Table 1.
Criteria for defining cytokine release syndrome (CRS) in COVID-19
| One or more of the following criteria should be present a |
| CRP >100 mg/L or >50 mg/L but doubled in the last 48 h |
| Lymphocyte count <0.6 × 109/L |
| Serum IL-6 level ≥3 × ULN |
| Ferritin >300 µg/L (or surrogate) with doubling within 24 h |
| Ferritin >600 µg/L at presentation and LDH >250 U/L |
| Elevated d-dimers (>1 µg/mL) |
COVID-19, coronavirus disease 2019; CRP, C-reactive protein; IL, interleukin; ULN, upper limit of normal; LDH, lactate dehydrogenase.
a
The risk of developing CRS was defined as follows: low risk, presence of one criterion; moderate risk, presence of two to three criteria; and high risk, presence of more than three criteria.