Bronchoalveolar lavage cellularity: lone cryptogenic fibrosing alveolitis compared with the fibrosing alveolitis of systemic sclerosis

Lone cryptogenic fibrosing alveolitis (CFA) is histologically identical to fibrosing alveolitis associated with systemic sclerosis (FASSc), but it has a much worse prognosis after matching for disease severity at presentation. The aims of this study were to gain insights into possible pathogenetic mechanisms contributing to this prognostic difference, by comparing bronchoalveolar lavage (BAL) cellularity in the two diseases, and to evaluate the relationships between BAL findings and the regional and global extent of disease, quantified by thin-section computed tomography (CT) and lung function indices. Patients with CFA were distinguished by more extensive fibrosing alveolitis on CT (p < 0.02) and by higher counts of neutrophils (total per ml, p < 0.02; percentage p < 0.03) and eosinophils (total per ml, p < 0.002; percentages, p < 0.02) in BAL fluid. After adjustment for functional and morphologic measures of disease extent, eosinophil percentages and total counts were increased in CFA (p < 0.05 in all 12 multivariate models), but they were not independently related to regional or global disease severity. Neutrophil percentages and total counts were virtually identical in CFA and FASSc in disease of comparable severity, and they increased with increasingly extensive lobar disease and global disease, as judged by CT, p < 0.0005 in all analyses. Neutrophil levels were more closely linked to the extent of disease on CT than to the severity of functional impairment, on univariate and multivariate analysis. The higher BAL eosinophil levels seen in CFA, compared with those seen in FASSc, after adjustment for disease extent, indicate that an eosinophilic influx may be linked to the pathogenesis of fibrosing alveolitis. By contrast, BAL neutrophil levels increase with increasingly extensive disease on CT, but they do not differ independently between CFA and FASSc, suggesting that neutrophil degradation products are unlikely to account for the excess mortality in CFA, compared with that in FASSc.

Computed tomographic imaging of bronchiolar disorders

The bronchiolitides can be categorized broadly as constrictive or proliferative, each with characteristic CT features. The cardinal CT signs of constrictive bronchiolitis are mosaic perfusion, enhanced on expiratory CT scan and variably associated with bronchiectasis and, less frequently, centrilobular branching structures. These features are common to postinfective bronchiolitis, bronchiolitis associated with collagen vascular disease, obliterative bronchiolitis following lung transplantation, and bronchiolitis following inhalation of toxic fumes and consumption of Sauropus androgynus. Proliferative bronchiolitis manifests on CT scan as patchy bilateral consolidation, variably associated with nodular abnormalities. The CT appearances of other rare bronchiolitides are discussed here including diffuse panbronchiolitis, follicular bronchiolitis, and respiratory bronchiolitis-associated interstitial lung disease.

Fibrosing alveolitis in systemic sclerosis: indices of lung function in relation to extent of disease on computed tomography

OBJECTIVE

Thin-section computed tomography (CT) provides a sensitive and reproducible method of quantifying the morphologic extent of disease in the clinical management of fibrosing alveolitis associated with systemic sclerosis (FASSc). The aim of this study was to determine which indices of lung function best reflect the extent of disease on CT in FASSc, and to determine the independent influences of smoking history, extent of fibrosing alveolitis, demographic features, and concurrent treatment upon functional impairment in FASSc.

METHODS

Sixty-four patients with FASSc were studied using CT and static and exercise lung function testing. Statistical relationships were determined by multiple regression analyses.

RESULTS

Five patients with overt pulmonary hypertension were characterized by severe impairment in 3 indices of lung function: diffusing capacity for carbon monoxide (DLCO), DLCO adjusted for alveolar volume (KCO), and arterial partial pressure of oxygen. On multiple regression analysis, the major determinant of functional impairment was the extent of fibrosing alveolitis on CT. A history of smoking was independently associated with preservation of total lung capacity and depression of KCO, but did not otherwise influence functional-morphologic correlations. The percent predicted DLCO correlated better with extent of disease on CT (r = -0.70) than did oxygen desaturation on exercise (r = 0.55), the physiologic component of the clinical-radiographic-physiologic score (CRP index) (r = 0.52), or other indices of lung function. Lung volume measures correlated poorly with disease extent on CT.

CONCLUSION

The percent predicted DLCO best reflects the extent of fibrosing alveolitis in FASSc, and therefore should be measured in routine evaluations. Exercise testing may also have a useful role in staging the severity of pulmonary fibrosis, but the CRP index offers no additional advantage over the DLCO and exercise testing.

Obliterative bronchiolitis: individual CT signs of small airways disease and functional correlation

PURPOSE

Individual features of small airways disease depicted at computed tomography (CT) were correlated with functional indexes in patients with obliterative bronchiolitis.

MATERIALS AND METHODS

Fifteen patients (all women) who fulfilled the strict criteria for diagnosis of obliterative bronchiolitis underwent thin-section CT at full inspiration and at end expiration. The CT scans were scored by two observers for extent of decreased attenuation of the lung parenchyma; end-expiration CT signs of air trapping; and bronchial dilation, wall thickening, and mucous plugging. The functional importance of each CT sign was evaluated.

RESULTS

Areas of decreased attenuation were present in all patients (median score at end expiration, 61%; range, 21%-83%). Bronchial wall thickening was identified in 13 of the 15 patients. Correlations of the extent of decreased attenuation and measures of air-flow obstruction were strongest between decreased attenuation at end expiration and air flow at low lung volumes (r(s) = -.70, P < .005). This relationship remained intact after correction for the severity of bronchial wall thickening.

CONCLUSION

In patients with obliterative bronchiolitis, the extent of decreased attenuation at CT was most strongly related to depression of pulmonary function tests of the small airways. Decreased attenuation is the cardinal sign for further quantitative studies of obliterative bronchiolitis.

Functional impairment in lone cryptogenic fibrosing alveolitis and fibrosing alveolitis associated with systemic sclerosis: a comparison

Lone cryptogenic fibrosing alveolitis (CFA) is histologically identical to fibrosing alveolitis associated with systemic sclerosis (FASSc), but it has a much worse prognosis after matching for disease severity at presentation. Thin-section CT scanning (CT) provides a reproducible method of quantifying the morphologic extent of fibrosing alveolitis. The aim of this study was to gain insights into contrasting pathophysiologic mechanisms in the two diseases by comparing patterns of functional impairment after matching for extent of disease on CT, demographic factors, smoking history, and concurrent treatment. Patients with emphysema on CT (n = 16) and patients with FASSc with overt pulmonary hypertension (n = 5) were excluded; 111 patients were studied (CFA, n = 54; FASSc, n = 57). Patients with CFA were distinguished by more severe functional impairment and more extensive disease on CT (40.1 versus 22.1%, p < 0.00005). On multivariate analysis, patients with CFA had greater reduction in arterial P(O2) (p < 0.0005), wider AaP(O2) (p < 0.0005), greater oxygen desaturation on maximal exercise (p < 0.03), and higher dyspnea scores (p < 0.02) than did patients with FASSc after controlling for extent of disease on CT and other covariates. Measures of lung volume and gas transfer did not differ independently between CFA and FASSc. These findings persisted in subanalyses of patients with limited disease, extensive disease, histologic confirmation of fibrosing alveolitis, and with the reinclusion of patients with emphysema and pulmonary hypertension. The patterns of functional impairment were indicative of more severe ventilation-perfusion mismatch or anatomic shunting in CFA after adjustment for disease extent; we speculate that perfusion of poorly ventilated lung parenchyma in CFA occurs through new vessels formed in areas of intense inflammation. This mechanism may contribute to the greater mortality of patients with CFA than of patients with FASSc because of the deleterious effects of hypoxia on concurrent cardiac disease.

Lone cryptogenic fibrosing alveolitis: a functional-morphologic correlation based on extent of disease on thin-section computed tomography

In most clinical series of patients with cryptogenic fibrosing alveolitis (CFA), disease severity is staged using lung function indices. However, many physiologic indices are measured in routine clinical practice; the choice of variable to evaluate functional severity is contentious. Computed tomography (CT) provides a reproducible means of quantifying the morphologic extent of disease. The aim of this study was to evaluate the functional consequences of smoking-related lung damage in CFA and to identify functional measures best reflecting the extent of fibrosing alveolitis on CT. Sixty-eight patients with CFA were studied. Fourteen patients with emphysema on CT were characterized by relative preservation of FVC and TLC (p < 0.005) and relative depression of DLCO (p < 0.05) and KCO (p < 0.00005). On multivariate analysis, the extent of fibrosing alveolitis and the presence of emphysema were independent determinants of functional impairment; there was no independent relationship between smoking history and functional abnormalities. In patients without emphysema on CT, percent predicted DLCO (r = -0.68), oxygen desaturation on exercise (r = 0.64), and the physiologic component of the clinical-radiographic-physiologic (CRP) score (r = 0.62) correlated much better with the extent of disease on CT than spirometric and plethysmographic volumes. A composite functional index was generated against the extent of disease on CT, using multivariate analysis; comparison with the CRP score suggested that the relationship between morphologic disease extent and the CRP score would be improved by the inclusion of DLCO and by the use of negative weighting for depression of FEV1. These findings indicate that in CFA, the presence of concurrent emphysema on CT has a more profound influence upon functional measures than the smoking history, and underline the importance of both the measurements of DLCO and exercise testing in the assessment of the severity of CFA.

Cryptogenic fibrosing alveolitis and the fibrosing alveolitis of systemic sclerosis: morphological differences on computed tomographic scans

BACKGROUND

The purpose of this study was to identify morphological differences on the computed tomographic (CT) scan between cryptogenic fibrosing alveolitis (CFA) and the fibrosing alveolitis associated with systemic sclerosis (FASSc), and to examine their biological relevance.

METHODS

One hundred and seven patients with CFA (n = 55) or FASSc (n = 52) who had undergone thin section CT scanning were included. Multivariate analysis was used to identify morphological differences on the CT scans between lone CFA and FASSc, and to determine whether the pattern and distribution of disease on the CT scans were functionally significant (as judged by the lung transfer factor (TLCO), forced vital capacity (FVC), and arterial oxygen tension (PaO2)) or predictive of survival (independent of the type and extent of fibrosing alveolitis, age, sex, and smoking history).

RESULTS

Increasingly extensive disease on CT scans was associated with a coarser reticular pattern (increase in reticular score per percentage increase in disease extent = 0.06, 95% confidence interval (CI) 0.03 to 0.09, p < 0.0005) and increasing upper zone involvement (increase in ratio of upper zone to total disease per percentage increase in disease extent = 0.002, 95% CI 0.000 to 0.003, p < 0.04). Patients with CFA were characterised by a higher upper zone ratio (difference = 0.08, 95% CI 0.02 to 0.13, p < 0.004) and a weak trend towards a coarser reticular pattern (p = 0.09), independent of disease extent. Smokers with CFA had more upper zone involvement (difference = 0.11, 95% CI 0.05 to 0.16, p < 0.0005) and a coarser reticular pattern (difference in reticular score = 1.92, 95% CI 0.27 to 3.55, p < 0.02) than smokers with FASSc. The extent of disease on the CT scan was predictive of lung function impairment and survival but the pattern and distribution of disease were not.

CONCLUSIONS

Patients with CFA have relatively more upper zone involvement than those with FASSc independent of the extent of disease on the CT scan. This finding may result from smoking related damage but is not functionally significant.

Effects of airway infection by Pseudomonas aeruginosa: a computed tomographic study

BACKGROUND

Pseudomonas aeruginosa commonly infects the airways of patients with bronchiectasis. A study was undertaken to examine the relationship between infection of the airways with this pathogen, the morphological pattern of bronchiectasis on thin section computed tomographic (CT) scanning, symptom duration, smoking habits of the patients, and the presence of airflow obstruction.

METHODS

Thin section CT scans of 22 adult patients with bronchiectasis and concurrent sputum infected by P aeruginosa (Pa +ve) and those of 45 randomly selected patients not infected by P aeruginosa (Pa -ve) were analysed independently by two thoracic radiologists. Patients with cystic fibrosis were excluded. Each scan was scored at a lobar level for extent of bronchiectasis, severity of bronchial wall thickening and dilatation, predominant pattern of bronchiectasis, presence of mucus plugging, and degree of decreased attenuation of the lung parenchyma.

RESULTS

The Pa +ve group had more extensive bronchiectasis and a greater degree of bronchial wall thickening and dilatation on the CT scan than the Pa -ve group; more extensive decreased attenuation was seen in the Pa +ve group. These findings were robust on multivariate analysis; decreased attenuation was also independently related to the duration of sputum production.

CONCLUSION

Patients with bronchiectasis infected by P aeruginosa have more extensive and severe bronchiectasis on thin section CT scanning than those without P aeruginosa infection. The bronchi and small airways are both involved, reflecting the end result of complex interactions between host airways and the numerous virulence factors produced by P aeruginosa.

Functional impairment in fibrosing alveolitis: relationship to reversible disease on thin section computed tomography

Thin-section computed tomography (CT) provides a reproducible method of quantifying global disease extent and can also discriminate between fibrotic disease, with predominance of reticular abnormalities, and reversible inflammatory cell infiltration, shown as ground-glass attenuation. The aim of this study was to determine whether functional impairment varied according to the presence of ground-glass attenuation on CT, independently of extent of disease on CT, demographic factors, smoking history, therapeutic status, and the type of fibrosing alveolitis (lone cryptogenic fibrosing alveolitis (CFA) versus fibrosing alveolitis associated with systemic sclerosis (FASSc)). Patients with concurrent emphysema on CT (n = 16) and FASSc patients with end-stage pulmonary hypertension (n = 5) were excluded. One hundred and eleven patients were studied (CFA, n = 54; FASSc, n = 57). The severity of functional impairment did not vary independently with the presence of predominant ground-glass attenuation, mixed appearance and predominant reticulation on CT. In 34 treated patients undergoing serial CT scanning, the severity of functional impairment did not differ independently between patients with and without regression of ground-glass attenuation at follow-up. We conclude that the severity of functional impairment does not discriminate between inflammatory and fibrotic disease in fibrosing alveolitis, as judged by initial and serial computed tomographic scanning, after adjustment for the morphological extent of disease on computed tomography.

Comparison of Doppler echocardiography and right heart catheterization to assess pulmonary hypertension in systemic sclerosis

Pulmonary hypertension (PHT) is an important complication of systemic sclerosis (SSc). Echocardiography can be used to detect PHT and, with Doppler echocardiography, the pulmonary arterial systolic pressure (PASP) can often be estimated. We have undertaken a study to compare echocardiographic assessment with right heart catheterization (RHC) in 33 SSc patients in whom clinical assessment [including ECG, chest X-ray, lung function tests and high-resolution computed tomography (HRCT) had raised strong suspicion of PHT. The mean (S.D.) interval between echocardiography and RHC was 1.8 (2.3) months. Twenty-one patients (64%) had PHT (PASP > or = 30 mmHg) on RHC, and echocardiography correctly identified 19 of these (sensitivity 90%). Of the 12 patients without PHT on RHC, nine were correctly identified by echocardiography (specificity 75%). The five incorrectly classified patients all had PASP in the borderline normal/abnormal range. The presence of tricuspid regurgitation allowed Doppler measurement of PASP in 20 patients (61%) and this correlated significantly with RHC values (r = 0.83, P < 0.001). We conclude that echocardiography is a reliable method for detecting PHT and it may be particularly useful for the early detection and monitoring of this potentially fatal complication in SSc.

Bronchiectasis: a neglected cause of respiratory morbidity and mortality

Bronchiectasis is a progressive condition characterized by irreversible destruction and dilation of airways generally associated with chronic bacterial infections. Although in Western countries, the morbidity and mortality from bronchiectasis is considered to have declined markedly in the modern era, the condition continues to cause significant morbidity and mortality in the south-west Pacific and probably also in South-East Asia. There is a high prevalence in indigenous populations in the region and factors such as poverty, substandard housing, malnutrition, barriers to medical care and inadequate education are all likely to have a major impact on prevalence and outcome of bronchiectasis. Although bronchiectasis has been viewed as a disease of medium and large airways, there is now increasing evidence of the importance of small airways disease in bronchiectasis and that it may play an integral role in pathogenesis. Chronic inflammation of the bronchial wall by mononuclear cells is common to all types of bronchiectasis. A vicious cycle of bacteria (mediated lung toxicity and bacteria) provoked, host-mediated inflammatory lung damage has been described. If progressive lung damage with its attendant morbidity and mortality is to be prevented, this vicious cycle needs to be broken. The two distinct therapeutic goals in bronchiectasis are to reduce morbidity and to prevent progression of underlying disease. It may be possible to modulate the host response directly and thus reduce tissue damage, but the precise role of immuno-modulatory therapy in bronchiectasis is still unclear. The management of this hitherto neglected disease, which reaches almost epidemic proportions in some ethnic groups and is an ongoing source of considerable morbidity and mortality, requires a comprehensive, multidisciplinary approach, which can be modelled on the successful management of chronic asthma in New Zealand.

Changes in cross-sectional area of the lungs on end expiratory computed tomography in normal individuals

With the increasing use of expiratory computed tomography (CT) for the detection of air-trapping, and specifically the diagnosis of small airways disease, information about the range of excursion of the chest wall in normal individuals is needed. CT was performed, in full inspiration and end expiration, in 78 individuals (age range 17-70 years) with no demonstrable lung disease. The area of the lungs was measured at the level of the carina, in inspiration and end expiration, and the percentage change in area was calculated. In normal subjects there is, on average, a 55% (SD 8.7%) change in cross-sectional area of the lungs at the level of the carina. Awareness of the normal change in area is of value in assessing the severity of air-trapping in patients undergoing CT for suspected obstructive lung disease.

Hypersensitivity pneumonitis: correlation of individual CT patterns with functional abnormalities

PURPOSE

To correlate the pattern and extent of abnormalities on thin-section computed tomographic (CT) scans with pulmonary function test results in subacute and chronic hypersensitivity pneumonitis.

MATERIALS AND METHODS

Thin-section scans (1-3 mm collimation) obtained in 22 patients were assessed for pattern of abnormality and extent of disease. CT scores were correlated with functional parameters by using Spearman rank correlation and forward stepwise regression analysis.

RESULTS

The most common CT patterns were decreased attenuation and mosaic perfusion (n = 19), ground-glass opacification (n = 18), small nodules (n = 12), and a reticular pattern (n = 8). Areas of decreased attenuation correlated with severity of air trapping indicated by residual volume (r = .58, P < .01), whereas ground-glass opacification and reticulation correlated independently with restrictive lung function.

CONCLUSION

Areas of decreased attenuation and mosaic perfusion are an important ancillary CT finding in hypersensitivity pneumonitis, and obstructive functional abnormalities indicate that this phenomenon is caused by bronchiolitis.

CT evaluation of fibrosing alveolitis--applications and insights

The clinical management of patients with fibrosing alveolitis has traditionally been empirical; without lung biopsy, a definitive diagnosis may be impossible and decisions about treatment are often arbitrary. With the advent of high-resolution computed tomography (CT), the proportion of patients needing lung biopsy for confirmation of the diagnosis of fibrosing alveolitis has declined. There is now much evidence that CT provides an accurate guide to disease activity, and more recent work has shown the important role of CT in providing new insights into the biologic behaviour and pathogenesis of fibrosing alveolitis.

CT findings in bronchiectasis: limited value in distinguishing between idiopathic and specific types

OBJECTIVE

The purpose of this study was to determine whether the pattern and distribution of bronchiectasis shown on CT scans can be used to discriminate between idiopathic cases and those with an identifiable cause.

MATERIALS AND METHODS

The CT scans of 168 patients with chronic purulent sputum production and who were suspected of having bronchiectasis were analyzed (117 patients with idiopathic bronchiectasis, 15 with allergic bronchopulmonary aspergillosis, 15 with hypogammaglobulinemia, 15 with impaired mucociliary clearance, and seven with cystic fibrosis diagnosed in adult life). The scans were analyzed in random order by two observers. The extent, site, type, and lobar distribution of bronchiectasis and the severity of bronchial dilatation and bronchial wall thickening were scored. The frequency of these features in the known-cause groups was compared with that in the idiopathic group to identify any significant differences.

RESULTS

Compared with idiopathic bronchiectasis, no significant lobar predominance was seen in any of the known-cause groups, apart from a higher frequency of lower lobe involvement in the patients with syndromes of impaired mucociliary clearance (p < .02). The bronchiectasis of allergic bronchopulmonary aspergillosis and adult cystic fibrosis was more often widespread (five or six lobes involved (p < .001 and p < .01, respectively) than idiopathic bronchiectasis. Central bronchiectasis was more common in allergic bronchopulmonary aspergillosis (p < .005), although the sensitivity when this was used as a diagnostic feature was only 37%. In all groups, cylindrical bronchiectasis was the most common type, with varicose and cystic bronchiectasis occurring more frequently in allergic bronchopulmonary aspergillosis (p < .01). On multiple regression analysis, allergic bronchopulmonary aspergillosis and adult cystic fibrosis showed more extensive disease than idiopathic bronchiectasis (p < .0005 and p < .001, respectively), independent of other CT features. In hypogammaglobulinemia, dilatation of the bronchial lumen was less than in idiopathic bronchiectasis (p < .02) independent of disease extent and bronchial wall thickness.

CONCLUSION

Although differences in distribution and morphology of bronchiectasis may be seen on CT scans in groups of patients with bronchiectasis of different causes, CT findings applied to individual patients are of limited value in discriminating between idiopathic bronchiectasis and bronchiectasis of various known causes.

Elevated levels of exhaled nitric oxide in bronchiectasis

Bronchiectasis is characterized by chronic inflammation in one or more bronchi, but the extent of inflammation is difficult to monitor. The concentration of nitric oxide (NO) in exhaled air is increased in asthmatic patients, possibly as a result of the chronic inflammatory process. We have measured exhaled NO in patients with documented bronchiectasis and investigated whether the concentration of exhaled NO is related to the extent of disease as defined by computed tomography (CT) and lung function. In 20 patients with bronchiectasis who were not taking inhaled steroids, the peak concentration of NO in exhaled air, measured by a modified chemiluminescence analyzer, was significantly elevated (285 +/- 49.0 ppb) as compared with values for 79 normal subjects (89 +/- 2.7 ppb, p < 0.01) and 19 patients with bronchiectasis treated with inhaled steroids (88 +/- 13.4 ppb, p < 0.01). Thin-section CT was used to quantify the extent of bronchiectasis in the 19 patients. There was a significant correlation between the CT score and FEV1 (r = 0.73, p < 0.01). In patients not treated with inhaled steroids there was a significant relationship between CT score and peak exhaled NO (r = 0.81, n = 12, p < 0.02), but this was not the case for patients treated with regular inhaled steroids (n = 7). We conclude that untreated bronchiectasis is associated with an increase in exhaled NO, and that this is correlated with disease severity, whereas patients treated with inhaled steroids have levels of exhaled NO within the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance scanning in cystic fibrosis: comparison with computed tomography

Comparison has been made between two different spin-echo sequence MR scans and CT scans of the lungs in 17 patients with cystic fibrosis. Scans were assessed for bronchial dilation, bronchial wall thickening and mucus plugging. The resolution of MR does not, at present, compare with CT. TE7 ms matched with CT for demonstrating the extent of bronchiectasis whereas TE30 ms scans were inferior to CT. Stronger background lung signal and less artefact was seen on TE7 ms scans compared with TE30 ms scans. MR is a developing technology that does not involve ionizing radiation which, with further refinement, may prove to be useful in imaging lung pathology in cystic fibrosis.

Fibrosing alveolitis in systemic sclerosis: increase in memory T-cells in lung interstitium

Despite the large numbers of T-cells present in the lungs in fibrosing alveolitis, their pathogenetic role is poorly understood. If these cells are involved in pathogenesis, they are more likely to express the CD45RO+ memory phenotype. To test this hypothesis, open lung biopsies from patients with fibrosing alveolitis associated with systemic sclerosis (FASSc) were compared with grossly normal lung taken from the periphery of lobes resected for lung cancer. Biopsies from eight patients with FASSc were compared with tissue from seven cancer controls. Paraffin sections were stained with a polyclonal anti-CD3 antibody for T-lymphocytes, monoclonal anti-CD45 antibody for leucocyte common antigen, and monoclonal anti-CD45RO antibody for primed T-lymphocytes. Staining was assessed quantitatively by computerized image analysis: in each case, the number of immunopositive cells was related to alveolar wall area and alveolar wall length. Mean alveolar wall thickness was increased in patients with FASSc (60.7 +/- 24.0 microns) compared with cancer controls (15.7 +/- 5.3 microns). Patients with FASSc had greater numbers of CD45+, CD3+ and CD45RO+ cells.mm-1 alveolar wall length compared with the controls. CD45RO+ cells made up 77% (median) of the CD3+ cells in FASSc, and their numbers per unit alveolar wall length were positively associated with alveolar wall thickness (r = 0.61). In conclusion, in fibrosing alveolitis of systemic sclerosis, most interstitial T-lymphocytes express the phenotype of memory cells; these cells are likely to be involved in the persistent inflammatory process.

Effective use of cyclosporin in sarcoidosis: a treatment strategy based on computed tomography scanning

Cyclosporin was used successfully in a patient with severe pulmonary sarcoidosis, a poor response and unacceptable side-effects from corticosteroid therapy. Computed tomography (CT) scanning initially suggested reversible disease, and subsequently detected improvement earlier than other indices of disease activity. This information was critical in the decision to commence and to continue cyclosporin. The literature on the use of cyclosporin in sarcoidosis is reviewed.

Bronchiectasis: functional significance of areas of decreased attenuation at expiratory CT

PURPOSE

To characterize areas of decreased attenuation on expiratory computed tomographic (CT) scans in patients with bronchiectasis.

MATERIALS AND METHODS

CT scans were obtained at full inspiration and end expiration in 70 patients with chronic purulent sputum production. Inspiratory scans were scored at a lobar level for the extent of bronchiectasis, and inspiratory and expiratory scans were scored for the presence and extent of areas of decreased attenuation. Total lobar observations were analyzed (n = 840).

RESULTS

Bronchiectasis was identified in 434 of 840 lobar observations. The total decreased attenuation score was related to extent of bronchiectasis (r = .49; P < .001), independent of functional indexes. Negative correlations were found between forced expiratory volume in 1 second (FEV1) and total decreased attenuation score (P < .002) and FEV1 to forced vital capacity ratio (P < .004) but not with indexes of gas transfer.

CONCLUSION

Areas of decreased attenuation on expiratory CT scans are common in severe bronchiectasis. Such areas in lobes without overt bronchiectasis suggest that small airways disease may precede the development of bronchiectasis.

Fibrosing alveolitis in systemic sclerosis. Bronchoalveolar lavage findings in relation to computed tomographic appearance

Fibrosing alveolitis in systemic sclerosis is histologically identical to lone cryptogenic fibrosing alveolitis (CFA) (idiopathic pulmonary fibrosis). The inflammatory cell content of bronchoalveolar lavage (BAL) samples has been used as a guide to prognosis and treatment in CFA. In this study, the relationship was explored between BAL findings and the extent and pattern of disease within the lavaged lobe, as judged by thin-section computed tomography (CT), in systemic sclerosis. Thirty-eight nonsmoking patients were studied; none had been treated with corticosteroids or immunosuppressive agents, and 11 had no evidence of fibrosing alveolitis on CT. BAL neutrophils were markedly increased in association with extensive disease on CT compared with less extensive disease (p < 0.001) and normal appearances (p < 0.001); the extent of a reticular pattern on CT (denoting fibrosis) correlated with the neutrophil percentage count (p < 0.005) and total neutrophil count/ml (p < 0.01). BAL eosinophils were increased in less extensive as well as in extensive disease when compared with lobes with a normal CT appearance (p < 0.01); eosinophil percentage counts but not total eosinophil counts/ml correlated with the extent of a ground-glass pattern on CT (through to denote inflammation) (p < 0.05). These findings indicate that in systemic sclerosis a BAL neutrophilia is generally associated with extensive fibrotic disease, whereas a BAL eosinophilia is often seen in less advanced disease, particularly when CT appearances suggest lung inflammation.

Fibrosing alveolitis associated with systemic sclerosis has a better prognosis than lone cryptogenic fibrosing alveolitis

Fibrosing alveolitis associated with systemic sclerosis (FASSc) is considered to be histologically and radiologically indistinguishable from lone cryptogenic fibrosing alveolitis (CFA). To date, the natural history of the two diseases has not been compared directly in large groups of patients followed at a single institution. We evaluated the survival of 205 patients with CFA and 68 patients with FASSc. Deaths during the follow-up period were reported in 142 patients with CFA (70%) and in 11 patients with FASSc (16%). Unadjusted survival from the onset of dyspnea was less in CFA than in FASSc (odds ratio, 3.3; p < 0.001); this difference persisted after adjustment for age of onset of dyspnea and smoking history. Survival from presentation was less in CFA (odds ratio approximately 3.3) after adjustment for age of presentation, smoking history, and initial pulmonary function indices. These differences persisted when analysis was confined to patients with histologic confirmation of fibrosing alveolitis and after adjustment for treatment. In patients undergoing computed tomography (CT) of the lungs, survival was less in CFA after adjustment for extent of abnormal lung on CT and CT pattern of disease (odds ratio, 3.9; p < 0.001). These findings indicate that despite their histologic and radiologic similarities, lone CFA and FASSc have different courses.

Observer variation in pattern type and extent of disease in fibrosing alveolitis on thin section computed tomography and chest radiography

In fibrosing alveolitis the pattern type on thin section computed tomography (CT) predicts histological appearances at open lung biopsy and the likelihood of response to treatment. To test the level of inter- and intra-observer variability on CT and chest radiography (CXR), the pattern type and extent of disease were assessed by four observers (two experienced, two inexperienced). A total of 126 CT examinations and 108 concurrent postero-anterior chest radiographs were scored on two occasions, at least 8 weeks apart. A confidence rating was assigned to each observation. Three out of four observers agreed on pattern type in 81% of cases on CT compared with 54% on CXR (kappa coefficient 0.48 and 0.16 for CT and CXR, respectively). Inter-observer variability in categorizing pattern type on CT was lowest in patients with the highest confidence scores (kappa = 0.63). Confident observations were associated with extensive or moderately extensive disease (P < 0.001), and with a predominantly reticular pattern (P < 0.0001). Intra-observer variability for pattern type on CT was less for the experienced observers (kappa = 0.78 and 0.70) than for the inexperienced group (kappa = 0.50 and 0.37). Inter-observer variability for extent of disease was significantly less on CT than on CXR (standard deviations 7.8% and 9.2% respectively, P < 0.001). This study shows that observer variability using a clinical grading system is lower with CT than with chest radiography in fibrosing alveolitis.

The reproducibility of bronchial circumference measurements using computed tomography

Objective measurement of bronchial damage in patients with bronchiectasis is needed to identify progressive disease. This study evaluates the inter- and intraobserver variation in computed tomography (CT) measurements of bronchial wall circumference and examines the precision with which CT measurements of the bronchi can be repeated in patients with bronchiectasis. Twelve patients were scanned and the circumferences of 61 subsegmental bronchi were measured independently on two occasions, by three observers, using a tracing facility on the CT console. To determine the accuracy with which previously acquired sections could be repeated, five patients were scanned on two separate occasions. The mean bronchial circumference measured by the three observers was 16.1 +/- 8.3 mm. The standard deviations of differences between first and second measurements of bronchial circumference for the three observers (intraobserver variability) were: 0.60 mm, 0.67 mm and 0.40 mm. The standard deviation of readings for interobserver variability was 0.71 mm. The standard deviations of differences (and coefficients of variation) for measurements of bronchial circumference following rescanning were: 1.82 mm, 1.40 mm and 1.74 mm (9.9%, 7.6% and 9.3%, respectively). The reproducibility of measurements of wall circumference, between and within observers and between examinations, indicates that such measurements may be clinically useful in demonstrating the progression of bronchiectasis.