No BCL-2 protein over expression but BCL-2/IgH rearrangements in B cells of patients with persistent polyclonal B-cell lymphocytosis.
BACKGROUND
Persistent polyclonal B-cell lymphocytosis is a rare hematological disorder, characterized by a chronic, stable and absolute polyclonal lymphocytosis, the presence of binucleated lymphocytes, a polyclonal increase in serum IgM immunoglobulin and clonal cytogenetic abnormalities involving chromosome 3. For explaining the expansion of B-lymphocytes pool in PPBL, an association with cigarette smoking and/or chronic Epstein-Barr virus infection have been suggested but both hypotheses have been ruled out.


METHODS
We studied the presence of BCL-2/IgH rearrangements in a series of eight PPBL patients (seven females and one male) by a nested polymerase chain reaction (PCR), targeting the Major Breakpoint Region in BCL-2 locus and we explored the BCL-2 protein expression by Western blot.


RESULTS
We demonstrated: (a) the constant presence of BCL-2/IgH rearrangements in eight out of eight DNA samples, (b) multiple rearrangements in three out of eight cases and, (c) normal BCL-2 protein expression, as compared to BCL-2 level in B-lymphocytes from healthy population.


CONCLUSIONS
Despite the presence of BCL-2/IgH rearrangements, the accumulation of B lymphocytes in PPBL is not related to an overexpression of BCL-2 protein.
Lancry
L
L
UPRES-EA 2128, UFR de Médecine, CHU Côte de Nacre, Caen, France.
Roulland
S
S
Roué
G
G
Mossafa
H
H
Salaün
V
V
Chèze
S
S
Gauduchon
P
P
Hardouin
A
A
Sola
B
B
Troussard
X
X
D000328:Adult; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D001483:Base Sequence; D015153:Blotting, Western; D005260:Female; D015322:Gene Rearrangement, B-Lymphocyte / Q000235:genetics*; D005803:Genes, Immunoglobulin / Q000235:genetics*; D006801:Humans; D008218:Lymphocytosis / Q000209:etiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism*
D019253:Proto-Oncogene Proteins c-bcl-2