Background: Glucocorticoids (GCs) have been shown to reduce mortality and the need for invasive mechanical ventilation (IMV) in SARS-CoV-2-induced acute respiratory distress syndrome (ARDS). It has been suggested that serum cytokines levels are markers of disease severity in ARDS, although there is only limited evidence of a relationship between the longitudinal cytokine profile and clinical outcomes in patients with SARS-CoV-2-induced ARDS treated with GC.
Methods: We conducted a single-center observational study to investigate serial plasma cytokine levels in 17 patients supported with non-invasive ventilation (NIV) in order to compare the response in five patients who progressed to IMV versus 12 patients who continued with NIV alone. All patients received methylprednisolone 80 mg/day continuous infusion until clinical improvement.
Results: The study groups were comparable at baseline. All patients survived. Although IL-6 was higher in the NIV group at baseline, several cytokines were significantly higher in the IMV group on day 7 (IL-6, IL-8, IL-9, G-CSF, IP-10, MCP-1, MIP-1α) and 14 (IL-6, IL-8, IL-17, G-CSF, MIP-1α, RANTES). No significant differences were observed between groups on day 28.
Conclusions: Patients in the IMV group had higher inflammation levels at intubation than the NIV group, which may indicate a higher resistance to glucocorticoids. Higher GC doses or a longer treatment duration in these patients might have allowed for a better control of inflammation and a better outcome. Further studies are required to define the prognostic value of cytokine patterns, in terms of both GC treatment tailoring and timely initiation of IMV.
Keywords: COVID-19; acute respiratory distress syndrome (ARDS); cytokines; glucocorticoids; non-invasive ventilation (NIV).