BACKGROUND: Natural killer (NK) cells play an essential role against viruses. NK cells express killer cell immunoglobulin-like receptors (KIRs) which regulate their activity and function. The polymorphisms in KIR haplotypes confer differential viral susceptibility and disease severity caused by infections. We investigated the association between KIR genes and COVID-19 disease severity. METHODS: 424 COVID-19 positive patients were divided according to their disease severity into mild, moderate and severe. KIR genes were genotyped using next generation sequencing (NGS). Association between KIR genes and COVID-19 disease severity was conducted and significant correlations were reported. RESULTS: In the COVID-19 patients, KIR Bx genotype was more common than AA genotype. The Bx genotype was found more frequently in patients with mild disease. The KIR2DS4 gene carried the highest risk for severe COVID-19 infection (OR 8.48, pc = 0.0084) followed by KIR3DL1 (OR 7.61, pc = 0.0192) suggesting their role in risk for severe COVID-19 disease.
Association of KIR gene polymorphisms with COVID-19 disease