Figure 2.

(A) Venn graph showed the overlap of differentially expressed lncRNAs between different groups. Yellow: upregulated lncRNAs in AECOPD vs control; purple: upregulated lncRNAs in AECOPD vs stable COPD; green: upregulated lncRNAs in stable COPD vs control; red: downregulated lncRNAs in stable COPD vs control. (B) Validation of the selected lncRNAs in CD4⁺ T cells in the AECOPD group compared with the stable COPD group and control by qRT-PCR. The relative expression levels of NR-026690 and ENST00000447867 are shown. **P<0.01, ***P<0.001. (C) ROC curve of lncRNAs. The diagnostic values of NR-026690 and ENST00000447867 are shown.

Abbreviations: LncRNA, long noncoding RNA; AECOPD, acute exacerbation of COPD; qRT-PCR, quantitative real-time reverse transcription-polymerase chain reaction; ROC, receiver operating characteristic.