Sturek, Jeffrey M

Abstract Background: Pulmonary function tests, forced expiratory volume in 1 s (FEV₁) and diffusing capacity for carbon monoxide (DLCO), are integral to pre-transplant evaluation of allogeneic hematopoietic cell transplantation (HCT) candidates because they estimate the risk of early post-HCT death and respiratory failure. Interpretation has historically relied on race-specific Global Lung Function Initiative equations from 2012 (GLI-2012). In 2021 the Initiative released race-neutral equations (GLI-Global). The influence of adopting GLI-Global on risk stratification, outcome prediction, and transplant eligibility is unknown. Methods: We retrospectively analyzed 8808 adults who underwent first allogeneic HCT at four United States centers between 1999 and 2021. FEV₁ values were converted to z-scores with both GLI-2012 and GLI-Global, whereas DLCO z-scores were calculated with GLI-2017 which is a race neutral equation. Pulmonary impairment was graded with the Lung Function Score (LFS); each component [FEV₁ and DLCO] receives 1 to 6 points based on percent predicted (> 80 % = 1, 70-79 % = 2, 60-69 % = 3, 50-59 % = 4, 40-49 % = 5, < 40 % = 6) and the sum of 2 to 12 maps to grades I (2), II (3-5), III (6-9), and IV (10-12). Primary endpoints were non-relapse mortality (NRM) at 120 days and 2 years, intensive care unit admission, and invasive mechanical ventilation. Prediction was assessed with Cox proportional hazards models and Harrell c-statistics. Results: Switching to GLI-Global reclassified 4.2 % of patients (368 of 8808) across LFS strata. Reclassification was racially asymmetric: 12.2 % of Black patients moved to higher-risk grades whereas 3.9 % of White patients moved to lower-risk grades. C-statistics for FEV₁ z-scores were nearly identical with GLI-Global versus GLI-2012: 2-year NRM 0.544 vs 0.542, 120-day NRM 0.566 vs 0.568, intensive care admission 0.545 vs 0.538, and mechanical ventilation 0.605 vs 0.605; confidence intervals overlapped for every comparison. Continuous z-score models consistently outperformed categorical cut-offs for each outcome: 2-year NRM 0.544 vs 0.518, 120-day NRM 0.566 vs 0.523, intensive care admission 0.545 vs 0.515, and mechanical ventilation 0.605 vs 0.529; confidence intervals did not overlap for every comparison. The composite LFS outperformed models that used FEV₁ or DLCO alone. Extrapolating cohort reclassification rates to 38,606 adults aged 40 to 84 who received allogeneic HCTs reported to the Center for International Blood and Marrow Transplant Research between 2009 and 2018 predicts that 1521 patients, including 509 Black adults, would shift LFS grades and could face altered transplant eligibility. Conclusions: Race-neutral GLI-Global equations modestly change pulmonary risk categorization, disproportionately raising scores for Black HCT candidates, yet maintain predictive accuracy for early mortality, respiratory failure, and intensive care use. Continuous dual-variable models and the composite LFS provide superior prediction. Although race-neutral interpretation aligns with current society guidelines, its tendency to classify Black individuals as higher risk highlights the need for refined continuous models that limit unnecessary reclassification and increased disparities in transplant eligibility.

Abstract Rationale High-attenuation area (HAA) is a computed tomography (CT) tool that correlates with lung inflammation and fibrosis. Systemic molecular correlates of HAA (e.g., plasma proteins) may inform biological processes involved in interstitial lung disease. Objectives To identify plasma proteins that associate with HAA and correlate with a higher probability of developing new-onset fibrotic or subpleural interstitial lung abnormalities (ILAs). Methods Plasma protein levels were measured using a semiquantitative aptamer-based platform in MESA (the Multi-Ethnic Study of Atherosclerosis; N = 5,486) and SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study; N = 1,781). Linear regression models identified HAA-associated proteins after adjustment for demographic and socioeconomic factors, CT scanner parameters, study center, and batch. Associations of HAA-related proteins with new-onset fibrotic or subpleural ILAs were examined in MESA participants with ILA assessments on full-lung CT 10 years later. Immunohistochemical staining of select proteins was performed in lung tissue from pulmonary fibrosis cases. Measurements and Main Results There were 75 proteins detected that were significantly associated with HAA in MESA and SPIROMICS. Gene Ontology analysis of these proteins identified processes involved in immune cell chemotaxis and cellular growth and apoptosis. Seven proteins were associated with a higher probability of new-onset fibrotic or subpleural ILAs in MESA, and two of these, junctional adhesion molecule-like protein and GTP cyclohydrolase 1 feedback regulatory protein, stained in areas of fibrosis in lung tissue from patients with interstitial lung disease. Conclusions Plasma proteins associated with more HAA are involved in immune and cellular processes and associate with new-onset fibrotic-subpleural ILA.

Abstract The long-term physiological consequences of SARS-CoV-2, termed Post-Acute Sequelae of COVID-19 (PASC), are rapidly evolving into a major public health concern. The underlying cellular and molecular etiology remain poorly defined but growing evidence links PASC to abnormal immune responses and/or poor organ recovery post-infection. Yet, the precise mechanisms driving non-resolving inflammation and impaired tissue repair in the context of PASC remain unclear. With insights from three independent clinical cohorts of PASC patients with abnormal lung function and/or viral infection-mediated pulmonary fibrosis, we established a clinically relevant mouse model of post-viral lung sequelae to investigate the pathophysiology of respiratory PASC. By employing a combination of spatial transcriptomics and imaging, we identified dysregulated proximal interactions between immune cells and epithelial progenitors unique to the fibroproliferation in respiratory PASC but not acute COVID-19 or idiopathic pulmonary fibrosis (IPF). Specifically, we found a central role for lung-resident CD8+ T cell macrophage interactions in maintaining Krt8hi transitional and ectopic Krt5+ basal cell progenitors, thus impairing alveolar regeneration and driving fibrotic sequelae after acute viral pneumonia. Mechanistically, CD8+ T cell derived IFN-γ and TNF stimulated lung macrophages to chronically release IL-1β, resulting in the abnormal accumulation of dysplastic epithelial progenitors and fibrosis. Notably, therapeutic neutralization of IFN-γ and TNF, or IL-1β after the resolution of acute infection resulted in markedly improved alveolar regeneration and restoration of pulmonary function. Together, our findings implicate a dysregulated immune-epithelial progenitor niche in driving respiratory PASC. Moreover, in contrast to other approaches requiring early intervention, we highlight therapeutic strategies to rescue fibrotic disease in the aftermath of respiratory viral infections, addressing the current unmet need in the clinical management of PASC and post-viral disease.

The relationship between diabetes and coronavirus disease 2019 (COVID-19) is bidirectional: Although individuals with diabetes and high blood glucose (hyperglycemia) are predisposed to severe COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can also cause hyperglycemia and exacerbate underlying metabolic syndrome. Therefore, interventions capable of breaking the network of SARS-CoV-2 infection, hyperglycemia, and hyperinflammation, all factors that drive COVID-19 pathophysiology, are urgently needed. Here, we show that genetic ablation or pharmacological inhibition of mitochondrial pyruvate carrier (MPC) attenuates severe disease after influenza or SARS-CoV-2 pneumonia. MPC inhibition using a second-generation insulin sensitizer, MSDC-0602K (MSDC), dampened pulmonary inflammation and promoted lung recovery while concurrently reducing blood glucose levels and hyperlipidemia after viral pneumonia in obese mice. Mechanistically, MPC inhibition enhanced mitochondrial fitness and destabilized hypoxia-inducible factor–1α, leading to dampened virus-induced inflammatory responses in both murine and human lung macrophages. We further showed that MSDC enhanced responses to nirmatrelvir (the antiviral component of Paxlovid) to provide high levels of protection against severe host disease development after SARS-CoV-2 infection and suppressed cellular inflammation in human COVID-19 lung autopsies, demonstrating its translational potential for treating severe COVID-19. Collectively, we uncover a metabolic pathway that simultaneously modulates pulmonary inflammation, tissue recovery, and host metabolic health, presenting a synergistic therapeutic strategy to treat severe COVID-19, particularly in patients with underlying metabolic disease.