Median absolute peripheral blood CD4⁺, CD8⁺, CD16⁺56⁺, CD19⁺, and monocytic cell levels after alemtuzumab therapy. Cell levels were measured at baseline (0), 6 and 12 weeks (W), and 6-24 months (M) after alemtuzumab therapy. The number of patients evaluated at each time point were as follows: 0, n = 26; 6W, n = 18; 12W, n = 22; 6M, n = 16; 9M, n = 17; 12M, n = 13; 15M, n = 10; 18M, n = 11; and 24M, n = 8.