Assessment of expression of selected Bcl-2 family proteins in lymphoid infiltration in patients with B-cell chronic lymphocytic leukaemia treated with nucleoside analogues.

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Assessment of expression of selected Bcl-2 family proteins in lymphoid

infiltration in patients with B-cell chronic lymphocytic leukaemia treated with

nucleoside analogues.

D Lemancewicz, J Dzieciol, J Piszcz, A Lebelt, K Mazgajska-Barczyk, B Klim, and

J Kloczko

Folia Histochem Cytobiol, January 1, 2008; 46(3): 361-6.

Department of Human Anatomy, Medical University of Bialystok Department of

Haematology, Medical University of Bialystok.

B-cell chronic lymphocytic leukaemia (B-CLL) is characterized by clonal growth

and accumulation of mature lymphoid cells due to disturbance in genetically

regulated form of cell death called apoptosis. The intrinsic mechanism of

apoptosis is controlled by Bcl-2 family proteins. Purine nucleoside analogues

induce the apoptosis in cells in a state of quiescence. The aim of the study was

to assess expression of selected Bcl-2 family proteins in neoplastic

infiltration in bone marrow in patients with B-CLL treated with nucleoside

analogues. The study comprised examination of bone marrow obtained routinely by

trephine biopsy from 18 patients with B-CLL diagnosed before administration of

purine nucleoside analogues treatment and after its completion. Expression of

Bcl-2, Bcl-x and Bax proteins was examined. Lymphoid cells in bone marrow were

present in all patients before administration of treatment. After treatment in

two patients bone marrow was infiltrated in diffuse pattern, whereas other

patients presented nodular pattern of infiltration. The difference between stage

of infiltration before and after treatment was statistically significant

(p<0.002). High percentage of infiltration cells with positive anti Bcl-2

reaction from 42.0% in one patient to 85.33+/-3.06% in four patients before

treatment was observed. After treatment percentage of infiltration cells with

positive anti Bcl-2 antibody reaction was from 33.0+/-18.38% in two patients to

99.0% in one patient. Positive correlation between stage of infiltration and

expression of Bcl-2 protein was confirmed before and after treatment. Such

correlations were not observed in case of Bax and Bcl-x. Strong staining of

immunohistochemical reaction of cells in lymphoid infiltration with Bcl-2

antibody was confirmed. There was a difference between Bcl-/Bax ratio before and

after treatment. Immunohistochemical assessment of expression of Bcl-2 family

proteins in cells of lymphoid infiltration in bone marrow of patients with CLL

is an important method in detection of minimal residual disease (MRD) after

treatment.

PMID: 19056541