High-resolution CT and pulmonary function tests in collagen vascular disease: comparison with idiopathic pulmonary fibrosis

Comparison of clinical courses and mortality of connective tissue disease-associated interstitial pneumonias and chronic fibrosing idiopathic interstitial pneumonias

Interstitial lung disease (ILD) is a common pulmonary manifestation of connective tissue diseases (CTD). Prognostic effect of radiological usual interstitial pneumonia (UIP) pattern in CTD-associated interstitial lung disease (CTD-ILD) is unknown. This study aimed to investigate the disease progression and mortality of patients with CTD-ILD and idiopathic interstitial pneumonias (IIP) including idiopathic pulmonary fibrosis (IPF) and idiopathic nonspecific interstitial pneumonia and the prognostic impact of the radiological UIP pattern on both disease groups. The medical records of 91 patients (55 with CTD-ILD and 36 with IIP) diagnosed with ILD at pulmonary medicine department, Faculty of Medicine, Gazi University from 2004 to 2014 were retrospectively reviewed. Patients included whose baseline high-resolution computed tomography (HRCT) scans showed either a UIP or non-UIP pattern. While 67.3% (n = 37) of CTD-ILD patients possessed UIP pattern, 38.9% (n = 14) of IIP patients had UIP pattern in HRCT. Respiratory functions including the forced expiratory volume in the first second (FEV₁ ), functional vital capacity (FVC), and transfer coefficient for carbon monoxide (diffusing capacity of the lung for carbon monoxide [DLCO]) of IIP group at the time of diagnosis were significantly lower than CTD-ILD group (P = .007, P = .002, and P = .019, respectively). There was no significant survival difference between CTD-ILD and IIP by using the log-rank test (P = .76). Multivariate analysis revealed that UIP pattern in HRCT (Hazard ratio: 1.85; 95% Confidence interval = 1.14-3; P = .013), annual FVC (Hazard ratio: 0.521; 95% Confidence interval = 0.32-0.84; P = .007), and annual DLCO declines (Hazard ratio: 0.943; 95% Confidence interval = 0.897-0.991; P = .02) were independent risk factors for mortality in both CTD-ILD and IIP groups. We found that UIP pattern in HRCT and annual losses in respiratory functions were the main determinants of prognosis of ILDs either idiopathic or CTD-associated.

Lower-lobe shrinkage relative to total lung volume in collagen vascular diseases

PURPOSE

It has been reported that the prognosis differs between patients who have collagen vascular diseaseassociated interstitial pneumonia (CVD-IP) and those with idiopathic IP (IIP). In this study, chest computed tomography (CT) findings were compared between patients with CVD-IP and IIP.

MATERIALS AND METHODS

A retrospective analysis was performed of 47 consecutive patients (23 with CVD-IP and 24 with IIP). The lower-lobe volume (LLV), total lung volume (TLV), and their ratio (LLV/TLV) were determined by volumetry using three-dimensional computed tomography (CT).

RESULTS

There was no significant difference of the LLV/TLV ratio between the CVD-IP and IIP groups. However, the LLV/TLV ratio was <0.33 in 9/23 patients with CVD-IP versus 2/24 patients with IIP, and there was a significant difference in the percentage of patients with a ratio<0.33 between the CVD-IP and IIP groups (p = 0.01). The LLV/TLV ratio was not influenced by the severity of lung disease.

CONCLUSIONS

Measuring the LLV/TLV ratio by threedimensional CT can help distinguish between CVD-IP and IIP at initial diagnosis, especially in patients with CVD-IP who have pulmonary involvement before other organ diseases and symptoms caused by CVD.

Lung disease related to collagen vascular disease

Collagen vascular disease is one of the most common causes of chronic infiltrative lung disease. Patterns of lung injury from collagen vascular disease include nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia, organizing pneumonia, bronchiectasis, obliterative bronchiolitis, and pulmonary arterial hypertension. The prevalence of each entity varies according to the specific disease entity. NSIP and pulmonary hypertension are common in scleroderma, whereas usual interstitial pneumonia, bronchiectasis, and obliterative bronchiolitis are commonly found in rheumatoid arthritis. In systemic lupus erythematosus, pleural effusions and pulmonary hemorrhage are the salient features. In polymyositis, a combination of organizing pneumonia and NSIP is characteristic. Sjögren syndrome is characterized by bronchiectasis and lymphoid interstitial pneumonia, often associated with thin-walled cysts. Ankylosing spondylitis is associated with upper lobe fibrosis, and may be complicated by mycetoma.

Comparison of disease progression and mortality of connective tissue disease-related interstitial lung disease and idiopathic interstitial pneumonia

OBJECTIVE

To compare disease progression and mortality between idiopathic interstitial pneumonia (IIP) and interstitial lung disease (ILD) due to connective tissue diseases (CTD) including scleroderma, rheumatoid arthritis, systemic lupus, polymyositis, dermatomyositis, Sjögren's syndrome, and mixed CTD.

METHODS

A case-control study of patients with CTD-ILD (n = 46) and IIP controls (n = 51), seen at the University of Michigan between July 1,1998 and June 30,1999 and followed until March 30, 2002, was conducted. Survival analysis and Cox regression were performed to estimate survival, accounting for demographic and clinical parameters, including pulmonary function tests and high resolution computed tomography (HRCT) diagnosis and scoring.

RESULTS

Median followup time was 4.4 person-years. Five-year survival in the IIP group was 51.9% (95% confidence interval [95% CI] 30.8-69.4) versus 43.4% (95% CI 21.1-63.9) in the CTD-ILD group. There were no significant differences among HRCT diagnostic categories between IIP and CTD-ILD. A fibrotic score > or = 2 was associated with decreased survival among the entire group. Age at diagnosis and most recent forced vital capacity were significant predictors of mortality when adjusted for IIP versus CTD-ILD diagnosis, sex, and interstitial score.

CONCLUSION

Contrary to expectation, CTD-ILD compared with IIP appears to be associated with a worse prognosis when adjusted for age. A higher fibrotic score is suggestive of decreased survival.

CT features of lung disease in patients with systemic sclerosis: comparison with idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia

PURPOSE

To evaluate computed tomographic (CT) patterns of lung disease in patients with systemic sclerosis (SSc) and compare them with CT appearance in patients with biopsy-proved idiopathic pulmonary fibrosis (IPF) and idiopathic nonspecific interstitial pneumonia (NSIP).

MATERIALS AND METHODS

The CT features of consecutive patients with SSc (n = 225; male patients, 44; female patients, 181; median age, 47 years; age range, 16-78 years), IPF (n = 40; men, 26; women, 14; median age, 54.5 years; age range, 36-77 years) and NSIP (n = 27; men, 18; women, nine; median age, 53 years; age range, 32-68 years) were quantified separately by two observers. The extent of interstitial lung disease, ground-glass opacification, emphysema, and the coarseness of a reticular pattern were quantified. Group comparisons were made nonparametrically with the Wilcoxon rank sum test. Differences in CT features were identified with multiple logistic regression analysis.

RESULTS

The coarseness of fibrosis was similar in patients with SSc and idiopathic NSIP but strikingly different between patients with SSc (median coarseness score, 5.5; range, 0.0-13.3) and IPF (median coarseness score, 8.8; range, 2.5-15.0) (P <.001). The proportion of ground-glass opacification at CT was similar in patients with SSc and idiopathic NSIP but differed significantly between patients with SSc (median proportion, 49.9%; range, 0.0%-100.0%) and IPF (median proportion, 23.5%; range, 0.0%-97.2%) (P <.001). At logistic regression analysis, there were no differences in the CT features between patients with SSc and those with NSIP after controlling for age, disease extent, and the percentage predicted forced vital capacity and carbon monoxide diffusing capacity.

CONCLUSION

Interstitial lung disease in patients with SSc is less extensive, less coarse, and characterized by a greater proportion of ground-glass opacification than that in patients with IPF. The CT features of lung disease in patients with SSc closely resemble those in patients with idiopathic NSIP.

High-resolution CT of idiopathic interstitial pneumonias

Important recent changes have occurred in our understanding of the IIPs. IPF (characterized histologically as UIP) is recognized as a progressive disease with a relatively poor prognosis, and with a characteristic CT appearance. The radiologist must be able to distinguish between UIP and the other IIPs. Complications of IPF include accelerated progression, lung cancer, and secondary infection. NSIP has a better prognosis than IPF, and has ground-glass attenuation as its salient CT feature. COP (formerly known as BOOP) is included as an IIP because its clinical, physiologic, and imaging features overlap with those of the other IIPs. It is characterized on CT by consolidation and ground-glass attenuation. AIP is the idiopathic form of ARDS. LIP and DIP are less common IIPs, both characterized by ground-glass attenuation.

Interstitial pneumonia in progressive systemic sclerosis: serial high-resolution CT findings with functional correlation

PURPOSE

The aim of our study was to assess the serial high-resolution CT findings and their correlation with the results of pulmonary function tests in patients with progressive systemic sclerosis (PSS) and interstitial pneumonia.

METHOD

The study included 40 patients with symptoms or signs of PSS and interstitial pneumonia, who underwent serial high-resolution CT scans (mean follow-up period 39 months). Seventeen patients simultaneously had serial pulmonary function tests (mean follow-up period 40 months). On high-resolution CT, the pattern and extent of parenchymal abnormalities were retrospectively analyzed. Serial changes on high-resolution CT were correlated with the changes of pulmonary function tests.

RESULTS

On initial CT, areas of ground-glass opacity (mean +/- SD extent 17.7 +/- 12.3% in all patients), irregular linear opacity (4.4 +/- 4.4% in 36 patients), small nodules (3.9 +/- 12.5% in 28), consolidation (1.9 +/- 4.2% in 13), and honeycombing (1.9 +/- 3.8% in 12) were seen. The total disease extent (p = 0.042) and extents of ground-glass opacity (18.9 +/- 15.5%; p = 0.04) and honeycombing (5.0 +/- 7.2%; p = 0.002) increased significantly on follow-up CT. Both forced vital capacity (from 2.4 +/- 0.4 to 2.0 +/- 0.4 L; p = 0.002) and forced expiratory volume in 1 s (from 2.0 +/- 0.4 to 1.6 +/- 0.3 L; p = 0.013) decreased significantly on follow-up examination. The increase in the extent of honeycombing on CT correlated significantly with the decrease in diffusing capacity for carbon monoxide (r = -0.411, p = 0.049).

CONCLUSION

In patients with PSS and interstitial pneumonia, the overall extent of disease and extents of honeycombing and ground-glass opacity increase significantly on follow-up CT. Increase of honeycombing correlates well with decrease of diffusing capacity for carbon monoxide.

High-resolution computed tomography in the evaluation of fibrosing alveolitis

High-resolution computed tomography (HRCT) is now widely used in the investigation of patients with suspected or known diffuse lung disease. This article reviews some of the technical aspects of HRCT and the pathologic considerations that should be appreciated in the context of diagnosing fibrosing alveolitis. The precise quantitation of disease extent and characterization of disease pattern on HRCT has been used to provide new insights about the prognosis and pathophysiology of fibrosing lung disease.

Clinical, laboratory and radiological findings in pulmonary fibrosis with and without connective tissue disease

Uncertainty exists over whether to consider "lone" idiopathic pulmonary fibrosis (LIPF) and pulmonary fibrosis associated with connective tissue disorders (PFCTD) as significantly different entities. We retrospectively analysed data collected at the time of first diagnosis in 17 patients with LIPF and in 14 patients with PFCTD and compared survival in the two groups. At first evaluation, the time from onset of respiratory symptoms, spirometric volumes and the diffusing capacity for carbon monoxide were not significantly different between the two groups. However, arterial oxygen tension was significantly lower in LIPF than in PFCTD (63 +/- 3 vs 88 +/- 3 mmHg, p < 0.001). The radiological profusion scores relative to the upper and middle lung fields were significantly higher in LIPF than in PFCTD (upper regions: 6.9 +/- 0.6 vs 3.4 +/- 0.6, p < 0.005 - middle regions: 7.1 +/- 0.5 vs 4.8 +/- 0.7, p < 0.025), whereas the scores relative to the lower fields were similar (7.4 +/- 0.4 in LIPF and 8.4 +/- 0.6 in PFCTD). Survival since onset of respiratory symptoms was significantly better in the PFCTD than in LIPF patients, with a hazard ratio of 4.16 (95% CI 1.12-15.58, p=0.034). Thus, in our series of patients, those with LIPF had a more severe disease than those with PFCTD as shown by the higher frequency of hypoxaemia, the more diffuse pulmonary involvement demonstrated by the chest X-ray and the decreased survival.