In the group of patients with severe disease, the mean age was 9 years higher than in the group with non-severe disease; hypertension and diabetes were more prevalent, tachypnea was observed more often, the changes in chest radiography on admission were more intense, oxygen saturation was decreased, the patients had higher values of CRP, PCT, D-dimers, LDH, lower lymphocyte counts and lymphocyte/neutrophil index. This evidence concerns the gene CRP and diabetes mellitus.