Transforming growth factor-β1 as a biomarker in COPD patients with pulmonary fibrosis

Abstract Background: TGF-β1 has been reported to be associated with COPD and pulmonary fibrosis, however, there is a lack of research on TGF-β1 in COPD patients with pulmonary fibrosis. In our study, we studied the influence of TGF-β1 and its single nucleotide polymorphism (SNP) on COPD and COPD complicated with pulmonary fibrosis. Methods: In this research, six GEO datasets were included to screen dysregulated genes in COPD patients. The dysregulated genes were detected by PCR-DNA sequencing based on 98 COPD patients and 90 healthy volunteers. Results: Five genes were upregulated in COPD patients. However, only TGF-β1 highly expressed in 1-4 stage of COPD versus 0 stage. Moreover, allele C of TGF-β1 +869 locus was associated with the susceptibility of COPD. The predicted value of FEV1% (FEV1, Forced Expiratory Volume in One Second) in patients with CC of +869 locus was significantly lower than that in patients with TT (P < 0.05). The genotype frequencies of CC, CT and TT were 6.5%, 58.7% and 34.8% in Mild-to-Moderate airflow restriction patients, however, they were 23.1%, 57.7% and 19.2% in severe airflow restriction patients. The distribution of CC genotype in severe airflow restriction COPD patients was significantly higher than that in Mild-to-Moderate airflow restriction COPD patients (P = 0.037). Further, the frequency of C allele was higher in patients with severe airflow restriction than that patients with Mild-to-Moderate airflow restriction (P = 0.024). Overall, TGF-β1 upregulated in COPD patients and its SNP at +869 is closely related to the susceptibility and airflow restriction of COPD patients.Conclusion: This study provides the basis for early prevention, targeted intervention and gene targeted therapy of COPD susceptible population.