title: Immunophenotypic analysis of CD103+ B-lymphoproliferative disorders: hairy cell leukemia and its mimics.
abstract: CD103 is characteristically expressed in hairy cell leukemia (HCL), a B-lymphoproliferative disorder highly responsive to treatment with purine analogs. Other CD103+ diseases are rare and do not respond well to the same therapy, including HCL variant (HCLv) and splenic marginal zone B-cell lymphoma (SMZL) variants. We analyzed 215 cases of CD103+ B-lymphoproliferative disorders to further delineate their immunophenotypic features. Flow cytometric analysis revealed that 78.6% of all cases expressed CD25 and CD103, characteristic of classical HCL. Cases analyzed immunohistochemically were also invariably positive for annexin-A1; a subset coexpressed CD10 (33/169 [19.5%]) or BCL1 (26/65 [36.9%]). In contrast, 21.4% of cases lacked CD25, a subset of which was analyzed and was invariably negative for annexin-A1, CD10, and BCL1. The CD25- cases had variable morphologic features ranging from HCLv and SMZL to prolymphocytic leukemia and diffuse large B-cell lymphoma. Clinically, patients with CD25- disease tended to be older (P= .001), typically had leukocytosis (P= .014), and did not respond well to cladribine or pentostatin. We suggest categorizing CD103+ B-lymphoproliferative disorders into 2 groups. While HCL coexpresses CD25 and annexin-A1, diseases lacking CD25 and annexin-A1 behave clinically differently and can be separated from HCL on diagnosis.
authors.affiliation: Genzyme Genetics, 521 W 57th St, New York, NY 10019, USA.
authors.forename: Henry Y
authors.initials: HY
authors.lastname: Dong
authors.forename: James
authors.initials: J
authors.lastname: Weisberger
authors.forename: Zach
authors.initials: Z
authors.lastname: Liu
authors.forename: Sorina
authors.initials: S
authors.lastname: Tugulea
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis*; D003937:Diagnosis, Differential; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D039001:Integrin alpha Chains / Q000096:biosynthesis*; D053645:Interleukin-2 Receptor alpha Subunit / Q000096:biosynthesis*; D007943:Leukemia, Hairy Cell / Q000145:classification* / Q000378:metabolism / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000145:classification / Q000378:metabolism / Q000473:pathology; D018000:Receptors, Peptide / Q000096:biosynthesis*
chemical_list: D015703:Antigens, CD; D039001:Integrin alpha Chains; D053645:Interleukin-2 Receptor alpha Subunit; D018000:Receptors, Peptide; C091367:alpha E integrins; C515222:annexin-A1 receptor, human