COVID-19 infection induces readily detectable morphological and inflammation-related phenotypic changes in peripheral blood monocytes, the severity of which correlate with patient outcome

Dan Zhang; Rui Guo; Lei Lei; Hongjuan Liu; Yawen Wang; Yili Wang; Tongxin Dai; Tianxiao Zhang; Yanjun Lai; Jingya Wang; Zhiqiang Liu; Aili He; Michael O'Dwyer; Jinsong Hu

Patients experience a spectrum of disease from a mild illness, through varying severity of pneumonia all the way to ARDS and sepsis with multi-organ failure and death. Initial clinical features at disease onset are fever (77-98%), dry cough (46-82%), myalgia or fatigue (11-52%) and dyspnea (3-31%) . 3 The majority of patients develop pneumonia, which can proceed in up to 20-30% of cases to respiratory failure requiring intubation and ventilatory support. In those COVID-19 patients who go on to develop pneumonia, dyspnea develops a median of 8 days after onset of illness. Radiographic abnormalities (CT or chest x-ray) consisting of ground-glass opacities and focal consolidation are seen in patients with pneumonia. Major causes of death include respiratory failure and myocardial damage due to myocarditis. Acute kidney injury, secondary infection and coagulopathy are each seen in approximately 50% of non-survivors. Mortality increases with age and in patients with underlying co-morbidities, such as hypertension, diabetes mellitus, coronary heart disease, chronic lung disease, and cancer. According to a recent retrospective report from Wuhan, clinical predictors of increased mortality on multivariate analysis included advanced age, progressive organ failure and elevated D-Dimers on admission. 4 Other factors significantly associated with poor outcome on univariate analysis included elevated levels of serum ferritin, interleukin-6 (IL-6), Alanine amino transferase (ALT), lactate dehydrogenase (LDH) and highly sensitive cardiac Troponin I, as well as reduced levels of lymphocytes, Hemoglobin (Hb), Platelets and serum albumin.