Fibrosing alveolitis may occur alone (CFA) or in association with systemic sclerosis (FASSc). FASSc was recently shown to have a prognostic advantage over CFA. Because interleukin-8 (IL-8) is likely to be a major determinant of neutrophil alveolitis, we evaluated IL-8 expression in patients with CFA and FASSc and compared it with that in normal individuals and sarcoidosis and systemic sclerosis patients without pulmonary involvement (SSc no FA). IL-8 protein in bronchoalveolar lavage fluid (BALF) was assessed by immunoassay, and IL-8 mRNA expression was assessed using Northern analysis and reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization of lung parenchyma. Compared with normal subjects, IL-8 concentration was significantly greater in both CFA (p < 0.001) and FASSc groups (p < 0.05) but no different in sarcoidosis. The IL-8 concentration in CFA was higher than in FASSc (p < 0.01) and was related to BAL % neutrophils (rs = 0.48, p < 0.01). IL-8 mRNA expression evaluated by Northern analysis was seen only in patients with CFA and FASSc and was related to BAL % neutrophils (rs = 0.63, p < 0.01). We suggest that IL-8 is a key factor in the pathogenesis of fibrosing alveolitis and that the poorer prognosis of CFA compared with FASSc is related to higher levels of IL-8 within the lower respiratory tract.

Different cytokine profiles in cryptogenic fibrosing alveolitis and fibrosing alveolitis associated with systemic sclerosis: a quantitative study of open lung biopsies. S. Majumdar, D. Li, T. Ansari, P. Pantelidis, C.M. Black, M. Gizycki, R.M. du Bois, P.K. Jeffery. ERS Journals Ltd 1999. ABSTRACT: Differences in the inflammatory response and prognosis of cryptogenic fibrosing alveolitis (CFA) and that associated with systemic sclerosis (FASSc) are beginning to emerge. It is hypothesized that these differences may be reflected in a distinct pattern of T-helper (Th)-1 and Th-2-type cytokines.Open lung biopsies were obtained from clinically well-documented cases of CFA and FASSc and, as a control, compared with grossly and histologically normal parenchyma obtained from smokers whose lungs were resected for cancer (n=5 in each group). In situ hybridization (ISH) was applied to the samples using anti-sense and sense Between 52±91% of cells expressing the cytokines studied were present in the alveolar interstitium rather than in lumenal cells or the alveolar epithelial lining. The highest values for all four cytokines were present in the patients with FASSc, i.e., 22± 39 ISH positive cells . mm -2 alveolar tissue compared with 1±19 cells . mm -2 and 4±5 cells . mm -2 in CFA and control subjects, respectively. Whereas the proportions of the four cytokines in FASSc were similar to the control subjects, IL-4 and IL-5 predominated significantly in CFA (p<0.001). For example, the ratio of IL-5 to IFN-c was 22:1 in CFA, significantly higher than in the cases with FASSc (2:1) or the control subjects (4:1) (p<0.05).In conclusion, cryptogenic fibrosing alveolitis is an inflammatory condition which is characterized, like asthma, by a predominance of gene expression for T-helper-2-type regulatory cytokines, whereas cryptogenic fibrosing alveolitis associated with systemic sclerosis appears to have a distinct mixed T-helper-1/T-helper-2 functional phenotype and a greater number of cells expressing each of these pro-inflammatory cytokines.