Coexisting lung cancer and pulmonary tuberculosis (LC-PTB) is clinically challenging in diagnosis and treatment, and its mechanisms are unclear.

A study published in the journal iMetaMed aimed to explore its immune and molecular basis to identify diagnostic biomarkers.

We prospectively enroled LC patients, LC-PTB patients, and controls.

Lymphocyte subsets were analysed by flow cytometry.

Key markers were identified through blood transcriptome sequencing and bioinformatics (differential expression, GSEA, GO/KEGG), and validated by RT-qPCR and immunohistochemistry.

Analysis included 138 subjects (50 controls, 50 LC, 38 LC-PTB).

Compared to LC alone, LC-PTB demonstrated significantly increased CD4⁺ T cells (p = 0.0064) and NK cells (p = 0.0447), with an elevated CD4/CD8 ratio.

Transcriptome analysis identified 144 upregulated and 435 downregulated genes in LC-PTB versus controls, and 216 upregulated and 388 downregulated genes versus LC alone (|Fold Change| ≥ 2, p < 0.05).

Enrichment analysis revealed involvement of antigen presentation, oxidative phosphorylation, and nitrogen metabolism.

Six key genes (ANK2, EPB42, CA1, HBB, HBD, MYL4) were identified.

A four-gene model (CA1, HBD, MYL4, ANK2) discriminated LC-PTB from LC (AUC 0.940, 95% CI 0.846–1.000).

We provide the first immune-transcriptomic map of LC-PTB and a validated four-gene diagnostic signature ready for external evaluation.

Source: FAR Publishing Limited