Peripheral and pulmonary telomere lengths in patients with non-idiopathic pulmonary fibrosis interstitial lung diseases.

Introduction: Telomere and telomerase abnormalities play critical roles in interstitial lung diseases (ILDs). This study aimed to explore the telomere lengths (TL) in cells in the peripheral blood and bronchoalveolar lavage fluid (BALF) of healthy individuals and patient with various types of non-idiopathic pulmonary fibrosis (IPF)-ILD and to evaluate the correlation between TL and clinical indicators.

Methods: We enrolled 48 patients with ILDs and 21 control individuals who presented at our hospital from September 2023 to September 2024. The relative TL of genomic deoxyribonucleic acid (DNA) in peripheral blood mononuclear cells (PBMCs) and BALF macrophages were measured using quantitative polymerase chain reaction (qPCR).

Results: Patients with non-IPF-FILD had significantly shorter PBMC TL than controls (p < 0.001) and non-F-ILD patients (p < 0.001). There was a linear correlation between the TL in cells in the BALF and peripheral blood. Compared with control individuals, patients with non-F-ILD also had no significant difference in TL in cells both in the PBMC and BALF. TL was strongly associated with the presence of autoantibodies (η² = 0.275, p = 0.012) and the use of immunosuppressants (η² = 0.246, p = 0.010).

Conclusions: The PBMC TL of non-IPF-FILD patients were significantly shorter than that of control and non-F-ILD patients. However, there was no significant difference in TL in cells in the BALF and peripheral blood between non-F-ILD patients and control individuals. TL were closely correlated with the presence of autoantibodies and treatment with immunosuppressants.