title: Monoclonal CD5+ and CD5- B-lymphocyte expansions are frequent in the peripheral blood of the elderly.
abstract: The responsiveness and diversity of peripheral B-cell repertoire decreases with age, possibly because of B-cell clonal expansions, as suggested by the incidence of serum monoclonal immunoglobulins and of monoclonal chronic lymphocytic leukemia (CLL)-like B lymphocytes in clinically silent adults. We phenotyped peripheral blood cells from 500 healthy subjects older than 65 years with no history or suspicion of malignancies and no evidence of lymphocytosis. In 19 cases (3.8%) a kappa/lambda ratio of more than 3:1 or less than 1:3 was found: 9 were CD5+, CD19+, CD23+, CD20low, CD79blow, sIglow (classic CLL-like phenotype); 3 were CD5+, CD19+, CD23+, CD20high, CD79blow, sIglow (atypical CLL-like), and 7 were CD5-, CD19+, CD20high, CD23-, CD79bbright, FMC7+, sIgbright (non-CLL-like). In 2 subjects, 2 phenotypically distinct unrelated clones were concomitantly evident. No cases were CD10+. Polymerase chain reaction (PCR) analysis demonstrated a monoclonal rearrangement of IgH genes in 15 of 19 cases. No bcl-1 or bcl-2 rearrangements were detected. Using a gating strategy based on CD20/CD5/CD79 expression, 13 additional CLL-like B-cell clones were identified (cumulative frequency of classic CLL-like: 5.5%). Thus, phenotypically heterogeneous monoclonal B-lymphocyte expansions are common among healthy elderly individuals and are not limited to classic CLL-like clones but may have the phenotypic features of different chronic lymphoproliferative disorders, involving also CD5- B cells.
authors: Istituto per la Ricerca e la Cura del Cancro, Candiolo, Italy. paolo.ghia@unito.it
authors: Paolo
authors: P
authors: Ghia
authors: Giuseppina
authors: G
authors: Prato
authors: Cristina
authors: C
authors: Scielzo
authors: Stefania
authors: S
authors: Stella
authors: Massimo
authors: M
authors: Geuna
authors: Giuseppe
authors: G
authors: Guida
authors: Federico
authors: F
authors: Caligaris-Cappio
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D018956:CD5 Antigens / Q000276:immunology*; D002999:Clone Cells; D005260:Female; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D019940:Genes, bcl-1 / Q000276:immunology; D019254:Genes, bcl-2 / Q000276:immunology; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood / Q000235:genetics; D016130:Immunophenotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology; D008297:Male
chemical_list: D018956:CD5 Antigens; D007147:Immunoglobulin Light Chains