Acute Cellular Rejection Episodes Research Articles

Basiliximab Induction and Postoperative Steroid-free Immunosuppression With Tacrolimus in Pediatric Liver Transplantation: A Randomized Clinical Trial.

Optimizing the immunosuppressive regimen is essential to improve the long-term outcomes of pediatric liver transplant recipients. We conducted a prospective, randomized, open-label study to compare the safety and efficacy of 2 treatment approaches during pediatric liver transplantation: tacrolimus monotherapy following basiliximab induction (the study group) and a dual regimen of tacrolimus plus steroids (the control group). A total of 150 patients were enrolled, with 75 patients allocated to each group. In both groups, recipients achieved graft and recipient overall survival rates exceeding 93%, with no statistically significant differences between them. However, the study group exhibited a significantly lower incidence of acute cellular rejection (ACR), delayed occurrence of ACR, and an improved ACR-free survival rate at 2 y compared with the control group. Notably, the study group also showed a significant reduction in the incidence of de novo donor-specific antibodies at 3-mo and 2-y posttransplant. Furthermore, 6 mo after the transplant, the study group demonstrated significant improvements in weight-for-age Z score and height-for-age Z score. No notable differences were observed in postoperative complications or the incidence of liver fibrosis between the 2 groups. Basiliximab induction combine with tacrolimus (TAC) monotherapy is a safe and effective immunosuppressive regimen to reduce the episodes of ACR without influencing the development of liver fibrosis and graft and recipient survival rate after pediatric liver transplantation.

Rejection in the setting of combined Heart and Liver Transplantation

IntroductionEach year the number of combined heart-liver transplants (HLT) increases, with two distinct patient populations proceeding down this pathway. The first are patients with congenital heart disease (CHD), most commonly single ventricle patients palliated with Fontan. The second group are those with long standing congestive hepatopathy, amyloidosis, hemochromatosis, or alcohol induced myopathies and liver disease.One argument for HLT has been the low rate of rejection even among sensitized patients, with reported rejection rates ranging from 0% to 31%. Historically, those with CHD have been highly sensitized which in some cases may prevent or at least delay transplantation. As such, a recent consensus statement by Emamaulee et al. suggest that “there may be an immunological benefit to proceed with HLT with significantly fewer acute cellular and humoral rejection episodes”. The aim of this study is to demonstrate that HLT patients remain at risk for rejection and have required treatment for it. ResultsThere were 15 patients who underwent HLT from January 2017 to February 2022. Of the four patients who did not have CHD, none were considered sensitized, and all underwent induction with basiliximab per our institutional protocol. One of these had rejection. Rejection episodes were identified in four of the 11 CHD patients (36%) patients. ConclusionsIn our study of 15 HLT, including 11 CHD patients (73% denied transplant at ≥ 1 center) demonstrated a higher rate of rejection than previously reported. While theoretically, HLT may mitigate the likelihood of rejection, the risk still exists, and patients benefit from close monitoring commensurate with single organ transplant.

CLINICAL OUTCOMES OF INFLAMMATORY BOWEL DISEASE AFTER ORTHOTOPIC HEART TRANSPLANT

Abstract BACKGROUND Limited data are available on outcomes of patients with pre-existing inflammatory bowel disease (IBD) who undergo orthotopic heart transplantation (OHT) or develop de novo IBD post-OHT. We aimed to assess the incidence and disease outcomes of pre-existing and de novo IBD in OHT patients while evaluating the effect of IBD on OHT outcomes. METHODS A retrospective review of records was performed from a tri-site tertiary care system between July 2000 and July 2022. A total of 83 OHT receipients were concomitantly diagnosed with colitis of infectious or inflammatory etiology. Only patients with a diagnosis of IBD were included. Sub-analyses of the outcomes and immunosuppressive regimens of OHT recepients were done relative to those with pre-existing or de novo IBD. RESULTS A total of 8 OHT patients with concomitant IBD were identified. The median patient age (IQR) was 54 (23) with OHT and IBD onset at 50 (21.2) and 32.5 (15.7), respectively. Six patients were diagnosed with ulcerative colitis (UC) and 2 were diagnosed with Crohn’s disease. Five of the patients were female. All patients developed IBD within 11.5 (8) years within OHT. Only 1 patient developed de novo IBD 15 years after the first OHT and 7 years prior to a second OHT. OHT immunosuppressive regimens included a combination of tacrolimus (TAC) and prednisone (n=2), TAC and mycophenolate mofetil (MMF) (n=2), TAC, MMF, and sirolimus (n=2), TAC and sirolimus (n=1), and MMF with sirolimus (n=1). Therapy for pre-existing IBD included maintenance of 5-aminosalicylic (5-ASA) (n=3), escalation to vedolizumab (VD) (n=2), and discontinuation of IBD therapy (5-ASA and azathioprine) (n=3). De novo IBD consistent with UC (15 years post-OHT) was managed with 5-ASA (n=1). Six patients (including de novo IBD case) maintained clinical and endoscopic remission of IBD with no flares post-OHT while 2 patients (1 UC and 1 CD) with active disease flares responded clinically and endoscopically to VD escalation from 5-ASA and azathioprine. Among two UC patients with ileal J-pouch pre-OHT, 1 developed refractory pouchitis requiring diverting ileostomy (while on TAC and prednisone) with no pouchitis in the other (maintained on TAC and MMF). Good graft tolerance limited to mild acute cellular rejection episodes was noted in 6 patients, while multiple or no rejection episodes were noted in the remaining two. None of the patients developed CMV or MMF-induced colitis. One patient died due to progressive functional decline unrelated to graft failure or IBD. DISCUSSION The clinical course and treatment of IBD preceding OHT or de novo (though rare) is not significantly worsened or altered post-OHT. The majority of patients achieve clinical and endoscopic remission while on heart transplant-related immunosuppression. Biologic therapy escalation to VD resulted in clinical remission with no effect on graft tolerance. Table 1 Clinical outcomes of OHT patients with concomitant IBD

Higher Molecular Injury at Diagnosis of Acute Cellular Rejection Increases the Risk of Lung Allograft Failure: A Clinical Trial.

Rationale: The association of acute cellular rejection (ACR) with chronic lung allograft dysfunction (CLAD) in lung transplant recipients has primarily been described before consensus recommendations incorporating restrictive phenotypes. Furthermore, the association of the degree of molecular allograft injury during ACR with CLAD or death remains undefined. Objectives: To investigate the association of ACR with the risk of CLAD or death and to further investigate if this risk depends on the degree of molecular allograft injury. Methods: This multicenter, prospective cohort study included 188 lung transplant recipients. Subjects underwent serial plasma collections for donor-derived cell-free DNA (dd-cfDNA) at prespecified time points and bronchoscopy. Multivariable Cox proportional-hazards analysis was conducted to analyze the association of ACR with subsequent CLAD or death as well as the association of dd-cfDNA during ACR with risk of CLAD or death. Additional outcomes analyses were performed with episodes of ACR categorized as "high risk" (dd-cfDNA ⩾ 1%) and "low risk" (dd-cfDNA < 1%). Measurements and Main Results: In multivariable analysis, ACR was associated with the composite outcome of CLAD or death (hazard ratio [HR], 2.07 [95% confidence interval (CI), 1.05-4.10]; P = 0.036). Elevated dd-cfDNA ⩾ 1% at ACR diagnosis was independently associated with increased risk of CLAD or death (HR, 3.32; 95% CI, 1.31-8.40; P = 0.012). Patients with high-risk ACR were at increased risk of CLAD or death (HR, 3.13; 95% CI, 1.41-6.93; P = 0.005), whereas patients with low-risk status ACR were not. Conclusions: Patients with ACR are at higher risk of CLAD or death, but this may depend on the degree of underlying allograft injury at the molecular level. Clinical trial registered with www.clinicaltrials.gov (NCT02423070).

Outcomes of lung transplantation from donors with hepatitis C viremia with outpatient initiation of antiviral therapy

Transplantation of lungs from donors with active hepatitis C viremia with early initiation of antiviral therapy has been shown to have similar short- and medium-term outcomes compared to transplantation of lungs from non-viremic donors. Consideration of hepatitis C viremic lungs is particularly helpful in patients with anticipated prolonged time on the waiting list. Whether clinical outcomes remain favorable with delay of initiation of antiviral therapy to the outpatient setting or in patients with higher severity of illness is not well understood. Our transplant center considered hepatitis C nucleic acid testing positive (NAT+) donors for all waitlisted lung transplant candidates without chronic liver disease. For those transplanted with hepatitis C NAT+ lungs, we initiated anti-viral therapy in the outpatient setting and continued treatment for 12 weeks. In a retrospective single center study of 15 lung transplant recipients receiving hepatitis C NAT+ lungs and 88 recipients receiving non-viremic lungs, we tested the hypothesis that deferral of antiviral therapy after transplantation of lungs from hepatitis C NAT+ donors to the outpatient setting would result in similar 1 year survival compared to transplantation of lungs from non-viremic donors. Patients receiving hepatitis C NAT+ lungs had similar baseline characteristics, but had longer index hospital lengths of stay (24 vs. 13 days, p=0.021). Patients receiving hepatitis C NAT+ lungs had fewer episodes of acute cellular rejection in the first year. Patients receiving hepatitis C NAT+ lungs had similar one year survival to patients receiving lungs from non-viremic donors, after controlling for age and lung allocation score (p=0.638). In this small single-center study, outpatient initiation of antiviral therapy for donor-derived hepatitis C is associated with acceptable clinical outcomes and can be considered in patients with high severity of illness.

An Immune Atlas of T Cells in Transplant Rejection: Pathways and Therapeutic Opportunities.

Short-term outcomes in allotransplantation are excellent due to technical and pharmacological advances however, improvement in long-term outcomes has been limited. Recurrent episodes of acute cellular rejection, a primarily T cell-mediated response to transplanted tissue, have been implicated in the development of chronic allograft dysfunction and loss. Although it is well established that acute cellular rejection is primarily a CD4+ and CD8+ T cell mediated response, significant heterogeneity exists within these cell compartments. During immune responses, naïve (orthography) (orthography) CD4+ T cells are activated and subsequently differentiate into specific T helper subsets under the influence of the local cytokine milieu. These subsets have distinct phenotypic and functional characteristics, with reported differences in their contribution to rejection responses specifically. Of particular relevance are the regulatory subsets and their potential to promote tolerance of allografts. Unraveling the specific contributions of these cell subsets in the context of transplantation is complex, but may reveal new avenues of therapeutic intervention for the prevention of rejection.

Heart transplantation and human immunodeficiency virus–navigating drug-drug interactions: a case report

BackgroundAntiretroviral therapy (ART) has led to a decline in human immunodeficiency virus (HIV)-related mortality, but comorbidities, including organ dysfunction, are increasingly the focus of care. Heart transplant (HT) is a very effective therapeutic strategy for end-stage heart failure (HF); however, clinicians may be hesitant due to concerns of complex drug-drug interactions (DDIs) between ART and HT immunosuppressive regimens and the potential impact of ART on long-term HT outcomes. In this report, we describe long-term (76-month) follow-up of a patient with HIV-positive status who underwent orthotopic HT with special emphasis on complex drug interactions.Case presentationA 58-year-old man with HIV-1 developed ischemic cardiomyopathy, progressed to end-stage HF and underwent orthotopic HT. To avoid DDIs with planned immunosuppressive therapies, the ART regimen was modified to consist of lamivudine, tenofovir disoproxil fumarate, rilpivirine, and raltegravir. Following HT, the patient’s immunosuppression consisted of tacrolimus and mycophenolate mofetil. He has had normal cardiac function and no opportunistic infections and was subsequently switched to tenofovir alafenamide, emtricitabine, and bictegravir in combination for convenience. Serial HIV-1 RNA blood levels were constantly below the limit of quantification, and his CD4 count remained above 200 cells/mm3 (30–35%). Several DDIs were identified and addressed; however, his long-term post-HT complications included one episode of asymptomatic acute cellular rejection, adenocarcinoma of the prostate, basal cell carcinoma, cardiac allograft vasculopathy, and peripheral neuropathy.ConclusionThe clinical outcome of this case supports the conclusion of previously published reports, summarized here within, demonstrating that HIV-1 positive status should not preclude HT in carefully selected individuals. Both addressing potential DDIs prior to HT and long-term monitoring for routine post-transplant complications and secondary and incidental malignancies are imperative.

Heart transplantation and anti-HLA antibodY: myocardial dysfunction and prognosis - HeartLAy study.

The presence of anti-human leucocyte antigen (HLA) antibodies has been implicated in a higher incidence of complications as well as mortality rate in heart transplantation. The aim of the study was to identify through non-invasive parameters early signs of myocardial dysfunction in the presence of anti-HLA antibodies but without evidence of antibody-mediated rejection (AMR) and its possible prognostic impact. A total of 113 heart-transplanted patients without acute cellular rejection (ACR) and AMR or cardiac allograft vasculopathy (CAV) were prospectively enrolled and divided into two groups ['HLA+' (50 patients) and 'HLA-' (63 patients)], based on the presence of anti-HLA antibodies. Each patient was followed for 2years after the enrolment, recording episodes of AMR, ACR, CAV, and mortality. Clinical characteristics were similar between the two groups. Among laboratory data, N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin values were significantly higher in the presence of anti-HLA antibodies (P<0.001 and P=0.003, respectively). The echocardiographic parameters that showed a statistically significant difference between the two groups were deceleration time of E wave (DecT E, P<0.001), left ventricular global longitudinal strain (P<0.001), tricuspid annular plane systolic excursion (P=0.011), tricuspid S' wave (P=0.002), and free wall right ventricular longitudinal strain (fwRVLS, P=0.027), whereas left atrial strain did not differ significantly (P=0.408). Univariate analysis showed that anti-HLA antibodies were associated with the development of CAV at both 1 and 2year follow-up [odds ratio (OR) 11.90, 95% confidence interval (CI) 1.43-90.79, P=0.022 and OR 3.37, 95% CI 1.78-9.67, P=0.024, respectively]. Bivariate analysis demonstrated that both fwRVLS and DecT E were predictors of CAV development independently from HLA status. The presence of circulating anti-HLA antibodies is correlated with a mild cardiac dysfunction, even in the absence of AMR, and CAV development. Interestingly, reduced values of DecT E and fwRVLS were predictors of future development of CAV, independently from anti-HLA antibody.

Frailty: A Strong Impact on Lung Transplant Outcomes?

Frailty: A Strong Impact on Lung Transplant Outcomes?

The Association Between Frailty and Chronic Lung Allograft Dysfunction After Lung Transplantation.

After lung transplantation, both frailty and chronic lung allograft dysfunction (CLAD) commonly develop, and when they do, are associated with poorer outcomes. Given their potential shared mechanisms, we sought to explore the temporal relationship between frailty and CLAD onset. In a single center, we prospectively measured frailty by the short physical performance battery (SPPB) repeatedly after transplant. Because of the nature of the relationship between frailty and CLAD is unknown, we tested the association between frailty, modeled as a time-dependent predictor, and CLAD development as well as CLAD development, modeled as a time-dependent predictor, and frailty development. To do so, we used Cox proportional cause-specific hazards and conditional logistic regression models adjusted for age, sex, race, diagnosis, cytomegalovirus serostatus, posttransplant body mass index, and acute cellular rejection episodes as time-dependent covariates. We tested SPPB frailty as a binary (≤9 points) and continuous predictor (12-point scale); as an outcome, we defined frailty as SPPB ≤9. The 231 participants were a mean age of 55.7 y (SD 12.1). After adjusting for covariates, the development of frailty within 3 y after lung transplant was associated with cause-specific CLAD risk (adjusted cause-specific hazard ratio: 1.76; 95% confidence interval [CI], 1.05-2.92 when defining frailty as SPPB ≤9 and adjusted cause-specific hazard ratio: 1.10, 95% CI, 1.03-1.18 per 1-point worsening in SPPB). CLAD onset did not appear to be a risk factor for subsequent frailty (odds ratio, 4.0; 95% CI, 0.4-197.0). Studying the mechanisms underlying frailty and CLAD could provide new insights into the pathobiology of both and potential targets for intervention.

Ineffective esophageal motility is associated with acute rejection after lung transplantation independent of gastroesophageal reflux.

Gastroesophageal reflux is associated with poorer outcomes after lung transplant, likely through recurrent aspiration and allograft injury. Although prior studies have demonstrated a relationship between impedance-pH results and transplant outcomes, the role of esophageal manometry in the assessment of lung transplant patients remains debated, and the impact of esophageal dysmotility on transplant outcomes is unclear. Of particular interest is ineffective esophageal motility (IEM) and its associated impact on esophageal clearance. To assess the relationship between pre-transplant IEM diagnosis and acute rejection after lung transplantation. This was a retrospective cohort study of lung transplant recipients at a tertiary care center between 2007 and 2018. Patients with pre-transplant anti-reflux surgery were excluded. Manometric and reflux diagnoses were recorded from pre-transplant esophageal function testing. Time-to-event analysis using Cox proportional hazards model was applied to evaluate outcome of first episode of acute cellular rejection, defined histologically per International Society of Heart and Lung Transplantation guidelines. Subjects not meeting this endpoint were censored at time of post-transplant anti-reflux surgery, last clinic visit, or death. Fisher's exact test for binary variables and student's t-test for continuous variables were performed to assess for differences between groups. Of 184 subjects (54% men, mean age: 58, follow-up: 443 person-years) met criteria for inclusion. Interstitial pulmonary fibrosis represented the predominant pulmonary diagnosis (41%). During the follow-up period, 60 subjects (33.5%) developed acute rejection. The all-cause mortality was 16.3%. Time-to-event univariate analyses demonstrated significant association between IEM and acute rejection [hazard ratio (HR): 1.984, 95%CI: 1.03-3.30, P = 0.04], confirmed on Kaplan-Meier curve. On multivariable analysis, IEM remained independently associated with acute rejection, even after controlling for potential confounders such as the presence of acid and nonacid reflux (HR: 2.20, 95%CI: 1.18-4.11, P = 0.01). Nonacid reflux was also independently associated with acute rejection on both univariate (HR: 2.16, 95%CI: 1.26-3.72, P = 0.005) and multivariable analyses (HR: 2.10, 95%CI: 1.21-3.64, P = 0.009), adjusting for the presence of IEM. Pre-transplant IEM was associated with acute rejection after transplantation, even after controlling for acid and nonacid reflux. Esophageal motility testing may be considered in lung transplant to predict outcomes.

Evaluation and management of abnormal liver enzymes in the liver transplant recipient: When, why, and what now?

Evaluation and management of abnormal liver enzymes in the liver transplant recipient: When, why, and what now?

Intra-subject variability in oscillometry correlates with acute rejection and CLAD post-lung transplant.

Chronic lung allograft dysfunction (CLAD) is the major cause of death post-lung transplantation, with acute cellular rejection (ACR) being the biggest contributing risk factor. Although patients are routinely monitored with spirometry, FEV1 is stable or improving in most ACR episodes. In contrast, oscillometry is highly sensitive to respiratory mechanics and shown to track graft injury associated with ACR and its improvement following treatment. We hypothesize that intra-subject variability in oscillometry measurements correlates with ACR and risk of CLAD. Of 289 bilateral lung recipients enrolled for oscillometry prior to laboratory-based spirometry between December 2017 and March 2020, 230 had ≥ 3 months and 175 had ≥ 6 months of follow-up. While 37 patients developed CLAD, only 29 had oscillometry at time of CLAD onset and were included for analysis. These 29 CLAD patients were time-matched with 129 CLAD-free recipients. We performed multivariable regression to investigate the associations between variance in spirometry/oscillometry and the A-score, a cumulative index of ACR, as our predictor of primary interest. Conditional logistic regression models were built to investigate associations with CLAD. Multivariable regression showed that the A-score was positively associated with the variance in oscillometry measurements. Conditional logistic regression models revealed that higher variance in the oscillometry metrics of ventilatory inhomogeneity, X5, AX, and R5-19, was independently associated with increased risk of CLAD (p < 0.05); no association was found for variance in %predicted FEV1. Oscillometry tracks graft injury and recovery post-transplant. Monitoring with oscillometry could facilitate earlier identification of graft injury, prompting investigation to identify treatable causes and decrease the risk of CLAD.

Conversion to belatacept after lung transplantation: Report of 10 cases.

Calcineurin inhibitors (CNIs) remain the cornerstone of maintenance immunosuppression (IS) after lung transplantation (LTx), although CNI-related life-threatening toxic effects may occur. Belatacept, a novel immunosuppressant that blocks a T-cell co-stimulation pathway, is a non-nephrotoxic drug indicated as an alternative to CNIs in kidney Tx. In LTx, there are only a few reports of belatacept conversion as a CNI-free or CNI-sparing IS treatment. We reviewed a series of 10 LTx recipients with conversion to a CNI-free belatacept IS regimen within the first year post-LTx (n = 7) or a belatacept/low-dose CNI combination after the first year (n = 3). Use of belatacept was triggered by severe renal failure in 9 patients and under-IS with previous other IS-related toxicities in 1 patient. Mean estimated glomerular filtration rate after starting belatacept significantly improved at 6 months after initiation and at the last-follow-up (p = 0.006, and p = 0.002 respectively). The incidence of recurrent and/or severe acute cellular rejection (ACR) episodes was high in patients with CNI-free belatacept-based IS (n = 4/7). Chronic graft allograft dysfunction developed in 2 of 9 recipients under belatacept IS. Belatacept was stopped in 6 patients because of recurrent/severe ACR (n = 3), recurrent opportunistic infections (n = 1), center modified policy (n = 1), or other cause (n = 1). Early conversion to CNI-free belatacept-based IS improved renal function in this series but was counterbalanced by a high incidence of recurrent ACR, including life-threatening episodes. Other studies are needed to better determine the indications for its use after LTx, possibly with lower immunological risk IS regimens, such as CNI-sparing belatacept.

T-cell infiltrate intensity is associated with delayed response to treatment in late acute cellular rejection in pediatric liver transplant recipients.

Late acute cellular rejection (ACR) is associated with donor-specific antibodies (DSA) development, chronic rejection, and allograft loss. However, accurate predictors of late ACR treatment response are lacking. ACR is primarily T-cell mediated, yet B cells and plasma cells (PC) also infiltrate the portal areas during late ACR. To test the hypothesis that the inflammatory milieu is associated with delayed response (DR) to rejection therapy, we performed a single-center retrospective case-control study of pediatric late liver ACR using multiparameter immunofluorescence for CD4, CD8, CD68, CD20, and CD138 to identify immune cell subpopulations. Pediatric liver transplant recipients transplanted at <17 years of age and treated for biopsy-proven late ACR between January 2014 and 2019 were stratified into rapid response (RR) and DR based on alanine aminotransferase (ALT) normalization within 30 days of diagnosis. All patients received IV methylprednisolone as an initial rejection treatment. Immunofluorescence was performed on archived formalin-fixed paraffin embedded (FFPE) liver biopsy tissue. Liver biopsies from 60 episodes of late ACR in 54 patients were included in the analysis, of which 33 were DR (55%). Anti-thymocyte globulin was only required in the DR group. The frequency of liver-infiltrating CD20+ and CD8+ lymphocytes and the prevalence of autoantibodies were higher in the DR group. In univariate logistic regression analysis, serum gamma-glutamyl transpeptidase (GGT) level at diagnosis, but not ALT, Banff score or presence of DSA, predicted DR. Higher serum GGT level, presence of autoantibodies, and increased CD8+ T-cell infiltration portends DR in late ACR treatment in children.

Induction Versus Maintenance Immunosuppression After Intestinal Transplant: Determining Which Treatment Most Impacts Long-Term Patient And Graft Survival.

Immunosuppressive strategies for intestinal transplant have changed over time. However, specific intestinal transplant-oriented protocols and reports on long-term maintenance regimens are scarce. Our objective was to evaluate the impact of 2 different initial immunosuppressive protocols based on thymoglobulin (group A) and basiliximab (anti-interleukin 2 antibody) (group B) and of changes to maintenance immunosuppression over long-term follow-up in intestinal transplant recipients. We performed a retrospective analysis of a prospectively established protocol for intestinal transplant immunosuppression, conducted between May 2006 and December 2020. We analyzed 51 intestinal transplant recipients, with 6 patients excluded because of early death or graft loss. Acute cellular rejection frequency and grade, number of acute cellular rejection episodes, time to the first acute cellular rejection episode, response to treatment, number of patients who progressed to chronic allograft rejection, kidney function, infections, incidence of posttransplant lymphoproliferative disorder and graft-versus-host disease, and patient and graft survival were analyzed. In the study groups, there were 87 acute cellular rejection episodes in 45 patients (33 in group A and 54 in group B). We found degree of acute cellular rejection to be mild in 45 patients, moderate in 18, and severe in 24 (not significant between groups). Our comparison of induction therapy (thymoglobulin [group A] vs interleukin 2 antibody [group B]) did not show any statistical difference during clinical followup. Long-term review showed that all patients were on tacrolimus. Five-year patient and graft survival rates were 62% and 45% for group A and 54% and 46% for group B, respectively (not significant). Long-term patient and graft outcomes reflected the use of an individualized follow-up with adjustments and changes in immunosuppressive medications according to the patient's clinical course and complications rather than based on the induction immunosuppressive protocol used.

420.6: Transplantation of Organs From SARS-CoV-2-Positive Donors To Uninfected (Non-lung) Solid Organ Transplant Recipients Has Not Resulted in Significant SARS-CoV-2 Related Morbidity Or Mortality

Introduction: The SARS-CoV-2 pandemic has conferred significant morbidity and mortality across the globe, especially for solid organ transplant (SOT) recipients. This has led to reluctance of using organs from SARS-CoV-2 infected donors due to concerns of disease transmission. However, this must be offset with an increase in wait list mortality. We sought to evaluate the use of organs from SARS-CoV-2 donors into (non-Lung) Solid Organ Transplant Recipients in a prospective fashion. Methods: We evaluated the use of organs from SARS-CoV-2 donors between 6/17/2021 to 2/24/2022. 18 patients were transplanted with SARS-CoV-2-positive donor (COVID+) organs: 3 heart, 4 liver, and 11 kidney recipients. SOT recipients were tested for presence of SARS-CoV-2 by RT-PCR prior to and after their operations. Induction immunosuppression was standard and not altered from protocol. Postoperatively, recipients were kept in modified droplet precautions and received post-exposure treatment recommended by Transplant Infectious Disease. Treatment regimens included remdesivir and monoclonal antibodies directed against SARS-CoV-2 (Figure 1). Perioperative and post discharge care was administered by a multidisciplinary care team with no significant alterations in care protocols. Results: SOT recipients of COVID+ organs at our institution have not experienced any significant morbidity or mortality from SARS-CoV-2. All patients are alive at current follow up with excellent allograft function with a median follow up for heart, liver, and kidney recipients of 235, 67, and 86 days respectively. All patients were vaccinated except for one liver patient who was status 1A due to fulminant acute liver failure. 13/18 patients had post-operative nasopharyngeal swabbing for RT-PCR based viral testing and two tested positive for SARS-CoV-2 at POD #8. Neither patient experience clinical symptoms of disease. Use of of SARS-CoV-2 did not appear to increase inpatient hospital stay. Median LOS for heart, liver, and kidney recipients was 40, 12.3, and 7.4 days respectively. Neither pre-transplant vaccination, use of COVID+ organs, nor post exposure prophylaxis resulted in increased risk of immunologic complications as only one recipient (heart) has experienced an acute cellular rejection episode to date Conclusion: Our experience indicates that COVID+ organs can be utilized successfully. The decision to use these organs was based on organ quality, individual patient need at the time the organ offer was made and whether a potential similar quality, COVID negative organ would be available to the patient in the near future. As evidenced by our data, successful use of COVID+ organs is dependent on multidisciplinary wait list and perioperative management to ensure appropriate donor:recipient selection and mitigation of transmission risk with use of post-exposure prophylaxis.

The Role of Left Atrial Longitudinal Strain in the Diagnosis of Acute Cellular Rejection in Heart Transplant Recipients.

Our aim was to investigate the role of left atrial longitudinal strain (LALS) in the non-invasive diagnosis of acute cellular rejection (ACR) episodes in heart transplant (HTx) recipients. Methods: We performed successive echocardiographic exams in 18 consecutive adult HTx recipients in their first year after HTx within 3 h of the routine surveillance endomyocardial biopsies (EMB) in a single center. LALS parameters were analyzed with two different software. We investigated LALS association with ACR presence, as well as inter-vendor variability in comparable LALS values. Results: A total of 147 pairs of EMB and echo exams were carried out. Lower values of LALS were significantly associated with any grade of ACR presence. Peak atrial longitudinal strain (PALS) offered the best diagnostic value for any grade of ACR, with a C statistic of 0.77 using one software (95% CI 0.68–0.84, p < 0.0005) and 0.64 with the other (95% CI 0.54–0.73, p = 0.013) (p = 0.02 for comparison between both curves). Reproducibility between comparable LALS parameters was poor (intraclass correlation coefficients were 0.60 for PALS, 95% CI 0.42–0.73, p < 0.0005; and 0.42 for PALS rate, 95% CI −0.13–0.68, p < 0.0005). Conclusions: LALS variables might be a sensitive marker of ACR in HTx recipients, principally discriminating between those studies without rejection and those with any grade of ACR. Inter-vendor variability was significant.

Risk factors and outcomes of sudden cardiac arrest in pediatric heart transplant recipients

Sudden cardiac arrest (SCA) is a prevailing cause of mortality after pediatric heart transplant (HT) but remains understudied. We analyzed the incidence, outcomes, and risk factors for SCA at our center. Retrospective review of all pediatric HT patients at our center from January 1, 2009 to January 1, 2021. SCA was defined as an abrupt loss of cardiac function requiring cardiopulmonary resuscitation and/or mechanical circulatory support (MCS). Events that occurred in the setting of limited resuscitative wishes, or while on MCS were excluded. Patient characteristics and risk factors were analyzed. Fourteen of 254 (6%) experienced SCA at a median of 3 (1, 4) years post-HT. Seven (50%) events occurred out-of-hospital. Eleven (79%) died from their initial event, 2 (18%) after failure to separate from extracorporeal membrane (ECMO). In univariate analysis, black race, younger donor age, prior acute cellular rejection (ACR) episode, pacemaker and/or ICD in place, and pre-mortem diagnosis of allograft vasculopathy were associated with SCA (P=.003-0.02). In multivariable analysis, history of ACR, younger donor age, and black race retained significance. [OR=6.3, 95% CI: 1.6-25.4, P=.01], [OR=0.9, 95% CI: 0.8-1, P=.04], and [OR=7.3, 95% CI: 1.1-49.9, P=.04], respectively. SCA occurred in 3 patients with a functioning ICD or pacemaker, which failed to restore a perfusing rhythm. SCA occurs relatively early after pediatric HT and is usually fatal. Half of events happen at home. Those who received younger donors, have a history of ACR, or are of black race are at increased risk. ICDs/pacemakers may offer limited protection.

Induction Strategies in Lung Transplantation: Alemtuzumab vs. Basiliximab a Single-Center Experience.

BackgroundInduction therapy is used in about 80% of lung transplant centers and is increasing globally. Currently, there are no standards or guidelines for the use of induction therapy. At our institution, we have two induction strategies, basiliximab, and alemtuzumab. The goal of this manuscript is to share our experience and practice since this is an area of controversy.MethodsWe retrospectively reviewed 807 lung transplants performed at our institution between 2011 and 2020. Indications for the use of the basiliximab protocol were as follows: patients over the age of 70 years, history of cancer, hepatitis C virus or human immunodeficiency virus infection history, and cytomegalovirus or Epstein-Barr virus (donor positive/ recipient negative). In the absence of these clinical factors, the alemtuzumab protocol was used.Results453 patients underwent alemtuzumab induction and 354 patients underwent basiliximab. There were significant differences in delayed chest closure (24.7% alemtuzumab vs 31.4% basiliximab, p = 0.037), grade 3 primary graft dysfunction observed within 72 hours (19.9% alemtuzumab vs 29.9% basiliximab, p = 0.002), postoperative hepatic dysfunction (8.8% alemtuzumab vs 14.7% basiliximab, p = 0.009), acute cellular rejection in first year (39.1% alemtuzumab vs 53.4% basiliximab, p < 0.001). The overall survival rate of the patients with alemtuzumab induction was significantly higher than those of the patients with basiliximab induction (5 years survival rate: 64.1% alemtuzumab vs 52.3%, basiliximab, p < 0.001). Multivariate Cox regression analysis confirmed lower 5-year survival for basiliximab induction (HR = 1.41, p = 0.02), recipient cytomegalovirus positive (HR = 1.49, p = 0.01), postoperative hepatic dysfunction (HR = 2.20, p < 0.001), and acute kidney injury requiring renal replacement therapy (HR = 2.27, p < 0.001).ConclusionsIn this single center retrospective review, there was a significant difference in survival rates between induction strategies. This outcome may be attributable to differences in recipient characteristics between the groups. However, the Alemtuzumab group experienced less episodes of acute cellular rejection within the first year.