Table 2.

Comparison of grading systems

Grading system and application	Grade/severity and definitions
CTCAE v5.0* for infusion-related reactions [29]	Grade 1 Mild transient reaction Infusion interruption not indicated Intervention not indicated	Grade 2 Therapy or infusion interruption indicated but responds promptly to symptomatic treatment (e.g., antihistamines, NSAIDs, opioids, intravenous fluids)	Grade 3 Prolonged (e.g., not rapidly responsive to symptomatic medication and/or brief interruption of infusion) Recurrence of symptoms following initial improvement Hospitalization indicated for other clinical sequelae	Grade 4 Life-threatening consequences Urgent intervention indicated
Brown grading system for general HSRs [30]	Grade 1 (mild) Skin and subcutaneous tissues only, e.g., generalized erythema, urticaria, periorbital edema, or angioedema	Grade 2 (moderate) Features suggesting respiratory, cardiovascular, or gastrointestinal organ involvement, e.g., dyspnea, stridor, wheeze, nausea, vomiting, dizziness (presyncope), diaphoresis, chest or throat tightness, or abdominal pain		Grade 3 (severe) Hypoxia, hypotension, or neurological organ compromise, i.e., cyanosis or SpO2 ≤ 92% at any stage, hypotension (SBP < 90 mmHg in adults), confusion, collapse, LOC, or incontinence
Brown grading system, example of adaptation for taxane HSRs [32]	Grade 1 (mild) Symptoms limited to the skin (e.g., flushing) or involve a single organ/system and are mild (e.g., mild back pain)	Grade 2 (moderate) Symptoms involve at least 2 organs/systems (e.g., flushing and dyspnea), but there is no significant decrease in blood pressure or oxygen saturation		Grade 3 (severe) Symptoms typically involve at least 2 organs/systems, and there is a significant decrease in blood pressure (systolic ≤ 90 mm Hg and/or syncope) and/or oxygen saturation (≤ 92%)

^*CTCAE also includes grade 5 which is death