The deletion variant of the CCR5 gene (rs333) but not the ACE gene (rs4340) is associated with long-term respiratory support in patients with COVID-19 pneumonia

Abstract

Резюме. The aim was to analyze the effect of the ACE gene (c.2306-117_404I/D, rs4340) and the CCR5 gene (del32, rs333) variants on the course of severe COVID-19 pneumonia in patients treated at the intensive care unit. Materials and methods. The study group included 31 patients (16 men and 15 women) with diagnosis «viral COVID-19 pneumonia». All patients underwent standard daily repeated clinical, instrumental and laboratory examinations. Determination of the ACE and CCR5 gene variants was carried out by a molecular method using allele-specific polymerase chain reaction. Results. The results of our retrospective study did not confirm the association of investigated genes variants with lethal outcomes. Clinical predictors of lethal outcomes were: low of SpO2/FiO2 ratio, tachypnea, tachycardia, low systolic blood pressure, anemia, leukocytosis during the first days of hospitalization and need of mechanical lung ventilation. Patients with heterozygous W/del32 genotype of the CCR5 gene in comparison with patients with genotype W/W had significantly longer respiratory support, namely a significantly increased duration of oxygen therapy using an oxygen mask (4.50±3.70 vs. 2.19±1.28 days, respectively), significantly longer mechanical lung ventilation (15.00±4.24 vs. 4.40±4.98 days, respectively) and the significantly greater total duration of oxygen therapy (9.60±5.68 vs. 4.19±3.84 days, respectively). Patients with the W/del32 genotype of the CCR5 gene had significantly increased white blood cell counts as compared to patients with the W/W genotype (13.64±10.66 vs. 8.38±2.85, respectively). Conclusions. Significant clinical predictors of lethal outcomes in patients with severe COVID-19 pneumonia were found on admission: lower SpO2/FiO2 ratios, tachypnea, tachycardia, anemia, leukocytosis during the first days of hospitalization, and need of mechanical lung ventilation. The variant of the CCR5 gene was the genetic predictor of severe course of COVID-19 pneumonia with increased need for respiratory support. The variant of the CCR5 gene was associated with elevated white blood cell count in the complete blood test.The obtained results indicate the need for further multifaceted research in this direction to determine the leading genetically mediated pathogenetic mechanisms of severe viral COVID-19 pneumonia.