Michael Y. Shino

Colonization with Small Conidia Aspergillus Species is associated with Bronchiolitis Obliterans Syndrome: A Two-Center Validation Study

Aspergillus colonization after lung transplantation may increase the risk for bronchiolitis obliterans syndrome (BOS), a disease of small airways. We hypothesized that colonization with small conidia Aspergillus species would be associated with a greater risk of BOS, based upon an increased likelihood of deposition in small airways. We studied adult primary lung recipients from two large centers; 298 recipients at University of California, Los Angeles and 482 recipients at Duke University Medical Center. We grouped Aspergillus species by conidia diameter ≤3.5 μm. We assessed the relationship of colonization with outcomes in Cox models. Pre‐BOS colonization with small conidia Aspergillus species, but not large, was a risk factor for BOS (p = 0.002, HR 1.44, 95% CI 1.14–1.82), along with acute rejection, single lung and Pseudomonas. Colonization with small conidia species also associated with risk of death (p = 0.03, HR 1.30, 95% CI 1.03–1.64). Although other virulence traits besides conidia size may be important, we have demonstrated in two large independent cohorts that colonization with small conidia Aspergillus species increases the risk of BOS and death. Prospective evaluation of strategies to prevent Aspergillus colonization of small airways is warranted, with the goal of preserving lung allograft function as long as possible.

Usefulness of immune monitoring in lung transplantation using adenosine triphosphate production in activated lymphocytes

BACKGROUND The ImmuKnow (Cylex Inc, Columbia, MD) assay measures the amount of adenosine triphosphate (ATP) produced by helper CD4(+) cells after stimulation with a T-cell mitogen. We hypothesized that this assay can be used to assess the immune function of lung transplant recipients and identify those at risk of developing acute cellular rejection and respiratory infection. METHODS Lung transplant recipients at University of California Los Angeles between January 1, 2006 and December 31, 2009 received a bronchoscopy with broncheoalveolar lavage, transbronchial biopsy and ImmuKnow values drawn at regular intervals as well as during episodes of clinical deterioration. The recipients clinical condition at each time-point was classified as healthy, acute cellular rejection, or respiratory infection. Mixed-effects models were used to compare the ATP levels among these groups, and odds ratios for rejection and infection were calculated. RESULTS The mean ATP level was 431 ± 189 ng/ml for the rejection group vs 377 ± 187 ng/ml for the healthy group (p = 0.10). A recipient with an ATP level > 525 ng/ml was 2.1 times more likely to have acute cellular rejection (95% confidence interval [CI] 1.1-3.8). Similarly, the mean ATP level was 323 ± 169 ng/ml for the infection group vs 377 ± 187 ng/ml for the healthy group (p = 0.03). A recipient with an ATP level < 225 ng/ml was 1.9 times more likely to have respiratory infection (95% CI, 1.1-3.3). However, the test was associated with poor performance characteristics. It had low sensitivity, specificity with an area under the receiver operating characteristic curve of only 0.61 to diagnose rejection and 0.59 to diagnose infection. CONCLUSIONS The ImmuKnow assay appears to have some ability to assess the overall immune function of lung transplant recipients. However, this study does not support its use as a reliable predictor of episodes of acute cellular rejection or respiratory infection.

Lung Transplant Outcomes in Systemic Sclerosis with Significant Esophageal Dysfunction. A Comprehensive Single-Center Experience

RATIONALE Consideration of lung transplantation in patients with systemic sclerosis (SSc) remains guarded, often due to the concern for esophageal dysfunction and the associated potential for allograft injury and suboptimal post-lung transplantation outcomes. OBJECTIVES The purpose of this study was to systematically report our single-center experience regarding lung transplantation in the setting of SSc, with a particular focus on esophageal dysfunction. METHODS We retrospectively reviewed all lung transplants at our center from January 1, 2000 through August 31, 2012 (n = 562), comparing the SSc group (n = 35) to the following lung transplant diagnostic subsets: all non-SSc (n = 527), non-SSc diffuse fibrotic lung disease (n = 264), and a non-SSc matched group (n = 109). We evaluated post-lung transplant outcomes, including survival, primary graft dysfunction, acute rejection, bronchiolitis obliterans syndrome, and microbiology of respiratory isolates. In addition, we defined severe esophageal dysfunction using esophageal manometry and esophageal morphometry criteria on the basis of chest computed tomography images. For patients with SSc referred for lung transplant but subsequently denied (n = 36), we queried the reason(s) for denial with respect to the concern for esophageal dysfunction. MEASUREMENTS AND MAIN RESULTS The 1-, 3-, and 5-year post-lung transplant survival for SSc was 94, 77, and 70%, respectively, and similar to the other groups. The remaining post-lung transplant outcomes evaluated were also similar between SSc and the other groups. Approximately 60% of the SSc group had severe esophageal dysfunction. Pre-lung transplant chest computed tomography imaging demonstrated significantly abnormal esophageal morphometry for SSc when compared with the matched group. Importantly, esophageal dysfunction was the sole reason for lung transplant denial in a single case. CONCLUSIONS Relative to other lung transplant indications, our SSc group experienced comparable survival, primary graft dysfunction, acute rejection, bronchiolitis obliterans syndrome, and microbiology of respiratory isolates, despite the high prevalence of severe esophageal dysfunction. Esophageal dysfunction rarely precluded active listing for lung transplantation.

Sarcoidosis-Associated Pulmonary Hypertension and Lung Transplantation for Sarcoidosis

Pulmonary hypertension (PH) is a significant complication of sarcoidosis, occurring in approximately 6 to > 20% of cases, and markedly increases mortality among these patients. The clinician should exercise a high index of suspicion for sarcoidosis-associated PH (SAPH) given the nonspecific symptomatology and the limitations of echocardiography in this patient population. The pathophysiology of PH in sarcoidosis is complex and multifactorial. Importantly, there are inherent differences in the pathogenesis of SAPH compared with idiopathic pulmonary arterial hypertension, making the optimal management of SAPH controversial. In this article, we review the epidemiology, diagnosis, prognosis, and treatment considerations for SAPH. Lung transplantation (LT) is a viable therapeutic option for sarcoid patients with severe pulmonary fibrocystic sarcoidosis or SAPH refractory to medical therapy. We discuss the role for LT in patients with sarcoidosis, review the global experience with LT in this population, and discuss indications and contraindications to LT.

Altered Exosomal RNA Profiles in Bronchoalveolar Lavage from Lung Transplants with Acute Rejection

RATIONALE The mechanism by which acute allograft rejection leads to chronic rejection remains poorly understood despite its common occurrence. Exosomes, membrane vesicles released from cells within the lung allograft, contain a diverse array of biomolecules that closely reflect the biologic state of the cell and tissue from which they are released. Exosome transcriptomes may provide a better understanding of the rejection process. Furthermore, biomarkers originating from this transcriptome could provide timely and sensitive detection of acute cellular rejection (AR), reducing the incidence of severe AR and chronic lung allograft dysfunction and improving outcomes. OBJECTIVES To provide an in-depth analysis of the bronchoalveolar lavage fluid exosomal shuttle RNA population after lung transplantation and evaluate for differential expression between acute AR and quiescence. METHODS Serial bronchoalveolar lavage specimens were ultracentrifuged to obtain the exosomal pellet for RNA extraction, on which RNA-Seq was performed. MEASUREMENTS AND MAIN RESULTS AR demonstrates an intense inflammatory environment, skewed toward both innate and adaptive immune responses. Novel, potential upstream regulators identified offer potential therapeutic targets. CONCLUSIONS Our findings validate bronchoalveolar lavage fluid exosomal shuttle RNA as a source for understanding the pathophysiology of AR and for biomarker discovery in lung transplantation.

The Role of TGF-β in the Association Between Primary Graft Dysfunction and Bronchiolitis Obliterans Syndrome.

Primary graft dysfunction (PGD) is a possible risk factor for bronchiolitis obliterans syndrome (BOS) following lung transplantation; however, the mechanism for any such association is poorly understood. Based on the association of TGF‐β with acute and chronic inflammatory disorders, we hypothesized that it might play a role in the continuum between PGD and BOS. Thus, the association between PGD and BOS was assessed in a single‐center cohort of lung transplant recipients. Bronchoalveolar lavage fluid concentrations of TGF‐β and procollagen collected within 24 h of transplantation were compared across the spectrum of PGD, and incorporated into Cox models of BOS. Immunohistochemistry localized expression of TGF‐β and its receptor in early lung biopsies posttransplant. We found an association between PGD and BOS in both bilateral and single lung recipients with a hazard ratio of 3.07 (95% CI 1.76–5.38) for the most severe form of PGD. TGF‐β and procollagen concentrations were elevated during PGD (p < 0.01), and associated with increased rates of BOS. Expression of TGF‐β and its receptor localized to allograft infiltrating mononuclear and stromal cells, and the airway epithelium. These findings validate the association between PGD and the subsequent development of BOS, and suggest that this association may be mediated by receptor/TGF‐β biology.

Pulmonary hypertension complicating interstitial lung disease and COPD.

Pulmonary hypertension (PH) may complicate parenchymal lung disease, specifically interstitial lung diseases and chronic obstructive pulmonary disease, and uniformly increases the mortality risk. The epidemiology and degree of PH is variable and unique to the underlying lung disease. The clinician should exercise a high index of suspicion for PH complicating parenchymal lung disease especially given the nonspecific symptomatology and the limitations of echocardiography in this patient population. In general, PH-specific therapies in this setting have been poorly studied, with concern for increased shunting and/or ventilation/perfusion (V/Q) mismatch and resultant hypoxemia. A better understanding of the mechanisms underlying PH related to parenchymal lung disease may lead to novel pharmacological targets to prevent or treat this serious complication.

Validation and Refinement of Chronic Lung Allograft Dysfunction Phenotypes in Bilateral and Single Lung Recipients.

RATIONALE The clinical course of chronic lung allograft dysfunction (CLAD) is heterogeneous. Forced vital capacity (FVC) loss at onset, which may suggest a restrictive phenotype, was associated with worse survival for bilateral lung transplant recipients in one previously published single-center study. OBJECTIVES We sought to replicate the significance of FVC loss in an independent, retrospectively identified cohort of bilateral lung transplant recipients and to investigate extended application of this approach to single lung recipients. METHODS FVC loss and other potential predictors of survival after the onset of CLAD were assessed using Kaplan-Meier and Cox proportional hazards models. MEASUREMENTS AND MAIN RESULTS FVC loss at the onset of CLAD was associated with higher mortality in an independent cohort of bilateral lung transplant recipients (hazard ratio [HR], 2.75; 95% confidence interval [CI], 2.02-3.73; P < 0.0001) and in a multicenter cohort of single lung recipients (HR, 1.80; 95% CI, 1.09-2.98; P = 0.02). Including all subjects, the deleterious impact of FVC loss on survival persisted after adjustment for other relevant clinical variables (HR, 2.36; 95% CI, 1.77-3.15; P < 0.0001). In patients who develop CLAD without FVC loss, chest computed tomography features suggestive of pleural or parenchymal fibrosis also predicted worse survival in both bilateral (HR, 2.01; 95% CI, 1.16-5.20; P = 0.02) and single recipients (HR, 2.47; 95% CI, 1.24-10.57; P = 0.02). CONCLUSIONS We independently validated the prognostic significance of FVC loss for bilateral lung recipients and demonstrated that this approach to CLAD classification also confers prognostic information for single lung transplant recipients. Improved understanding of these discrete phenotypes is critical to the development of effective therapies.

Voriconazole Increases the Risk for Cutaneous Squamous Cell Carcinoma after Lung Transplantation

Lung transplant recipients (LTR) are at high risk of cutaneous squamous cell carcinoma (SCC). Voriconazole exposure after lung transplant has recently been reported as a risk factor for SCC. We sought to study the relationship between fungal prophylaxis with voriconazole and the risk of SCC in sequential cohorts from a single center. We evaluated 400 adult LTR at UCLA between 7/1/2005 and 12/22/2012. On 7/1/2009, our center instituted a protocol switch from targeted to universal antifungal prophylaxis for at least 6 months post‐transplant. Using Cox proportional hazards models, time to SCC was compared between targeted (N = 199) and universal (N = 201) prophylaxis cohorts. Cox models were also used to assess SCC risk as a function of time‐dependent cumulative exposure to voriconazole and other antifungal agents. The risk of SCC was greater in the universal prophylaxis cohort (HR 2.02, P < 0.01). Voriconazole exposure was greater in the universal prophylaxis cohort, and the cumulative exposure to voriconazole was associated with SCC (HR 1.75, P < 0.01), even after adjustment for other important SCC risk factors. Voriconazole did not increase the risk of advanced tumors. Exposure to other antifungal agents was not associated with SCC. Voriconazole should be used cautiously in this population.

Staphylococcus via an Interaction With the ELR+ CXC Chemokine ENA-78 Is Associated With BOS

Staphylococcus aureus is the most commonly isolated gram‐positive bacterium after lung transplantation (LT) and has been associated with poor posttransplant outcomes, but its effect on bronchiolitis obliterans syndrome (BOS) and death in the context of the allograft inflammatory environment has not been studied. A three‐state Cox semi‐Markovian model was used to determine the influence of allograft S. aureus and the ELR+ CXC chemokines on the survival rates and cause‐specific hazards for movement from lung transplant (State 1) to BOS (State 2), from transplant (State 1) to death (State 3), and from BOS (State 2) to death (State 3). Acute rejection, pseudomonas pneumonia, bronchoalveolar lavage fluid (BALF) CXCL5 and its interaction with S. aureus all increased the likelihood of transition from transplant to BOS. Transition to death from transplant was facilitated by pseudomonas infection and single lung transplant. Movement from BOS to death was affected by the interaction between aspergillus, pseudomonas and CXCL5, but not S. aureus. S. aureus isolation had state specific effects after LT and only in concert with elevated BALF CXCL5 concentrations did it augment the risk of BOS. Pseudomonas and elevated BALF concentrations of CXCL5 continued as significant risk factors for BOS and death after BOS in lung transplantation.