Cytokine Release Syndrome (CRS) is a life-threatening hyperinflammatory syndrome triggered by immune effector cell therapies, characterized by:

• Massive T cell and macrophage activation following CAR-T cell infusion or bispecific antibody administration
• IL-6 cytokine storm — the central driver of fever, hypotension, and hypoxia
• Macrophage amplification loop — IFN-γ and GM-CSF activate macrophages → IL-6 ↑↑ → further endothelial damage
• Multi-organ involvement — cardiovascular (Takotsubo cardiomyopathy), hepatic, renal, coagulopathy
• ICANS (Immune Effector Cell-Associated Neurotoxicity Syndrome) — BBB disruption, cerebral edema

CRS occurs in 50-90% of CD19 CAR-T patients (grade ≥ 2 in 20-30%) and virtually all bispecific antibody patients (grade 1-2 most common). Mortality from severe CRS/ICANS has declined from >10% to <3% with modern management.

Click image to open high-resolution SVG. Contains 10 clusters, 100+ nodes covering: immunotherapy trigger, T cell activation/expansion, T cell–derived cytokines, macrophage/myeloid activation, IL-6/JAK-STAT signaling network, endothelial/vascular response, ASTCT CRS grading, ICANS neurotoxicity, drug PK/PD (tocilizumab, siltuximab, DEX, ruxolitinib, anakinra), and clinical outcomes.

22 ODE compartments — CAR-T dynamics, cytokine cascade, macrophage activation, IL-6 signaling, endothelial/vascular response, CRS severity, organ damage + drug PK:

5 Treatment Scenarios:

1. Patient Profile — CAR-T therapy type selector, tumor burden/dose sliders, treatment checkboxes, CRS grade trajectory, pathophysiology summary
2. Drug PK — Concentration-time profiles for all 5 drugs, PK parameter table, mechanism-of-action summary
3. Cytokine Storm — IFN-γ & IL-6 (key drivers), IL-1β & TNF-α, macrophage activation, CAR-T expansion, IL-6 downstream (STAT3, endothelial)
4. Clinical Endpoints — CRS severity (0-4), survival probability, organ damage, temperature/fibrinogen, ICANS score
5. Scenario Comparison — Side-by-side for all 5 treatment scenarios: IFN-γ, IL-6, CRS severity, survival, summary table
6. Biomarkers & CRS Grading — CRS biomarker index, ferritin (log scale), CRP, ICANS trajectory, ASTCT criteria tracker

Run the Shiny app:

install.packages(c("shiny", "shinydashboard", "ggplot2", "dplyr", "tidyr", "plotly"))
shiny::runApp("crs_shiny_app.R")

CAR-T Infusion / Bispecific Ab Administration (Day 0)
         |
         v
Antigen Recognition → CAR-T Activation → IL-2 (autocrine), IFN-γ↑↑, GM-CSF↑
         |                                                     |
         v                                                     v
T Cell Expansion (peak Day 7-14)                    IFN-γ + GM-CSF →
(CD28: faster/severe)                               Macrophage M1 Activation
(4-1BB: slower/milder)                              (JAK1-STAT1 pathway)
                                                              |
                                                              v
                                                    IL-6↑↑↑ (main CRS driver)
                                                    IL-1β↑ (NLRP3 inflammasome)
                                                    TNF-α↑
                                                              |
                    ┌─────────────────────────────────────────┤
                    │                                         │
                    v                                         v
         IL-6 → Endothelial Activation              IL-1β + IL-6 → Fever
         → NO↑ → Vasodilation → HYPOTENSION         (hypothalamus PGE2)
         → VEGF/ANG2 → Vascular Leak → HYPOXIA
                    │
                    v
         BBB disruption → CNS macrophage activation
         → ICANS (encephalopathy, seizures)
                    │
                    v
         ASTCT CRS Grade 1→2→3→4
         (Fever → Hypotension/Hypoxia → Vasopressors → Vent/ECMO)

TREATMENT:
Tocilizumab → IL-6R blockade (gp130 + sIL-6R trans-signaling)  [Grade ≥2 CRS]
Siltuximab  → Direct IL-6 neutralization                        [Alternative]
DEX         → NF-κB inhibition → ↓IL-6, TNF, IFN-γ + BBB       [All ICANS grades]
Ruxolitinib → JAK1/2 inhibition → ↓pSTAT3, ↓pSTAT1             [Refractory]
Anakinra    → IL-1R blockade → ↓NLRP3 pathway                   [MAS-type/pediatric]

Note: Any one of fever, hypotension, or hypoxia determines grade.

See crs_references.md for 55 PubMed-cited references covering:

• Pivotal CAR-T trials (ZUMA-1, JULIET, TRANSCEND, KymRAH Phase 3)
• Bispecific antibody studies (blinatumomab, teclistamab, glofitamab)
• CRS grading systems (Lee 2014, ASTCT 2019)
• Macrophage biology (Giavridis 2018 Nat Med, Norelli 2018 Nat Med)
• Cytokine biomarkers (Teachey 2016 Cancer Discov)
• Tocilizumab PK/PD
• Ruxolitinib + anakinra for refractory CRS/HLH

Model created: 2026-06-26 | Part of the QSP Disease Model Library