Non-proliferating plasma cells in the brain of multiple sclerosis patients. a DAPI (blue), CD138 (green) and Ki67 (red) were stained in the CNS of patient biopsies with multiple sclerosis (n = 4). Representative images are shown. Scale bar represents 50 µm. b HE, MBP, CD3, CD8, CD4, CD68, CD20 and CD138 staining was performed in the CNS of patients with multiple sclerosis (n = 5) in serial slides. Representative images of one patient are shown. Scale bars represent 100 μm.