CAR-T and cytokine release syndromeMANAGEMENT

HEMATOLOGIC AND ONCOLOGIC PRESENTATIONS · 12 SECTIONS

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470 items

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Cardiovascular Presentations71▾

Respiratory Presentations52▾

Neurological Presentations83▾

Gastrointestinal Presentations74▾

Genitourinary and Reproductive Presentations48▾

Infectious Disease Presentations148▾

Trauma Presentations89▾

Toxicologic Presentations80▾

Psychiatric Presentations26▾

Musculoskeletal and Rheumatologic Presentations96▾

Dermatology Presentations23▾

Environmental and Exposure Presentations27▾

Hematologic and Oncologic Presentations36▾

Acute chest syndrome Acute Hemolytic Transfusion Reaction Anticoagulant reversal (warfarin, DOAC, heparin)Aplastic Anemia (Crisis)Autoimmune Hemolytic Anemia CAR-T and cytokine release syndrome Coagulopathy Delayed Hemolytic Transfusion Reaction Disseminated Intravascular Coagulation (DIC)Essential Thrombocythemia Febrile Non-hemolytic Transfusion Reaction Graft Versus Host Disease (Acute)Hemolytic Uremic Syndrome (HUS)Hemophilia A (Bleeding Crisis)Heparin-Induced Thrombocytopenia (HIT)Hyperviscosity syndrome Immune checkpoint inhibitor toxicity Immune Thrombocytopenic Purpura (ITP)Leukemoid Reaction Leukostasis Massive transfusion protocol Myelofibrosis Neutropenic enterocolitis (typhlitis)Paroxysmal Nocturnal Hemoglobinuria Polycythemia Vera (Crisis)Pure Red Cell Aplasia Sickle Cell (Acute Chest Syndrome)Sickle Cell (Splenic Sequestration)Sickle cell crisis (vaso-occlusive)Symptomatic anemia Thrombocytopenia (severe)Thrombotic Thrombocytopenic Purpura (TTP)Transfusion-Associated Circulatory Overload (TACO)Transfusion-Related Acute Lung Injury (TRALI)Tumor lysis syndrome Von Willebrand Disease (Bleeding)

Pediatric-Specific Presentations19▾

Endocrine and Metabolic Presentations45▾

ENT and Maxillofacial Presentations27▾

Ophthalmologic Presentations19▾

Obstetric Presentations23▾

Systemic and Miscellaneous Presentations17▾

01Approach to the Critical Patient/attcp36

Dual pathway activation

›Simultaneous sepsis and CRS pathway

›Fever plus distributive shock in a recent CAR-T recipient

›Clinically indistinguishable from septic shock at the bedside

›Cytokine release syndrome and sepsis are treated simultaneously, not sequentially

›Concurrent obligate actions

›Blood cultures times two before antibiotics when feasible

›Broad spectrum antibiotics per neutropenic sepsis pathway

›Cytokine release syndrome directed therapy started in parallel

›Rationale for concurrent treatment

›Most CAR-T recipients are genuinely neutropenic from lymphodepleting chemotherapy

›Delaying antibiotics to see if fever is cytokine release syndrome risks missed sepsis

›Delaying cytokine release syndrome therapy to see if antibiotics work risks progression to refractory shock

Recognition and grading trigger

›Toxicity recognition

›Timeline anchor

›Chimeric antigen receptor T-cell infusion within the preceding 30 days

›Fever, hypotension, or hypoxia after infusion

›Grading on presentation

›ASTCT cytokine release syndrome grade assigned at first assessment

›ASTCT immune effector cell-associated neurotoxicity syndrome grade assigned at first assessment

›Escalation triggers

›Any vasopressor requirement

›Any new hypoxia requiring supplemental oxygen

›Any decline in immune effector cell encephalopathy score

›Any seizure

Immediate contact and stabilization

›Time zero actions

02History/hx39

Cell therapy and infusion timeline

›Product and treatment details

›Chimeric antigen receptor T-cell product name

›Anti-CD19 constructs for B-cell malignancies

›Anti-BCMA constructs for multiple myeloma

›Days since infusion

›Day of infusion counted as day 0

›Onset day for the current symptoms

›Lymphodepleting chemotherapy exposure

›Fludarabine and cyclophosphamide typical regimen

›Timing relative to CAR-T infusion

›Prior toxicity with this admission course

›Tocilizumab already administered

›Corticosteroids already administered

Symptom evolution

›Cytokine release syndrome symptom pattern

›Fever as the sentinel symptom

›Myalgia and malaise

›Progressive dyspnea

›Progressive lightheadedness or presyncope

›Neurotoxicity symptom pattern

›Early language change

›Word-finding difficulty

›Expressive aphasia progression

›Early motor change

›New tremor

›Handwriting deterioration

›Advanced features reported by family or staff

03Physical Exam/exam37

Shock and perfusion assessment

›Vital sign trend

›Temperature trend

›Corticosteroid or antipyretic use masking fever

›Hypotension trend

›Relative hypotension compared with pre-infusion baseline

›Oxygen requirement by device

›Device escalation is itself a grading criterion

›Perfusion exam

›Capillary refill time

›Skin mottling

›Warm extremities in early distributive physiology

Serial neurologic exam

›Immune effector cell encephalopathy components at the bedside

›Orientation to year, month, city, and hospital

›Naming three objects

›Following a simple command

›Writing a standard sentence

›Counting backward from 100 by tens

›Motor and seizure screen

›Tremor

›Handwriting sample comparison to prior exam

›Focal weakness

›Witnessed or reported seizure activity

›Raised intracranial pressure screen

›Papilledema

›Cushing triad

›Hypertension

04Differential Diagnosis/ddx21

Life-threatening mimics and overlaps

›Distributive shock differential

›Bacterial sepsis and septic shock

›Cytokine release syndrome

›Anaphylaxis to infused product or concurrent medication

›Transfusion reaction

›Neurotoxicity mimics

›Immune effector cell-associated neurotoxicity syndrome

›Central nervous system disease progression or relapse

›Posterior reversible encephalopathy syndrome

›Intracranial hemorrhage in the setting of thrombocytopenia

›Metabolic encephalopathy

›Hyponatremia

›Hypoglycemia

›Hepatic or uremic encephalopathy

›Concurrent oncologic emergencies

›Tumor lysis syndrome

›Immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome

›Disseminated intravascular coagulation

Coding anchor

›ICD-10 parent code

›Cytokine release syndrome D89.83

›Use the parent code when the precise grade-specific subdivision is not certain

05Laboratory Tests/lt45

Core labs and interpretation

›Baseline severity and organ function

›Complete blood count with differential

›Absolute neutrophil count for concurrent neutropenia

›Severe neutropenia defined as ANC less than 0.5 x 10^9/L

›Cytopenias out of proportion to expected nadir

›Comprehensive metabolic panel

›Sodium mmol/L

›Potassium mmol/L

›Creatinine trend for drug dosing

›Liver enzymes and bilirubin

›Transaminase elevation as a hepatic toxicity or HLH-like marker

›Coagulation studies

›Fibrinogen for HLH-like coagulopathy

›INR and PTT for DIC concern

›Lactate

›Hypoperfusion marker shared with sepsis assessment

Inflammatory and macrophage activation markers

›Cytokine release syndrome and HLH-like markers

›C-reactive protein

›Rises with cytokine release syndrome severity

›Nonspecific for infection versus cytokine release syndrome

›Ferritin

›Trend more informative than a single value

›Markedly elevated ferritin, often above 10,000 ng/mL, raises concern for immune effector cell-associated HLH-like syndrome

›Triglycerides

›Elevation supports HLH-like overlap

›Interleukin-6 level where locally available

06Diagnostic Tests/dt51

Scoring Systems

›ASTCT consensus grading

›Cytokine release syndrome grade

›Grade 1 fever without hypotension or hypoxia

›Grade 2 fever with hypotension not requiring a vasopressor, or hypoxia requiring low-flow nasal cannula

›Grade 3 fever with hypotension requiring one vasopressor with or without vasopressin, or hypoxia requiring high-flow nasal cannula, facemask, or non-rebreather

›Grade 4 fever with hypotension requiring multiple vasopressors excluding vasopressin, or hypoxia requiring positive pressure ventilation

›Immune effector cell-associated neurotoxicity syndrome grade

›Grade based on the immune effector cell encephalopathy score, level of consciousness, seizure, motor findings, and elevated intracranial pressure or cerebral edema

›Grade 1 immune effector cell encephalopathy score 7 to 9 with spontaneous awakening

›Grade 2 immune effector cell encephalopathy score 3 to 6 with awakening to voice

›Grade 3 immune effector cell encephalopathy score 0 to 2 with awakening only to tactile stimulus, or any seizure that resolves rapidly, or focal edema on neuroimaging

›Grade 4 unarousable and unable to perform the immune effector cell encephalopathy assessment, or life-threatening prolonged or repetitive seizure, or deep focal motor weakness, or diffuse cerebral edema

›Immune effector cell encephalopathy score components, 10 points total

›Orientation to year, month, city, and hospital, 4 points

›Naming three objects, 3 points

›Following a simple command, 1 point

›Writing a standard sentence, 1 point

›Counting backward from 100 by tens, 1 point

MRI

›Brain MRI role

›Evaluation of high-grade neurotoxicity

›Diffuse edema

›Posterior reversible encephalopathy syndrome-like changes

›Interpretation pitfall

›Brain MRI is frequently normal despite clinically severe immune effector cell-associated neurotoxicity syndrome

›A normal MRI does not downgrade the clinical neurotoxicity grade

›Practical limitations

07Disposition/dispo30

Level of care by grade

›Admission default

›Any grade 1 or higher cytokine release syndrome

›Any grade of immune effector cell-associated neurotoxicity syndrome

›Fever in a recent CAR-T recipient even before grading is complete

›ICU criteria

›Any vasopressor requirement

›Grade 3 or 4 cytokine release syndrome

›Grade 3 or 4 immune effector cell-associated neurotoxicity syndrome

›Airway concern from declining level of consciousness

›Suspected cerebral edema

Treating center coordination and transfer

›Mandatory notification

›Immediate telephone contact with the treating cellular therapy center for every presentation

›Product-specific management guidance

›Institutional toxicity management plan on file

›Wallet card information relay

›Product name

›Infusion date

›Trial or commercial protocol identifiers

›Transfer criteria

›Transfer back to the treating center for most stable patients requiring ongoing toxicity management

›Local stabilization first when transfer is unsafe

›Refractory shock

›Status epilepticus

›Airway compromise

›Do not delay tocilizumab, corticosteroids, or antibiotics while arranging transfer

08Treatment/t112

Concurrent empiric antibiotics

›Antibiotic strategy while CRS therapy is initiated

›Broad spectrum anti-pseudomonal coverage

›Cefepime IV 2 g every 8 hours if normal renal function

›Piperacillin-tazobactam IV 4.5 g every 6 hours if normal renal function as an alternative

›Timing target

›First dose within 60 minutes of recognition of possible neutropenic sepsis

›Do not withhold antibiotics while awaiting response to cytokine release syndrome therapy

Tocilizumab, the anchor therapy

›Tocilizumab dosing

›Interleukin-6 receptor antagonist

›8 mg/kg IV over 1 hour for patients 30 kg or greater

›12 mg/kg IV over 1 hour for patients under 30 kg

›Maximum single dose 800 mg

›Repeat dosing

›May repeat every 8 hours if inadequate clinical improvement

›Maximum 4 total doses

›Key asymmetry

›Tocilizumab does not reliably cross the blood-brain barrier

›Tocilizumab is not effective monotherapy for immune effector cell-associated neurotoxicity syndrome

›Corticosteroids, not tocilizumab, lead treatment when neurotoxicity is present

Corticosteroids

›Corticosteroids for cytokine release syndrome

›Added rather than leading

›Added for grade 2 cytokine release syndrome not responding to tocilizumab

›Added for grade 3 or 4 cytokine release syndrome alongside tocilizumab

›Typical regimen

›Dexamethasone 10 mg IV every 6 hours

›Methylprednisolone 1 mg/kg IV every 12 hours as an alternative regimen

›Taper

›Taper once symptoms improve rather than abrupt discontinuation

›Corticosteroids for neurotoxicity, the lead therapy

›Grade 2 immune effector cell-associated neurotoxicity syndrome

›Dexamethasone 10 mg IV every 6 hours

›Grade 3 immune effector cell-associated neurotoxicity syndrome

›Dexamethasone 10 to 20 mg IV every 6 hours

›Grade 4 immune effector cell-associated neurotoxicity syndrome or cerebral edema

›High-dose methylprednisolone, commonly 1000 mg IV daily for 3 days

›Initiate concurrently with emergent neurosurgical and critical care consultation

Refractory disease escalation

›Escalation beyond tocilizumab and corticosteroids

›Anakinra

›Interleukin-1 receptor antagonist

›100 mg subcutaneous or intravenous once or twice daily

›Better central nervous system penetration than tocilizumab, considered for steroid-refractory neurotoxicity

›Siltuximab

›Direct anti-interleukin-6 antibody, distinct from the tocilizumab receptor target

›11 mg/kg IV over 1 hour

›Consider before tocilizumab dosing is exhausted, since it binds circulating interleukin-6 and can confound interpretation of interleukin-6 levels if given after tocilizumab

›Additional immunosuppression for hematology-directed refractory management

›Etoposide-based therapy for immune effector cell-associated HLH-like syndrome refractory to the above

›150 mg/m2 IV, per HLH-directed protocol dosing, hematology-directed

Hemodynamic support and iatrogenic-harm review

›Fluids

›Cautious crystalloid boluses with reassessment

›Capillary leak physiology increases pulmonary edema risk with aggressive fluid loading

›Smaller aliquots with lung ultrasound reassessment between boluses

›Vasopressors

›Norepinephrine first line

›Starting range 0.05 to 0.1 mcg/kg/min titrated to mean arterial pressure 65 mmHg or higher

›Vasopressin as an add-on that does not itself change the cytokine release syndrome grade

›Fixed dose 0.03 units/min

›Grading implication of pressor choice

›One vasopressor without vasopressin is consistent with grade 3

›Multiple vasopressors excluding vasopressin defines grade 4

›Standard ED interventions requiring modification in this patient

›Intubation and sedation

›Sedating agents blunt the immune effector cell encephalopathy exam and can mask evolving neurotoxicity

›Document a pre-sedation neurologic exam whenever intubation is anticipated

›Oxygen delivery

›The oxygen device itself, not just the saturation number, determines the cytokine release syndrome grade

›Escalating device without documenting FiO2 requirement risks under-grading

›Mechanical circulatory support

›Intra-aortic balloon pump has no established role in cytokine release syndrome shock

›Veno-arterial ECMO considered only for catecholamine-refractory shock at a center with the capability

›Anticoagulation

›High risk given concurrent thrombocytopenia and HLH-like coagulopathy

›Reserve for a clear indication such as confirmed catheter-associated thrombosis

›Fibrinolysis

›Not indicated for cytokine release syndrome shock and relatively contraindicated given coagulopathy and thrombocytopenia

›Analgesia and antipyretics

›Acetaminophen 650 to 1000 mg PO or IV every 4 to 6 hours, maximum 4 g/day, maximum 3 g/day with hepatic impairment

›Avoid routine NSAIDs given thrombocytopenia and renal risk

›Opioids used cautiously, since sedation can obscure the neurotoxicity exam

Therapy not working, troubleshooting node

›Refractory cytokine release syndrome or neurotoxicity

›Reassess the diagnosis

›Repeat blood cultures and source survey for an untreated infection

›Reconsider immune effector cell-associated HLH-like syndrome as a driver

›Escalate therapy

›Second tocilizumab dose if within the 8-hour interval and dose maximum not reached

›Escalate corticosteroid dose or switch to methylprednisolone

›Add anakinra or siltuximab

›Escalate level of care

›ICU transfer for vasopressor titration

›Repeat neuroimaging for new or worsening neurologic decline

Tumor lysis syndrome management

›Prophylaxis and treatment

›Risk-based prophylaxis

›Aggressive isotonic IV fluids

›Rasburicase 0.15 to 0.2 mg/kg IV once daily for high-risk tumor burden

›Contraindicated in glucose-6-phosphate dehydrogenase deficiency, risk of hemolysis

›Allopurinol 300 mg PO daily for lower-risk prophylaxis

›Electrolyte management

›Avoid potassium-containing fluids

›Correct hypocalcemia only if symptomatic, since calcium administration can worsen calcium-phosphate precipitation

›ECG monitoring for tumor lysis electrolyte shifts

›Peaked T waves with hyperkalemia

›QT prolongation with hypocalcemia

Hematologic and infection prevention adjuncts

›Prolonged cytopenia and B-cell aplasia support

›B-cell aplasia and hypogammaglobulinemia

›Immunoglobulin G replacement threshold, commonly below 400 to 500 mg/dL with recurrent infection

›IVIG 400 to 600 mg/kg IV monthly for replacement

›Growth factor caution

›Filgrastim 5 mcg/kg/day subcutaneous for neutropenia support

›Avoid or delay growth factor support during active cytokine release syndrome due to theoretical concern for exacerbating cytokine release

›Transfusion support per oncology thresholds

›Symptomatic anemia

›Severe thrombocytopenia with bleeding risk

09Special Populations/sp32

Pregnancy

›Pregnancy specific considerations

›CAR-T therapy is not typically administered during pregnancy

›Presentation more often reflects a patient treated before conception or a rare compassionate scenario

›Maternal stabilization priority

›Sepsis and cytokine release syndrome pathways proceed as in the non-pregnant patient

›Early obstetric consultation

›Drug considerations

›Tocilizumab and corticosteroid use individualized with hematology and obstetrics given limited pregnancy safety data

›Fetal monitoring based on gestational age

Geriatric

›Older adult considerations

›Atypical presentation

›Afebrile cytokine release syndrome

›Delirium as the presenting neurotoxicity sign rather than classic word-finding difficulty

›Fluid and pressor tolerance

›Higher pulmonary edema risk with fluid loading

›Baseline cardiac disease increasing vasopressor sensitivity

›Goals of care

›Early discussion given higher toxicity-related mortality in older recipients

Pediatrics

›Pediatric CAR-T toxicity considerations

›Recognition differences

›Irritability or behavioral change as an early neurotoxicity clue

›Institutional pediatric CAR-T toxicity pathway typically drives management

›Weight-based dosing examples

›Tocilizumab 12 mg/kg IV for patients under 30 kg, 8 mg/kg IV for patients 30 kg or greater

›Verify against current pediatric guideline before use

10Background/b31

Epidemiology

›Incidence

›Cytokine release syndrome of any grade

›Roughly 70 to 90 percent of CD19-directed CAR-T recipients

›Severe, grade 3 or higher, cytokine release syndrome in roughly 10 to 30 percent

›Immune effector cell-associated neurotoxicity syndrome

›Roughly 20 to 40 percent of CD19-directed CAR-T recipients overall

›Severe, grade 3 or higher, neurotoxicity in roughly 10 to 30 percent depending on product

›Mortality

›Direct cytokine release syndrome mortality under 5 percent with current management

›Cerebral edema carries a substantially higher case mortality than other neurotoxicity presentations

Pathophysiology

›Mechanism

›T-cell activation cascade

›Engineered T-cell engagement of the target antigen

›Massive release of interleukin-6, interferon-gamma, and other cytokines

›Endothelial activation

›Capillary leak

›Distributive vasodilation

›Neurotoxicity mechanism

›Cytokine-mediated endothelial activation across the blood-brain barrier

›Passage of activated immune cells and cytokines into the central nervous system, distinct from the systemic interleukin-6 pathway that tocilizumab blocks

›HLH-like overlap mechanism

›Macrophage activation from sustained cytokine exposure

›Hemophagocytosis and coagulopathy in severe cases

Therapeutic Considerations

›Rationale for key interventions

›Early tocilizumab reduces progression to severe cytokine release syndrome without reducing CAR-T efficacy in most reported experience

11Patient Discharge Instructions/pdi24

Copy discharge instructions

›Discharge only after direct treating-center confirmation

›Diagnosis and expected course

›Explanation of cytokine release syndrome and its expected timeline

›Temperature monitoring

›Check temperature at least twice daily

›Return immediately for temperature 38.0 C or higher

›Neurologic self and caregiver monitoring

›Caregiver instructed to check orientation, speech, and handwriting daily

›Return immediately for new confusion, word-finding difficulty, tremor, or weakness

›Return to ED immediately for

›Fever

›Chills or rigors

›Shortness of breath

›Dizziness or fainting

›New confusion or personality change

›New tremor, slurred speech, or weakness

›Any seizure activity

›Severe headache

›Decreased urination

›Wallet card and follow-up

›Carry the CAR-T wallet card at all times

›Show the wallet card to any treating provider immediately

›Treating cellular therapy center contact information provided and confirmed

›Follow-up within 24 to 48 hours with the treating center

12References/r12

Guidelines and consensus

›American Society for Transplantation and Cellular Therapy consensus grading for cytokine release syndrome and neurotoxicity, Lee et al, 2019

›Cytokine release syndrome grading by fever, hypotension, and hypoxia

›Immune effector cell-associated neurotoxicity syndrome grading by the immune effector cell encephalopathy score, consciousness, seizure, motor findings, and cerebral edema

›National Comprehensive Cancer Network guidance on management of immunotherapy-related toxicities

›Tocilizumab and corticosteroid sequencing by grade

›Tocilizumab prescribing information for cytokine release syndrome, US Food and Drug Administration approved indication

›Weight-based dosing and maximum dose and repeat-dosing limits

Landmark trials and product data

›ZUMA-1 trial of axicabtagene ciloleucel in large B-cell lymphoma

›Cytokine release syndrome and neurotoxicity incidence and grading data informing current management

›JULIET and ELIANA trials of tisagenlecleucel

›Cytokine release syndrome incidence data in pediatric and adult populations

›Source file

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed September 13, 2026

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.