The following is a summary of “Novel subtypes of severe COVID-19 respiratory failure based on biological heterogeneity: a secondary analysis of a randomized controlled trial,” published in the February 2024 issue of Critical Care by Lechner et al.
Although inflammatory markers predict poor outcomes in COVID-19 patients, treatment success varies, suggesting Latent class analysis (LCA) could reveal acute respiratory distress syndrome (ARDS) subtypes with distinct responses.
Researchers conducted a retrospective study of the I-SPY COVID trial to investigate biological variations and clinical outcomes in severe COVID-19 patients with hypoxemic respiratory failure.
They examined clinical and plasma protein biomarker data from 400 trial participants enrolled (September 2020 and October 2021), all with severe COVID-19 needing ≥ 6 L/min supplemental oxygen. At enrollment, seventeen specific protein biomarkers were measured using multiplex Luminex panels or ELISA. Biomarkers and clinical data were analyzed to identify different subtypes and changes in biomarker levels were investigated over time for each subtype. Validated models compared interleukin-8, bicarbonate, and protein C with non-COVID ARDS subtypes.
The results showed an average participant age of 60 ± 14 years, 67% male, and a 25% mortality rate at 28 days. Upon enrollment, 85% of participants required high-flow oxygen or non-invasive ventilation, and 97% were on dexamethasone. Several inflammation biomarkers (IL-6, IL-8, IL-10, sTNFR-1, TREM-1), epithelial injury (sRAGE), and endothelial injury (Ang-1, thrombomodulin) were associated with 28- and 60-day mortality. Two latent subtypes were identified, with Subtype 2 (27% of participants) showing higher mortality rates and more severe biomarker derangements than Subtype 1. The previously validated non-COVID ARDS model identified only one individual as hyper-inflammatory.
Investigators concluded that COVID-19 patients with hypoxemic failure fall into 2 unique subtypes requiring distinct treatment approaches, not captured by existing ARDS classifications.
Source: ccforum.biomedcentral.com/articles/10.1186/s13054-024-04819-0