Prospective Evaluation of Coronavirus Disease 2019 (COVID-19) Vaccine Responses Across a Broad Spectrum of Immunocompromising Conditions: the COVID-19 Vaccination in the Immunocompromised Study (COVICS).

BACKGROUND: We studied humoral responses after coronavirus disease 2019 (COVID-19) vaccination across varying causes of immunodeficiency. METHODS: Prospective study of fully vaccinated immunocompromised adults (solid organ transplant [SOT], hematologic malignancy, solid cancers, autoimmune conditions, human immunodeficiency virus [HIV]) versus nonimmunocompromised healthcare workers (HCWs). The primary outcome was the proportion with a reactive test (seropositive) for immunoglobulin G to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor-binding domain. Secondary outcomes were comparisons of antibody levels and their correlation with pseudovirus neutralization titers. Stepwise logistic regression was used to identify factors associated with seropositivity. RESULTS: A total of 1271 participants enrolled: 1099 immunocompromised and 172 HCW. Compared with HCW (92.4% seropositive), seropositivity was lower among participants with SOT (30.7%), hematological malignancies (50.0%), autoimmune conditions (79.1%), solid tumors (78.7%), and HIV (79.8%) (P < .01). Factors associated with poor seropositivity included age, greater immunosuppression, time since vaccination, anti-CD20 monoclonal antibodies, and vaccination with BNT162b2 (Pfizer) or adenovirus vector vaccines versus messenger RNA (mRNA)-1273 (Moderna). mRNA-1273 was associated with higher antibody levels than BNT162b2 or adenovirus vector vaccines after adjusting for time since vaccination, age, and underlying condition. Antibody levels were strongly correlated with pseudovirus neutralization titers (Spearman r = 0.89, P < .0001), but in seropositive participants with intermediate antibody levels, neutralization titers were significantly lower in immunocompromised individuals versus HCW. CONCLUSIONS: Antibody responses to COVID-19 vaccines were lowest among SOT and anti-CD20 monoclonal recipients, and recipients of vaccines other than mRNA-1273. Among those with intermediate antibody levels, pseudovirus neutralization titers were lower in immunocompromised patients than HCWs. Additional SARS-CoV-2 preventive approaches are needed for immunocompromised persons, which may need to be tailored to the cause of immunodeficiency.

Rate of recipient-derived alveolar macrophage development and major histocompatibility complex cross-decoration after lung transplantation in humans.

Alveolar macrophages (AM) play critical roles in lung tissue homeostasis, host defense, and modulating lung injury. The rate of AM turnover (donor AM replacement by circulating monocytes) after transplantation has been incompletely characterized. Furthermore, the anatomic pattern of recipient-derived lung macrophages repopulation has not been reported, nor has their ability to accumulate and present donor major histocompatibility complex (a process we refer to as MHC cross-decoration). We longitudinally characterized the myeloid content of bronchoalveolar lavage (BAL) and biopsy specimens of lung transplant recipients and found a biphasic rate in AM turnover in the allograft, with a rapid turnover perioperatively, accelerated by both the type of induction immunosuppression and the presence of primary graft dysfunction. We found that recipient myeloid cells with cell surface AM phenotype repopulated the lung in a disorganized pattern, comprised mainly of large clusters of cells. Finally, we show that recipient AM take up and present donor peptide-MHC complexes yet are not able to independently induce an in vitro alloreactive response by circulating recipient T cells.

Risk factors of bronchial dehiscence after primary lung transplantation.

BACKGROUND: Although the incidence of bronchial dehiscence following lung transplantation has decreased significantly due to improvements in perioperative managements and surgical techniques, it remains a devastating postoperative complication associated with high morbidity and mortality. METHODS: We retrospectively reviewed 811 lung transplantation performed at our institution between January 2011 and December 2020. Bronchial dehiscence was confirmed with flexible bronchoscopy, computed tomography (CT) scan, or clinical findings grade using International Society for Heart and Lung Transplantation recommendations. RESULTS: Bronchial dehiscence was diagnosed in 38 patients (4.7%). The overall survival rates of the patients with bronchial dehiscence were significantly worse than those of the patients without bronchial dehiscence (p = .003). Multivariate analysis identified use of our basiliximab induction protocol (odds ratio = 3.03, p = .008) as an independent predictive factor of postoperative airway dehiscence in our multivariable model, along with total ventilator duration (odds ratio = 1.02, p = .002). CONCLUSIONS: Based on our analysis, patients that underwent our basiliximab induction protocol for lung transplantation experienced a higher rate of postoperative bronchial dehiscence when compared with patients who receive alemtuzumab induction. We believe this may be associated with a higher steroid exposure in this population. Additional studies are necessary to further characterize the relationship between different induction protocols and bronchial dehiscence following transplantation.

Isavuconazole Is as Effective as and Better Tolerated Than Voriconazole for Antifungal Prophylaxis in Lung Transplant Recipients.

BACKGROUND: Invasive fungal infections (IFIs) are common following lung transplantation. Isavuconazole is unstudied as prophylaxis in organ transplant recipients. We compared effectiveness and tolerability of isavuconazole and voriconazole prophylaxis in lung transplant recipients. METHODS: A single-center, retrospective study of patients who received isavuconazole (September 2015-February 2018) or voriconazole (September 2013-September 2015) for antifungal prophylaxis. IFIs were defined by EORTC/MSG criteria. RESULTS: Patients received isavuconazole (n = 144) or voriconazole (n = 156) for median 3.4 and 3.1 months, respectively. Adjunctive inhaled amphotericin B (iAmB) was administered to 100% and 41% of patients in the respective groups. At 1 year, 8% of patients receiving isavuconazole or voriconazole developed IFIs. For both groups, 70% and 30% of IFIs were caused by molds and yeasts, respectively, and breakthrough IFI (bIFI) rate was 3%. Outcomes did not significantly differ for patients receiving or not receiving iAmB. Independent risk factors for bIFI and breakthrough invasive mold infection (bIMI) were mold-positive respiratory culture and red blood cell transfusion >7 units at transplant. Bronchial necrosis >2 cm from anastomosis and basiliximab induction were also independent risk factors for bIMI. Isavuconazole and voriconazole were discontinued prematurely due to adverse events in 11% and 36% of patients, respectively (P = .0001). Most common causes of voriconazole and isavuconazole discontinuation were hepatotoxicity and lack of oral intake, respectively. Patients receiving ≥90 days prophylaxis had fewer IFIs at 1 year (3% vs 9%, P = .02). IFIs were associated with increased mortality (P = .0001) and longer hospitalizations (P = .0005). CONCLUSIONS: Isavuconazole was effective and well tolerated as antifungal prophylaxis following lung transplantation.

Type-1 immunity and endogenous immune regulators predominate in the airway transcriptome during chronic lung allograft dysfunction.

Chronic lung allograft dysfunction (CLAD) remains the major complication limiting long-term survival among lung transplant recipients (LTRs). Limited understanding of CLAD immunopathogenesis and a paucity of biomarkers remain substantial barriers for earlier detection and therapeutic interventions for CLAD. We hypothesized the airway transcriptome would reflect key immunologic changes in disease. We compared airway brush-derived transcriptomic signatures in CLAD (n = 24) versus non-CLAD (n = 21) LTRs. A targeted assessment of the proteome using concomitant bronchoalveolar lavage (BAL) fluid for 24 cytokines/chemokines and alloimmune T cell responses was performed to validate the airway transcriptome. We observed an airway transcriptomic signature of differential genes expressed (DGEs) in CLAD marked by Type-1 immunity and striking upregulation of two endogenous immune regulators: indoleamine 2, 3 dioxygenase 1 (IDO-1) and tumor necrosis factor receptor superfamily 6B (TNFRSF6B). Advanced CLAD staging was associated with a more intense airway transcriptome signature. In a validation cohort using the identified signature, we found an area under the curve (AUC) of 0.77 for CLAD LTRs. Targeted proteomic analyses revealed a predominant Type-1 profile with detection of IFN-γ, TNF-α, and IL-1ß as dominant CLAD cytokines, correlating with the airway transcriptome. The airway transcriptome provides novel insights into CLAD immunopathogenesis and biomarkers that may impact diagnosis of CLAD.

Dabigatran reversal with idarucizumab prior to lung transplantation.

BACKGROUND: When the transplant candidates are receiving oral anticoagulation therapy before transplantation, it is crucial to have an urgent reversal strategy to prevent hemorrhagic complications perioperatively. The aim of this study was to present the experience with idarucizumab to reverse the anticoagulant activity of dabigatran prior to lung transplantation. METHODS: A single-center retrospective study was performed to analyze the clinical outcomes of idarucizumab use before lung transplantation. RESULTS: Between July 2016 and June 2019, six patients were on dabigatran at the time of transplantation. Out of the six patients, four patients received idarucizumab. These four recipients received a median of 3 units (range 0-4 units) of packed red blood cells (pRBCs) and 450 ml (range 250-1500 ml) of intraoperative salvage of shed blood (cell saver blood) during the lung transplant. The two patients who were not administered idarucizumab received 5 units and 13 units of pRBCs and 900 ml and 3600 ml of cell saver blood, respectively. There was no grade 3 primary graft dysfunction (PGD) at 72 hours after transplantation or in-hospital mortality in idarucizumab group. In the group without idarucizumab, there was one case of grade 3 PGD without any in-hospital mortality. CONCLUSION: Dabigatran reversal with idarucizumab provides reasonable hemostasis during lung transplantation.

A review of liver dysfunction in the lung transplant patient.

Liver dysfunction is an increasingly common finding in patients evaluated for lung transplantation. New or worsening dysfunction in the perioperative period, defined by presence of clinical ascites/encephalopathy, high model for end-stage liver disease (MELD) score, and/or independent diagnostic criteria, is associated with high short- and long-term mortality. Therefore, a thorough liver function assessment is necessary prior to listing for lung transplant. Unfortunately, identification and intraoperative monitoring remain the only options for prevention of disease progression with isolated lung transplantation. Combined lung and liver transplantation may provide an option for definitive long-term management in selecting patients with known liver disease at high risk for postoperative progression. However, experience with the combined operation is extremely limited and indications for combined lung and liver transplant remain unclear. Herein, we present a comprehensive literature review of patients with liver dysfunction undergoing lung transplantation with and without concurrent liver transplant in an effort to illuminate the risks, benefits, and clinical judgement surrounding decision to pursue combined lung-liver transplantation (CLLT). We also argue description of liver function is currently a weakness of the current lung allocation scoring system. Additional algorithms incorporating liver function may aid in risk stratification and decision to pursue combined transplantation.

Lung transplantation for the treatment of irreversible acute respiratory distress syndrome.

BACKGROUND: Despite advances in critical care for acute respiratory distress syndrome (ARDS), some survivors in the acute phase are unable to wean from extracorporeal membrane oxygenation (ECMO) or mechanical ventilation. To date, little is known regarding whether lung transplantation confers a survival benefit for irreversible ARDS. METHODS: This retrospective study was conducted using the United Network for Organ Sharing database (May 2005-December 2018). Patients with restrictive lung disease were divided into two groups: patients with and without ARDS. Propensity score matching identified recipients without ARDS for the control group. RESULTS: A total of 63 patients with ARDS were waitlisted for lung transplantation, while 39 received a lung transplant after a median waitlist duration of 8 days. Seventy-eight patients were matched as controls. In the ARDS group, the median age was 30 years, and the median lung allocation score was 88.4. Among the 39 recipients, 30 (76.9%) received ECMO support prior to transplantation. Lung transplantation for ARDS and restrictive lung disease showed similar 90-day (87.2% vs. 88.5%, p = .80), 1-year (82.1% vs. 85.9%, p = .52), and 3-year (69.2% vs. 65.4%, p = .94) survival rates. CONCLUSIONS: Lung transplantation provides acceptable outcomes in selected patients with irreversible ARDS.

Bilateral sequential lung transplantation in Jehovah's Witnesses.

The ethical concerns of refusing lifesaving treatments after receiving an already limited resource such as a solid organ transplantation in a Jehovah's Witness patient have been discussed in the literature. Many of these studies have concluded that with a multidisciplinary approach, solid organ transplantation is possible in the setting of Jehovah's Witness patients. To date, there are no reported cases of bilateral sequential lung transplantation in the literature. We report two successful cases of bilateral sequential lung transplantation in Jehovah's Witness patients with excellent long-term follow-up.

Idiopathic pulmonary fibrosis lung transplant recipients are at increased risk for EBV-associated posttransplant lymphoproliferative disorder and worse survival.

Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disorder (EBV-PTLD) is a serious complication in lung transplant recipients (LTRs) associated with significant mortality. We performed a single-center retrospective study to evaluate the risks for PTLD in LTRs over a 7-year period. Of 611 evaluable LTRs, we identified 28 cases of PTLD, with an incidence of 4.6%. Kaplan-Meier analysis showed a decreased freedom from PTLD in idiopathic pulmonary fibrosis (IPF)-LTRs (P < .02). Using a multivariable Cox proportional hazards model, we found IPF (hazard ratio [HR] 3.51, 95% confidence interval [CI] 1.33-8.21, P = .01) and alemtuzumab induction therapy (HR 2.73, 95% CI 1.10-6.74, P = .03) as risk factors for PTLD, compared to EBV mismatch (HR: 34.43, 95% CI 15.57-76.09, P < .0001). Early PTLD (first year) was associated with alemtuzumab use (P = .04), whereas IPF was a predictor for late PTLD (after first year) (P = .002), after controlling for age and sex. Kaplan-Meier analysis revealed a shorter time to death from PTLD in IPF LTRs compared to other patients (P = .04). The use of alemtuzumab in EBV mismatch was found to particularly increase PTLD risk. Together, our findings identify IPF LTRs as a susceptible population for PTLD. Further studies are required to understand the mechanisms driving PTLD in IPF LTRs and develop strategies to mitigate risk.

Impaired Cytomegalovirus Immunity in Idiopathic Pulmonary Fibrosis Lung Transplant Recipients with Short Telomeres.

RATIONALE: Cytomegalovirus (CMV)-related morbidities remain one of the most common complications after lung transplantation and have been linked to allograft dysfunction, but the factors that predict high risk for CMV complications and effective immunity are incompletely understood. OBJECTIVES: To determine if short telomeres in idiopathic pulmonary fibrosis (IPF) lung transplant recipients (LTRs) predict the risk for CMV-specific T-cell immunity and viral control. METHODS: We studied IPF-LTRs (n = 42) and age-matched non-IPF-LTRs (n = 42) and assessed CMV outcomes. We measured lymphocyte telomere length and DNA sequencing, and assessed CMV-specific T-cell immunity in LTRs at high risk for CMV events, using flow cytometry and fluorescence in situ hybridization. MEASUREMENTS AND MAIN RESULTS: We identified a high prevalence of relapsing CMV viremia in IPF-LTRs compared with non-IPF-LTRs (69% vs. 31%; odds ratio, 4.98; 95% confidence interval, 1.95-12.50; P < 0.001). Within this subset, IPF-LTRs who had short telomeres had the highest risk of CMV complications (P < 0.01) including relapsing-viremia episodes, end-organ disease, and CMV resistance to therapy, as well as shorter time to viremia versus age-matched non-IPF control subjects (P < 0.001). The short telomere defect in IPF-LTRs was associated with significantly impaired CMV-specific proliferative responses, T-cell effector functions, and induction of the major type-1 transcription factor T-bet (T-box 21;TBX21). CONCLUSIONS: Because the short telomere defect has been linked to the pathogenesis of IPF in some cases, our data indicate that impaired CMV immunity may be a systemic manifestation of telomere-mediated disease in these patients. Identifying this high-risk subset of LTRs has implications for risk assessment, management, and potential strategies for averting post-transplant CMV morbidities.

Concomitant surgical aortic valve replacement with bilateral orthotopic lung transplantation.

Concomitant cardiac surgery at the time of lung transplantation while uncommon has been shown to have acceptable morbidity and mortality. We present a case of a 66-year-old man with a history of interstitial pulmonary fibrosis with end-stage lung disease who presented with moderate aortic stenosis and severe aortic regurgitation. He underwent a bioprosthetic surgical aortic valve replacement at the time of bilateral orthotopic lung transplant and recovered without any major complications.

Organ Transplantation for Cystic Fibrosis.

Cystic fibrosis (CF) remains the most common indication for lung transplantation in children and the third most common in adults and has the highest median survival posttransplant for all pretransplant diagnoses. Criteria for transplant in patients with CF vary widely among transplant centers and early referral to multiple centers may be needed to maximize opportunities for lung transplantation. Comorbidities unique to CF such as resistant and atypical pathogens like Burkholderia and Mycobacterium abscessus, and cirrhosis require special consideration for lung transplantation but should not be considered as absolute contraindications. For those patients who are listed for lung transplantation, mechanical support with extracorporeal membrane oxygenation and mechanical ventilation can be efficacious as bridges to lung transplantation in experienced centers with adequate resources. Liver and pancreas transplantations are also acceptable options for end-organ disease related to CF and can provide improvements in both quantity and quality of life.

Increasing tacrolimus time-in-therapeutic range is associated with superior one-year outcomes in lung transplant recipients.

Calcineurin inhibitors (CNIs) are the backbone of traditional immunosuppressive regimens for lung transplant recipients (LTR). The CNIs are both narrow therapeutic index drugs with significant interpatient and intrapatient variability that require therapeutic drug monitoring to ensure safety and effectiveness. We hypothesized that tacrolimus time-in-therapeutic range (TTR) affects acute and chronic rejection rates in LTRs. This was a single-center, observational, cross-sectional study of 292 adult LTRs. Subjects who received tacrolimus posttransplant for the first year were included. TTR was calculated at 1 year using protocol goal ranges (12-15 mg/mL months 0-6; 10-12 mg/mL for months 7-12). The primary outcome was acute cellular rejection (ACR) burden at 1 year. Chronic lung allograft dysfunction (CLAD), mortality, and infection rate were assessed as secondary outcomes at 1 year. Primary and secondary outcomes were assessed using logistic regression. Increasing TTR by 10% was associated with a significantly lower likelihood of high-burden ACR at 1 year on univariable (OR 0.46, 95% CI 0.40-0.54, P < .001) and multivariable (OR 0.64, 95% CI 0.47-0.86, P = .003) assessment, controlling for age and induction agent. Increasing TTR by 10% was also associated with lower rates of CLAD (P < .001) and mortality (P < .001) at 1 year. Prospective studies confirming these findings appear warranted.

Patent foramen ovale repair at the time of double lung transplantation: Necessary or not?

INTRODUCTION: Patient foramen ovale (PFO) is a common and often incidental intraoperative finding during lung transplantation (LTx). We sought to characterize the potential outcomes related to the decision making of whether the PFO was repaired or left unrepaired. METHODS: We retrospectively evaluated bilateral LTx recipients between 2005 and 2015 from our prospective database. Incidence of postoperative stoke, 90-day mortality, and overall survival was compared between the PFO-positive and PFO-negative groups, and secondly compared between repaired PFO (rPFO) and non-repaired PFO (nrPFO) groups. RESULTS: A total of 831 LTx recipients were analyzed: 185 PFO-positive (140 nrPFO, 45 rPFO) and 646 PFO-negative. Study groups were similar with regard to age and comorbidity. The presence of PFO was not associated with a difference in postoperative stroke (P = .89) or 90-day mortality (P = .64). In patients with PFO, intraoperative repair resulted in a lower, but non-significant rate of stroke (0% vs 5%; P = .20) and no difference in mortality (P = .26). As expected, PFO and PFO repair were both associated with a higher incidence of cardiopulmonary bypass utilization, but no difference in pump-related complications. CONCLUSIONS: The protective effect of PFO repair remains unclear. However, it is not associated with an increased incidence of stroke or postoperative mortality following LTx.

Systematic review and meta-analysis of post-transplant lymphoproliferative disorder in lung transplant recipients.

A systematic review of papers in English on post-transplant lymphoproliferative disorder (PTLD) in lung transplant recipients (LTR) using MEDLINE, EMBASE, SCOPUS, and Cochrane databases was performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations were strictly adhered to. Pooled odds ratios (pOR) were calculated from a random-effects model, and heterogeneity among studies was quantitated using I2 values. Fourteen studies published from 2005 to 2015 were included in the meta-analysis. One hundred and sixty-four lung transplant recipients were included. LTRs who received single vs bilateral were associated with a 7.67-fold risk of death after PTLD (6 studies with 64 LTRs; pOR 7.67 95% CI 1.98-29.70; P = .003). pOR of death for early onset PTLD (<1 year post-LT) vs late onset (>1 year post-LT) was not different (3 studies with 72 LTRS; pOR 0.62, 95% CI 0.20-1.86, P = .39). Standardized mean difference (SMD) in time from transplant to PTLD onset between LTRs who died vs alive was not different (9 studies with 109 LTRs; SMD 0.03, 95% CI -0.48-0.53, P = .92). Survival in polymorphic vs monomorphic PTLD and extranodal vs nodal disease was similar (4 studies with 31 LTRs; pOR 0.44, 95% CI 0.08-2.51; P = .36. 6 studies with 81 LTRs; pOR 1.05 95% CI 0.31-3.52, P = .94). This meta-analysis demonstrates that single LTRs are at a higher risk of death vs bilateral LTRs after the development of PTLD.

Belatacept for maintenance immunosuppression in cardiothoracic transplantation: The potential frontier.

Current immunosuppressive regimens with calcineurin inhibitors have improved the management of patients after transplantation. However, their adverse effects are linked to increased morbidity and limit the long-term survival of heart and lung transplant recipients. Belatacept, a costimulation inhibitor interfering with the interaction between CD28 on T cells and the B7 ligands on antigen presenting cells, has shown success and is currently approved for use in renal transplant recipients. Furthermore, it lacks many of the cardiovascular, metabolic, neurologic, and renal adverse of effects of calcineurin inhibitors that have the largest impact on long-term survival in cardiothoracic transplant. Additionally, it requires no therapeutic drug monitoring and is only administered once a month. Limitations to belatacept use have been observed that must be considered when comparing immunosuppression options. Despite this, maintenance immunosuppression with belatacept has the potential to improve outcomes in cardiothoracic transplant recipients, as it has with kidney transplant recipients. However, no large clinical trials investigating belatacept for maintenance immunosuppression in heart and lung transplant recipients exist. There is a large need for focused research of belatacept in cardiothoracic transplantation. Belatacept is a viable treatment option for maintenance immunosuppression, and it is reasonable to pursue more evidence in cardiothoracic transplant recipients.

Detrimental Association of Hypogammaglobulinemia With Chronic Lung Allograft Dysfunction and Death Is Not Mitigated by On-Demand Immunoglobulin G Replacement After Lung Transplantation.

BACKGROUND:: Hypogammaglobulinemia (HGG), immunoglobulin G (IgG) <700 mg/dL, is associated with infections, chronic lung allograft dysfunction, and death following lung transplantation. This study evaluates the use of on-demand intravenous IgG in lung transplant recipients with HGG. MATERIALS AND METHODS:: This single-center retrospective cohort study of adult lung recipients evaluated 3 groups, no, untreated (u), or treated (t) HGG at first IgG administration or a matched time posttransplant. Primary outcome was freedom from allograft dysfunction. Secondary outcomes included development of advanced dysfunction, rejection, infection burden, and mortality. RESULTS:: Recipients included 484 (no HGG: 76, uHGG: 192, tHGG: 216). Freedom from chronic allograph dysfunction was highest in the non-HGG group 2 years post-enrollment (no HGG 77.9% vs uHGG 56.4% vs tHGG 52.5%; P = .002). Freedom from advanced dysfunction was significantly different 2 years post-enrollment (no HGG 90.5% vs uHGG 84.7% vs tHGG 75.4%; P = .017). Patients without HGG and those with uHGG had less mortality at 2 years post-enrollment (no HGG 84.2% vs uHGG 81.3% vs tHGG 64.8%; P < .001). Gram-negative pneumonias occurred more often in the tHGG group ( P = .02). CONCLUSIONS:: Development of chronic lung allograft dysfunction, patient survival, rejection burden, and key infectious outcomes in lung transplant recipients were still problematic in the context of on-demand IgG therapy. Prospective studies are warranted.

Rescue alemtuzumab for refractory acute cellular rejection and bronchiolitis obliterans syndrome after lung transplantation.

Refractory acute cellular rejection (rACR) is associated with death and bronchiolitis obliterans syndrome (BOS) post-lung transplantation. We report the largest cohort of lung transplant recipients (LTRs) treated with rescue alemtuzumab for rACR or BOS. RACR outcomes included burden of ACR 30 days before and 180 days after rescue assessed by a novel composite rejection standardized score (CRSS, range 0-6) and freedom from ≥A2 ACR. BOS outcomes included freedom from BOS progression and FEV1 decline >10%. Univariate parametric and nonparametric statistical approaches were used to assess treatment response. Kaplan-Meier method with log rank conversion was used to assess freedom from events. Fifty-seven alemtuzumab doses (ACR 40 and BOS 17) given to 51 patients were included. Median time to rescue was 722 (IQR 42-1403) days. CRSS declined significantly (3 vs 0.67, P<0.001) after rescue. Freedom from ≥A2 was 62.5% in rACR. Freedom from BOS progression was 52.9% at 180 days in the BOS cohort. Freedom from FEV1 decline >10% was 70% in BOS grade 1 and 14.3% in advanced BOS grades 2-3. Infections developed in 72.5% and 76.5% of rACR and BOS groups. Rescue alemtuzumab appears useful for rACR. Patients with BOS 1 may have transient benefit, and patients with advanced BOS seem not to respond to alemtuzumab.

Effect of aerosolized antipseudomonals on Pseudomonas positivity and bronchiolitis obliterans syndrome after lung transplantation.

PURPOSE: To describe the effects of aerosolized antipseudomonals (AAPs) on Pseudomonas (PS) culture positivity, bronchiolitis obliterans syndrome (BOS), and acute cellular rejection (ACR) in lung transplant recipients (LTRs). METHODS: Single-center, retrospective cohort study was performed of adult LTRs treated with either AAP for ≥28 days vs no AAP therapy or AAP therapy <28 days, indexed to a matched median date post lung transplantation (LT). Primary outcome was freedom from PS positivity by positive bronchoalveolar lavage or bronchial wash at 1 year. Secondary outcomes were freedom from BOS or BOS progression and ACR burden (defined by the novel composite rejection standardized score. Normality was assessed, and univariate and multivariate parametric and non-parametric statistical tests were used to assess baseline characteristics and outcomes, where appropriate. Freedom from events was compared using the Kaplan-Meier method with log-rank conversion and risk was assigned using multivariable Cox proportional hazards (PH) modeling. RESULTS: In total, 293 LTRs (105 with AAP, 188 with no AAP) were included. Median ages in AAP and control cohorts were 51 (30-63) and 62 (54-67) years (P<.01). Median AAP duration was 198 (interquartile range 94-395) days. Time to median positive PS culture was similar between AAP (median 1.02 [95% confidence interval {CI} 0.74-1.22] years) and control (median 0.96 [95% CI 0.72-1.21] years). Log-rank test for time-to-PS positivity was similar for both groups (log-rank P=.26). Incidence of PS culture positivity at 1 year was similar in APP vs controls (59.0% vs 54.8%, P=.48). In the non-cystic fibrosis (CF) subgroup, AAP use was protective against PS recurrence on univariate Cox PH model (hazard ratio [HR] 0.55, 95% CI 0.38-0.83) and on multivariate Cox PH adjusting for age and induction (HR 0.56, 95% CI 0.38-0.83). Incidence of new-onset BOS or BOS progression in APP vs control at 1 (17.1% vs 14.9%, P=.61) and 3 (38.1% vs 37.8%, P=.96) years was similar. CRSS was similar in APP vs control group at 1 year (0.42 vs 0.33, P=.41). CONCLUSION: AAP use was not associated with less PS positivity, BOS, or ACR in all LTRs. In the non-CF subgroup analysis, treatment with AAPS was associated with protection against recurrent PS. Limitations include retrospective design, heterogeneous AAP therapy among LTRs, and potential convenience sampling of LTRs receiving AAPs for >28 days at our center. Larger assessments and better controlled analyses are required to further define efficacy of AAPs after LT.