Clinical features and prognosis of patients with idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease

<sec> <title>BACKGROUND</title> Idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) share common risk factors. They could therefore be expressed in a single patient. However, the prevalence, clinical characteristics and prognosis of individuals with comorbid IPF and COPD are not known. </sec> <sec> <title>METHOD</title> From 2003 to 2007, the Korean Interstitial Lung Disease Study Group created a register for idiopathic interstitial pneumonia using 2002 ATS/ERS (American Thoracic Society/European Respiratory Society) criteria. Of the 1546 IPF patients assessed, 143 had decreased lung function consistent with COPD (IPF-COPD). COPD was diagnosed based on age (≥40 years) and pulmonary function (forced expiratory volume in 1 sec [FEV₁]/forced vital capacity [FVC] ratio < 0.7). </sec> <sec> <title>RESULTS</title> The median age of the IPF-COPD group was 71.0 years (interquartile range 66.0-76.0); most patients were male (88.1%). FVC (%) was significantly higher in the IPF-COPD group; however, FEV₁ (%) was significantly lower in the IPF-COPD group (P < 0.001). Diffusing capacity of the lung for carbon monoxide (DL_CO) was not significantly different between the two groups. In survival analysis, age and FVC (%), but not COPD, were significantly associated with prognosis (respectively P = 0.003, 0.001 and 0.401). COPD severity was also not related to prognosis (P = 0.935). </sec> <sec> <title>CONCLUSION</title> The prevalence of IPF-COPD was estimated to be ∼9.2% among all IPF patients; prognosis of patients with IPF-COPD was not worse than those with IPF alone. </sec>.

Toxocariasis as a cause of new pulmonary infiltrates

SETTING

Patients with new pulmonary infiltrates on chest computed tomography (CT) scans at a tertiary centre in South Korea.

OBJECTIVE

To demonstrate associations among radiological changes, blood eosinophilia (E) and Toxocara (T) seropositivity.

DESIGN

We retrospectively reviewed blood eosinophilia, Toxocara seropositivity, history of raw meat intake and radiological features, and divided study patients into four groups according to blood eosinophilia and Toxocara seropositivity.

RESULTS

Among 150 patients, 62 were E- and T-positive (E+T+), 45 were E-negative and T-positive (E-T+), 7 were E-positive and T-negative (E+T-), and 36 were E- and T-negative (E-T-). History of raw meat intake was found in 95 (63%) patients. The type and number of lesions on CT did not show any significant differences among the four groups. Among 119 patients who were not diagnosed with a specific disease, transient or migrating lesions were seen in 93% of E+T+, 93% of E-T+, 80% of E+T- and 52% of E-T- patients (P < 0.0001). Furthermore, the frequencies of migrating or new lesions and improvement were significantly higher in the Toxocara-positive group (88/95, 93%) than in the Toxocara-negative group (14/24, 58%; P = 0.002).

CONCLUSION

Transient and migratory pulmonary infiltrates on chest CT scans were associated with blood eosinophilia and Toxocara seropositivity. Clinicians should consider asymptomatic toxocariasis as a cause of unexplained new pulmonary infiltrates in countries with dietary habits of raw meat intake.

Initial lactate level and mortality in septic shock patients with hepatic dysfunction

An elevated serum lactate level is associated with morbidity and mortality in patients with severe sepsis and septic shock. In patients with hepatic dysfunction, however an elevated serum lactate level may be due to either impaired lactate clearance or excessive production. Thus, we evaluated whether the initial serum lactate level was also associated with mortality in septic shock patients with hepatic dysfunction. A retrospective observational study enrolled 307 patients with septic shock admitted to the intensive care unit (ICU) between May 2007 and July 2009. Hepatic dysfunction was defined as a serum total bilirubin > 34.2 micromol/l (2 mg/dl). Selected patients were divided into high (> or = 4 mmol/l) and low (< 4 mmol/l) lactate groups, according to the initial serum lactate level. Of 307 patients with septic shock, 118 (38%) patients with hepatic dysfunction were eligible for this study. The median lactate levels were 5.9 (interquartile range 4.7 to 9.0) and 2.6 (interquartile range 1.7 to 3.2) mmol/l for the high and low lactate groups respectively (P < 0.001). The initial serum lactate level was strongly associated with in hospital mortality in a univariate analysis (P < 0.001). After adjusting for potential confounding factors, the initial serum lactate level remained significantly associated with in-hospital mortality (odds ratio 1.281, 95% confidence interval 1.097 to 1.496, P = 0.002). In conclusion, the serum lactate level could be useful in predicting the outcome of patients with septic shock regardless of hepatic dysfunction.

Vitamin D-receptor polymorphisms and non-tuberculous mycobacterial lung disease in Korean patients

This study investigated the potential role of vitamin D-receptor (VDR) gene polymorphisms in susceptibility to lung disease caused by non-tuberculous mycobacteria (NTM). TaqI and FokI polymorphisms were compared in 124 patients and 127 controls. The genotype, allele and haplotype frequencies did not differ between patients and controls. TaqI and FokI polymorphisms of the VDR gene do not appear to be responsible for host susceptibility to NTM lung disease, at least in this Korean population. An association cannot, however, be completely ruled out, as only two single nucleotide polymorphisms of the VDR gene were studied in this report.

Safety and usefulness of bronchoscopy in ventilator-dependent patients with severe thrombocytopenia

Flexible bronchoscopy is a useful diagnostic procedure in patients with respiratory failure due to unexplained pulmonary infiltrates, but its safety and usefulness in ventilator-dependent patients with severe thrombocytopenia have not been established. A retrospective review of the medical records of all patients who underwent bronchoscopy while receiving mechanical ventilation support at Samsung Medical Centre, Seoul, Korea between January 2002 and July 2006 was conducted. The medical records of 37 patients with severe thrombocytopenia (platelet count <50,000 /microl) at the time of bronchoscopy were analysed. Mean platelet count was 27,300+/-12,500 /microl. The most common underlying condition was haematologic malignancy, which occurred in 21(56.7%) patients, followed by severe sepsis in five (13.6%) and post-liver transplantation complications and autoimmune disease in four each (10.8%). The procedures performed were bronchoalveolar lavage in 33 patients, washing in three and transbronchial lung biopsy in five. Two patients died within 24 hours of completing the procedure. In patients surviving longer than 24 hours, there was no significant decline in oxygenation index (PaO2/FiO2), sequential organ failure assessment score or simplified acute physiological score II after the procedure. Lung compliance significantly decreased at two hours post-bronchoscopy but recovered to the pre-bronchoscopy level by 24 hours. Intensive care unit mortality was 51.4% (19 of 37 patients). Bronchoscopy was helpful in confirming the diagnosis in 17 patients (45.9%). Therapeutic modifications were made in 14 patients (37.8%) after bronchoscopy. Severe thrombocytopenia per se should not preclude bronchoscopy, even in patients receiving mechanical ventilation.

Impaired expression of Toll-like receptor 2 in nontuberculous mycobacterial lung disease

The aims of the present study were to investigate the expression of Toll-like receptor (TLR)2 on the peripheral blood monocytes of patients with nontuberculous mycobacterial (NTM) lung disease and healthy controls, and to assess the responses of these monocytes to TLR2 agonists such as Mycobacterium avium and lipoteichoic acid (LTA). Reverse transcriptase-PCR was used to analyse TLR2 mRNA expression in peripheral blood monocytes from 17 NTM patients and 10 healthy controls. mRNA and protein secretion levels were also determined for the cytokines interleukin (IL)-12 p40 and tumour necrosis factor (TNF)-alpha. Expression of TLR2 mRNA by peripheral blood monocytes after stimulation with M. avium or LTA was lower in NTM patients than in healthy controls. IL-12 p40 and TNF-alpha mRNA and cytokine secretion levels were also lower in patients than in healthy controls. Treatment with anti-TLR antibody decreased M. avium- and LTA-induced IL-12 p40 and TNF-alpha production in healthy controls, but not in NTM patients. The present results suggest that the downregulation of Toll-like receptor 2 and the resulting decreased production of interleukin-12 p40 and tumour necrosis factor-alpha following Mycobacterium avium or lipoteichoic acid stimulation may contribute to host susceptibility to nontuberculous mycobacterial lung disease.

Pulmonary TB and NTM lung disease: comparison of characteristics in patients with AFB smear-positive sputum

OBJECTIVE

To compare the clinical and radiographic features of pulmonary tuberculosis (PTB) and non-tuberculous mycobacteria (NTM) lung disease in patients with acid-fast bacilli (AFB) positive sputum specimens.

DESIGN

The initial clinical and radiographic features of 229 PTB patients were compared with those of 70 patients with NTM lung disease. The most commonly involved organisms in the NTM lung disease cases were Mycobacterium avium complex (n = 38, 54%) and M. abscessus (n = 26, 37%).

RESULTS

Clinical and radiographic findings that were more common in patients with NTM lung disease than in PTB patients were: older age (P < 0.001), non-smoker (P < 0.001), history of previous TB treatment (P < 0.001), absence of pleural effusion (P = 0.017), involvement of middle and/or lower lung zones (P = 0.007), and bilateral disease (P = 0.005). Multivariate analysis showed that older age (> or = 40 years), non-smoker, previous TB treatment, absence of pleural effusion and involvement of middle and/or lower lung zones were significant independent predictors for NTM lung disease.

CONCLUSIONS

There is considerable overlap in the clinical and radiographic appearances of PTB and NTM lung disease. The isolation and identification of causative organisms are mandatory for a correct diagnosis in patients with AFB-positive sputum specimens.

Recovery rate of NTM from AFB smear-positive sputum specimens at a medical centre in South Korea

OBJECTIVE

To investigate the recovery rate of non-tuberculous mycobacteria (NTM) from acid-fast bacilli (AFB) smear-positive sputum specimens at a tertiary care medical centre in South Korea with a high pulmonary tuberculosis (PTB) burden.

DESIGN

Retrospective analysis of data from AFB smear- and culture-positive sputum specimens collected between January 1998 and December 2001.

RESULTS

Over 4 years, 1328 sputum specimens collected from 616 patients were AFB smear- and culture-positive. NTM were recovered from 9.1% (121/1328) of the smear-positive sputum specimens, and from 8.1% (50/616) of patients with smear-positive sputum. NTM were isolated at least twice in 94% (47/50) of the patients from whom NTM was recovered. The most common organism found was Mycobacterium avium complex, followed by M. abscessus.

CONCLUSION

These results suggest that a substantial proportion of patients at a tertiary care medical centre in South Korea with AFB smear-positive sputum specimens may have NTM lung disease rather than PTB.

Predictors for benign solitary pulmonary nodule in tuberculosis-endemic area

BACKGROUND

Solitary pulmonary nodule (SPN) may show different presentation in tuberculosis (TB)-endemic countries. The aim of this study was to identify clinical and radiological predictors favoring benign or malignant SPN in TB-endemic region.

METHODS

Two hundred one SPNs in 201 consecutive Korean patients were included (< 3 cm in diameter, all confirmed by pathology or bacteriology, 93 benign and 108 malignant diseases). For clinical parameters, age, sex, smoking status and amount, and past history of pulmonary tuberculosis and diabetes mellitus were investigated retrospectively. For radiological parameters, size, location, margin characteristics, presence of calcification, pleural tag, surrounding satellite nodule, cavitation, internal low attenuation, open bronchus sign, surrounding ground-glass opacity, enhancement pattern of the SPNs and mediastinal lymph node (LN) enlargement were analyzed on chest CT scans.

RESULTS

Patients with a older age (60.7 +/- 9.6 vs 56.2 +/- 13.1, p = 0.008) and more than 40-pack years smoking (27.8% vs 14.0%, p = 0.017) were more frequently related with malignant than benign SPN. On chest CT scans, spiculated margin, contrast enhancement more than 20 Hounsfield unit and presence of pleural tag and mediastinal LN enlargement were more frequently observed in malignant than benign SPNs. In contrast to previous studies, satellite lesions (21.5% vs 1.9%, p < 0.001) and cavitation (20.4% vs 5.6%, p = 0.001) were more frequently seen in benign than malignant SPN. Positive predictive values of benignity were 90.9% and 76.0%, respectively, when satellite lesions and cavitation were found in cases of SPN.

CONCLUSION

Satellite lesions and cavitation on chest CT scan could be useful predictors for benign SPN in TB-endemic areas.

Pulmonary alveolar hemorrhage in patients with rheumatic diseases in Korea

Pulmonary alveolar hemorrhage (PAH) is a rare and often fatal presenting feature of rheumatic diseases, with high mortality rate ranging from 40% to 90%. This study was undertaken to review the clinical manifestations, disease course, prognosis, and treatment of PAH in rheumatic diseases in Korea. A retrospective analysis was performed from October 1995 to March 1999 at the Samsung Medical Center. Ten cases were diagnosed as having pulmonary hemorrhage with rheumatic diseases that comprised the following: 6 systemic lupus erythematosus (SLE), 3 microscopic polyangiitis (MPA), and 1 mixed connective tissue disease (MCTD). In 80% of the patients in the present series, PAH was the first clinical manifestation of rheumatic diseases. The most consistent systemic manifestation occurring in conjunction with PAH was renal involvement (80%). The overall patient mortality rate was 50% (5/10) in the current series. Our study suggests that PAH often occurs as the first clinical manifestation of rheumatic diseases and needs urgent medical treatment including plasmapheresis in addition to cyclophosphamide and methylprednisolone.

Partial liquid ventilation shows dose-dependent increase in oxygenation with PEEP and decreases lung injury associated with mechanical ventilation

PURPOSE

The purpose of this article is to evaluate the effect of positive end-expiratory pressure (PEEP) during partial liquid ventilation (PLV) and to investigate if lung damage associated with mechanical ventilation can be reduced by PLV.

MATERIALS AND METHODS

Twenty-two New-Zealand white rabbits were ventilated in pressure-controlled mode maintaining constant tidal volume (10 mL/kg). Lung injury was induced by repeated saline lavage (PaO2 < 100 mm Hg). Two incremental PEEP steps maneuvers (IPSMs) from 2 to 10 cm H2O in 2 cm H2O steps were performed sequentially. The control group received the first IPSM in the supine position and were turned prone for the second IPSM. In the PLV group (n = 7), 12 mL/kg of perfluorodecalin was instilled after lung injury before the two IPSMs. The early prone group (n = 7) received both IPSMs in the prone position. Parameters of gas exchange, lung mechanics, and hemodynamics as well as pathology were examined.

RESULTS

During the first IPSM, the PLV group showed a significant increase in PaO2 after instillation of perfluorodecalin (P < .05) and then showed a dose-dependent increase in PaO2 with PEER. The control and EP groups showed improvement in PaO2 only at higher PEEP, eventually showing no intergroup differences at PEEP of 10 cm H2O. During the second IPSM only the PLV group retained its ability to increase PaO2 to the level obtained during the first IPSM (P < .05 compared with control and EP groups). During the first IPSM all three groups showed increasing trend in static compliance (Cst) with PEEP peaking at PEEP of 8 cm H2O. During the second IPSM, only the PLV group showed increase in static compliance with PEEP (P < .05 compared with other groups). Lung histology revealed significantly less hyaline membrane formation in the PLV group (P < .05).

CONCLUSION

PLV shows dose-dependent increase in oxygenation with PEEP and may reduce lung damage associated with mechanical ventilation.

Thoracic involvement of systemic lupus erythematosus: clinical, pathologic, and radiologic findings

Thoracic involvement occurs more frequently in systemic lupus erythematosus than in any other connective tissue diseases, and more than half of patients with the disease suffer from the involvement. Primary intrathoracic manifestations include pleural disease (effusions and/or thickening), acute lupus pneumonitis, subacute interstitial lung disease including bronchiolitis obliterans organizing pneumonia and non-specific interstitial pneumonia with fibrosis, chronic interstitial lung disease of usual interstitial pneumonia, pulmonary hemorrhage, pulmonary vascular disease, small airway disease of bronchiolitis obliterans, and pulmonary arterial hypertension. Secondary intrathoracic manifestations include atelectasis due to diaphragmatic dysfunction, opportunistic pneumonia, drug and oxygen toxicity, aspiration, and pleuropulmonary consequences of cardiac and renal failure.

Partial liquid ventilation with perfluorocarbon improves gas exchange and decreases inflammatory response in oleic acid-induced lung injury in beagles

The aim of this study was to determine the effect of partial liquid ventilation (PLV) using a perfluorocarbon (PFC) on gas exchange and lung inflammatory response in a canine acute lung injury model. After inducing severe lung injury by oleic acid infusion, beagle dogs were randomized to receive either gas ventilation only (control group, n = 6) or PLV (PLV group, n = 7) by sequential instillation of 10 mL/kg of perfluorodecalin (PFC) at 30 min intervals till functional residual capacity was attained. Measurements were made every 30 min till 210 min. Then the lungs were removed and bronchoalveolar lavage (BAL) (35 mL/kg) was performed on the right lung and the left lung was submitted for histologic analysis. There was significant improvement in PaO2 and PaCO2 in the PLV group compared to the control group (p < 0.05) which was associated with a significant decrease in shunt (p < 0.05). There was no significant difference in parameters of lung mechanics and hemodynamics. There was a significant decrease in cell count and neutrophil percentage in BAL fluid and significantly less inflammation and exudate scores in histology in the PLV group (p < 0.05). We conclude that PLV with perfluorodecalin improves gas exchange and decreases inflammatory response in the acutely-injured lung.

Nonspecific interstitial pneumonia with fibrosis: serial high-resolution CT findings with functional correlation

OBJECTIVE

We assessed serial changes in high-resolution CT findings and pulmonary function in patients with nonspecific interstitial pneumonia with fibrosis.

MATERIALS AND METHODS

Serial high-resolution CT findings in 13 patients with biopsy-proven nonspecific interstitial pneumonia with fibrosis (mean follow-up period, 11 months) and pulmonary function tests (mean follow-up period, 11 months) were retrospectively analyzed. On CT, the presence and extent of ground-glass opacity, irregular linear opacity, honeycombing, and consolidation were assessed.

RESULTS

On initial CT, all patients had areas of ground-glass opacity (mean +/- SD, 21.6% +/-14.4) and irregular linear opacity (5.0% +/- 5.2). The areas of ground-glass opacity decreased significantly on follow-up CT (13.5% +/- 10.5, p = .003). The areas of irregular linear opacity decreased slightly (4.2% +/- 5.2, p > .05). Initial forced vital capacity (69.4% +/- 16.0) improved significantly on follow-up examination (83.9% +/- 16.5) (p = .003). The decrease in the extent of ground-glass opacity on CT correlated significantly with changes in forced vital capacity (r = -.702, p = .007) and diffusing capacity for carbon monoxide (r = - .597, p = .031).

CONCLUSION

In patients with nonspecific interstitial pneumonia with fibrosis, areas of ground-glass opacity decrease on follow-up high-resolution CT, and the extent of decrease correlates significantly with that of functional improvement.

Squalene-induced extrinsic lipoid pneumonia: serial radiologic findings in nine patients

PURPOSE

The purpose of this work was to demonstrate the initial and follow-up radiologic findings of squalene-induced extrinsic lipoid pneumonia.

METHOD

Follow-up chest radiographs (n = 9) and high-resolution CT scans (n = 3) as well as initial radiographs (n = 9) and CT scans (n = 8) were obtained in nine patients with squalene-induced extrinsic lipoid pneumonia. The serial radiologic findings were analyzed retrospectively by three chest radiologists, focusing on the pattern and distribution of parenchymal abnormalities.

RESULTS

The most frequent pattern of parenchymal abnormalities on chest radiograph was areas of ground-glass opacity (n = 9, bilateral 6), followed by consolidation (n = 7, bilateral 3) and poorly defined small nodules (n = 4, bilateral 2). The abnormalities were distributed in the right lower lung (n = 9), left lower lung (n = 6), and right middle lung (n = 6) zones. Initial CT scans (n = 8) demonstrated bilateral areas of ground-glass attenuation (n = 8), poorly defined centrilobular nodules (n = 8), crazy paving (n = 6), and consolidation (n = 3). The abnormalities were distributed in the right middle lobe (n = 8) and in both lower lobes (n = 5). Follow-up chest radiograph (n = 9) showed complete disappearance (n = 2) and decrease (n = 7) in the extent of the parenchymal abnormalities. Follow-up CT scans (n = 3) demonstrated decrease (n = 2) and no change (n = 1) in the extent of the abnormalities.

CONCLUSION

Squalene-induced extrinsic lipoid pneumonia most commonly appears as areas of ground-glass attenuation mixed with poorly defined centrilobular nodules and crazy paving on CT, being distributed mainly in the right middle and both lower lobes. The lesions are indolent and remain after cessation of squalene ingestion.

Ring-down artifacts posterior to the right hemidiaphragm on abdominal sonography: sign of pulmonary parenchymal abnormalities

The aim of our study was to verify whether ring-down artifacts posterior to the right hemidiaphragm on abdominal sonography reflected pulmonary parenchymal abnormalities. Forty patients (group 1) with abdominal diseases and 32 patients (group 2) with proved various pulmonary abnormalities involving the right lung base underwent abdominal sonography with 2-4 MHz transducers. In these two groups, the presence and number of ring-down artifacts were assessed and correlated with peridiaphragmatic lung findings on chest radiographs or computed tomographic scans. In 21 patients (group 3) with multiple (more than five) or numerous (10 or more) ring-down artifacts, chest radiographs were reviewed to see if any peridiaphragmatic pulmonary abnormalities were present. In group 1, one or several (less than five) ring-down artifacts were shown in 27 of 40 (68%) patients. In these patients, computed tomography showed insignificant focal intra- and interlobular septal thickening in the peridiaphragmatic right lung. In group 2, 31 of 32 (97%) patients showed multiple or numerous ring-down artifacts. In group 3, chest radiographs showed various pulmonary abnormalities in 20 of 21 (95%) patients, including emphysema, idiopathic interstitial pneumonia, bronchopneumonia, and interstitial edema. Although nonspecific, ring-down artifacts posterior to the right diaphragm on abdominal sonography may be used to predict pulmonary abnormalities when encountered on abdominal sonography in patients without specific pulmonary symptoms.

Idiopathic interstitial pneumonias: clinical findings, pathogenesis, pathology and radiologic findings

Idiopathic interstitial pneumonias are currently classified into four categories: usual interstitial pneumonia, nonspecific interstitial pneumonia with fibrosis, acute interstitial pneumonia and desquamative interstitial pneumonia. The fibrotic process in interstitial pneumonias appears to result from a complex interaction between fibroblasts, other lung parenchymal cells and macrophages. The complex relationship between the local release of growth-promoting cytokines by alveolar macrophages and resident fibroblasts represents a necessary step for fibrosis or remodeling after lung injury. Injury to the epithelium and basement membranes is likely necessary for the fibrotic process to occur. Usual interstitial pneumonia, most frequent among interstitial pneumonias and has a poor prognosis, appears on high-resolution CT as patchy subpleural areas of ground-glass attenuation, irregular linear opacity, and honeycombing. Nonspecific interstitial pneumonia with fibrosis, the second most frequent and has a better prognosis than usual interstitial pneumonia, appears as subpleural patchy areas of ground-glass attenuation with associated areas of irregular linear opacity on CT. Acute interstitial pneumonia with high mortality rate presents as extensive bilateral airspace consolidation and patchy or diffuse bilateral areas of ground-glass attenuation. Desquamative interstitial pneumonia with good prognosis presents as patchy subpleural areas of ground-glass attenuation in middle and lower lung zones.

Nonspecific interstitial pneumonia with fibrosis: high-resolution CT and pathologic findings

OBJECTIVE

The purpose of our study was to describe high-resolution CT findings of nonspecific interstitial pneumonia with fibrosis and to compare findings seen on CT with pathologic findings.

MATERIALS AND METHODS

High-resolution CT findings of biopsy-proven non-specific interstitial pneumonia with fibrosis from 23 consecutive patients (one man and 22 women) were analyzed retrospectively by two chest radiologists. CT findings were compared with pathologic findings.

RESULTS

The predominant high-resolution CT finding, seen in all patients, was bilateral patchy areas of ground-glass opacity with (35%) or without (65%) areas of consolidation. Irregular linear opacities (87%), thickening of bronchovascular bundles (65%), and bronchial dilatation (52%) were also frequently seen. Honeycombing was not seen in any patient. All parenchymal abnormalities showed subpleural predominance. Areas of ground-glass opacity with or without irregular linear opacity or bronchial dilatation on CT corresponded pathologically to areas of interstitial thickening caused by varying degrees of interstitial inflammation and fibrosis showing temporal uniformity. Areas of consolidation, seen at five biopsy sites, represented the areas of bronchiolitis obliterans organizing pneumonia, foamy cell collections in alveolar spaces, or microscopic honeycombing with mucin stasis.

CONCLUSION

On high-resolution CT, nonspecific interstitial pneumonia with fibrosis is most commonly revealed as patchy subpleural areas of ground-glass opacity mixed with irregular linear opacity or bronchial dilatation. These areas represent interstitial thickening caused by varying degrees of interstitial inflammation, fibrosis, or both.

Nitric oxide expression in airway epithelial cells in response to tubercle bacilli stimulation

In order to investigate the role of airway epithelial cells in pulmonary tuberculosis, inducible nitric oxide synthetase (iNOS) expression and nitric oxide (NO) production were studied in A549 cells. Peripheral blood mononuclear cells (PBMC) from normal volunteers were separated and cultured for 24 h with LPS or tubercle bacilli (H37Rv, H37Ra). Thereafter, A549 cells were stimulated for another 24 h with culture supernatant fluids of PBMC. iNOS messenger RNA (mRNA) expression was measured with Northern blot analysis and NO production was measured with the Griess reaction, which can measure nitrite concentration. iNOS mRNA expression and NO production were minimal in the control cells. iNOS mRNA expression and NO production were significantly increased with LPS (P < 0.05) or tubercle bacilli (P < 0.01) stimulation. However, there was no difference in iNOS mRNA expression and NO production between H37Rv and H37Ra stimulations. Interestingly, iNOS mRNA expression and NO production were greater in A549 cells stimulated with tubercle bacilli-conditioned media than in the cells stimulated with LPS-conditioned media. IL-1beta, tumour necrosis factor-alpha and interferon gamma concentrations were increased in culture supernatant fluids of PBMC stimulated with tubercle bacilli. These findings suggest that airway epithelial cells may play a certain role in the pathogenesis of pulmonary tuberculosis by producing NO. However, the role of airway epithelial cells, regarding the virulence of tubercle bacilli, was not clear in this study.

Bronchial stenosis due to anthracofibrosis

STUDY OBJECTIVES

To define the clinical characteristics of the patients showing bronchoscopic findings of bronchial narrowing or obliteration with black pigmentation on overlying mucosa (we named this finding as "anthracofibrosis"), and to determine the association of anthracofibrosis with tuberculosis.

PATIENTS AND METHODS

The subjects of this study consisted of 28 patients; 8 men and 20 women, ranging in age from 42 to 86 years. The distinctive clinical features, natures of bronchoscopic lesions, and radiologic findings were analyzed retrospectively and summarized. Bacteriologic studies and results of pathologic examinations were also assessed.

RESULTS

Chief complaints were cough (20/28) and dyspnea on exertion (17/28). The abnormal bronchoscopic findings were identified most frequently in the right middle lobe bronchus (n=21/28) while more than one part of the bronchial tree was narrowed in 22 patients. Abnormalities of bronchial airways on CT were associated with peribronchial cuffs of soft tissue or surrounding lymph nodes. In 17 patients, active tuberculous infection was confirmed either bacteriologically (n=15) and/or histologically (n=8). Pathologic study of the lesion obtained by bronchoscopic biopsy or thoracotomy showed dense bronchial and/or peribronchial fibrosis with interspersed black pigments.

CONCLUSIONS

These findings strongly suggest that bronchial stenosis or obliteration with anthracotic pigmentation in the mucosa was caused by a fibrotic response to active or old tuberculous infection. To prevent the spread of tuberculosis and avoid unnecessary invasive procedures, detailed examinations for the presence of active tuberculosis should be performed in patients with this unique bronchoscopic finding.

Bronchiolitis in adults: pathology and imaging

The most common high resolution CT (HRCT) findings of bronchiolitis are centrilobular nodules and branching linear structures in the secondary pulmonary lobules or areas of air trapping. These findings can be helpful in suggesting the presence of bronchiolitis. However, they are nonspecific because there are overlapping features among various kinds of bronchiolitis. Bronchiolar or peribronchiolar inflammation appears as centrilobular nodule, while bronchiolectasis filled with secretions manifests with branching linear structure on HRCT. Air trapping is secondary to bronchiolitis. Proliferative bronchiolitis with the findings of patchy areas of consolidation or ground-glass opacity can be distinguished from other bronchiolitis. Mineral dust-induced bronchiolitis and peribronchiolar lesions in sarcoidosis present with perilymphatic (centrilobular plus perilobular) micronodules in the secondary pulmonary lobule. Bronchiolitis in hypersensitivity pneumonia appears with poorly defined centrilobular nodules, associated with ground-glass opacity and air trapping.

Airway obstruction in interstitial lung disease

There is no question that most interstitial lung diseases result in structural alteration of the small airways as well as the alveoli. These structural changes of the airways produce airflow abnormalities that, depending on their extent and severity, are reflected in a variety of tests of pulmonary function. However, in most situations, obstructive lung disease rarely dominates the clinical picture. Airflow limitation may be the predominant defect in patients with Wegener's granulomatosis, lymphangioleiomyomatosis, and chronic eosinophilic pneumonia. Concomitant risk factors such as cigarette smoking or dust inhalation may contribute to airway obstruction. Sporadic cases of interstitial lung disease progressing to overt airflow obstruction have been reported. The clinical significance of airway narrowing in interstitial lung disease is a maldistribution of ventilation that causes abnormalities on gas exchange, thereby increasing the work of breathing and possibly the sensation of dyspnea.

Evaluation of tracheobronchial disease with helical CT with multiplanar and three-dimensional reconstruction: correlation with bronchoscopy

The advantage of volumetric computed tomography in the thorax is the possibility of acquiring both multiplanar and three-dimensional (3D) images, thus enabling precise diagnosis and evaluation of extent of disease involving the airways. Multiplanar and 3D images appear to be useful for global understanding of the status of the tracheobronchial tree, particularly for evaluation of focal stenosis of the airways. Such images seem to be especially useful in evaluating the longitudinal extent of airway lesions, thus providing valuable information for preparing a road map for bronchoscopy, for surgical planning, and for follow-up of treatment response. However, multiplanar and 3D images do not appear to be useful in lesion detection or evaluation of transaxial extension. Multiplanar and 3D images also seem to be helpful in demonstrating whether a lesion is endobronchial, submucosal, or peribronchial. The quality of such images appears to be excellent or good in almost all patients.

Tuberculosis of the trachea and main bronchi: CT findings in 17 patients

OBJECTIVE

The purpose of our study was to describe the CT findings of tuberculosis of the trachea and main bronchi.

MATERIALS AND METHODS

Initial (n = 17) and follow-up (n = 7) CT scans were available from 17 patients (five men and 12 women; aged 25-82 years old) with tracheobronchial tuberculosis. The diagnosis of tuberculosis was based on bronchoscopic, microbiologic, or pathologic findings.

RESULTS

The trachea (n = 6), the right main bronchus (n = 6), and the left main bronchus (n = 4) were involved in 10 patients with actively caseating tuberculosis. These airways showed irregular (n = 11) or smooth (n = 4) circumferential narrowing and occlusion (n = 1). Also, the trachea (n = 2), the right main bronchus (n = 1), and the left main bronchus (n = 6) were involved in seven patients with fibrotic tuberculosis. These airways showed smooth (n = 4) or irregular (n = 3) circumferential narrowing and occlusion (n = 2). Mediastinitis (increased densities in mediastinal fat) was seen in four of 10 patients with active tuberculosis but not in any of the seven patients with fibrotic disease. Tracheal tuberculosis, which has always been associated with bronchial disease, involved the distal trachea and exceeded 3 cm in length. After the seven patients underwent initial scans and antituberculous chemotherapy, serial CT scans showed improvement in seven of 11 lesion sites: normalized airways (n = 4) or smoothing from irregular narrowing (n = 3). The remaining four sites showed no change.

CONCLUSION

On CT scans, actively caseating tracheobronchial tuberculosis showed circumferential and predominantly irregular luminal narrowing and mediastinitis. When fibrotic disease was found, a CT scan revealed equal distribution of smooth and irregular narrowing and less wall thickening than was seen in patients with active disease. On CT scans, tracheal tuberculosis involved the long segment of the distal trachea, a condition associated with bronchial tuberculosis.

Utility of CT in the evaluation of pulmonary tuberculosis in patients without AIDS

OBJECTIVE

To assess the utility of CT in the evaluation of pulmonary tuberculosis in patients without AIDS.

PATIENTS AND METHODS

This-section CT scans for suspicion of pulmonary tuberculosis were obtained from 226 patients. A total of 38 patients were excluded; the reasons were unavailability of final results (n = 18), patient unavailability for follow-up (n = 13), and coexistence of tuberculosis and aspergilloma (n = 7). The results from 188 patients were used for this study. After assessing the patterns of parenchymal lesion, involved segments, and presence of cavity, bronchiectasis, and bronchogenic spread of the lesion with CT, tentative diagnosis and disease activity were recorded.

RESULTS

With CT, 133 of 146 patients (91%) with tuberculosis were correctly diagnosed as having pulmonary tuberculosis whereas 32 of 42 patients (76%) without tuberculosis were correctly excluded. CT diagnosis of lung cancer (n = 8), bacterial pneumonia (n = 2), pulmonary metastasis (n = 1), chronic hypersensitivity pneumonia (n = 1), and diffuse panbronchiolitis (n = 1) turned out to be tuberculosis. Conversely CT diagnoses of tuberculosis appeared pathologically as lung cancer (n = 5), bacterial pneumonia (n = 4), and pulmonary paragonimiasis (n = 1). Active (71/89, 80%) and inactive state (51/57, 89%) of disease respectively could be correctly differentiated by CT.

CONCLUSION

CT can be helpful in the diagnosis of pulmonary tuberculosis in most cases. On the basis of CT findings, distinction of active from inactive disease can be made in most cases.

Contrast sensitivity in a large adult population

The contrast sensitivity test (using Vistech charts) was performed on a consecutive sample of 1612 eyes of 807 Republic of Singapore Air Force personnel (two diseased eyes excluded), which had no known ophthalmic disorder. This yielded a large sample norm of spatial Contrast Sensitivity Function (CSF) distribution curves, based on the local population. Although all subjects had their refractive errors fully corrected by spectacles, whenever necessary, to visual acuity of 6/6 or better, myopes had lower mean contrast sensitivity, in the higher spatial frequencies, compared to the emmetropic. Postulates were offered to explain this association, including the concept of micro-amblyopia. Pilots and aircrew performed consistently better than the ground crew, suggesting that target acquisition training may improve contrast sensitivity. Interestingly, sex was also shown to be associated with differences in contrast sensitivity: females were found to have lower spatial contrast sensitivity compared to males. Age was associated with poorer contrast sensitivity only at the lower spatial frequencies in this study sample, while race, with that of higher frequencies; Chinese having lower contrast sensitivity than other races (a heterogeneous group consisting of Malays, Indians, Eurasians and Others). The association of contrast sensitivity with race highlights the importance of using normograms based on the local population. All the above associations were statistically significant at P = 0.05, and independent of each other, based on analysis by multiple regression.(ABSTRACT TRUNCATED AT 250 WORDS)

Human IL-3 (multi-CSF): identification by expression cloning of a novel hematopoietic growth factor related to murine IL-3

A cDNA clone encoding a novel hematopoietic growth factor activity produced by a gibbon T cell line has been identified using a mammalian cell expression cloning system. The sequence of this cDNA proved to have significant homology to the sequence encoding murine interleukin 3 (IL-3). The human gene, which was readily identified because of its high degree of homology to the gibbon sequence, also displayed significant homology with the murine IL-3 sequence. The recombinant gibbon IL-3 protein proved to have multipotent colony stimulating activity when tested with normal human bone marrow cells, proving that this primate hematopoietin is not only structurally but also functionally related to murine IL-3.