Type 3 procollagen peptide in bronchoalveolar lavage fluid. Poor indicator of course and prognosis in sarcoidosis

Type III and type I procollagen markers in fibrosing alveolitis

Deposition of types I and III collagen is a typical feature in the development of pulmonary fibrosis. We assessed the propeptides of these procollagens as prognostic markers in 18 patients with fibrosing alveolitis. We analyzed the amino-terminal propeptide of type III procollagen (PIIINP) and the carboxy-terminal propeptide of type I procollagen (PICP) from samples of bronchoalveolar lavage fluid (BALF) and serum, and also estimated their concentrations in epithelial lining fluid (ELF) by the urea method. The level of PIIINP in serum (p < 0.05), BALF (p < 0.05), and ELF (p < 0.05), and the levels of PICP in BALF (p < 0.001) and ELF (p < 0.001) but not in serum, were significantly increased in the patients with fibrosing alveolitis as compared with 17 controls who had been investigated for minor respiratory symptoms. In the BALF and ELF of patients with fibrosing alveolitis, PICP but not PIIINP had significant negative correlations with the specific diffusion coefficient for carbon monoxide (DLCO/ VA). The amino-terminal propeptide of type III procollagen and the carboxy-terminal propeptide of type I procollagen in BALF correlated significantly with one another. During the follow-up period of 6 yr, seven of the 18 patients with fibrosing alveolitis died of the disease, 3 others died of malignancy, and one patient died from an unknown cause. DLCO (p < 0.05) differed significantly between the surviving patients and those who died of fibrosing alveolitis, and detectable PIIINP in BALF predicted death from fibrosing alveolitis (p = 0.05). In conclusion, these results show that PIIINP in BALF, ELF, and serum, and PICP in BALF and ELF, are increased in patients with fibrosing alveolitis. A high level of PICP in BALF, and especially in ELF, suggests a chronic process and increased synthesis of type I collagen in the lungs, whereas PIIINP in BALF and ELF suggests active disease and a poor prognosis.

Biochemical changes in sarcoidosis

Biochemical markers in sarcoidosis are closely related to the immunological events and the activity of inflammatory effector cells at sites of granuloma formation. The markers can be measured in serum, then reflecting whole body concentration, or in BAL fluid, then indicating activity in the lung. Only calcium and ACE serum levels have gained a proven value in the clinical field.

Transient increases in albumin and hyaluronan in bronchoalveolar lavage fluid after quitting smoking: possible signs of reparative mechanisms

Inhalation of tobacco smoke results in an accumulation of cells in the lower respiratory tract. The inflammatory response in the alveoli and lung interstitium may also be reflected by increased bronchoalveolar lavage (BAL) fluid concentrations of extracellular matrix components. The present study investigated the influence of smoking on the BAL fluid concentrations of albumin (ALB), hyaluronan (HA) and fibronectin (FN). Lavage fluids from 18 smokers were analysed before and at 1, 3, 6, 9 and 15 months after smoking cessation. Never-smokers (n = 112) served as a reference group. The total cell concentration and the concentrations of macrophages, lymphocytes, neutrophils and eosinophils were higher (P < 0.001-0.01) in smokers' BAL fluid than in never-smokers', but the values returned to normal within 9 months of smoking cessation. The HA concentration was higher (P < 0.001) in smokers' than in never-smokers' BAL fluid, but FN and ALB did not differ. Transient increases in the concentrations of ALB and HA (P < 0.01 for both) was observed within 6 months of smoking cessation. These findings indicate a temporary heightened alveolar-capillary permeability and an increased production and/or degradation of HA, being enhanced following smoking cessation. The findings probably reflect an initiation of a reparative process.

Hyaluronan and procollagen type III aminoterminal peptide in serum and bronchoalveolar lavage fluid from patients with pulmonary fibrosis

Previous studies of the collagen synthesis markers hyaluronan (hyaluronic acid) (HA) and procollagen type III aminoterminal peptide (PIIINP) in pulmonary fibrosis have reported elevated levels in bronchoalveolar lavage fluid (BALF) and suggested an association with disease activity. The objective of the present study was to evaluate whether HA and PIIINP in BALF and serum (S) correlated with paraclinical markers of disease activity (chest X-ray profusion score, pulmonary function tests (FEV1, FVC, TLC, DLCO)) in patients with pulmonary fibrosis. The material comprised 27 patients with biopsy-proven pulmonary fibrosis (12 cryptogenic and 15 due to connective tissue diseases) and 24 control subjects with normal lung function. BAL was performed in the right middle lobe with 250 ml saline. HA and PIIINP were measured in the cell-free BALF supernatant and in serum. Patients had higher BALF-HA (mean 86 +/- 17 (SEM) micrograms/l) than controls (39 +/- 2 micrograms/l (p < 0.01)), higher BALF-albumin (124 +/- 24 mg/l) than controls (58 +/- 4 mg/l (p < 0.01)) and higher BALF/S-HA ratio (2.4 +/- 0.6) than controls (1.2 +/- 0.6 (p < 0.05)). There were no significant differences respecting BALF-PIIINP, S-HA, or S-PIIINP. Patients (n = 14) with progressive disease had higher BALF-HA, higher BALF-albumin, higher S-PIIINP, and higher S-immunoglobulins than those with stable disease, but the differences did not reach statistical significance. Smokers (n = 18) had lower BALF-HA, lower S-HA, lower S-PIIINP, lower S-immunoglobulins, and higher lung function tests than non-smokers, but the differences did not reach statistical significance. In patients, significantly positive correlations were found between BALF-HA and BALF-albumin, between BALF-PIIINP and BALF-albumin, and a significantly negative correlation between S-PIIINP and TLC. None of the BALF or serum markers correlated with chest X-ray profusion score or any of the other lung function measurements. It is concluded that disease activity may be associated with elevated HA and PIIINP levels. Smoking may influence the immunological processes in pulmonary fibrosis and may be a confounder in studies of these patients.

Fibroblast chemotactic response elicited by native bronchoalveolar lavage fluid from patients with fibrosing alveolitis

BACKGROUND

In fibrosing alveolitis activation of lung fibroblasts is the decisive event in the pathogenetic sequence leading to pulmonary fibrosis. Fibroblast stimulating activity was measured in bronchoalveolar lavage (BAL) fluid to assess its relationship to the activity of fibrosing alveolitis.

METHODS

Nine control subjects and 40 patients with fibrosing alveolitis caused by idiopathic pulmonary fibrosis (n = 22) or pulmonary involvement in systemic sclerosis (n = 18) were studied. All patients were followed up by lung function testing for a minimum of six months (mean (SE) 13.3 (1.4) months). Twenty five patients received immunosuppressive therapy and 15 refused. At the beginning of follow up BAL was performed and, as a possible indicator of fibroblast stimulating mediators within the lungs, chemotactic migration of cultured human fibroblasts elicited by native BAL fluid was measured in Boyden-type chambers and expressed as a percentage of the chemoattractant effect of 25 ng/ml platelet derived growth factor. The procollagen III peptide level in BAL fluid served as a marker for collagen synthesis.

RESULTS

Chemoattractant activity was elevated in the patients with idiopathic pulmonary fibrosis and systemic sclerosis compared with the control group, (mean (SE) 56.4% (8.5%)) and 72.3% (16.3%) v 12.6% (4.0%). Chemoattractant activity was inversely correlated with total lung capacity (TLC) (r = -0.45) and with vital capacity (VC) (r = -0.33). Procollagen III peptide concentrations in BAL fluid and chemoattractant activity were not significantly correlated. For further evaluation chemoattractant activity of 36% (mean value of controls +2 SD) was used to separate normal (< 36%) from elevated (> or = 36%) activity. At the end of follow up, untreated patients with high chemoattractant activity (> or = 36%) showed a significant reduction of VC, TLC, and exercise arterial oxygen tension (PaO2) and a small decrease in carbon monoxide transfer factor (TLCO), whereas a significant improvement in VC, TLC, and TLCO and a small increase of exercise PaO2 occurred in treated patients with high chemoattractant activity. Patients with low chemoattractant activity (< 36%) showed no consistent change in lung function measurements, irrespective of treatment. In contrast, lung function results and differential cell counts in BAL fluid failed to identify progressive disease.

CONCLUSIONS

In patients with fibrosing alveolitis the chemoattractant activity of BAL fluid seems to be an independent indicator of lung fibroblast stimulating activity providing relevant information about disease activity, and may help to improve the clinical management of these patients.

Study of functional and biochemical indicators of subclinical lung damage in bleomycin-treated patients

In 30 patients affected by testicular non-seminomatous cancer we evaluated pulmonary function tests before and after bleomycin-including combination chemotherapy. We paid particular attention to changes in diffusing lung capacity (DCO) and its two components, namely diffusing capacity of the alveolar-capillary membrane (Dm) and pulmonary capillary blood volume (Vc). In the same patients we also evaluated the behaviour of serum procollagen III aminopeptide (sP-III-P), assumed to be a biochemical equivalent to Dm, and of serum angiotensin converting enzyme (S-ACE), assumed to be a biochemical equivalent to Vc. We found that, after chemotherapy, patients showed a significant decline in several pulmonary function parameters, namely VC, TLC, and FEV1 (P < 0.0001, P = 0.0351, P = 0.0004, respectively), when compared to pre-treatment values. DCO was significantly impaired after chemotherapy (P < 0.0001), but with regard to its components, Vc values showed a significant decline (P = 0.0002), whereas Dm values were unchanged. Values of sP-III-P raised significantly after chemotherapy (P = 0.003), whereas S-ACE activity did not show any significant variation. When we looked at relationships between functional and biochemical parameter variations, the only significant correlation we found was between DCO and S-ACE (r2 = 0.112; P < 0.02). We conclude that in asymptomatic patients treated by bleomycin-including combination chemotherapy, DCO impairment is likely to occur because of a subclinical injury to pulmonary vessels, as suggested by Vc decline. Although the occurrence of pulmonary interstitial fibrosis after chemotherapy was excluded by chest X-ray examination and by stable values of Dm, sP-III-P elevation would suggest an accelerated type III collagen turnover in interstitial fibroblasts activated by bleomycin.

Hyaluronic acid (hyaluronan) in BAL fluid distinguishes farmers with allergic alveolitis from farmers with asymptomatic alveolitis

Pulmonary function measurements, bronchoalveolar lavage (BAL), and analyses of precipitating antibodies in blood were performed in 12 farmers wtih no symptoms from the airways and 12 farmers who were admitted to the hospital due to acute symptoms of alveolitis (all nonsmokers). In addition, a bronchial methacholine provocation test was performed in the asymptomatic farmers. In 11 of the 12 symptomatic farmers but in none of the asymptomatic farmers, precipitating antibodies against one or more of the microorganisms which usually occur in a farmer's environment were found. In the farmers with symptomatic alveolitis, a restrictive impairment of pulmonary function was found, while pulmonary function was normal in all asymptomatic farmers. Findings in the BAL fluid showed increased concentrations of total cells, lymphocytes, and neutrophils and elevated levels of albumin, fibronectin, and angiotensin-converting enzyme in asymptomatic farmers compared with our own reference group. The same analyses in BAL fluid from the symptomatic farmers revealed a further increase in all parameters compared with the asymptomatic farmers. The BAL fluid from asymptomatic farmers had normal levels of hyaluronic acid (hyaluronan) and procollagen 3 N-terminal peptide, while these levels were significantly increased in the symptomatic group. We conclude that inflammation in the alveolar space and signs of activation of alveolar macrophages are present in farmers regardless of respiratory symptoms, although these findings are more pronounced in the presence of symptoms of acute alveolitis; however, the findings of impaired pulmonary function and the occurrence of precipitins and elevated levels of hyaluronic acid and procollagen 3 N-terminal peptide in BAL fluid were exclusively found in the farmers with airways symptoms. We postulate the hyaluronic acid, due to its pronounced ability to immobilize water, may be of importance in the development of the pulmonary function impairment observed in farmer's lung disease.

Elevated serum procollagen III aminopeptide levels in sarcoidosis

Procollagen III aminopeptide (P-III-P), a peptide released during the conversion of type III procollagen to type III collagen, is considered a potential marker of fibroblast activity in a variety of pulmonary and extrapulmonary diseases. The aim of the present article was to investigate the levels of P-III-P in serum samples (sP-III-P) from a large number of sarcoid patients, in particular looking at its relationship with other markers of disease activity and its presumed role as a marker of pulmonary fibrosis. sP-III-P has been radioimmunoassayed in an overall series of 57 patients and the levels were higher (19.18 +/- 9.17 ng/ml) than in 25 age- and sex-matched controls (11.32 +/- 2.15 ng/ml; p less than 0.001). The elevation was neither sex-related nor related to obvious liver sarcoid localization. Although sP-III-P levels were slightly higher in patients with stage II, there was no significant difference in patients with stage I or III. We found a positive relationship with serum angiotensin-converting enzyme (S-ACE) levels (p less than 0.04), but not with other markers of disease activity (67Ga uptake, bronchoalveolar lavage [BAL] lymphocyte percent, vital capacity, and lung diffusing capacity). The relationship with S-ACE was confirmed in a longitudinal follow-up study, where sP-III-P strictly paralleled the S-ACE behavior. Finally, the initial sP-III-P levels did not predict cases either with disease relapse or resistance to corticosteroid treatment. We conclude that, in our study, sP-III-P levels failed to characterize sarcoid patients with radiologic fibrotic pattern (stage III), and, in addition, were unable to predict which patients would have a poor prognosis. Rather, they reflect a metabolic activity of sarcoid granuloma cells. Thus, the usefulness of sP-III-P in the treatment of patients with sarcoid may be considered similar to that of S-ACE.

Bronchoalveolar lavage in patients with mild and severe rheumatoid lung disease

The reported prevalence of interstitial lung disease in patients with rheumatoid arthritis has varied from 10% to 50%, yet less than 5% of patients with arthritis develop severe fibrosing interstitial lung disease. This suggests that subclinical disease may not always presage progressive disease. Bronchoalveolar lavage fluid from patients with rheumatoid arthritis and either clinically evident interstitial lung disease or subclinical disease was examined for the presence of factors with a putative role in the development of interstitial fibrosis. Patients with subclinical disease were identified by prospective radiographic and lung function screening of 93 patients with rheumatoid arthritis. Fourteen patients were identified in this manner and an association between subclinical disease and smoking history was noted. Eleven patients with established interstitial lung disease had increased neutrophils (p less than 0.05), collagenase, and type III procollagen N terminal peptide levels (p less than 0.01) in the bronchoalveolar lavage fluid. Preliminary characterisation of the bronchoalveolar lavage collagenase suggested that it originated from neutrophils. Ten patients with subclinical interstitial lung disease underwent bronchoalveolar lavage. Of these, one had increased neutrophils and two had increased collagenase concentrations--abnormalities associated with advanced interstitial lung disease and a poor prognosis. These results suggest that in arthritis patients with evidence of subclinical pulmonary interstitial disease bronchoalveolar lavage might be useful in identifying those who may require careful monitoring in the hope that early treatment will prevent severe fibrosis.