Fig. 4.

APRIL and BAFF CSF levels are associated with treatment response and relapse—a representative patient example. CSF levels of APRIL and BAFF (a) and corresponding, representative MRI images (b–g, T1 after gadolinium) of a 61-year-old female patient with newly diagnosed multilocular PCNSL in the right temporal lobe, the left posterior splenium, the left temporopolar lobe, and meningeosis lymphomatosa with basal meningeal enhancement over a period of 14 months. Initially, CSF levels of APRIL and BAFF decrease during 6 cycles of MTX-based polychemotherapy (CT), corresponding to radiological response (b–e). At relapse, APRIL and BAFF CSF level increase (a), while MRI (f) shows relapsed disease next to the third ventricle, which subsided after 3 (of 6) cycles of repeated CT (g). Correspondingly, APRIL and BAFF CSF levels decreased (a)