Correlation of Low Levels of α-1 Antitrypsin and Elevation of Neutrophil to Lymphocyte Ratio with Higher Mortality in Severe COVID-19 Patients

BACKGROUND: Variations in COVID-19 prevalence, severity, and mortality rate remain ambiguous. Genetic or individual differences in immune response may be an explanation. Moreover, hyperinflammation and dysregulated immune response are involved in the etiology of severe forms of COVID-19. Therefore, the aim of the present study was to analyze serum alpha-1 antitrypsin (AAT) levels, as an acute-phase plasma protein with immunomodulatory effect and neutrophil to lymphocyte ratio (NLR) as a marker of inflammation response in severe COVID-19 illness. METHODS: In this retrospective observational cohort study, 64 polymerase chain reaction (PCR) positive COVID-19 hospitalized patients were studied for AAT, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), troponin, complete blood count (CBC), random blood sugar, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), and arterial oxygen saturation (O2sat) at admission and during hospitalization. RESULTS: The results showed that hospitalized patients with COVID-19 had low serum levels of AAT and high CRP levels at the first days of hospitalization. In particular, the percentages of individuals with low, normal, and high AAT levels were 7.80%, 82.80%, and 9.40%, respectively, while high and low values of CRP accounted for 86.70% and 13.30% of patients. Most of the patients had an upward neutrophil to lymphocyte ratio (NLR) trend, with a higher mortality rate (p < 0.05) and troponin levels (p < 0.05). However, comorbidities, CRP alterations, ESR alterations, nonfasting blood sugar, SGOT, SGPT, O2sat, RBC, and PLT values were not significantly different between the NLR downward and upward trend groups. CONCLUSIONS: The current study revealed that severe COVID-19 patients had low serum AAT levels related to CRP values. Therefore, AAT response may be considered as a new mechanism by which some COVID-19 patients show immune dysregulation and more severe symptoms.