Lung transplant recipients with telomere-mediated pulmonary fibrosis have increased risk for hematologic complications.

Idiopathic pulmonary fibrosis lung transplant recipients (IPF-LTRs) are enriched for short telomere length (TL) and telomere gene rare variants. A subset of non-transplant short-TL patients are at increased risk for bone marrow (BM) dysfunction. We hypothesized that IPF-LTRs with short-TL and/or rare variants would be at increased risk for post-transplant hematologic complications. Data were extracted from a retrospective cohort of 72 IPF-LTRs and 72 age-matched non-IPF-LTR controls. Genetic assessment was done using whole genome sequencing or targeted sequence panel. TL was measured using flow cytometry and fluorescence in-situ hybridization (FlowFISH) and TelSeq software. The majority of the IPF-LTR cohort had short-TL and 26% IPF-LTRs had rare variants. Compared to non-IPF controls, short-TL IPF-LTRs were more likely to have immunosuppression agents discontinued due to cytopenias (p=0.0375), and BM dysfunction requiring BM biopsy was more prevalent (29% vs 4%, p=0.0003). IPF-LTRs with short-TL and rare variants had increased requirements for transfusion and growth factor support. Multivariable logistic regression demonstrated short-TL, rare variants and lower pre-transplant platelet counts were associated with BM dysfunction. Pre-transplant TL measurement and genetic testing for telomere gene rare variants identified IPF-LTRs at increased risk for hematologic complications. Our findings, support stratification for telomere-mediated pulmonary fibrosis in lung transplant candidates.