mRNA expression of YY1, TNF-α a TGF-β in lung samples gained by transbronchial biopsies (TBB) in patients with different interstitial lung diseases (ILDs)

Abstract

Background: Fibrotic types of ILDs, e.g. idiopathic pulmonary fibrosis (IPF) are associated with grim prognosis. Lung fibrosis results from proliferation of fibroblasts in response to cytokines such as TGF-β and TNF-α. It has been shown that TGF-β and TNF-α induce YY1 expression in lung fibroblasts. These were upregulated in lung sections from humans with IPF and also in fibrotic murine models.

Aim of the study: To study the clinical potential of these findings in differential diagnosis between different types of ILDs, as well as in staging and prognosis prediction.

Methods: 53 patients with different ILDs(table) underwent bronchoscopy with TBB. Gene expression of YY1, TNF-α and TGF-β from TBBs were measured. Lung function testing was performed. CT scans at the time of diagnosis were scored using Gay S. procedure. Groups (defined by diagnosis) were compared, relation between HRCT score, function parameters and mRNA expression were estimated.

Results: There was no statistically significant difference in mRNA expression between diagnosis. We did not find any correlation between expressions and various clinical parameters. We did not prove association between bad prognosis and expression profiles.

Conclusion: Expression of TGF-β, TNF-α and YY1 in TBB did not prove to be good markers for severity of the disease, differential diagnostic tool between different ILDs or progression predictor. This is most probably due to relatively small samples gained by TBB in the context of non homogeneous nature of these proceses.