Secondary hematological dysplasia after CAR-T for acute lymphoblastic leukemia in children

In adults, secondary myelodysplastic syndromes (MDS) after CAR-T have been described. There are currently no data on the risk of MDS following CAR-T in children treated for acute lymphoblastic leukemia (ALL). A study at Hospital Sant Joan de Déu in Barcelona (Spain) investigated this risk. A total of 106 pediatric patients received CAR-T for ALL. Among 40 patients without early relapse or subsequent therapy after CAR-T, four fulfilled the WHO criteria for myelodysplasia. These four patients had received hematopoietic stem cell transplantation (HSCT) prior to CAR-T and presented cytopenias with severe dysplastic changes in bone marrow after CAR-T. One patient had clonal MDS with high-risk cytogenetics arising from the host cells requiring a HSCT. Three patients had non-progressive dysplasia arising from the donor cells. Two are alive in complete remission with stable cytopenias and one succumbed to ALL relapse. The authors conclude that this is the first description of post-CAR-T MDS and hematological dysplasia in children and highlights the need to monitor childred with persistent post-CAR-T cytopenias.