Table 1.
Grading of CRS in CAR T-cell treatment for B-NHL
| Symptom or sign of CRS | Grade 1 | Grade 2 | Grade 3 | Grade 4 |
|---|---|---|---|---|
| Fever (temperature ≥ 38 °C) | Yes | Yes | Yes | Yes |
| And | ||||
| Hypotension (systolic blood pressure < 90 mmHg) | No | Vasopressors not required | Response to one type of vasopressor | Multiple vasopressors required |
| And/or | ||||
| Hypoxia (oxygen requirement: SaO2 > 90%) | No | Low-flow* nasal oxygen required | High-flow* oxygen through a nasal cannula, a mask, a nonrebreather mask, or a venturi mask‡ required | Positive pressure mechanical ventilation (noninvasive mechanical ventilation, or tracheal intubation and mechanical ventilation) required |
| And/or | ||||
| Inflammatory manifestations of lesions, surrounding tissues, and organs | No | Enlarged lesion not causing compression symptoms or affecting functions of organs around the tumor | Enlarged lesion resulting in compression symptoms or serous effusion in tissues around the tumor, etc.; potentially compensation of functions of adjacent organs | Enlarged lesion resulting in compression symptoms, edema/bleeding/perforation in the surrounding tissues, or massive serous effusion, etc.; decompensated functions of surrounding organs |
CRS, cytokine-release syndrome; CAR, chimeric antigen receptor; B-NHL, B-cell non-Hodgkin lymphoma; SaO2, arterial oxygen saturation. *Low flow is defined as ≤ 6 L/min, and high flow is defined as > 6 L/min. ‡Venturi mask: a mask manufactured based on the Venturi effect. As oxygen flows into the mask through the narrow pores, a negative pressure is created surrounding the jet airflow, thus resulting in air flowing into the mask from the open edge; the size of the edge determines the ratio of oxygen to air.