Inflammatory mediators and lung function in older COVID-19 survivors.

<bold>Background:</bold> Severe COVID-19 in older adults is associated with multisystemic inflammation, leading to poor outcomes. The long-term consequences and how subacute inflammation affects pulmonary function remain unclear. <bold>Aim:</bold> to analyze the relationship between inflammatory cytokines four months after discharge and lung function one year later in severe COVID-19 older survivors, and the influence of steroid use in their performance. <bold>Methods:</bold> Twenty patients, predominantly female, were recruited from a specialized Post-COVID Care Clinic. Blood samples were collected four months after discharge, and flow cytometry was performed to measure intracellular cytokines in CD4+ T-cells. Pulmonary function tests were conducted one-year post-discharge. A Pearson correlation was done to assess the relationship between cytokine levels and pulmonary function. <bold>Results:</bold> At the four-month assessment, it was observed that patients exhibiting CD4+ T cells expressing IFN-γ (rho −0.673, p=0.008), IL-10 (rho −0.705, p=0.007), and IL-4 (rho −0.716, p=0.013) displayed a negative correlation with DLCO levels at the one-year follow-up. <bold>Conclusions:</bold> There is a statistically significant correlation between intracellular cytokines and reduced pulmonary function, particularly DLCO, at the one-year mark. Detection of inflammatory mediators four months after discharge from critical illness can help anticipate long-term pulmonary impairment in older survivors. Fig 1. Inverse correlation between four-months intracellular cytokines and one-year pulmonary function test in older adults who survived COVID-19