Kinetics of humoral deficiency in CART19-treated children and young adults with acute lymphoblastic leukaemia
Àngela Deyà‐Martínez, Anna Alonso‐Saladrigues, A. P. García, Anna Faura, Montserrat Torrebadell, Alexandru Vlagea, Albert Català, Ana Esteve‐Solé, Manel Juan, Susana Rives, Laia Alsina
Abstract
CD19-CAR T-cell therapy (CART19) causes B-cell aplasia (BCA) and dysgammaglobulinemia but there is a lack of information about the degree of its secondary immunodeficiency. We conducted a prospective study in children and young adults with acute lymphoblastic leukaemia treated with CART19, analysing the kinetics of BCA and dysgammaglobulinemia during therapy, as well as the B-cell reconstitution in those with CART19 loss. Thirty-four patients were included (14 female) with a median age at CART19 infusion of 8.7 years (2.9-24.9). Median follow-up after infusion was 7.1 months (0.5-42). BCA was observed 7 days after infusion (3-8), with persistence at 24 months in 60% of patients. All patients developed a progressive decrease in IgM and IgA: 71% had undetectable IgM levels at 71 days (41-99) and 13% undetectable IgA levels at 185 days (11-308). Three of 12 patients had protective levels of IgA in saliva. In two of three patients who lost CART19, persistent B-cell dysfunction was observed. No severe infections occurred. In conclusion, BCA occurs soon after CART19 infusion, with a progressive decrease in IgM and IgA, and with less impairment of IgA, suggesting the possibility of an immune reservoir. A persistent B-cell dysfunction might persist after CART19 loss in this population.