Soluble interleukin-2 receptor levels on admission associated with mortality in coronavirus disease 2019.

OBJECTIVES: Early and simple detection of high-risk groups is crucial for minimizing severe coronavirus disease 2019 (COVID-19)-related deaths. Soluble interleukin 2 receptors (sIL2R) have been suspected as being prognostic markers for infectious diseases. This study validated the usefulness of sIL2R as a marker for deaths related to COVID-19. METHODS: This retrospective observational study enrolled participants who showed positive results for severe acute respiratory syndrome coronavirus 2 RNA admitted to the current hospital between 01 April and 30 September 2020. Of the 102 patients enrolled in this study, sIL2R levels were measured in 87 patients. For comparisons between survival and non-survival groups, potential confounding variables were entered into univariate models, and variables showing significant correlations (p < 0.05) in those models were added to a multivariate model. RESULTS: Being aged ≥60 years and sIL2R levels ≥1060 U/ml were significantly associated with mortality on univariate analyses; only sIL2R levels significantly correlated with mortality on multivariate logistic regression analysis. Further, sequential sIL2R levels in three patients were increased at progression or death. CONCLUSION: SIL2R on admission and sequential monitoring of sIL2R might reflect disease severity.

Markers of endothelial cell activation and immune activation are increased in patients with severe leptospirosis and associated with disease severity.

OBJECTIVES: Previous studies concluded that haemorrhage is one of the most accurate prognostic factors of mortality in leptospirosis. Therefore, endothelial cell activation was investigated in relation to disease severity in severe leptospirosis. METHODS: Prospective cohort study of severe leptospirosis patients. Plasma levels of sE-selectin and Von Willebrand factor (VWF) were determined. Consequently, an in vitro endothelial cell model was used to assess endothelial activation after exposure to virulent Leptospira. Finally, immune activation, as a potential contributing factor to endothelial cell activation, was determined by soluble IL2-receptor (sIL-2r) and soluble Fas-ligand (sFasL) levels. RESULTS: Plasma levels of sE-selectin and VWF strongly increased in patients compared to healthy controls. Furthermore, sE-selectin was significantly elevated (203 ng/ml vs. 157 ng/ml, p < 0.05) in survivors compared to non-survivors. Endothelial cells exposed to virulent Leptospira showed increased VWF expression. E-selectin and ICAM-1 expression did not change. Immunohistochemistry revealed the presence of intracellular Leptospira and qPCR suggested replication. In vivo analysis showed that increased levels of sFasL and sIL-2r were both strongly associated with mortality. Furthermore sIL-2r levels were increased in patients that developed bleeding and significantly correlated to duration of hospital stay. DISCUSSION: Markers of endothelial activation and immune activation were associated with disease severity in leptospirosis patients.