IL6 and lymphopenia: Lymphocytopenia, low levels of serum calcium, total cholesterol and total protein levels, high levels of serum CRP, ferritin, IL-6 glucose, LDH, procalcitonin (PCT), and high-sensitivity (hs) troponin I predicted a severe course of illness as measured by disease course classification, the need for oxygen supplementation, higher demand for oxygen supplementation, length of hospital stay, the need for mechanical ventilation, and ICU admission.