Transient lymphocytosis in CLL patients after treatment with the BTK inhibitor ibrutinib or GCs. (A) Trended ALC, hemoglobin levels (Hb), absolute neutrophil counts (ANC), and platelet counts (Plt) in 2 CLL patients (CLL #1, CLL #2) during continuous therapy with the BTK inhibitor ibrutinib at a dose of 420 MG daily. The horizontal axis shows the time of treatment. Please note the early, transient lymphocytosis, which peaked during the first weeks of therapy, then resolved, and both patients continue on therapy at 24+ months. (B) Effect of prednisone therapy on white cell counts in CLL patients (adapted from Shaw et al55 ) is shown. In 16 of 18 patients a rapid increase in the total white cell count occurred during prednisone administration. This increase in the white count was noted early, the maximum occurring at 2 weeks, and could almost entirely be accounted for by an increase in lymphocytes. Subsequently the white cell count gradually decreased, reaching pretreatment values at the end of prednisone therapy and 2 months later were significantly below pretreatment values.
