β 2 -microglobulin ( β 2 -m), a 11.8 kDa protein, pairs non-covalently with the α3 domain of the major histocompatibility class (MHC) I α -chain and is essential for the conformation of the MHC class I protein complex. Shed β 2 -m is measurable in circulation, and various disorders are accompanied by increases in β 2 -m levels, including several viral infections. Therefore, we explored whether β 2 -m levels could also be elevated in Coronavirus disease 2019 (Covid-19) and whether they predict disease severity. Serum β 2 -m levels were measured in a cohort of 34 patients infected with SARS-CoV-2 on admission to a tertiary care hospital in Riyadh, Saudi Arabia, as well as in an approximately age-sex matched group of 34 uninfected controls. Mean β 2 -m level was 3.25±1.68 mg/l (reference range 0.8–2.2 mg/l) in patients (mean age 48.2±21.6) and 1.98±0.61 mg/l in controls (mean age 48.2±21.6). 17 patients (mean age 36.9± 18.0) with mean β 2 -m levels of 2.27±0.64 mg/l had mild disease by WHO severity categorization, 12 patients (mean age 53.3±18.1) with mean β 2 -m levels of 3.57±1.39 mg/l had moderate disease, and five patients (of whom 2 died; mean age 74.4±13.8) with mean β 2 -m levels of 5.85±1.85 mg/l had severe disease ( P < = 0.001, by ANOVA test for linear trend). In multivariate ordinal regression β 2 -m levels were the only significant predictor of disease severity. Our findings suggest that higher β 2 -m levels could be an early indicator of severity of disease and predict outcome of Covid-19. As the main limitations of the study are a single-center study, sample size and ethnicity, these results need confirmation in larger cohorts outside the Arabian Peninsula in order to delineate the value of β 2 -m measurements. The role of β 2 -m in the etiology and pathogenesis of severe Covid-19 remains to be elucidated.
【초록키워드】 coronavirus disease, Coronavirus disease 2019, Pathogenesis, severe COVID-19, severity, disease severity, hospital, outcome, viral infections, Saudi Arabia, Protein, Cohort, Ethnicity, Viral, Patient, Control, Mild, age, MHC class I, WHO, Severity of disease, circulation, etiology, disease, Admission, Care, predict, MHC, Mild disease, severe disease, on admission, Arabian Peninsula, Sample size, confirmation, moderate disease, Increases, domain, conformation, limitation, single-center study, disorder, protein complex, ANOVA test, MHC class, microglobulin, Shed, uninfected, FIVE, controls, elevated, linear, kDa, were measured, the major histocompatibility, accompanied, increases in, infected with SARS-CoV-2, 【제목키워드】 disease,