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

Abstract

Summary. 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 sequenced. An average of 73% of these sequences were mutated. The mean number of mutation per sequence was 6AE9, a number similar to those observed in the MZ B-cell compartment.

Intravascular bone marrow accumulation in persistent polyclonal lymphocytosis: a misleading feature for B-cell neoplasm

“…Although normal karyotypes were observed here in five patients, we observed one case of trisomy 3, a chromosomal anomaly reported in a few cases of PPBL. [27][28][29] We also observed a deletion of chromosome 6 in one case, as did Salcedo et al 29 However, the predominant chromosomal anomaly, the follicular lymphoma-associated t(14;18) translocation has been reported in most of PPBL patients, 30 including four out of the six patients tested in our series. Multiple Bcl-2/IgH gene rearrangements were present in most of the PPBL cases we report, indicating that an alteration of the B-cell population could result in the generation of several clones of B cells carrying variants of the t(14;18).…”

Response to antiviral treatment in hepatitis C virus-associated marginal zone lymphomas

“…44 Trisomy 3 is recurrent in MZL 45 and PPLB shares immunophenotypic characteristics with the normal CD27 compartment of the marginal zone. 46 Therefore, this particular case of HCVassociated lymphoid proliferation could represent a relationship between PPBL and MZL Antiviral treatment resulted in hematologic response in patients 1-5. A correlation between hematologic and virologic response was noted in some cases.…”

SAIVGeM: Spreadsheet Analysis of Immunoglobulin V H Gene Mutations

“…Fifty-one immunoglobulin sequences from persistent polyclonal B lymphocytosis (PPBL) patients (16) were downloaded from GenBank (accession nos. AYO33238AYO33288) and formatted for SAIVGeM analysis using the Megalign v5.06 sequence alignment software (DNAStar, Madison, WI, USA).…”