CHRNA3 and COVID-19: No associations were found between the clinical manifestations of COVID-19 in COPD patients and the polymorphic variants IREB2 rs2568494 and CHRNA3/5 rs16969968 (χ2 = 1.72, df = 2, p = 0.19 and χ2 = 1.61, df = 2, p = 0.2, respectively).