS (> 34.5) recipients with low LUNDON score (≤ 40) donors had the worst survival at 1 year compared with any other combination. Additionally, we constructed a model that predicts 1-year and 3-year survival using the LUNDON acceptability score and CAS values. These results suggest that caution should be exercised when using marginally acceptable donor lungs in high-priority recipients. The use of the LUNDON score with CAS value can potentially guide clinical decision-making for optimal donor-recipient matches for LTx.

Two single lung transplantations from one donor: lung twinning in the LAS era.

The implementation of the Lung Allocation Score (LAS) in the Eurotransplant international collaborative framework decreased waiting list mortality, but organ shortage remains a significant problem. Transplantation of two single lungs from one donor into two recipients (lung twinning) may decrease waiting list mortality. We sought to analyze if this strategy can lead to an acceptable intermediate-term outcome. Since the LAS-implementation we performed 32 paired single-lung transplantations from 16 postmortal donors. Data and outcome were analyzed retrospectively comparing recipients receiving the first lung (first twins) with recipients receiving the second lung (second twins), left versus right transplantation and restrictive versus obstructive disease. Survival at one year was 81% and 54% at five years. Veno-venous ECMO had been successfully used as bridge-to-transplant in three patients with ECMO-explantation immediately after surgery. Bronchial anastomotic complications were not observed in any patient. First twins and second twins exhibited similar survival (p = 0.82) despite higher LAS in first twins (median 45 versus 34, p < 0.001) and longer cold ischemic time in second twins (280 ± 83 vs. 478 ± 125min, p < 0.001). Survival of left and right transplantation was similar (p = 0.45) with similar best post-transplant FEV1 (68 ± 15% versus 62 ± 14%, p = 0.26). Survival was similar in restrictive and obstructive disease (p = 0.28) with better post-transplant FEV1 (70 ± 15% versus 57 ± 11%, p = 0.02) in restrictive disease. Performing two single-lung transplantations from one donor can be performed safely with encouraging intermediate-term outcome and good functional capacity. Lung twinning maximizes the donor pool and may help to overcome severe organ shortage. This research is not a clinical trial. Thus no registration details will be provided.

Outcomes after lung transplantation from selected donors older than 70 years in a single centre: time to close the debate?

The aim of this study was to compare the outcomes of lung transplantations using grafts from donors aged over 70 years against those performed using younger donors. This retrospective single-centre analysis includes lung transplants conducted at our institution from January 2014 to June 2022. Lung recipients were classified into 2 groups based on donor age (group A <70 years; group B ≥70 years). Variables regarding demographics, peri and postoperative outcomes and survival were included. The statistical analysis approach included univariable analysis, propensity score matching to address imbalances in donor variables (smoking status), recipient characteristics (sex, age, diagnosis and lung allocation score) and calendar period and survival analysis. A total of 353 lung transplants were performed in this period, 47 (13.3%) using grafts from donors aged over 70 years. Donors in group B were more frequently women (70.2% vs 51.6%, P = 0.017), with less smoking history (22% vs 43%, P = 0.002) and longer mechanical ventilation time (3 vs 2 days, P = 0.025). Recipients in group B had a higher lung allocation score (37.5 vs 35, P = 0.035). Postoperative variables were comparable between both groups, except for pulmonary function tests. Group B demonstrated lower forced expiratory volume 1 s levels (2070 vs 2580 ml, P = 0.001). The propensity score matching showed a lower chance of chronic lung allograft dysfunction by 12% for group B. One-, three- and five-year survival was equal between the groups. The use of selected expanded-criteria donors aged over 70 years did not result in increased postoperative morbidity, early mortality or survival in this study.

Preservation of recipient plasma sphingosine-1-phosphate levels reduces transfusion-related acute lung injury.

Cold-stored (CS) platelets are once again being reintroduced for clinical use. Transfused CS platelets offer benefits over room temperature-stored (RTS) platelets such as increased hemostatic effects and prolongation of shelf-life. Despite these advantages little is known about their association with transfusion-related acute lung injury (TRALI). TRALI is associated with prolonged storage of RTS platelets and has a mortality of >15%. Determining the safety of CS platelets is important considering their proposed use in TRALI-vulnerable populations with inflammation such as surgical patients or patients with trauma. Donor platelet-derived ceramide causes TRALI, whereas donor platelet sphingosine-1-phosphate (S1P) is barrier protective. Females have higher plasma levels of S1P than males. Cold temperatures increase S1P levels in cells. Therefore, we hypothesized that female (donors or recipients) and/or CS platelets would decrease TRALI. To test this, we compared how male and female donor and recipient allogeneic platelet transfusions of CS (4°C) versus RTS (23°C) platelets stored for 5 days influence murine TRALI. Transfusion of CS platelets significantly reduced recipient lung tissue wet-to-dry ratios, bronchoalveolar lavage total protein, lung tissue myeloperoxidase enzyme activity, histological lung injury scores, and increased plasma sphingosine-1-phosphate (S1P) levels compared with RTS platelet transfusions. Female as opposed to male recipients had less TRALI and higher plasma S1P levels. Female donor mouse platelets had higher S1P levels than males. Mouse and human CS platelets had increased S1P levels compared with RTS platelets. Higher recipient plasma S1P levels appear protective considering females, and males receiving platelets from females or male CS platelets had less TRALI.NEW & NOTEWORTHY Transfusion-related acute lung injury (TRALI) though relatively rare represents a severe lung injury. The sphingolipid sphingosine-1-phosphate (S1P) regulates the severity of platelet-mediated TRALI. Female platelet transfusion recipient plasmas or stored platelets from female donors have higher S1P levels than males, which reduces TRALI. Cold storage of murine platelets preserves platelet-S1P, which reduces TRALI in platelet-transfused recipients.

Lung transplantation: current situation and developments

Lung transplantation is currently the gold standard treatment for end-stage lung diseases. Advances in the preservation of donor lungs, the surgical technique and immunosuppressive therapy have led to lung transplantation now being a routine procedure. Nevertheless, the shortage of donor organs, the acute and particularly chronic lung allograft dysfunction (CLAD) still represent major challenges even in experienced centers. Research in this area is still necessary to improve the long-term survival of lung recipients.

Isavuconazole for Treating Invasive Mould Disease in Solid Organ Transplant Recipients.

Solid organ transplant (SOT) recipients have a higher risk of developing invasive mould diseases (IMD). Isavuconazole is a novel broad-spectrum azole active against Aspergillus spp. and Mucor, well tolerated, with an excellent bioavailability and predictable pharmacokinetics, that penetrates in most tissues rapidly, and has few serious adverse effects, including hepatic toxicity. Contrary to other broad-spectrum azoles, such as voriconazole and posaconazole, isavuconazole appears to show significant smaller drug-drug interactions with anticalcineurin drugs. We have performed an extensive literature review of the experience with the use of isavuconazole in SOT, which included the SOTIS and the ISASOT studies, and published case reports. More than 140 SOT recipients treated with isavuconazole for IMD were included. Most patients were lung and kidney recipients treated for an Aspergillus infection. Isavuconazole was well tolerated (less than 10% of patients required treatment discontinuation). The clinical responses appeared comparable to that found in other high-risk patient populations. Drug-drug interactions with immunosuppressive agents were manageable after the reduction of tacrolimus and the adjustment of mTOR inhibitors at the beginning of treatment. In conclusion, isavuconazole appears to be a reasonable option for the treatment of IMD in SOT. More clinical studies are warranted.

Hepatitis B virus reactivation in hepatitis B core antibody positive lung transplant recipients

BackgroundSolid organ transplant recipients with resolved hepatitis B (HBV) infection are at risk for reactivation, however, most of the studies have focused on kidney transplant recipients and have short to intermediate term follow up. Risk factors for reactivation are also uncertain, with some studies suggesting surface antibody (anti-HBs) may be protective. MethodsThis retrospective single center study aimed to assess the risk of HBV reactivation (HBVr) in lung transplant recipients with prior HBV infection as well as the value of anti-HBs titers in predicting HBVr. Surface antigen (HBsAg) negative, core antibody (anti-HBc) positive adult lung and heart-lung SOTR from 2005 to 2019 were included. The primary outcome was HBVr after transplant, defined as seroreversion to HBsAg positivity. The secondary outcome compared anti-HBs titers at transplant and at posttransplant month 12. ResultsThe cohort included 38 lung and heart-lung recipients with anti-HBc positive, HBsAg negative pretransplant serology. Reactivation occurred in 3 of 38 (8%) at 49, 69 and 94 months posttransplant. Two (5% of cohort) subjects died as a consequence of HBVr. Two of the 3 HBVr patients had anti-HBs titers >10 IU/ml at transplant and one had anti-HBs >100 IU/ml at time of HBV reactivation. We did not find a statistically significant decrease in anti-HBs titers one year after transplant in subjects with baseline anti-HBs>10 IU/ml. ConclusionThe prolonged time to reactivation highlights the lifelong risk. The 8% rate of reactivation and 5% mortality support a preferred strategy of indefinite HBV antiviral prophylaxis over monitoring in anti-HBc positive lung recipients.

Suspected Legionella Transmission from a Single Donor to Two Lung Transplant Recipients — Pennsylvania, May 2022

In July 2022, the Pennsylvania Department of Health received two reports of laboratory-confirmed Legionnaires disease in patients who had recently received lung transplants from the same donor at a single Pennsylvania hospital. The donor’s cause of death was freshwater drowning in a river, raising suspicion of potential donor-derived transmission, because Legionella bacteria naturally live in fresh water. Further investigation of patients receiving other organs from the same donor did not identify additional legionellosis cases. Health care–associated infection caused by water exposure at the hospital was also evaluated as a potential source of infection and was found to be unlikely. Hospital water quality parameter measurements collected during May–June 2022 were within expected ranges and no water disruptions were noted, although no testing for Legionella was performed during this period. Notifiable disease data did not identify any other Legionnaires disease cases with exposure to this hospital within the 6 months before or after the two cases. Although laboratory testing did not confirm the source of recipient infections, available data suggest that the most likely source was the donor lungs. This cluster highlights the need for increased clinical awareness of possible infection with Legionella in recipients of lungs from donors who drowned in fresh water before organ recovery.

Prevalence and significance of clonal hematopoiesis of indeterminate potential in lung transplant recipients

BackgroundClonal hematopoiesis of indeterminate potential (CHIP), the age-related acquisition of somatic mutations that leads to an expanded blood cell clone, has been associated with development of a pro-inflammatory state. An enhanced or dysregulated inflammatory response may contribute to rejection after lung transplantation, however the prevalence of CHIP in lung recipients and influence of CHIP on allograft outcomes is unknown.MethodsWe analyzed whole-exome sequencing data in 279 lung recipients to detect CHIP, defined by pre-specified somatic mutations in 74 genes known to promote clonal expansion of hematopoietic stem cells. We compared the burden of acute rejection (AR) over the first post-transplant year in lung recipients with vs. without CHIP using multivariable ordinal regression. Multivariate Cox proportional hazards models were used to assess the association between CHIP and CLAD-free survival. An exploratory analysis evaluated the association between the number of CHIP-associated variants and chronic lung allograft dysfunction (CLAD)-free survival.ResultsWe detected 64 CHIP-associated mutations in 45 individuals (15.7%), most commonly in TET2 (10.8%), DNMT3A (9.2%), and U2AF1 (9.2%). Patients with CHIP tended to be older but did not significantly differ from patients without CHIP in terms of race or native lung disease. Patients with CHIP did not have a higher incidence of AR over the first post-transplant year (p = 0.45) or a significantly increased risk of death or CLAD (adjusted HR 1.25, 95% CI 0.88–1.78). We did observe a significant association between the number of CHIP variants and CLAD-free survival, specifically patients with 2 or more CHIP-associated variants had an increased risk for death or CLAD (adjusted HR 3.79, 95% CI 1.98–7.27).ConclusionsLung recipients have a higher prevalence of CHIP and a larger variety of genes with CHIP-associated mutations compared with previous reports for the general population. CHIP did not increase the risk of AR, CLAD, or death in lung recipients.

Real-life experience in two cases of secondary prophylaxis with letermovir for CMV infection in solid organ transplantation.

The use of valganciclovir as secondary prophylaxis for cytomegalovirus (CMV) infection in solid organ transplantation (SOT) is the most prevalent therapeutic choice, but it has been dismissed by the presence of resistance and toxicity. Letermovir (LMV) is indicated as primary prophylaxis in hematopoietic stem cell transplantation, but there is scarce clinical data on its use as secondary prophylaxis in SOT. We present two cases of SOT recipients (lung, liver) who underwent LMV secondary prophylaxis. One patient developed the L595S (UL97)-resistant mutation to ganciclovir/valganciclovir and experienced several CMV relapses under LMV therapy, but no LMV resistance mutations were detected. The second patient developed the C325F (UL56)-resistant mutation to LMV under secondary prophylaxis which was rescued by foscarnet. This observation reviews previously published clinical data on LMV secondary prophylaxis and recommends a cautious use of LMV in the clinical practice due to the early development of UL56 resistance mutations. IMPORTANCE This observation provides comprehensive data on the clinical correlates of both cytomegalovirus (CMV) genotypic follow-up and clinical monitoring and outcomes for two different solid organ transplantation recipients that received letermovir as secondary prophylaxis. Our study emphasizes that monitoring of CMV disease in the patient and early genotypic detection of resistance mutations are essential when using new antiviral drugs for off-label indication in patients experiencing CMV relapses or not responding to standard antiviral therapy. These cases and the bibliography reviewed can be helpful for other researchers and clinicians working in the field to optimize the use of new treatments for transplant recipients since drug-resistant CMV infection is an important emerging problem even with new developments in antiviral treatment.

Lung Transplantation from hepatitis C+ donor lungs: Reassuring midterm outcomes

The development of modern antiviral therapy for hepatitis C virus (HCV) has allowed for the transplantation of HCV nucleic acid amplification testing-positive (NAT+) donor lungs with acceptable short-term outcomes. We sought to evaluate trends and midterm outcomes of lung transplant recipients of HCV NAT+ donor allografts. All adults undergoing isolated lung transplantation in the United Network for Organ Sharing database from January 2016 to December 2022 were included in the study. Lung transplant recipients were stratified based on donor HCV status (HCV NAT+ vs NAT-). Propensity score matching was used to adjust for differences between groups. Several outcomes, including acute rejection by 1year, early (30-day and in-hospital) mortality, and both 1- and 3-year survival, were compared between matched groups. A total of 16,725 patients underwent lung transplantation during the study period, with 489 (3%) receiving HCV NAT+ donor lungs. Regions 1 (18%) and 6/8 (both 0%) had the highest and lowest proportions, respectively, of HCV NAT+ donor transplants. Utilization of HCV NAT+ donors increased throughout the study period from 2 (0.1%) in 2016 to a peak of 117 (5%) in 2019. Donors who were HCV NAT+ were younger (34 vs 36 years, p<0.001), more often female (44% vs 39%, p<0.01), and more commonly died due to drug intoxication (56% vs 15%, p<0.001). Recipients of HCV NAT+ donor lungs were similar in age (62 vs 62 years, p=0.69) and female gender (43% vs 39%, p=0.15) but had lower lung allocation scores (38 vs 41, p<0.001) compared to others. Rates of acute rejection (13% vs 17%, p=0.09), early mortality (30-day: 2% vs 1%, p=0.59, in-hospital: 3% vs 4%, p=0.38), as well as 1-year (90% vs 92%, p=0.29) and 3-year survival (69% vs 75%, p=0.13) were not significantly different between matched groups. Lung transplant recipients of HCV NAT+ donor allografts experience similar rates of acute rejection, early mortality, and 3-year survival compared to all other lung recipients. Increased use of HCV NAT+ donor allografts may help to expand the donor pool and alleviate donor shortages.

Thulium fiber laser use in interventional bronchoscopy in lung recipients

Bronchial stenosis is a major cause of severe postoperative period in lung recipients. One of the methods to restore airway patency is recanalization using laser. This technique is popular due to the combination of cutting and coagulation effects. In this article, we demonstrate the possibility of intraluminal use of a thulium fiber laser (TFL) to recanalize bronchial stenosis in lung recipients.

Fatal Infections Differentially Involve Allograft and Native Lungs in Single Lung Transplant Recipients.

Respiratory infections complicate lung transplantation and increase the risk of allograft dysfunction. Allograft lungs may have different susceptibilities to infection than native lungs, potentially leading to different disease severity in lungs of single lung transplant recipients (SLTRs). To study whether infections affect allograft and native lungs differently in SLTRs but similarly in double LTRs (DLTRs). Using an institutional database of LTRs, medical records were searched, chest computed tomography studies were systematically reviewed, and histopathologic features were recorded per lung lobe and graded semiquantitatively. A multilobar-histopathology score (MLHS) including histopathologic data from each lung and a bilateral ratio (MLHSratio) comparing histopathologies between both lungs were calculated in SLTRs and compared to DLTRs. Six SLTRs died of infection involving the lungs. All allografts showed multifocal histopathologic evidence of infection, but at least 1 lobe of the native lung was uninvolved. In 4 of 5 DLTRs, histopathologic evidence of infection was seen in all lung lobes. On computed tomography, multifocal ground-glass and/or nodular opacities were found in a bilateral distribution in all DLTRs but in only 2 of 6 SLTRs. In SLTRs, the MLHSAllograft was higher than MLHSNative (P = .02). The MLHSratio values of SLTR and DLTR were significantly different (P < .001). Allograft and native lungs appear to harbor different susceptibilities to infections. The results are important for the management of LTRs.

Donor and Recipient Age in Interstitial Lung Disease: Types of Lung Transplant Survival Outcomes

IntroductionLung transplantation is the last option for patients with end-stage interstitial lung disease (ILD), yet organ allocation remains a challenge. This single-center study investigated the correlation of procedure type and donor and recipient age with survival outcomes in patients with ILD. MethodsWe performed a retrospective study of lung recipients diagnosed with ILD who were transplanted in our center. Survival was assessed using Kaplan-Meier curves and log-rank tests according to the following variables: double lung transplant (DLT) or single lung transplant (SLT), recipient age <65 and ≥65, recipient sex, donor sex, and donor age. Cox proportional hazards regression was performed using the same variables. P values < 0.05 were considered significant. ResultsOf 969 lung recipients transplanted at our center, 648 (66.8%) were diagnosed with ILD. There was no significant difference in survival for patients <65 or ≥65 when compared by DLT versus SLT. There were no significant differences in survival based on donor age. Survival at 5 y was significantly higher for recipient age <65 versus ≥65 (P = 0.0014). For DLT patients <65 or ≥65, there was no significant survival difference. However, for SLT patients, survival at 5 y was significantly higher for patients <65 (P = 0.0109). ConclusionsOur findings suggest that donor age did not have a significant association with survival of patients with ILD posttransplant. In older patients with ILD, there was no significant difference for DLT versus SLT. However, within the SLT group, younger patients with ILD showed better survival compared to older patients.

Suspected Legionella Transmission from a Single Donor to Two Lung Transplant Recipients - Pennsylvania, May 2022.

In July 2022, the Pennsylvania Department of Health received two reports of laboratory-confirmed Legionnaires disease in patients who had recently received lung transplants from the same donor at a single Pennsylvania hospital. The donor's cause of death was freshwater drowning in a river, raising suspicion of potential donor-derived transmission, because Legionella bacteria naturally live in fresh water. Further investigation of patients receiving other organs from the same donor did not identify additional legionellosis cases. Health care-associated infection caused by water exposure at the hospital was also evaluated as a potential source of infection and was found to be unlikely. Hospital water quality parameter measurements collected during May-June 2022 were within expected ranges and no water disruptions were noted, although no testing for Legionella was performed during this period. Notifiable disease data did not identify any other Legionnaires disease cases with exposure to this hospital within the 6 months before or after the two cases. Although laboratory testing did not confirm the source of recipient infections, available data suggest that the most likely source was the donor lungs. This cluster highlights the need for increased clinical awareness of possible infection with Legionella in recipients of lungs from donors who drowned in fresh water before organ recovery.

Lung regeneration with rat fetal lung implantation and promotion of alveolar stem cell differentiation by corticosteroids

IntroductionThe lung is a difficult organ to regenerate, and the development of functional lungs has still not been achieved. In this study, we investigated lung regeneration using a rat fetal lung tissue-implanted model. This study aimed to evaluate the functioning of the implanted fetal lung tissue and investigate the graft differentiation and maturation mechanism, focusing on alveolar stem cells. MethodsFetal lung tissue fragments were obtained from Lewis rats on day 17 and implanted into adult lungs. Animals were divided into the following three groups: group 1, injection into the adult left lung parenchyma; group 2, injection with post-caval lobectomy; and group 3, injection with post-caval lobectomy and corticosteroid administration. Computed tomography was performed on weeks 1, 2, 4, and 8. The presence of alveolar pore, CD31 expression, and bipotential progenitor cell (podoplanin+/surfactant protein C+) localization were histologically evaluated. MiRNA expression was comprehensively compared among the three groups. ResultsThe grafts comprised type I and type II alveolar cells connected to the recipient lungs with alveolar pores and capillary networks in the interstitial tissue. The alveolar space was the largest and the computed tomography value was the lowest in the grafts of the corticosteroid-administered group. The number of bipotential progenitor cells was the lowest in the corticosteroid administration group on day 7. Moreover, microRNA-487-3p, 374-5p, and 20b-5p expression was changed by more than 2-fold between the post-caval lobectomy and corticosteroid administration groups. ConclusionsImplanted fetal lung tissues established airway and capillary communication with the recipient lungs, and corticosteroids accelerated their maturation by promoting the differentiation of progenitor cells. The study findings provide new insights into lung regeneration research.

Prospective assessment of pre-existing and de novo anti-HLA IgE in kidney, liver, lung and heart transplantation.

Antibody mediated rejection (ABMR) is a major factor limiting outcome after organ transplantation. Anti-HLA donor-specific antibodies (DSA) of the IgG isotype are mainly responsible for ABMR. Recently DSA of the IgE isotype were demonstrated in murine models as well as in a small cohort of sensitized transplant recipients. In the present study, we aimed to determine the frequency of pre-existing and de novo anti-HLA IgE antibodies in a cohort of 105 solid organ transplant recipients. We prospectively measured anti-HLA IgE antibodies in a cohort of kidney (n=60), liver, heart and lung (n=15 each) transplant recipients before and within one-year after transplantation, employing a single-antigen bead assay for HLA class I and class II antigens. Functional activity of anti-HLA IgE antibodies was assessed by an in vitro mediator release assay. Antibodies of the IgG1-4 subclasses and Th1 and Th2 cytokines were measured in anti-HLA IgE positive patients. Pre-existing anti-HLA IgE antibodies were detected in 10% of renal recipients (including 3.3% IgE-DSA) and in 4.4% of non-renal solid organ transplant recipients (heart, liver and lung cohort). Anti-HLA IgE occurred only in patients that were positive for anti-HLA IgG, and most IgE positive patients had had a previous transplant. Only a small fraction of patients developed de novo anti-HLA IgE antibodies (1.7% of kidney recipients and 4.4% of non-renal recipients), whereas no de novo IgE-DSA was detected. IgG subclass antibodies showed a distinct pattern in patients who were positive for anti-HLA IgE. Moreover, patients with anti-HLA IgE showed elevated Th2 and also Th1 cytokine levels. Serum from IgE positive recipients led to degranulation of basophils in vitro, demonstrating functionality of anti-HLA IgE. These data demonstrate that anti-HLA IgE antibodies occur at low frequency in kidney, liver, heart and lung transplant recipients. Anti-HLA IgE development is associated with sensitization at the IgG level, in particular through previous transplants and distinct IgG subclasses. Taken together, HLA specific IgE sensitization is a new phenomenon in solid organ transplant recipients whose potential relevance for allograft injury requires further investigation.

Results of a multicenter cluster-randomized controlled clinical trial testing the effectiveness of a bioinformatics-enabled pharmacist intervention in transplant recipients

An ambulatory medication safety dashboard was developed to identify missing labs, concerning labs, drug interactions, nonadherence, and transitions in care. This system was tested in a 2-year, prospective, cluster-randomized, controlled multicenter study. Pharmacists at 5 intervention sites used the dashboard to address medication safety issues, compared with usual care provided at 5 control sites. A total of 2196 transplant events were included (1300 intervention vs 896 control). During the 2-year study, the intervention arm had a 11.3% (95% confidence interval, 7.1%-15.5%) absolute risk reduction of having ≥1 emergency department (ED) visit (44.2% vs 55.5%, respectively; P < .001, respectively) and a 12.3% (95% confidence interval, 8.2%-16.4%) absolute risk reduction of having ≥1 hospitalization (30.1% vs 42.4%, respectively; P < .001). In those with ≥1 event, the median ED visit rate (2 [interquartile range (IQR) 1, 5] vs 2 [IQR 1, 4]; P = .510) and hospitalization rate (2 [IQR 1, 3] vs 2 [IQR 1, 3]; P = .380) were similar. Treatment effect varied by comorbidity burden, previous ED visits or hospitalizations, and heart or lung recipients. A bioinformatics dashboard-enabled, pharmacist-led intervention reduced the risk of having at least one ED visit or hospitalization, predominantly demonstrated in lower risk patients.