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Idiopathic pulmonary fibrosis (IPF) is a disease of unknown aetiology. Increased oxidant burden and antioxidant, e.g. glutathione (GSH), deficiency in the lower respiratory tract have been thought to play a role in the progression of IPF. Sputum induction is a safe noninvasive tool to study inflammation in the respiratory tract. The aim of the present study was to evaluate the direct measurement of GSH in induced sputum supernatant. Sixteen IPF patients and 15 healthy, nonsmoking subjects underwent sputum induction. Total GSH in sputum, saliva and plasma was measured spectrophotometrically. Sputum GSH was decreased more then four-fold in IPF patients when compared to healthy subjects (mean GSH 1.4+/-0.34 microM versus 5.8+/-0.98 microM). Salivary GSH was generally low or undetectable in all subjects. Plasma GSH levels were lower in IPF patients (0.26+/-0.1 versus 0.74+/-0.16 microM). In IPF patients, there was a borderline correlation of sputum GSH levels with disease duration and lung-function impairment. These data confirm the established role of oxidant/antioxidant imbalance in the pathogenesis of idiopathic pulmonary fibrosis, and show the potential of induced sputum to directly study inflammatory processes and surrogate markers in interstitial lung diseases like idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) has a high mortality rate, and current therapies are only marginally effective. A serum biomarker that predicts clinical outcome would be useful to stage disease, indicate prognosis and the need for aggressive therapy, and help stratify patients for clinical trials. The goals of this study were to determine whether serum levels of surfactant protein-A (SP-A) or surfactant protein-D (SP-D) would distinguish between IPF and other types of interstitial lung disease and whether serum SP-A or SP-D levels predict outcome in patients with IPF. The authors found that serum SP-A and SP-D levels were significantly elevated in patients with IPF and systemic sclerosis compared to sarcoidosis, beryllium disease and normal controls, and that SP-D correlated with radiographic abnormalities in patients with IPF. In addition, the authors found that both serum SP-A and SP-D levels were highly predictive of survival in patients with IPF. This is the largest North American data set of surfactant protein measurements in idiopathic pulmonary fibrosis and the first report using multivariate analysis comparing serum surfactant proteins-A and -D to other commonly measured predictors of survival in idiopathic pulmonary fibrosis. Based on these results, the authors propose that serum surfactant proteins may prove to be useful biomarkers in patients with idiopathic pulmonary fibrosis.

It was hypothesized that neutrophil elastase released from activated neutrophils may play an important role in the pathogenesis of pulmonary fibrosis. In the present study, we measured the neutrophil elastase:alpha-1-proteinase inhibitor complex (E-PI) in serum and bronchoalveolar lavage fluid (BALF) in 26 patients with pulmonary fibrosis and evaluated the correlation between E-PI levels and several parameters. E-PI levels in serum of patients with pulmonary fibrosis (635.8+/-112.0 ng.mL(-1)) were significantly elevated compared to normal nonsmokers (122.0+/-4.0 ng.mL(-1)) as well as normal smokers (132.8+/-8.4 ng.mL(-1)) (p<0.01). E-PI levels in serum significantly correlated with hepatocyte growth factor (HGF) levels in serum, C-reactive protein (CRP), and negatively correlated with arterial oxygen tension (Pa,O2), and arterial carbon dioxide tension (Pa,CO2). E-PI/albumin levels in BALF significantly correlated with HGF/albumin levels in BALF, lactate dehydrogenase (LDH)/albumin in BALF, total number of inflammatory cells (alveolar macrophages and neutrophils) in BALF, and several markers derived from epithelial cells in BALF. Our data demonstrated: 1) neutrophil elastase:alpha-1-proteinase inhibitor complex in serum increased in patients with pulmonary fibrosis; and 2) neutrophil elastase:alpha-1-proteinase inhibitor complex in serum and bronchoalveolar lavage fluid correlated with clinical parameters in pulmonary fibrosis. These results suggest that neutrophil elastase may play a significant role in the process of lung injury in pulmonary fibrosis.

Cryptogenic fibrosing alveolitis (CFA) is an interstitial lung disease, which by definition is of unknown aetiology. Recent evidence has suggested that smoking and occupational exposure to dusts may be environmental risk factors for the disease, but there has been little research into potential host risk factors. One previous study has suggested that the prevalence of abnormal alpha1-antitrypsin phenotypes may be increased in patients with CFA. Since alpha1-antitrypsin is important in regulating inflammation within the lung in response to environmental exposures, such abnormalities may be of aetiological importance in this disease. We have compared the alpha1-antitrypsin phenotypes of 189 patients with CFA with 189 age-, sex-, and community-matched controls. This sample size was sufficient to provide more than 95% power to detect an odds ratio (OR) of 2.5. Alpha1-antitrypsin phenotype was established by isoelectric focusing, and the prevalence of abnormal phenotypes in cases and controls was compared by conditional logistic regression. Personal smoking histories were obtained by postal questionnaire. The prevalence of abnormal alpha1-antitrypsin phenotypes was similar in cases and controls (12.7 versus 15.3%; OR 0.88; 95% confidence interval 0.49-1.57; p=0.66). No interaction was found between the presence of abnormal alpha1-antitrypsin phenotypes and a history of smoking. We conclude that cryptogenic fibrosing alveolitis is not associated with abnormal alpha1-antitrypsin phenotypes.

Despite extensive research, the role of the commonly employed tumour markers in the diagnosis of lung carcinoma is yet to be clarified. The utility of a new marker, CYFRA 21-1, in the preoperative evaluation of patients with bronchogenic carcinoma was investigated. CYFRA 21-1 was determined with a radiometric assay in serum of 280 patients with lung cancer and 208 patients with various nonmalignant lung diseases. The levels of the marker were significantly higher in lung cancer patients. Among benign lung diseases, elevated CYFRA 21-1 levels were found in pulmonary fibrosis. Using a cut-off of 3.2 ng.ml-1 (95th percentile of levels obtained in benign lung disease), the total sensitivity of the marker was 48%. The best sensitivity was obtained in squamous cell lung cancer (60%). The highest values of CYFRA 21-1 were found in metastatic lung cancer, and the marker sensitivity was more elevated in stage IIIb and IV. On the other hand, 40% of patients with surgically resectable lung cancer had CYFRA 21-1 levels above the cut-off. We conclude that CYFRA 21-1 may be satisfactorily employed in the differential diagnosis between malignant and benign lung diseases in association with other clinical and radiological data.

A three month old female infant presented with unproductive cough, diffuse bilateral fine crackles, tachypnoea and failure to thrive despite a four month therapy with beta 2-agonists and antibiotics. A chest radiograph showing bilateral periphilar infiltrates and a patchy infiltrate in the right upper lobe and lingula did not explain the physical examination with diffuse bilateral fine crackles. As the condition did not improve and arterial oxygen tension (PaO2) and oxygen saturation decreased during the following two months, an open lung biopsy was performed. The surgeon described the lungs as rubbery in consistency and histological findings showed patchy mild interstitial fibrosis and thickened alveolar septa. A therapy with prednisone daily was started and given over a period of four months, but did not show sufficient improvement. Only after addition of azathioprine was clinical improvement and normalization of blood gases noted.