title: Surface phenotype and Ig heavy-chain gene usage in chronic B-cell leukemias: expression of myelomonocytic surface markers in CD5- chronic B-cell leukemia.
abstract: We investigated the surface expression of leukocyte differentiation antigens and the Ig heavy-chain variable region (VH) gene family use in leukemic cells from 26 Japanese patients with chronic B-cell leukemias with special reference to CD5 antigen expression. CD5 was expressed on leukemic cells in 21 of 26 cases (CD5+) but not in 5 cases (CD5-). Myelomonocytic marker, CD13 antigen was expressed on the leukemic cells in all 5 CD5- cases but in none of CD5+ cases. Leukemic cells in CD5- cases also expressed CD11b antigen more frequently than those in CD5+ cases (80% v 11%; P < .01). Another myeloid marker, CD33, was expressed neither on CD5+ nor CD5- leukemic cells. CD22, a restricted B-cell marker, was expressed more frequently on CD5- leukemic cells than on CD5+ leukemic cells (80% v 33%; P < .05). Another restricted B-cell activation marker, CD23, was expressed at similar frequency in both the CD5+ and CD5- groups (67% v 60%). Although CD45RA was expressed on the majority of leukemic B cells, the CD45RA expression level was significantly higher among CD5- cases than CD5+ cases (P < .01). In the analysis of VH gene expressed in chronic B-cell leukemias by polymerase chain reaction amplification, CD5+ cases preferentially used VH4 family members (48%; 10 of 21). CD5- cases, on the other hand, mainly used VH3 family (80%; 4 of 5). Thus, from our present observation of an albeit limited patient population, we have found an association between VH gene family use and CD5 antigen expression in chronic B-cell leukemias. We have also shown the differential expression of myelomonocytic markers in the CD5+ and CD5- chronic B-cell leukemias. These result are in agreement with previous suggestions that CD5 positivity is the hallmark for distinct clinical entity commonly referred to in the literature as chronic lymphocytic leukemia.
authors.affiliation: First Department of Internal Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: W
authors.initials: W
authors.lastname: Ikematsu
authors.forename: H
authors.initials: H
authors.lastname: Ikematsu
authors.forename: S
authors.initials: S
authors.lastname: Okamura
authors.forename: T
authors.initials: T
authors.lastname: Otsuka
authors.forename: M
authors.initials: M
authors.lastname: Harada
authors.forename: Y
authors.initials: Y
authors.lastname: Niho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000032:analysis*; D001483:Base Sequence; D018956:CD5 Antigens; D005260:Female; D006098:Granulocytes / Q000276:immunology*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D016130:Immunophenotyping; D007564:Japan; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000032:analysis; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009000:Monocytes / Q000276:immunology*; D016133:Polymerase Chain Reaction
chemical_list: D015703:Antigens, CD; D018956:CD5 Antigens; D007143:Immunoglobulin Heavy Chains; D017493:Leukocyte Common Antigens