N. Dobashi et al., Circulating cytokeratin 8 : anti-cytokeratin 8 antibody immune complexes in sera of patients with pulmonary fibrosis, RESPIRATION, 67(4), 2000, pp. 397-401
Background: It has been suggested that the humoral immune system plays a ro
le in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and pulmonary
fibrosis associated with collagen vascular disorders (PF-CVD). Although ci
rculating immune complexes in patients' sera have been suggested, none of t
he antigens have been characterized. Objectives: The purpose of this study
is to characterize the antigen of the immune complexes in patients' sera of
pulmonary fibrosis. Methods: As we previously established that one of the
antibodies against A549 cells (lung alveolar type II cells) was anticytoker
atin 8 (CK8), we confirmed the existence of anti-CK8 antibody in patients'
sera by Western immunoblot. In addition, we tried to demonstrate circulatin
g CK8:anti-CK8 immune complexes in patients' sera by Western immunoblot. Fu
rthermore, we established an enzymelinked immunosorbent assay to quantitate
CK8:anti-CK8 immune complexes. Results: In patients with pulmonary fibrosi
s, anti-CK8 antibodies were dearly demonstrated in sera by Western immunobl
ot. In addition, circulating CK8:anti-CK8 immune complexes were also clearl
y demonstrated by Western immunoblot. It was possible to establish ELISA to
quantitate CK8:anti-CK8 immune complexes. If the cutoff value, which was d
etermined based on the highest value of normal volunteers, was introduced,
high CK8:anti-CK8 antibody complexes were demonstrated in 9 of 31 patients
(29.0%) with IPF and PF-CVD. Conclusions: This is the first study to clarif
y the antigen of the circulating immune complex in sera of patients with IP
F. These results suggest that circulating CK8:anti-CK8 immune complexes may
have played a role in the process of lung injury in pulmonary fibrosis. Co
pyright(C)2000S.KargerAG,Basel.