Am. J. Respir. Cell Mol. Biol., Vol 10, No. 1, 01 1994, 100-105.
Cryptogenic organizing pneumonia: increased expression of interleukin-8 and fibronectin genes by alveolar macrophages
PC Carre, TE King Jr, R Mortensen and DW Riches
Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206.
Cryptogenic organizing pneumonia (COP) is a fibrotic process that primarily
involves the alveolar spaces, alveolar ducts, and small conducting airways.
The pathogenesis is not understood. Recent histopathologic studies have
shown that during the cellular phase of COP, fibronectin deposits are
present in the lung. Moreover, a neutrophil alveolitis is frequently seen
in COP. Little is known about the involvement of alveolar macrophages in
the pathogenesis of COP. However, alveolar macrophages are the principal
resident cells in the airways, and they are thought to play a central role
in the fibrotic process by virtue of their ability to express and release
cytokines such as interleukin-8 (IL-8; a neutrophil chemotactic factor) and
fibronectin (FN; a fibrogenic matrix-associated protein). We have
quantified the spontaneous gene expression of IL-8 and FN by alveolar
macrophages from five nonsmoking individuals with COP and compared them
with 10 normal, healthy volunteers (five smokers, five nonsmokers).
Expression of IL-8 and FN was measured by a quantitative assay employing
reverse transcription of mRNA and the polymerase chain reaction. beta-actin
mRNA expression was quantified as an internal standard, and the expression
of FN and IL-8 transcripts was calculated as a ratio with beta-actin. The
mean +/- SEM of the IL-8/beta-actin ratio in alveolar macrophages from
patients with COP was 0.45 +/- 0.07, which was significantly higher than
the level from either normal smokers (0.19 +/- 0.02, P = 0.008) or normal
nonsmokers (0.16 +/- 0.01, P = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
