N-antigenemia detection by a rapid lateral flow test predicts 90-day mortality in COVID-19: A prospective cohort study.

OBJECTIVES: To evaluate if the detection of N antigen of SARS-CoV-2 in plasma by a rapid lateral flow test predicts 90-day mortality in COVID-19 patients hospitalized at the wards. METHODS: The presence of N-antigenemia was evaluated in the first 36 hours after hospitalization in 600 unvaccinated COVID-19 patients, by using the Panbio COVID-19 Ag Rapid Test Device from Abbott (Abbott Laboratories Inc., Chicago, IL, USA). The impact of N-antigenemia on 90-day mortality was assessed by multivariable Cox regression analysis. RESULTS: Prevalence of N-antigenemia at hospitalization was higher in nonsurvivors (69% (82/118) vs. 52% (250/482); p < 0.001). The patients with N-antigenemia showed more frequently RNAemia (45.7% (148/324) vs. 19.8% (51/257); p < 0.001), absence of anti-SARS-CoV-2 N antibodies (80.7% (264/327) vs. 26.6% (69/259); p < 0.001) and absence of S1 antibodies (73.4% (240/327) vs. 23.6% (61/259); p < 0.001). The patients with antigenemia showed more frequently acute respiratory distress syndrome (30.1% (100/332) vs. 18.7% (50/268); p = 0.001) and nosocomial infections (13.6% (45/331) vs. 7.9% (21/267); p = 0.026). N-antigenemia was a risk factor for increased 90-day mortality in the multivariable analysis (HR, 1.99 (95% CI,1.09-3.61), whereas the presence of anti-SARS-CoV-2 N-antibodies represented a protective factor (HR, 0.47 (95% CI, 0.26-0.85). DISCUSSION: The presence of N-antigenemia or the absence of anti-SARS-CoV-2 N-antibodies after hospitalization is associated to increased 90-day mortality in unvaccinated COVID-19 patients. Detection of N-antigenemia by using lateral flow tests is a quick, widely available tool that could contribute to early identify those COVID-19 patients at risk of deterioration.

Liver manifestations in COVID-19 and the influence of pre-existing liver disease in the course of the infection.

INTRODUCTION: patients with advanced chronic liver disease (CLD) may be at an increased risk of a severe course due to cirrhosis-associated immune dysfunction. The aim of this study was to determine the prevalence of CLD in COVID-19 patients and to analyze the course of the infection, compared with patients with non-liver disease. MATERIALS AND METHODS: this was a retrospective single center study of all patients with a positive SARS-CoV-2 polymerase chain reaction (PCR) test from March 23rd to April 30th, 2020. Clinical and biochemical data of patients with and without CLD and COVID-19 were collected from the medical records. RESULT: four hundred and forty-seven patients with a SARS-CoV-2 positive PCR were included, 6.3 % had CLD; 69.7 % of patients with CLD were male, with a median age of 65.5 years and active alcohol consumption and smoking; 75 % had non-advanced liver fibrosis and most had non-alcoholic fatty liver disease (NAFLD). The hospital admission rate (92.9 % vs 47.7 %, p < 0.001), concomitant comorbidities (diabetes 38.5 vs 16.5 %, p = 0.011; obesity 30.8 vs 8.5 %, p = 0.033; cancer 23.1 vs 5 %, p = 0.027; and chronic obstructive pulmonary disease (COPD) 19.2 vs 9 %, p = 0.009) and concomitant antibiotics treatment (19.3 vs 5 %, p = 0.018) were higher in patients with CLD than in those without CLD. In-patient hospital mortality rates were similar in both groups (30.8 vs 19.6 %, p = 0.289). The presence of CLD was not associated with mortality (OR = 1.06; 95 % CI = 0.35-3.18; p = 0.924). However, patients with CLD and COVID-19 who were male, obese or under concomitant antibiotic treatment had the highest risk of mortality according to the univariate analysis. CONCLUSION: patients with CLD had a higher risk of hospital admission, with worse outcomes during the COVID-19 infection associated to other concomitant comorbidities and a suspicion of bacterial co-infection.