Quadriparesis and paraparesis following chimeric antigen receptor T-cell (CART) therapy in children and adolescents.

Immune effector cell-associated neurotoxicity syndrome (ICANS) is a common but potentially severe adverse event associated with chimeric antigen receptor T-cell (CART) therapy characterized by the development of acute neurologic symptoms following CART infusion. ICANS encompasses a wide clinical spectrum typified by mild to severe encephalopathy, seizures and/or cerebral edema. As more patients have been treated with CART new ICANS phenomenology has emerged. We present the clinical course of five children who developed acute onset of quadriparesis or paraparesis associated with abnormal brain and/or spine neuroimaging after infusion of CD19 or CD22-directed CART, adverse events not previously reported in children. Orthogonal data from autopsy studies, cerebrospinal fluid (CSF) flow cytometry and CSF proteomics/cytokine profiling demonstrated chronic white matter destruction, but a notable lack of inflammatory pathologic changes and cell populations. Instead, children with quadriparesis or paraparesis post-CART therapy had lower levels of pro-inflammatory cytokines such as interferon gamma (IFN), CCL17, CCL23, and CXCL10 than those who did not develop quadriparesis or paraparesis. Taken together, these findings imply a non-inflammatory source of this newly described ICANS phenomenon in children. The pathophysiology of some neurologic symptoms following CART may therefore have a more complex etiology than exclusive T-cell activation and excessive cytokine production.

How I treat early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) in children.

Early T-precursor acute lymphoblastic leukemia (ETP-ALL) is a unique subtype of immature T-ALL that was initially associated with a dramatically inferior prognosis as compared to non-ETP T-ALL (Not-ETP) when it was first described in 2009. Analyses of larger patient cohorts treated with more contemporary regimens, however, have shown minimal survival differences between ETP and Not-ETP. In this manuscript we utilize representative cases to explore therapeutic advances and address common clinical questions regarding management of children, adolescents, and young adults with ETP-ALL. We describe our recommended treatment approach for a child or adolescent with newly diagnosed ETP-ALL, with an emphasis on the prognostic significance of induction failure and detectable minimal residual disease and the role for hematopoietic stem cell transplant in first remission. We discuss the interplay between the ETP immunophenotype and genomic markers of immaturity in T-ALL. Finally, we review novel therapeutic approaches that should be considered when managing relapsed or refractory ETP-ALL.