Age influences blood cell-based immune deregulation antibody response and unfavorable clinical outcomes in COVID-19 patients

COVID-19 is caused by SARS-CoV-2 and has a diverse spectrum of clinical presentations ranging from asymptomatic cases to severe and critical cases that result in the death of the patient. Alongside the viral factors host factors like Age, deregulation of the immune response and presence of comorbidity determine the patient's outcome. Here we sought to assess the impact of age on natural antibody response, CBC-based inflammatory markers, and outcome of COVID-19 patients. We divided the participants into three groups, young (≤ 35 years), middle-aged (40-60 years), and old (≥ 65 years) patients and collected and analyzed sociodemographic, clinical, and laboratory parameters. We found that elderly patients showed higher (P < 0.05) levels of inflammation like increased neutrophil percentages, NLR, lymphopenia, and low Hgb levels, compared to middle-aged and young patients. Interestingly these markers were also associated with mortality of COVID-19 patients. On the other hand, no significant difference was observed in ion concentration, lipid profile, and coagulation test between the three age groups. We also found that elderly patients showed significantly (P < 0.05) decreased levels of natural antibody response to SARS-CoV-2 infection compared with the two groups. Lastly, we assessed the effect of dexamethasone treatment, even if statistically not significant (P > 0.05) we observed a positive trend among patients under dexamethasone in the aspect of decreasing inflammatory markers. To conclude we showed that SARS-CoV-2 is characterized by an age-dependent deregulation of inflammatory markers that are associated with mortality among COVID-19 patients.