alpha 1-antitrypsin (alpha 1-A.T.) phenotypes were determined in 55 patients with rheumatoid arthritis (R.A.), 33 patients with R.A. and either obstructive airways disease or recurrent chest infections, 49 patients with fibrosing alveolitis (F.A.), 22 patients with R.A. and F.A., and 200 healthy controls.
YKL-40, a chitinase-like protein mainly secreted by macrophages, neutrophils and epithelial cells, is increased in patients with idiopathic interstitial pneumonia and sarcoidosis.
Fibrosing alveolitis (FA) is characterized by persistent inflammation and elevated production of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1beta), and interleukin-1 receptor antagonist (IL-1ra) in the lung.