COVID-19 patients classified as having a severe PI were older than those with mild PI (65 ± 16 vs. 54 ± 17 years, respectively) and presented a significant reduction in TLV (3,639 ± 931 vs. 4,890 ± 704 in moderate and 5,247 ± 1,067 ml in mild COVID-19 pneumonia), significant increase in lung weight (1,037 ± 251 vs. 935 ± 143 and 799 ± 159 g, respectively), and higher serum C-reactive protein concentrations at admission (62 ± 79 in severe vs. 23 ± 73 in moderate and 4 ± 5 mg/dl in mild COVID-19 pneumonia). Here, CRP is linked to COVID-19.