Rm du Bois

Marginal decline in forced vital capacity is associated with a poor outcome in idiopathic pulmonary fibrosis

In therapeutic studies in idiopathic pulmonary fibrosis (IPF), the low prevalence of significant change in pulmonary functional tests (PFTs) has been a major constraint. The prognostic value of “marginal” changes in PFTs in IPF and fibrotic non-specific interstitial pneumonia (NSIP) was evaluated. In patients with biopsy-proven IPF (n = 84) and NSIP (n = 72), forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DL,CO) trends at 6 months were categorised as “significant” (FVC >10%; DL,CO >15%) or “marginal” (FVC 5–10%; DL,CO 7.5–15%). Proportional hazards analysis and time-dependent receiver operating characteristic methodology were used to examine PFT trends against mortality. In IPF, reductions in FVC were significant in 22 cases (26%) and marginal in 19 cases (23%). Mortality was higher in patients with a significant decline in FVC (hazard ratio (HR) 2.80, 95% CI 1.54–5.06; p<0.001) and those with a marginal decline in FVC (HR 2.31, 95% CI 1.19–4.50; p = 0.01) than in those with stable disease. Progression-free survival was lower when the decline in FVC was marginal than in stable disease (HR 2.34, 95% CI 1.19–4.60; p = 0.01). Marginal changes in DL,CO in IPF and marginal changes in FVC and DL,CO in fibrotic NSIP did not provide useful prognostic information. Marginal change in FVC in IPF denotes a poor outcome. These findings are applicable to clinical practice and to the selection of patients with more progressive disease for therapeutic studies.

BAL findings in idiopathic nonspecific interstitial pneumonia and usual interstitial pneumonia.

Idiopathic pulmonary fibrosis (IPF), which has the histological pattern of usual interstitial pneumonia (UIP), is a progressive interstitial lung disease with a poor prognosis. Idiopathic interstitial pneumonias with a histological pattern of nonspecific interstitial pneumonia (NSIP) have a better prognosis than UIP, and may present with a clinical picture identical to IPF. The authors hypothesised that bronchoalveolar lavage (BAL) findings may distinguish between UIP and NSIP, and have prognostic value within disease subgroups. BAL findings were studied retrospectively in 54 patients with histologically proven (surgical biopsy) idiopathic UIP (n=35) or fibrotic NSIP (n=19), all presenting clinically as IPF. These findings were also compared with the BAL profile of patients with other categories of idiopathic interstitial pneumonias. BAL total and differential cell counts did not differ between the two groups. Survival was better in NSIP. In neither group were BAL findings predictive of survival or changes in lung function at 1 yr, even after adjustment for disease severity, smoking andtreatment. BAL differential counts in fibrotic NSIP differed from respiratory bronchiolitis-associated interstitial lung disease, but not from desquamative interstitial pneumonia or cellular NSIP. The authors conclude that bronchoalveolar lavage findings do not discriminate between usual interstitial pneumonia and nonspecific interstitial pneumonia in patients presenting with clinical features of idiopathic pulmonary fibrosis, and have no prognostic value, once the distinction between the two has been made histologically.

Class II HLA associations with autoantibodies in scleroderma: a highly significant role for HLA-DP

Scleroderma is a condition of variable phenotype characterised by fibrosis of the skin and internal organs. There is a range of disease-specific autoantibodies found in the sera of patients. The aims of this study were to: (1) investigate the role of the MHC and particularly HLA-DP in the production of autoantibodies; (2) investigate clinical associations with autoantibodies. We have performed HLA class II typing using PCR with sequence-specific primers on DNA samples from 202 scleroderma patients and 307 UK control subjects. All patients had well defined clinical phenotypes. Sera from patients were examined for the presence of disease specific autoantibodies in particular the anti-topoisomerase autoantibody (ATA), the anti-centromere autoantibody (ACA) and the anti-RNA polymerase autoantibody (ARA). There was a striking association between HLA-DPB1*1301 and ATA (Pcorr = 0.0001). In addition, ATA was associated with HLA-DRB1*11 and the anticentromere autoantibody (ACA) with HLA-DRB1*04, HLA-DRB1*08 (P = 0.001) and HLA-DQB1 alleles with a glycine residue at position 26. Very strong associations were detected between clinical phenotypes and autoantibodies. ATA was associated with pulmonary fibrosis (P = 0.00002), anti-RNA polymerase autoantibody (ARA) with renal involvement (P = 0.0000006) and diffuse skin disease (P = 0.00001), and ACA with limited skin involvement (P = 0.00002) and protection against pulmonary fibrosis (P = 0.0000003). We have identified a significant association between the ATA and HLA-DPB1*1301 which may provide an insight into how this autoantibody is formed. Patient clinical characteristics depend on the autoantibodies they carry.

Diverse cellular TGF-beta(1) and TGF-beta(3) gene expression in normal human and murine lung

A role for transforming growth factor-beta 1, (TGF-beta 1) has been proposed in lung development and in the pathogenesis of pulmonary disease. However, previous studies have not delineated the cells expressing TGF-beta 1 in normal adult lung, nor compared its gene expression with that of other TGF-beta isoforms. We used digoxigenin-labelled riboprobes to localize TGF-beta 1 and TGF-beta 3 gene expression in normal adult human and mouse lung. This procedure was technically simple, providing excellent resolution. TGF-beta 1 and TGF-beta 3 messenger ribonucleic acid (mRNA) transcripts were detected in a wide variety of cells. In human lung, mRNA for both isoforms was localized to bronchiolar epithelium and alveolar macrophages. TGF-beta 1, but not TGF-beta 3 mRNA was detected in mesenchymal and endothelial cells. In murine tissue, TGF-beta 1, mRNA was localized to bronchiolar epithelium, Clara cells, mesenchymal cells, pulmonary endothelium and alveolar cells, including macrophages. TGF-beta 3 mRNA was similarly distributed but not detected in endothelium. In summary, using a nonisotopic technique in lung tissue, we have detailed the cells expressing the transforming growth factor-beta 1 and beta 3 genes in human and murine lung. There was widespread expression of these cytokines in normal lung consistent with autocrine or paracrine roles in regulating cellular turnover, immune defence and matrix protein metabolism.

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.

Multiplex immune serum biomarker profiling in sarcoidosis and systemic sclerosis

Multiplex protein technology has the potential to identify biomarkers for the differentiation, classification and improved understanding of the pathogenesis of interstitial lung disease. The aim of this study was to determine whether a 30-inflammatory biomarker panel could discriminate between healthy controls, sarcoidosis and systemic sclerosis (SSc) patients independently of other clinical indicators. We also evaluated whether a panel of biomarkers could differentiate between the presence or absence of lung fibrosis in SSc patients. We measured 30 circulating biomarkers in 20 SSc patients, 21 sarcoidosis patients and 20 healthy controls using Luminex bead technology and used Fisher’s discriminant function analysis to establish the groups of classification mediators. There were significant differences in median concentration measurements between study groups for 20 of the mediators but with considerable range overlap between the groups, limiting group differentiation by single analyte measurements. However, a 17-analyte biomarker model correctly classified 90% of study individuals to their respective group and another 14-biomarker panel correctly identified the presence of lung fibrosis in SSc patients. These findings, if they are corroborated by independent studies in other centres, have potential for clinical application and may generate novel insights into the modulation of immune profiles during disease evolution.

Inhibitor kappa B-alpha (IκB-α) promoter polymorphisms in UK and Dutch sarcoidosis

The aetiology of sarcoidosis is uncertain; current thinking implicates exposure of genetically susceptible hosts to environmental factors. The nuclear factor kappa B (NF-κB) family of transcription factors are critical regulators of immediate transcriptional responses in inflammatory situations and immune responses. Inhibitor kappa B-alpha (IκB-α) inhibits NF-κB and plays a major role in controlling its activity. We investigated IκB-α promoter polymorphisms using sequence-specific primer-polymerase chain reaction, at positions −881 (A/G), −826 (C/T), and −297 (C/T) in Caucasian sarcoidosis patients (UK and Dutch [NL]), each with their own controls. Disease severity at presentation was assigned using chest radiography and pulmonary function indices. In the combined populations, the −297T allele carriage was more prevalent in patients than in controls (P=0.008). Three common haplotypes were found, of which haplotype 2 (GTT) was significantly associated with sarcoidosis in comparison with control subjects (P=0.01). Subgroup analysis revealed that the −826T allelic carriage was most prevalent in stage II disease, and more prevalent in stage III than in stage IV (P=0.01). The −826T allelic carriage did not show any association with lung function. These results indicate that the NF-κB activation pathway might be associated with the inflammation of sarcoidosis.

HLA-DPB POLYMORPHISMS: Glu 69 ASSOCIATION WITH SARCOIDOSIS

Sarcoidosis is a chronic granulomatous disorder, which is characterized by the accumulation of activated CD4+ T lymphocytes (T cells) at disease sites. There is up‐regulation of cell surface expression of MHC molecules in sarcoidosis, and it has been suggested that specific MHC class II alleles are associated with the disease. A study of chronic beryllium disease (CBD), a granulomatous disorder which is pathologically similar to sarcoidosis, has identified an association between this disease and the presence of a glutamine residue at position 69 (Glu 69+) of the B1 chain of the HLA‐DPB molecule. A further study also suggested the importance of Glu at position 55 of the same chain. The aims of the present study were to attempt to define MHC class II alleles associated with sarcoidosis by comparison of their frequency in two groups of subjects and to compare the frequency of HLA‐DPB1 Glu 69+/– and Glu 55+/– alleles in the same subjects. Forty‐one subjects with sarcoidosis and 76 normal subjects were studied. The polymorphic regions of the class II MHC were identified by PCR in association with sequence‐specific oligonucleotide probes. There were no significant differences in the phenotype frequencies of MHC class II or Glu 55+ alleles between the two groups of subjects. However, there was a significant increase (P = 0.02) in the frequency of HLA‐DPB1* Glu 69+ alleles compared with the control population. We therefore suggest that the presence of a Glu residue at position 69 on the DPB1 chain may play an important role in antigen presentation and recognition in chronic granulomatous diseases.

CC and C chemokine expression in pulmonary sarcoidosis

The chemokines RANTES (regulated on activation, T-cell expressed and secreted; CC chemokine ligand (CCL)-5) and monocyte inflammatory protein (MIP)-1α (CCL-3) have been implicated in the development of alveolitis in pulmonary sarcoidosis. The novel C chemokine single cysteine motif (SCM)-1α (XCL-1) and the CC chemokine monocyte chemoattractant protein (MCP)-1 (CCL-2) are also mononuclear-cell attractants and represent alternative candidate mediators of alveolitis. Therefore, the expression of MCP-1 and SCM-1α was investigated together with the expression of RANTES and MIP-1α in bronchoalveolar lavage fluid (BALF) from control subjects and patients with sarcoidosis. The relationship between chemokine expression and sarcoidosis clinical course was also explored. Messenger ribonucleic acid (mRNA) expression for all four chemokines was determined by semiquantitative reverse transcriptase-polymerase chain reaction of RNA extracted from unseparated bronchoalveolar cells (17 patients, 12 controls). RANTES, MIP-1α and MCP-1 proteins were measured by enzyme-linked immunosobent assay of unconcentrated BALF (60 patients, 17 controls). MCP-1, and namely RANTES and SCM-1α mRNA expression was upregulated in sarcoidosis, particularly in patients with more advanced disease. RANTES, and namely MCP-1 concentrations were elevated in BALF samples obtained from patients; MCP-1 levels were most increased in patients with chest radiographic stage 2 disease and also in patients with persistent and recurrent disease. In conclusion, chemokines monocyte chemotactive protein-1 and single cysteine motif-1α are, in addition to RANTES, associated with the development of alveolitis in sarcoidosis and their expression parallels the disease course.

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.