Persistent polyclonal B lymphocytosis: an expansion of cells showing IgVH gene mutations and phenotypic features of normal lymphocytes from the CD27+ marginal zone B-cell compartment.
Persistent polyclonal B-cell lymphocytosis (PPBL) is an unusual and benign lymphoproliferation characterized by a polyclonal expansion of B lymphocytes, whose nature remains undetermined. The phenotypic analysis of three cases revealed that these cells were CD27+ IgM(high) CD21(high) CD5(low) and CD23(low), a phenotype associated with the normal marginal zone (MZ) B-cell compartment. As MZ B cells have initiated immunoglobulin (Ig)V gene somatic mutations, PPBL IgVH genes were sequenced. An average of 73% of these sequences were mutated. The mean number of mutation per sequence was 6.9, a number similar to those observed in the MZ B-cell compartment.
Salcedo
Irene
I
Servicio de Inmunología and Unidad de Investigación, Hospital Universitario Puerta del Mar, Cádiz, Spain.
Campos-Caro
Antonio
A
Sampalo
Almudena
A
Reales
Elena
E
Brieva
José A
JA
D000328:Adult; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D002455:Cell Division / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D005803:Genes, Immunoglobulin / Q000235:genetics*; D006801:Humans; D016130:Immunophenotyping; D008218:Lymphocytosis / Q000235:genetics / Q000276:immunology*; D008875:Middle Aged; D009154:Mutation; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000032:analysis*
D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7