The rs16969968 Tobacco Smoking-Related Single-Nucleotide Variant Is Associated with Clinical Markers in Patients with Severe COVID-19.

Tobacco smoking is the leading risk factor for many respiratory diseases. Several genes are associated with nicotine addiction, such as CHRNA5 and ADAM33 . This research aims to evaluate the association of the polymorphisms rs16969968 ( CHRNA5 ) and rs3918396 ( ADAM33 ) in patients who developed severe COVID-19. We included 917 COVID-19 patients hospitalized with critical disease and oxygenation impairment. They were divided into two groups, tobacco-smoking ( n = 257) and non-smoker ( n = 660) patients. The genotype and allele frequencies of two single nucleotide variants, the rs16969968 ( CHRNA5 ) and rs3918396 ( ADAM33 ), were evaluated. The rs3918396 in ADAM33 does not show a significative association. We analyzed the study population according to the rs16969968 genotype (GA + AA, n = 180, and GG, n = 737). The erythrocyte sedimentation rate (ESR) shows statistical differences; the GA + AA group had higher values than the GG group ( p = 0.038, 32 vs. 26 mm/h, respectively). The smoking patients and GA or AA genotype carriers had a high positive correlation ( p < 0.001, rho = 0.753) between fibrinogen and C-reactive protein. COVID-19 patients and smokers carriers of one or two copies of the risk allele (rs16969968/A) have high ESR and a positive correlation between fibrinogen and C-reactive protein.