Leo C. Ginns

Genomewide linkage analysis of quantitative spirometric phenotypes in severe early-onset chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a common, complex disease associated with substantial morbidity and mortality. COPD is defined by irreversible airflow obstruction; airflow obstruction is typically determined by reductions in quantitative spirometric indices, including forced expiratory volume at 1 s (FEV(1)) and the ratio of FEV(1) to forced vital capacity (FVC). To identify genetic determinants of quantitative spirometric phenotypes, an autosomal 10-cM genomewide scan of short tandem repeat (STR) polymorphic markers was performed in 72 pedigrees (585 individuals) ascertained through probands with severe early-onset COPD. Multipoint variance-component linkage analysis (using SOLAR) was performed for quantitative phenotypes, including FEV(1), FVC, and FEV(1)/FVC. In the initial genomewide scan, significant evidence for linkage to FEV(1)/FVC was demonstrated on chromosome 2q (LOD score 4.12 at 222 cM). Suggestive evidence was found for linkage to FEV(1)/FVC on chromosomes 1 (LOD score 1.92 at 120 cM) and 17 (LOD score 2.03 at 67 cM) and to FVC on chromosome 1 (LOD score 2.05 at 13 cM). The highest LOD score for FEV(1) in the initial genomewide scan was 1.53, on chromosome 12, at 36 cM. After inclusion of 12 additional STR markers on chromosome 12p, which had been previously genotyped in this population, suggestive evidence for linkage of FEV(1) (LOD score 2.43 at 37 cM) to this region was demonstrated. These observations provide both significant evidence for an early-onset COPD-susceptibility locus on chromosome 2 and suggestive evidence for linkage of spirometry-related phenotypes to several other genomic regions. The significant linkage of FEV(1)/FVC to chromosome 2q could reflect one or more genes influencing the development of airflow obstruction or dysanapsis.

Analysis of T cell subsets in normal adults. Comparison of whole blood lysis technique to Ficoll-Hypaque separation by flow cytometry.

Analysis of peripheral blood T cells and T cell subsets by immunofluorescence and flow cytometry is employed commonly in studies of normal individuals and in certain disease states. Methods for separating T cells from granulocytes and erythrocytes vary. We have sought to determine whether or not such procedures alter the composition of cells being analyzed. In this communication, we report that, in normal individuals, Ficoll-Hypaque separation of lymphocytes selectively decreases the OKT8+ subset compared to the whole blood lysis technique (P less than 0.01). The decrease in the OKT8+ subset results in a significant increase (P less than 0.01) in the OKT4/OKT8 ratio. This disparity appears to be due to a selective loss of OKT8+ cells during centrifugation over Ficoll-Hypaque. With the Ficoll-Hypaque method, we have also found that the fixation of lymphocytes reacted with monoclonal antibodies is less stable than cells prepared by the whole blood lysis method. The interpretation of measurements of T cell subsets is influenced by the method by which these cells are isolated.

Relationship between pulmonary artery diameter at computed tomography and pulmonary artery pressures at right-sided heart catheterization

Rationale and Objectives. The purpose of the study was to determine the relationship between pulmonary artery (PA) size at computed tomography (CT) and PA pressures, to develop a noninvasive CT method of PA pressure measurement, and to determine a PA diameter that can enable differentiation of normal subjects from those with ptfimonary hypertension. Methods. PA vessel diameters in 55 candidates for lung and heart-lung transplantation were measured at CT and correlated with PA pressures with both linear and stepwise multiple regression. The multiple regression equations were then tested prospectively in 35 pretransplantation patients. Results. Combined main and left main PA cross-sectional area corrected for body surface area showed the best correlation with mean PA pressure ( r = .87). The multiple regression equations helped predict mean PA pressure within 5 mm Hg in 50% of patients with chronic lung disease and in only 8% of patients with pulmonary vascular disease. Conclusion. There was a very good correlation between main and left main PA size and mean PA pressure. At present, however, CT has not demonstrated sufficient accuracy to be used clinically.

Acquired tracheomalacia: detection by expiratory CT scan.

Purpose The purpose of this work was to determine whether cross-sectional area and coronal and sagittal diameter measurements of the trachea between inspiration and end-expiration on CT are significantly different between patients with acquired tracheomalacia and those without this condition. Method Inspiratory and end-expiratory CT scans of the trachea of 23 normal patients and 10 patients with acquired tracheomalacia were analyzed. Percent changes in cross-sectional area, coronal, and sagittal diameters were calculated. Results For patients with tracheomalacia, mean percent changes in the upper and middle trachea between inspiration and expiration were 49 and 44%; mean changes in the coronal and sagittal diameters in the upper and middle tracheal were 4 and 10% and 39 and 54%, respectively. Control group mean percent changes in the upper and middle tracheal area were 12 and 14%, respectively, and mean changes in the coronal and sagittal diameters in the upper and middle trachea were 4 and 4% and 11 and 13%, respectively. Significant differences were calculated for changes in cross-sectional area and sagittal diameter between groups (p < 10−5). Based on receiver operator curve analysis, a >18% change in the upper trachea and 28% change in the midtrachea between inspiration and expiration were observed; the probability of tracheomalacia was 89–100%. The probability of tracheomalacia was >89%, especially if the change in sagittal diameter was >28%. Conclusion By measuring changes in tracheal cross-sectional area and sagittal diameters between inspiratory and end-expiratory CT, a significant difference can be identified between normal patients and those with acquired tracheomalacia.

BLT1-mediated T cell trafficking is critical for rejection and obliterative bronchiolitis after lung transplantation

Leukotriene B4 is a lipid mediator that recently has been shown to have potent chemotactic activity for effector T lymphocytes mediated through its receptor, BLT1. Here, we developed a novel murine model of acute lung rejection to demonstrate that BLT1 controls effector CD8+ T cell trafficking into the lung and that disruption of BLT1 signaling in CD8+ T cells reduces lung inflammation and mortality in the model. In addition, we used BLT1-deficient mice and a BLT1 antagonist in two tracheal transplant models of lung transplantation to demonstrate the importance of BLT1 for the recruitment of T cells into tracheal allografts. We also show that BLT1-mediated CD8+ T cell recruitment plays an important role in the development of airway fibroproliferation and obliteration. Finally, in human studies of lung transplant recipients, we found that BLT1 is up-regulated on T lymphocytes isolated from the airways of patients with obliterative bronchiolitis. These data demonstrate that BLT1 contributes to the development of lung rejection and obliterative bronchiolitis by mediating effector T lymphocyte trafficking into the lung. This is the first report that describes a pathologic role for BLT1-mediated T lymphocyte recruitment in disease and identifies BLT1 as a potential therapeutic target after lung transplantation.

T-lymphocyte subsets in peripheral blood and lung lavage in idiopathic pulmonary fibrosis and sarcoidosis: Analysis by monoclonal antibodies and flow cytometry

Abstract Thymus-dependent (T) lymphocytes may contribute to the pathogenesis of human interstitial lung disease. In order to determine whether alterations of immunoregulatory T cells occur in patients with idiopathic pulmonary fibrosis (IPF) and sarcoidosis, we characterized T lymphocytes in peripheral blood (n = 8 and 11, respectively) and lung lavage (n = 4 and 6, respectively) in untreated patients with these diseases. In IPF, we found a decreased percentage, but normal total count of circulating OKT3+ (mature) and OKT4+ (inducer/helper) cells compared to normal controls. We observed a normal percentage and total count of circulating OKT8+ (cytotoxic/suppressor) cells. The ratio of OKT4+ to OKT8+ ( 4 8 ) lymphocytes, reflecting the balance of immunoregulatory cells, was normal in peripheral blood. Comparing peripheral blood to lung lavage, we noted a lower proportion of OKT4+ cells and a higher proportion of OKT8+ cells in lung lavage. The 4 8 ratio in lung lavage tended to be low compared to blood. In contrast, we found in sarcoidosis patients a decrease in both percentage and total circulating OKT3+, OKT4+, and OKT8+ cells as compared to normal. In lung lavage, there was an increase in OKT3+ cells, due to an increase in the OKT4+ subset. The percentage of OKT8+ cells in lung lavage was low. Compared to blood the 4 8 ratio was high in lung lavage. Thus, a number of alterations in circulating and lavage T cells were found both in patients with IPF and sarcoidosis. These results suggest that immunoregulatory abnormalities contribute to pathogenesis of these disorders.

FAMILIAL AGGREGATION OF FEF(25-75) AND FEF(25- 75)/FVC IN FAMILIES WITH SEVERE, EARLY ONSET COPD

Background: The Boston Early-Onset COPD study showed that current or ex-smoking first degree relatives of severe early onset COPD probands have significantly lower forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC) values than current or ex-smoking control subjects, which suggests the existence of genetic risk factors for the development of COPD in response to cigarette smoking. We hypothesised that first degree relatives of early onset COPD probands may also have lower values of spirometric parameters such as forced expiratory flow at the mid-portion of forced vital capacity (FEF25–75) and FEF25–75/FVC. Methods: Using generalised estimating equations, FEF25–75 and FEF25–75/FVC were analysed in 333 first degree relatives of probands with severe early onset COPD and 83 population based controls; analyses were also performed on data stratified by smoking status. Narrow sense heritability estimates were calculated using a variance component approach. Results: Significantly lower FEF25–75 and FEF25–75/FVC were observed in smoking (FEF25–75: β −0.788 l/s (95% CI −1.118 to −0.457), FEF25–75/FVC: β −20.4% (95% CI −29.3 to −11.6, p<0.0001 for both phenotypes) and non-smoking (FEF25–75: β −0.357 l/s (95% CI −0.673 to −0.041, p = 0.0271), FEF25−75/FVC: β −9.5% (95% CI −17.1 to −1.9, p = 0.0145)) first degree relatives of early onset COPD probands. Narrow sense heritability estimates for FEF25–75 (h2 = 0.38) and FEF25–75/FVC (h2 = 0.45) were similar to those for FEV1 and FEV1/FVC. Conclusion: Lower values of FEF25–75 and FEF25–75/FVC in non-smoking first degree relatives of early onset COPD probands than in controls suggest a genetic susceptibility to develop obstructive lung disease, independent of smoking, which is magnified by exposure to deleterious environments as suggested by the further decrements in FEF25–75 and FEF25–75/FVC seen in smoking first degree relatives. FEF25–75 and FEF25–75/FVC have high heritability and are important intermediate phenotypes for inclusion in genetic epidemiological studies of COPD.

CXCR3 and Its Ligands in a Murine Model of Obliterative Bronchiolitis: Regulation and Function

Lung transplantation remains the only effective therapy for patients with end-stage lung disease, but survival is limited by the development of obliterative bronchiolitis (OB). The chemokine receptor CXCR3 and two of its ligands, CXCL9 and CXCL10, have been identified as important mediators of OB. However, the relative contribution of CXCL9 and CXCL10 to the development of OB and the mechanism of regulation of these chemokines has not been well defined. In this study, we demonstrate that CXCL9 and CXCL10 are up-regulated in unique patterns following tracheal transplantation in mice. In these experiments, CXCL9 expression peaked 7 days posttransplant, while CXCL10 expression peaked at 1 day and then again 7 days posttransplant. Expression of CXCL10 was also up-regulated in a novel murine model of lung ischemia, and in bronchoalveolar lavage fluid taken from human lungs 24 h after lung transplantation. In further analysis, we found that 3 h after transplantation CXCL10 is donor tissue derived and not dependent on IFN-γ or STAT1, while 24 h after transplantation CXCL10 is from recipient tissue and regulated by IFN-γ and STAT1. Expression of both CXCL9 and CXCL10 7 days posttransplant is regulated by IFN-γ and STAT1. Finally, we demonstrate that deletion of CXCR3 in recipients reduces airway obliteration. However, deletion of either CXCL9 or CXCL10 did not affect airway obliteration. These data show that in this murine model of obliterative bronchiolitis, these chemokines are differentially regulated following transplantation, and that deletion of either chemokine alone does not affect the development of airway obliteration.

Outcome of Influenza Infection Managed With Oseltamivir in Lung Transplant Recipients

BACKGROUND Influenza causes significant morbidity and mortality in lung transplant recipients and likely predisposes to obliterative bronchiolitis. Neuraminidase inhibitors shorten the duration of symptoms and virus shedding and the number of antibiotic-requiring complications in ambulatory immunocompetent patients, although the efficacy of these agents in lung transplant recipients has not been assessed previously. METHODS In this study, 9 lung transplant patients who were treated with oseltamivir for influenza infections were identified and analyzed retrospectively. RESULTS Oseltamivir was well tolerated. Infection resolved in all patients and there were no deaths. Two patients developed pneumonia shortly after their influenza infection and both responded to antibiotic therapy. None of the patients had persistent abnormalities noted on chest imaging and most did not show significant changes on pulmonary function testing. Two patients with the lowest pulmonary function test (PFT) values pre-infection had persistent defects after infection. CONCLUSIONS Oseltamivir is well tolerated in lung transplant recipients and may reduce the risk of complications, although further studies are warranted.

CT manifestations of respiratory syncytial virus infection in lung transplant recipients.

PURPOSE The purpose of our study was to evaluate CT findings during respiratory syncytial virus (RSV) infection in lung transplant recipients and to identify sequelae. METHOD Thirty-nine CT scans prior to, during, and following acute infection in 10 lung transplant recipients were reviewed. Abnormalities that were new from baseline observations and occurred within 4 weeks of diagnosis were defined as acute. Chronic findings were defined as those present >4 weeks after diagnosis. RESULTS Findings in nine patients were ground-glass (seven), air-space (five), and tree-in-bud (four) opacities and acute bronchial dilatation (four) and wall thickening (four). Patients lacked pleural effusions or lymph node enlargement. Five of seven patients with follow-up exams had new air trapping (three), persistent bronchial dilatation (three), and thickening (two). Three and 2 of the 10 patients developed bronchiolitis obliterans syndrome and obliterative bronchiolitis, respectively. CONCLUSION During acute infection, patients commonly had ground-glass opacities but lacked pleural effusions and lymph node enlargement. There can be chronic sequelae after infection.