Change in serum total IgG concentrations after CD19-CARTx. (A) Spaghetti plot of serum total IgG concentrations before and after CD19-CARTx; 162 total IgG measurements were obtained for 35 participants. Each line represents 1 participant. A dashed reference line is shown at 400 mg/dL, the concentration below which IVIG was recommended. Data from samples obtained ≤16 weeks after IVIG administration were excluded.  (B) Forest plot showing linear mixed-effects model estimates for the mean change in serum total IgG concentrations. Exploratory subgroup estimates were computed from separate models, including the subgroup variable, the time period (post- vs pre–CD19-CARTx), and their interaction. For underlying disease, interaction P = .04. Filled squares represent the change estimates, and bars indicate the 95% CI. Dashed vertical reference lines are shown at our prespecified noninferiority margin and at no change. LCL, lower confidence limit of the 95% CI; UCL, upper confidence limit of the 95% CI.