American journal of respiratory and critical care medicine最新文献

Rationale: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease for which current treatment options only slow clinical progression. Previously, we identified a subset of patients with IPF with an accelerated disease course associated with fibroblast expression of Toll-Like Receptor 9 (TLR9) mediated by interactions with its ligand mitochondrial DNA (mtDNA).

Objectives: We aimed to show that TLR9 activation induces fibroproliferative responses that are abrogated by its antagonism by using two commercially-available indirect inhibitors and a proprietary, selective direct small molecule inhibitor.

Methods: We employed two independent cohorts of patients with IPF, multiple in vitro fibroblast cell culture platforms, an in vivo mouse model, and an ex vivo human precision cut lung slices system to investigate the clinical and biologic significance of TLR9 in this disease.

Measurements and main results: In two independent IPF cohorts, plasma mtDNA activates TLR9 in a manner associated with the expression of MCP-1, IL-6, TNFα, and IP-10 and worsened transplant-free survival. Our cell culture platform showed that TLR9 mediates fibroblast activation via TGFβ1 and stiff substrates, and that its antagonism, particularly direct inhibition, ameliorates this process, including production of these TLR9 associated pharmacodynamic endpoints. We further demonstrated that direct TLR9 inhibition mitigates these fibroproliferative responses in our in vivo and ex vivo models of pulmonary fibrosis.

Conclusions: In this novel study, we found that direct TLR9 inhibition mitigates fibroproliferative responses in preclinical models of pulmonary fibrosis. Our work demonstrates the therapeutic potential of direct TLR9 antagonism in IPF and related fibrotic lung diseases.

Rationale: Uncertainty remains regarding the risks associated with single dose use of etomidate.

Objectives: To assess use of etomidate in critically ill patients and compare outcomes for patients who received etomidate versus ketamine.

Methods: We assessed patients who received invasive mechanical ventilation (IMV), admitted to an ICU in the Premier Healthcare Database, 2008-2021. The exposure was receipt of etomidate on the day of IMV initiation and the main outcome was hospital mortality. Using multivariable regression we compared patients who received IMV within the first two days of hospitalization who received etomidate with propensity-score matched patients who received ketamine. We also assessed whether receipt of corticosteroids in the days after intubation modified the association between etomidate and mortality.

Measurements and main results: Of 1,689,945 patients who received IMV, nearly half (738,855; 43.7%) received etomidate. Among those who received IMV in the first two days of hospitalization, we established 22,273 matched pairs given either etomidate or ketamine. In the primary analysis, receipt of etomidate was associated with greater hospital mortality relative to ketamine (21.6% vs 18.7%; absolute risk difference: 2.8%, 95% CI 2.1%, 3.6%; adjusted odds ratio: 1.28, 95% CI 1.21,1.34). This was consistent across subgroups and sensitivity analyses. We found no attenuation of the association with mortality with receipt of corticosteroids in the days following etomidate use.

Conclusions: Use of etomidate on the day of IMV initiation is common and associated with a higher odds of hospital mortality compared with ketamine. This finding is independent of subsequent treatment with corticosteroids.