Establishing a Cohort and a Biorepository to Identify Biomarkers for Early Detection of Lung Cancer: The Nashville Lung Cancer Screening Trial Cohort.

Rationale: A prospective longitudinal cohort of individuals at high risk of developing lung cancer was established to build a biorepository of carefully annotated biological specimens and low-dose computed tomography (LDCT) chest images for derivation and validation of candidate biomarkers for early detection of lung cancer.Objectives: The goal of this study is to characterize individuals with high risk for lung cancer, accumulating valuable biospecimens and LDCT chest scans longitudinally over 5 years.Methods: Participants 55-80 years of age with a 5-year estimated risk of developing lung cancer >1.5% were recruited and enrolled from clinics at the Vanderbilt University Medical Center, Veteran Affairs Medical Center, and Meharry Medical Center. Individual demographic characteristics were assessed via questionnaire at baseline. Participants underwent an LDCT scan, spirometry, sputum cytology, and research bronchoscopy at the time of enrollment. Participants will be followed yearly for 5 years. Positive LDCT scans are followed-up according to standard of care. The clinical, imaging, and biospecimen data are collected prospectively and stored in a biorepository. Participants are offered smoking cessation counseling at each study visit.Results: A total of 480 participants were enrolled at study baseline and consented to sharing their data and biospecimens for research. Participants are followed with yearly clinic visits to collect imaging data and biospecimens. To date, a total of 19 cancers (13 adenocarcinomas, four squamous cell carcinomas, one large cell neuroendocrine, and one small-cell lung cancer) have been identified.Conclusions: We established a unique prospective cohort of individuals at high risk for lung cancer, enrolled at three institutions, for whom full clinical data, well-annotated LDCT scans, and biospecimens are being collected longitudinally. This repository will allow for the derivation and independent validation of clinical, imaging, and molecular biomarkers of risk for diagnosis of lung cancer.Clinical trial registered with ClinicalTrials.gov (NCT01475500).

Derivation and validation of a two-biomarker panel for diagnosis of ARDS in patients with severe traumatic injuries.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is common after severe traumatic injuries but is underdiagnosed and undertreated. We hypothesized that a panel of plasma biomarkers could be used to diagnose ARDS in severe trauma. To test this hypothesis, we derived and validated a biomarker panel in three independent cohorts and compared the diagnostic performance to clinician recognition of ARDS. METHODS: Eleven plasma biomarkers of inflammation, lung epithelial and endothelial injury were measured in a derivation cohort of 439 severe trauma patients. ARDS status was analyzed by two-investigator consensus, and cases were required to meet Berlin criteria on intensive care unit (ICU) day 1. Controls were subjects without ARDS during the first 4 days of study enrollment. A multivariable logistic regression model was used to generate probabilities for ARDS. A reduced model with the top two performing markers was then tested in two independent validation cohorts. To assess clinical diagnosis of ARDS, medical records in the derivation cohort were systematically searched for documentation of ARDS diagnosis made by a clinical provider. RESULTS: Among 11 biomarkers, the combination of the endothelial injury marker angiopoietin-2 (Ang-2) and the lung epithelial injury marker receptor for advanced glycation endproducts (RAGE) provided good discrimination for ARDS in the derivation cohort (area under the curve (AUC)=0.74 (95% CI 0.67 to 0.80). In the validation cohorts, the AUCs for this model were 0.70 (0.61 to 0.77) and 0.78 (0.71 to 0.84). In contrast, provider assessment demonstrated poor diagnostic accuracy for ARDS, with AUC of 0.55 (0.51 to 0.60). DISCUSSION: A two-biomarker panel consisting of Ang-2 and RAGE performed well across multiple patient cohorts and outperformed clinical providers for diagnosing ARDS in severe trauma. Clinical application of this model could improve both diagnosis and treatment of ARDS in patients with severe trauma. LEVEL OF EVIDENCE: Diagnostic study, level II.

Malignant hypertension with thrombotic microangiopathy and persistent acute kidney injury (AKI).

Two cases of malignant hypertension presenting with acute kidney injury, thrombocytopenia and hemolytic anemia are presented. In both patients a prolonged duration of renal replacement therapy was required. The plasma levels of ADAMTS13 enzyme were not helpful in delineating the precise pathogenesis in both cases, as the decrements were not severe. We discuss the clinic-pathologic correlation of the biopsy findings and persistence of AKI.

Gender and acute respiratory distress syndrome in critically injured adults: a prospective study.

BACKGROUND: The acute respiratory distress syndrome (ARDS) is a proinflammatory condition that often complicates trauma and critical illness. Animal studies have shown that both gender and sex hormones play an important role in inflammatory regulation. Human data are scant regarding the role of gender and sex hormones in developing ARDS. Our objective was to describe gender and hormonal differences in patients who develop ARDS in a large cohort of critically injured adults. METHODS: A prospective cohort study of adult trauma patients requiring intensive care unit admission for at least 48 hours was performed. Demographic and clinical data were collected prospectively, and sex hormones were assayed at study entry (48 hours). The primary outcome was the development of ARDS. Multivariate logistic regression was used to determine the adjusted odds of death associated with differences in gender. RESULTS: Six hundred forty-eight patients met entry criteria, and 180 patients developed ARDS (31%). Women were more likely to develop ARDS (35% vs. 25%, p=0.02). This association remained after adjusting for age, mechanism of injury, injury severity, and blood product transfusion (odds ratio, 1.6; 95% confidence interval: 1.1-2.4; p=0.02). Of patients with ARDS, there was no difference in mortality related to gender (22% mortality in women with ARDS vs. 20% in men; p=not significant). A proinflammatory sex hormone profile (low testosterone and high estradiol) was associated with ARDS in both men and women. CONCLUSION: Women are more likely than men to develop ARDS after critical injury. Despite the increased incidence in ARDS, the mortality in patients with ARDS does not differ according to gender. The inflammatory properties of sex hormones may contribute to ARDS, but they do not fully explain observed gender differences.

Prehospital statin and aspirin use and the prevalence of severe sepsis and acute lung injury/acute respiratory distress syndrome.

OBJECTIVES: To determine whether prehospital statin use is associated with a lower risk of sepsis, acute lung injury/acute respiratory distress syndrome, and mortality in critically ill patients. We also investigated the effect of combined prehospital use of both statins and aspirin. DESIGN: Cross-sectional analysis of a prospective cohort. PATIENTS: A total of 575 critically ill patients admitted to the medical or surgical intensive care unit of an academic tertiary-care hospital. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 575 patients, 149 (26%) were on statin therapy before hospitalization. A multivariable analysis including age, gender, current tobacco use, prehospital aspirin use, race, and Acute Physiology and Chronic Health Evaluation II score revealed that patients on statin therapy before hospitalization were less likely to have or develop severe sepsis (odds ratio 0.62, 95% confidence interval 0.40-0.96) or acute lung injury/acute respiratory distress syndrome (odds ratio 0.60, 95% confidence interval 0.36-0.99) during the first four intensive care unit days. In-hospital mortalities for patients with and without prehospital statin use (odds ratio 1.06, 95% confidence interval 0.62-1.83) were similar. Patients who had prehospital use of both statins and aspirin had the lowest rates of severe sepsis, acute lung injury/acute respiratory distress syndrome, and mortality. CONCLUSIONS: Prehospital use of statins may be protective against sepsis and acute lung injury. This effect may be potentiated by prehospital aspirin use.

Acute lung injury in patients with traumatic injuries: utility of a panel of biomarkers for diagnosis and pathogenesis.

BACKGROUND: The diagnosis of acute lung injury (ALI) is based on a consensus clinical definition. Despite the simplicity of this definition, ALI remains underdiagnosed and undertreated. Severe trauma is a well-described cause of ALI that represents a relatively homogeneous subset of patients with ALI. The aims of this study were to develop a panel of plasma biomarkers to facilitate diagnosis of trauma-induced ALI and to enhance our understanding of the pathogenesis of human ALI. METHODS: A retrospective nested case control of 192 patients admitted to the trauma intensive care unit at a university hospital between 2002 and 2006. We compared 107 patients with ALI to 85 patients without ALI. Plasma was collected within 72 hours of intensive care unit admission. Twenty-one plasma biomarkers were measured in duplicate in each plasma sample. RESULTS: Patients with ALI had higher severity of illness scores, more days of mechanical ventilation, longer hospital stays, and higher mortality versus controls. Seven biomarkers (receptor for advanced glycation end products, procollagen peptide III, brain natriuretic peptide, angiopoietin-2, interleukin-10, tumor necrosis factor alpha, and interleukin-8) had a high diagnostic accuracy as reflected by the area under the receiver operating characteristic curve of 0.86 (95% confidence interval, 0.82-0.92) in differentiating ALI from controls. CONCLUSIONS: A model using seven plasma biomarkers had a high diagnostic accuracy in differentiating patients with trauma-induced ALI from trauma patients without ALI. In addition, use of a panel of biomarkers provides insight into the likely importance of alveolar epithelial injury in the pathogenesis of early ALI.

Procoagulant alveolar microparticles in the lungs of patients with acute respiratory distress syndrome.

Coagulation and fibrinolysis abnormalities are observed in acute lung injury (ALI) in both human disease and animal models and may contribute to ongoing inflammation in the lung. Tissue factor (TF), the main initiator of the coagulation cascade, is upregulated in the lungs of patients with ALI/acute respiratory distress syndrome (ARDS) and likely contributes to fibrin deposition in the air space. The mechanisms that govern TF upregulation and activation in the lung are not well understood. In the vascular space, TF-bearing microparticles (MPs) are central to clot formation and propagation. We hypothesized that TF-bearing MPs in the lungs of patients with ARDS contribute to the procoagulant phenotype in the air space during acute injury and that the alveolar epithelium is one potential source of TF MPs. We studied pulmonary edema fluid collected from patients with ARDS compared with a control group of patients with hydrostatic pulmonary edema. Patients with ARDS have higher concentrations of MPs in the lung compared with patients with hydrostatic edema (25.5 IQR 21.3-46.9 vs. 7.8 IQR 2.3-27.5 micromol/l, P = 0.009 by Mann-Whitney U-test). These MPs are enriched for TF, have procoagulant activity, and likely originate from the alveolar epithelium [as measured by elevated levels of RAGE (receptor for advanced glycation end products) in ARDS MPs compared with hydrostatic MPs]. Furthermore, alveolar epithelial cells in culture release procoagulant TF MPs in response to a proinflammatory stimulus. These findings suggest that alveolar epithelial-derived MPs are one potential source of TF procoagulant activity in the air space in ARDS and that epithelial MP formation and release may represent a unique therapeutic target in ARDS.

Chylothoraces after lung transplantation for lymphangioleiomyomatosis: review of the literature and utilization of a pleurovenous shunt.

Chylous effusions are a well-described complication of lymphangioleiomyomatosis (LAM) in both pre- and post-transplant patients. Chylous effusions can cause significant morbidity among patients and most treatment modalities have limitations to complete success. We describe the use of a pleurovenous shunt to treat a refractory chylous effusion in a patient after lung transplant for LAM. After shunt placement, the patient had complete resolution of the chylous effusion and subsequent discharge home after a prolonged hospitalization. The use of a pleurovenous shunt for refractory chylous effusions is a viable option after conventional therapy fails.

Acute lung injury edema fluid decreases net fluid transport across human alveolar epithelial type II cells.

Most patients with acute lung injury (ALI) have reduced alveolar fluid clearance that has been associated with higher mortality. Several mechanisms may contribute to the decrease in alveolar fluid clearance. In this study, we tested the hypothesis that pulmonary edema fluid from patients with ALI might reduce the expression of ion transport genes responsible for vectorial fluid transport in primary cultures of human alveolar epithelial type II cells. Following exposure to ALI pulmonary edema fluid, the gene copy number for the major sodium and chloride transport genes decreased. By Western blot analyses, protein levels of alphaENaC, alpha1Na,K-ATPase, and cystic fibrosis transmembrane conductance regulator decreased as well. In contrast, the gene copy number for several inflammatory cytokines increased markedly. Functional studies demonstrated that net vectorial fluid transport was reduced for human alveolar type II cells exposed to ALI pulmonary edema fluid compared with plasma (0.02 +/- 0.05 versus 1.31 +/- 0.56 microl/cm2/h, p < 0.02). An inhibitor of p38 MAPK phosphorylation (SB202190) partially reversed the effects of the edema fluid on net fluid transport as well as gene and protein expression of the main ion transporters. In summary, alveolar edema fluid from patients with ALI induced a significant reduction in sodium and chloride transport genes and proteins in human alveolar epithelial type II cells, effects that were associated with a decrease in net vectorial fluid transport across human alveolar type II cell monolayers.

Splenosis: a review.

Splenosis is a common benign condition that occurs after splenic rupture via trauma or surgery. Splenosis is usually found incidentally and unless symptomatic, therapy is not indicated. However, since radiographically it can mimic malignancy, most patients have an extensive workup. The diagnostic method of choice is nuclear scintigraphy, specifically, a heat-damaged red blood cell scan. Splenosis usually occurs within the abdominal and pelvic cavities, but patients have been described with intrathoracic, subcutaneous, intrahepatic and intracranial lesions.