sCD22 vs tumor burden. sCD22 levels were obtained in 82 HCL patients with the indicated concentrations of circulating leukemic cells, determined by flow cytometry (A). The products of malignant cell counts and CD22 sites/cell are shown in panel B as cell-bound CD22 sites/mm³. sCD22 vs spleen height was assessed for 22 HCL patients with spleens present (C). The vertical dashed line indicates the spleen size (160 mm) used in comparing sCD22 levels in patients with large and small spleens by rank-order (Wilcoxon) analysis.