Immune and Inflammatory Markers May Help Assess CAR T-Cell Complication Risk

Identifying which patients are more likely to develop this complication remains a challenge before treatment, limiting opportunities for closer monitoring and risk assessment. A new study shows that baseline immune cell levels and inflammation are associated with CRS risk following CAR T-cell therapy.

Investigators at Universitätsklinikum Erlangen (Erlangen, Germany) and collaborating institutions evaluated biomarkers that could predict the incidence and severity of cytokine release syndrome (CRS) in patients with autoimmune diseases treated with autologous CAR T-cell therapy. The retrospective cohort study included patients from six centers in Germany and one in China and focused on immune and inflammatory markers measured before CAR T-cell administration.

The study included 108 patients with autoimmune diseases who received autologous CAR T-cell therapy between March 1, 2021, and July 1, 2025. CRS developed in 80% of patients following treatment. CRS was grade 1 in 66% of patients, grade 2 in 13%, and grade 3 in 1%.

Immune effector cell-associated neurotoxicity syndrome was also observed in three patients, representing 3% of the cohort. This included grade 1 cases in 2% of patients and grade 2 cases in 1%. Patients who developed CRS had significantly higher baseline B-cell counts, interleukin-6 (IL-6) concentrations, and C-reactive protein levels.

Multivariable logistic regression confirmed the association between CRS and both B-cell counts and IL-6 concentrations. The reported odds ratios were 1.31 for B-cell counts and 2.28 for IL-6 concentrations. The findings were published in the November issue of The Lancet Rheumatology and support biomarker-based identification of patients at increased risk for CRS, with the authors noting potential relevance for preventive treatment or more intensive monitoring before and after CAR T-cell administration.

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Universitätsklinikum Erlangen