Interleukin-4-producing cells in idiopathic pulmonary fibrosis: an immunohistochemical study.
OBJECTIVE
Interleukin-4 stimulates collagen synthesis in fibroblasts in vitro. The purpose of this study was to clarify the role of interleukin-4 in the pathogenesis of idiopathic pulmonary fibrosis.


METHODS
We compared interleukin-4 expressing cells in tissues from 11 patients with pathologically confirmed idiopathic pulmonary fibrosis with early stage inflammatory lesions versus advanced lesions. We also performed double staining in order to elucidate which inflammatory cells produce interleukin-4 in idiopathic pulmonary fibrosis.


RESULTS
Greater numbers of interleukin-4 positive cells were observed in the advanced lesions than in the early lesions. We also found that early stage lesions showed a predominance of CD3/interleukin-4 double positive cells whereas, the advanced stage lesions had higher percentages of the EG2/interleukin-4 double positive cells and the tryptase/interleukin-4 double positive cells.


CONCLUSIONS
Our results suggest that interleukin-4 may be involved in progression of interstitial fibrosis in idiopathic pulmonary fibrosis, in which we confirmed a significant contribution of eosinophils and mast cells to interleukin-4 production.
Ando
M
M
Third Department of Internal Medicine, Oita Medical University, Japan.
Miyazaki
E
E
Fukami
T
T
Kumamoto
T
T
Tsuda
T
T
D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015847:Interleukin-4 / Q000096:biosynthesis*; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000378:metabolism* / Q000473:pathology; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
D015847:Interleukin-4