Analysis of iron status after initiation of elexacaftor/tezacaftor/ivacaftor in people with cystic fibrosis.

BACKGROUND: Iron deficiency is highly prevalent in people with cystic fibrosis (PwCF). While elexacaftor/tezacaftor/ivacaftor (ETI) has shown remarkable improvements in respiratory symptoms in PwCF, the effect of ETI on iron status remains unknown. This study aims to identify the effect of ETI on iron status in PwCF. METHODS: A single-center retrospective cohort study of 127 adult PwCF was conducted to assess the impact of ETI on iron, ferritin, transferrin levels, and percent saturation of transferrin (PSAT). Data were collected from the electronic medical record from January 2017 to September 2022, encompassing 2 years before and after ETI initiation. The primary outcome was serum iron parameters: iron, ferritin, transferrin, and PSAT levels following ETI treatment. Secondary outcomes analyzed iron supplementation. Univariate and multivariate mixed-effects models were used for the analysis of ETI. RESULTS: After adjusting for covariates, following ETI initiation, the mean iron level increased by 20.24 µg/dL (p < .001), ferritin levels were 31.4% (p < .001) higher, PSAT showed a 5.09 percentage point increase (p < .001), and transferrin levels increased by 2.71 mg/dL (p = .439). Patients with and without iron supplementation experienced a significant increase in iron after ETI (p < .001). CONCLUSIONS: ETI is associated with a significant increase in iron, ferritin, and PSAT levels. Patients with and without iron supplementation demonstrated a significant increase in iron. This study shows the benefits of ETI on iron status in PwCF. However, further translational studies are required to understand the impact of ETI on iron absorption and metabolism in PwCF.

Real world study on elexacaftor-tezacaftor-ivacaftor impact on cholesterol levels in adults with cystic fibrosis.

INTRODUCTION: The introduction of the highly effective modulator therapy elexacaftor-tezacaftor-ivacaftor (ETI) has revolutionized the care of persons with cystic fibrosis (PwCF) with major improvements seen in lung function and body mass index. The effects of ETI therapy in real-world cohorts on other parameters such as cholesterol levels are largely unknown. METHODS: A single-center, retrospective chart review study was conducted to assess the change in lipid panels before and after ETI initiation. The study investigated total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels using both a univariate and multivariate mixed-effects model to evaluate the change after initiation of ETI in a cohort of PwCF. RESULTS: There were 128 adult PwCF included in the analysis. Statistically significant changes were seen in both univariate and multivariate analyses for TC, LDL-C, and HDL-C. On multivariate analysis, TC increased by an average of 15.0 mg/dL after ETI initiation (p < 0.0001), LDL-C increased by an average of 9.3 mg/dL (p < 0.001), and HDL-C increased by an average of 3.8 mg/dL (p < 0.001) after ETI initiation. CONCLUSION: In this real-world cohort of PwCF, cholesterol parameters increased after initiation with ETI therapy. Further consideration may need to be given for PwCF in regards to screening for cardiometabolic risk factors as PwCF age as well as the potential need for cholesterol-lowering therapies.

Central lung gene expression associates with myofibroblast features in idiopathic pulmonary fibrosis.

RATIONALE: Contribution of central lung tissues to pathogenesis of idiopathic pulmonary fibrosis (IPF) remains unknown. OBJECTIVE: To ascertain the relationship between cell types of IPF-central and IPF-peripheral lung explants using RNA sequencing (RNA-seq) transcriptome. METHODS: Biopsies of paired IPF-central and IPF-peripheral along with non-IPF lungs were selected by reviewing H&E data. Criteria for differentially expressed genes (DEG) were set at false discovery rate <5% and fold change >2. Computational cell composition deconvolution was performed. Signature scores were computed for each cell type. FINDINGS: Comparison of central IPF versus non-IPF identified 1723 DEG (1522 upregulated and 201 downregulated). Sixty-two per cent (938/1522) of the mutually upregulated genes in central IPF genes were also upregulated in peripheral IPF versus non-IPF. Moreover, 85 IPF central-associated genes (CAG) were upregulated in central IPF versus both peripheral IPF and central non-IPF. IPF single-cell RNA-seq analysis revealed the highest CAG signature score in myofibroblasts and significantly correlated with a previously published activated fibroblasts signature (r=0.88, p=1.6×10-4). CAG signature scores were significantly higher in IPF than in non-IPF myofibroblasts (p=0.013). Network analysis of central-IPF genes identified a module significantly correlated with the deconvoluted proportion of myofibroblasts in central IPF and anti-correlated with inflammation foci trait in peripheral IPF. The module genes were over-represented in idiopathic pulmonary fibrosis signalling pathways. INTERPRETATION: Gene expression in central IPF lung regions demonstrates active myofibroblast features that contributes to disease progression. Further elucidation of pathological transcriptomic state of cells in the central regions of the IPF lung that are relatively spared from morphological rearrangements may provide insights into molecular changes in the IPF progression.

Blood Transcriptomics Predicts Progression of Pulmonary Fibrosis and Associated Natural Killer Cells.

Rationale: Disease activity in idiopathic pulmonary fibrosis (IPF) remains highly variable, poorly understood, and difficult to predict. Objectives: To identify a predictor using short-term longitudinal changes in gene expression that forecasts future FVC decline and to characterize involved pathways and cell types. Methods: Seventy-four patients from COMET (Correlating Outcomes with Biochemical Markers to Estimate Time-Progression in IPF) cohort were dichotomized as progressors (≥10% FVC decline) or stable. Blood gene-expression changes within individuals were calculated between baseline and 4 months and regressed with future FVC status, allowing determination of expression variations, sample size, and statistical power. Pathway analyses were conducted to predict downstream effects and identify new targets. An FVC predictor for progression was constructed in COMET and validated using independent cohorts. Peripheral blood mononuclear single-cell RNA-sequencing data from healthy control subjects were used as references to characterize cell type compositions from bulk peripheral blood mononuclear RNA-sequencing data that were associated with FVC decline. Measurements and Main Results: The longitudinal model reduced gene-expression variations within stable and progressor groups, resulting in increased statistical power when compared with a cross-sectional model. The FVC predictor for progression anticipated patients with future FVC decline with 78% sensitivity and 86% specificity across independent IPF cohorts. Pattern recognition receptor pathways and mTOR pathways were downregulated and upregulated, respectively. Cellular deconvolution using single-cell RNA-sequencing data identified natural killer cells as significantly correlated with progression. Conclusions: Serial transcriptomic change predicts future FVC decline. An analysis of cell types involved in the progressor signature supports the novel involvement of natural killer cells in IPF progression.

Genetics of Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is the most common form of interstitial lung disease. IPF is a complex disease, with environmental and genetic factors variably contributing to disease susceptibility and outcomes. A host of common gene variants with modest effect size impart disease risk in patients with sporadic IPF, while rare variants with large effect size influence disease risk in those with familial interstitial pneumonia. In this review, we highlight several common and rare variants underpinning IPF risk and call attention to recently published studies informing our understanding of this risk.