Fig. 1

Increase of PD-1 and PD-L1 positivity after treatment with blinatumomab. a CD19 vs. CD34 expression of lymphoblasts detected by flow cytometry. Lymphoblasts showed homogenous expression of CD19 at baseline (pre-treatment) as well as after blinatumomab treatment (post-treatment). b Lymphocyte counts on peripheral blood during blinatumomab treatment. Lymphocyte counts decreased during blinatumomab treatment (1596/μl on day 0, 986/μl on day 7, 464/μl on day 14, 368/μl on day 21, and 217/μl on day 28). c Hematoxylin and eosin stain of paraffin embedded bone marrow core biopsy showing diffuse infiltration of immature progenitors at both time points (pre-treatment blast count 30 %, post-treatment 60 %). d Immunohistochemistry of paraffin embedded bone marrow core biopsy stained for CD3 showing spotted infiltration of CD3-positive T cells at baseline (5–10 %, pre-treatment) and diffuse infiltration after blinatumomab treatment (20–30 %, post-treatment). e Immunohistochemistry of paraffin embedded bone marrow core biopsy stained for PD-1 showing 5 % PD-1-positive cells at baseline (pre-treatment) vs. 15 % after blinatumomab treatment (post-treatment). f Immunohistochemistry of paraffin embedded bone marrow core biopsy stained for PD-L1 showing 2 % PD-L1-positive blasts at baseline (pre-treatment) vs. 40 % after blinatumomab treatment (post-treatment)