Impact Of The Number Of Prior Treatment Lines Received On The Distribution Of Peripheral Blood Leukocyte Subsets In Advanced-Stage B-Cell Chronic Lymphocytic Leukemia (CLL)

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4158-4158
Author(s):  
Georgiana Grigore ◽  
Susana Barrena ◽  
Martin Perez-Andres ◽  
Miriam Fierro ◽  
Marcos González ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Lymphocytic Leukemia ◽  
Advanced Stage ◽  
Absolute Count ◽  
Purine Analogues ◽  
Previously Treated Patients ◽  
Previously Treated ◽  
The Absolute ◽  
B Cell Subsets

Abstract Introduction It is currently well-known that B-cell chronic lymphocytic leukemia (CLL) patients have an impaired immune function -particularly in advanced disease-, which significantly contributes to a higher risk of infections. The introduction of new effective therapeutic agents, such as the purine analogues (or alkylating agents with concomitant properties of purine analogues) plusanti-CD20 monoclonal antibodies, have significantly increased the rate of complete responses in CLL, but so far their impact on the overall immune function and the spectrum of infections occurring in CLL patients after therapy, remains to be fully understood. Aim To evaluate the effect of the number of treatment lines received on the different normal circulating leucocyte cell populations, including normal B-cell subsets, in advanced-stage treated CLL. Material and Methods The distribution of peripheral blood (PB) leukocytes was analyzed in 85 untreated CLL patients, and compared to that of 63 patients who had previously been treated with 1 line of treatment (n=39) or >1 line of treatment (n=24), and who failed to respond. Analysis was performed by 8-color flow cytometry with monoclonal antibodies against CD3, CD4, CD5, CD8, TCRgd, CD19, CD20, CD27, CD38, CD45, CD56, sIgM, sIgA, sIgG, sIgLambda and sIgKappa. Results The absolute count of circulating malignant B cells was not significantly different (p>0.05) in the untreated vs. previously treated patients who received 1 or >1 line of treatment (77,627±84,211 vs 67,994±72,087 vs 59,282±74,206 cells/uL; respectively). In contrast, as compared to untreated patients, PB normal B cells were found to be reduced in patients who had received either 1 line or >1 line of treatment (89±142 vs 36±57 and 23±32 cells/uL, p=0.004 and p<0.001, respectively), but at similar levels between the two groups of previously treated patients (p>0.05). When dissecting the normal B-cell subsets, therapy-related decreased B-cell numbers were mostly due to a reduced number of circulating memory B cells (67±98 vs 21±45 and 15±26 cells/uL; p=0.001 and p<0.001, respectively), including all memory isotypes: IgM (24±31 vs 5±13 and 5±6 cells/uL, p<0.001), IgG (25±59 vs 10±32 and 6±13 cells/uL; p=0.008) and IgA (18±30 vs 5±10 and 6±12 cells/uL; p=0.001 and p=0.003). No significant differences were found as regards the absolute count of immature (5±11 vs 8±26 and 3±11 cells/uL; p>0.05) and naïve (16±55 vs 6±18 and 4±8 cells/uL; p>0.05) B cells, nor for circulating plasma cells (3±18 vs 5±21 and 2±6 cells/uL; p>0.05), regardless of the therapy status. As compared to untreated patients, the absolute count of CD4+ T cells and CD4/CD8 double negative TCRαβ cells were significantly lower in patients with >1 line of treatment (1,836±1,340 vs 1,256±1,027 and 131±165 vs 56±97 cells/uL, p=0.03 and p=0.007 respectively) but not in those who had received only 1 line (1,477±1,349 and 201±747 cells/uL; p>0.05). In contrast, therapy did not show a significant impact on the absolute count of PB T CD8+ and TCRgd cells. No statistically significant differences were observed in the number of PB innate immune subpopulations including, neutrophils, eosinophils, basophils, monocytes, NK cells and dendritic cells. Conclusions While there are no differences regarding the number of leukemic cells, previously treated patients have significantly reduced counts of total and memory (all isotypes) normal B-cell subsets when compared to untreated patients. Together with this, CD4+ helper T cells could also be compromised after more than 1 line of treatment. Monitoring of these therapy-related immune defects could contribute to a better management of infectious complications in advanced-stage CLL patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals B-lymphocyte subpopulations in patients with rheumatoid arthritis and the effect of an interleukin-6 receptor inhibitor on them.

2019 ◽  
Vol 56 (6) ◽  
pp. 731-738
Author(s):  
E. V. Gerasimova ◽  
T. V. Popkova ◽  
A. P. Aleksankin ◽  
A. V. Martynova ◽  
E. L. Nasonov
Keyword(s):  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
Interleukin 6 ◽  
B Lymphocyte ◽  
Memory B Cells ◽  
Absolute Count ◽  
The Absolute ◽  
B Cell Subsets ◽  
Receptor Inhibitor

The clinical efficacy and safety of interleukin-6 (IL-6) receptor blockade have been well studied, but the data on the impact of therapeutic inhibition of IL-6 on B cells are scarce and contradictory. Preliminary reports have shown that B cell function and a humoral immune response may be modulated by an IL-6 receptor inhibitor.Objective: to assess the effect of 12-month tocilizumab (TCZ) therapy on B-cell phenotype and gene expression in RA and to analyze the association between B-cell subsets and RA activity.Subjects and methods. Examinations were made in 24 active RA patients (20 women and 4 men) (median age, 55 [49; 64] years; disease duration, 72 [24; 108] months; DAS28 5.8 [5.3; 6.3]; the patients were seropositive for rheumatoid factor (RF) (100%) and for anti-cyclic citrullinated peptide antibodies (87.3%). The patients received TCZ 8 mg/kg every 4 weeks. After 12 months of therapy, 54% of patients were categorized as good responders, 46% as moderate responders according to the EULAR response criteria. A control group consisted of 29 volunteers (21 women and 8 men; median age, 58.5 [53.0; 62.0] years). Peripheral blood lymphocytes were immunophenotyped at the time of enrollment and after 12 months. The absolute and relative counts of CD19+B lymphocytes, memory B cells (CD19+CD27+), non-switched memory B cells (CD19+IgD+CD27+), switched memory B cells (CD19+IgDCD27+), naive (CD19+IgD+CD27-), double-negative (CD19+IgD-CD27-), transitional (CD19+IgD+CD10+CD38++CD27) B cells, plasma cells (CD19+СD38+), and plasmablasts (CD19+СD38+++IgD-CD27+CD20-) were estimated using multicolor flow cytometry. Results and discussion. The relative and absolute counts of memory B cells (CD19+CD27+) (1.3 [0.9; 1.7]%, 0015 [0.001; 0.003]•109/l), switched memory B cells (CD19+IgD-CD27+) (6.8 [3.6; 11.6]%, 0.01 [0.005; 0.02]•109/l), and the absolute number of transitional B cells (CD19+CD38++CD10+IgD+CD27-) (0.00009 [0; 0.00028]•109/l) were found to be lower in RA patients than in donors: 2.2 [1.1; 3.0]%, 0.003 [0.001; 0.007]•109/l; 12.8 [9.3; 17.0]%, 0.02 [0.01; 0.04]•109/l; 0.0001 [0; 0.0003]•109/l, respectively (p<0.05 for all cases). After 12 months of TCZ therapy initiation, there were decreases in the relative and absolute counts of plasmablasts (CD19+CD38+++CD27+IgD-CD20-) from 0.15 [0.1; 0.3] to 0.1 [0.01; 0.1]% and from 0.0003 [0.00007; 0.004]•109/l to 0.0001 [0; 0.0003]•109/l, respectively (p<0.05). At the same time, the relative and absolute counts of memory B cells (CD19+CD27+) and switched memory B cells (CD19+CD27+IgD-) remained lower in RA patients than in donors: 1.0 [0.7; 1.2] and 2.2 [1.1; 3.0]%; 0.001 [0.006; 0.003]•109/l and 0.003 [0.001; 0.007]•109/l; 3.1 [1.1; 4.2] and 12.8 [9.3; 17.0]%; 0.003 [0.002; 0.006]•109/l and 0.02 [0.01; 0.04]•109/l, respectively (p<0.05 for all cases). Following 12 months of TCZ therapy, the numbers of other B-cell subpopulations were not considerably altered. When included in the study, the patients with RA showed correlations between the absolute count of memory B cells (CD19+CD27+) and the level of C-reactive protein (r=0.50; p<0.05); between the absolute count of plasmablasts (CD19+CD38+++CD27+IgD-CD20-) and the level of RF (r=0.41 and r=0.52; p<0.05). There were no correlations of B cell subsets with clinical and laboratory findings after 12 months of TCZ initiation.Conclusion. Immunophenotyping of peripheral blood B lymphocyte subsets showed the lower relative and absolute counts of memory B cells (CD19+CD27+) and switched memory B cells (CD19+CD27+IgD-) in RA patients than in healthy donors. The found correlations between the counts of memory B cells and plasmablasts and the values of laboratory parameters in patients with high RA activity may suggest that B lymphocytes are involved in the pathogenesis of RA. There was a decline in plasmablast levels after 12 months of TCZ therapy.

Different Expression of FcgammaRIIb in Chronic Lymphocytic Leukemia and Human Normal B Lymphocytes

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3134-3134
Author(s):  
Carol Moreno ◽  
Rajendra Damle ◽  
Sonia Jansa ◽  
Gerardo Ferrer ◽  
Pau Abrisqueta ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
B Lymphocytes ◽  
Surface Membrane ◽  
Memory B Cells ◽  
Lymphocytic Leukemia ◽  
Cd38 Expression ◽  
B Cell Subsets

Abstract The Fcgamma receptors (FcγRs) are a family of molecules that modulate immune responses. FcγRIIb is an inhibitory FcγR that bears immunoreceptor tyrosine-based inhibitory motifs which transduce inhibitory signals on coligation with the surface membrane Ig of the B-cell antigen receptor (BCR). The role of FcγRIIb in controlling B cell activation through inhibition of BCR signaling has been extensively studied in animal models. Nevertheless, data on FcγRIIb are scant in human normal and neoplastic B cells, this being due to the lack of a specific antibody for human FcγRIIb. Consequently, there is little information on this receptor in chronic lymphocytic leukemia (CLL). Considering the activated nature of CLL cells and the central role of the BCR in the biology of the disease, studies of FcγRs are warranted. We used a novel specific mAb directly conjugated with Alexa 488 fluorophore that solely reacts with the human FcγRIIb (MacroGenics, Inc.) to investigate the receptors expression on CLL and normal human B cells. The study population included 84 patients with CLL and 24 age- and sex-matched controls. FcγRIIb expression was assessed as the mean fluorescence intensity (MFI) of surface membrane staining. In CLL cells, FcγRIIb was measured on CD19+CD5+ cells in combination with CD38, CD49d or CD69. Normal B cells were immunostained for CD19, CD5, IgD and CD38 expression and B cell subsets: naïve (IgD+CD38−), activated (IgD+CD38+) and memory B cells (IgD−CD38−) were studied for their relative expression of FcγRIIb. FcγRIIb expression was found significantly higher in naïve B cells compared to activated and memory B cells [median MFI: 17420 (11960–21180) vs. 11.140 (7899–16970) and 11.830 (6984–17100); p&lt;0.001]. Significant differences were also observed between CD5− and CD5+ normal B cells. In contrast, FcγRIIb expression was lower in CLL cells than in CD5+ and CD5− normal B lymphocytes [median MFI: 6901(1034–42600), 10180 (5856–14820) and 12120 (7776–16040); p&lt;0.05)]. Interestingly, FcγRIIb expression was variable within individual CLL clones, this being higher in CD38+ and CD49d+ cells than in CD38− and CD49d− cells (p&lt;0.05). Furthermore, the highest density of FcγRIIb was observed on those cells which coexpressed CD38 and CD49d. In contrast, no significant differences were observed between FcγRIIb and the expression of the activation antigen CD69. Although CD69 and CD38 expression was significantly higher on unmutated IGHV cases, no correlation was found between FcγRIIb levels and IGHV mutational status. Similarly, there was no correlation between FcγRIIb and other poor prognostic variables such as ZAP-70 (≥20%), CD38 (≥ 30%) or high risk cytogenetics. Nevertheless, cases with ≥ 30% CD49d+ cells had higher FcγRIIb expression than those with &lt;30% CD49d+ cells (p=0.006). The findings presented in this study suggest a hierarchy of FcγRIIb expression in normal B-cells, CLL cells and their subpopulations: circulating normal CD5− B cells &gt; circulating normal CD5+ B cells &gt; circulating CD5+ CLL B cells. In addition, although FcγRIIb is present on all normal B cell subsets its expression is higher in naïve B cells. Furthermore, in CLL FcγRIIb density is greater in CD38+ and CD49d+ cells within the clone. Although CD49d and FcγRIIb on CLL clones is linked in a direct manner, there is no relationship with FcγRIIb density and IGHV mutations, ZAP-70, CD38 and unfavorable cytogenetic markers. Finally, the relationship between FcγRIIb expression on CLL cells and functional responses to BCR and other receptor-mediated signals deserve further investigation.

Progressive Epigenetic Programming during B Cell Maturation Is Reflected in a Continuum of Epigenetic Disease Phenotypes in Chronic Lymphocytic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2436-2436 ◽  
Author(s):  
Christopher C. Oakes ◽  
Marc Seifert ◽  
Yassen Assenov ◽  
Lei Gu ◽  
Martina Przekopowitz ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Transcription Factor ◽  
Transcription Factors ◽  
B Cells ◽  
B Cell ◽  
Research Funding ◽  
Lymphocytic Leukemia ◽  
Malignant Phenotype ◽  
Epigenetic Programming ◽  
B Cell Subsets

Abstract The malignant phenotype combines characteristics that are acquired and inherited from the normal cell of origin. Hematological malignancies and related disease subtypes are thought to arise from diverse cell types that may reflect various developmental stages within the hematopoetic lineage. The contribution of different normal cell states and processes to the biological and clinical features of malignancy is not well understood. In chronic lymphocytic leukemia (CLL), two or three subtypes have been identified by variation in the degree of somatic IGHV mutations and recently uncovered epigenetic differences, respectively, suggesting that these subtypes derive from distinct normal B cell subsets at different stages of maturity. However, in CLL, as well as in most malignancies, the full possible extent of maturity states and the relative contribution of normal versus malignant developmental programs to the malignant phenotype have not been defined in a high-resolution manner. It is widely accepted that epigenetic patterns are important to establish and stabilize cellular phenotypes. Using whole genome bisulfite sequencing and sequence-specific methods, we assessed the dynamic DNA methylation events that occur during the maturation of B cells using six highly purified B cell subsets representing various stages of maturation. We confirmed previous reports that broad epigenetic programming affects about 25% of the genome from naïve to memory B cells, and further revealed that B cell subpopulations of intermediate maturity retained increasing degrees of the maturation program resulting in a singular developmental trajectory. Maturation was driven in part by the activity of a specific set of transcription factors (e.g. AP-1, EBF1, RUNX3, OCT2, IRF4 and NFkB). Using the developmental epigenetic signature defined by transcription factor binding site (TFBS) programming in normal cells to compare to tumor cells of 268 CLL revealed that tumors have the potential to derive from a continuum of possible maturation states that are reflected in the maturation stages of normal cells. Using RNA sequencing to measure gene expression, we found the degree of maturation achieved in tumors closely associates with the acquisition of a more indolent pattern of gene expression, evidenced by progressive downregulation of CLL oncogenes, such as ZAP70, TCL1 and BTK. Further assessment of the level of DNA methylation maturity in an independent sample cohort of 348 CLL cases revealed a quantitative, continuous relationship with increasingly favorable clinical outcomes. Although the majority of methylation differences found between tumor subtypes are naturally present in normal B cells, by identifying changes that are only present in CLL we further uncovered a previously unappreciated pathogenic role of transcription factor dysregulation. Specifically, a blockade in the epigenetic maturation of EBF and AP-1 TFBSs was found to define low-programmed (less mature, poor outcome) CLL cases and was associated with transcriptional and genetic loss of EBF1 and FOS transcription factors in tumor cells. Aberrantly acquired DNA methylation events in CLL were linked to excess activity of specific transcription factor families, namely EGR and NFAT. Intriguingly, we show that recurrent somatic mutations within the DNA binding domain of EGR2 selectively influence the methylation status of its cognate binding sites in mutant cases, establishing a role for this transcription factor in epigenetic dysregulation in CLL. Collectively, this work reveals that a unique epigenetic maturation signature, directed by normal developmental processes, defines individual CLL cases resulting in a spectrum of maturity across tumors. The majority of DNA methylation differences observed between individual CLLs reflects the state of maturity of the founder cell and profoundly influences the disease phenotype. We further propose that in CLL the disease-specific state results, in part, by dysregulation of key transcription factors that imbalance the normal B cell epigenetic program. Disclosures Kipps: Celgene: Consultancy, Honoraria, Research Funding; Gilead: Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria; AbbVie: Consultancy, Research Funding. Stilgenbauer:AbbVie: Consultancy, Other: travel grants, Research Funding; Amgen: Consultancy, Other: travel grants, Research Funding; Boehringer-Ingelheim: Consultancy, Other: travel grants, Research Funding; Celgene: Consultancy, Other: travel grants, Research Funding; Hoffman-LaRoche: Consultancy, Honoraria, Other: travel grants, Research Funding; Genentech: Consultancy, Other: travel grants, Research Funding; Genzyme: Consultancy, Other: travel grants, Research Funding; Gilead: Consultancy, Other: travel grants, Research Funding; GlaxoSmithKline: Consultancy, Other: travel grants, Research Funding; Janssen: Consultancy, Other: travel grants, Research Funding; Mundipharma: Consultancy, Other: travel grants, Research Funding.

scholarly journals Mitogen-reactive B cell subpopulations selectively express different sets of V regions.

1982 ◽  
Vol 156 (1) ◽  
pp. 181-190 ◽  
Author(s):  
D Primi ◽  
F Mami ◽  
C Le Guern ◽  
P A Cazenave
Keyword(s):  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
Absolute Frequency ◽  
The Absolute ◽  
Cell Subpopulations ◽  
B Cell Subsets ◽  
Beta Galactosidase

The experiments presented here were designed to investigate whether the idiotypic repertoire is equally distributed among B cells subpopulations as defined by mitogen reactivity. To this end we used lipopolysaccharides (LPS) and Nocardia delipidated cell mitogens (NDCM), which are two mitogens that have been described to act on different B cell subsets. The repertoire can be defined in quantitative terms as the frequency of B cells that are precursors for clones secreting immunoglobulin with a given specificity or with a determinate idiotype. We determined, therefore, the absolute frequency of LPS- and NDCM-sensitive B lymphocytes secreting immunoglobulin molecules that bear three idiotopes originally found on a monoclonal anti-beta galactosidase antibody. Because the frequencies of B cells carrying one of these idiotypes are dramatically different in the LPS- and NDCM-sensitive B cells subsets, we conclude that the idiotypic repertoire is not randomly distributed among mitogen-reactive B cell subpopulations.

Increased Apoptosis of Peripheral Blood and Bone Marrow B and T Cells Correlates with Advanced Stages and Poor Risk Factors in Patients with B-CLL

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4162-4162
Author(s):  
Malgorzata Sieklucka ◽  
Agnieszka Bojarska-Junak ◽  
Agata Surdacka ◽  
Iwona Hus ◽  
Ewa Wasik-Szczepanek ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Disease Progression ◽  
Peripheral Blood ◽  
Ex Vivo ◽  
Lymphocytic Leukemia ◽  
High Rate ◽  
Advanced Stage

Abstract B-cell chronic lymphocytic leukemia (B-CLL), is characterized by the accumulation of long-lived, neoplastic B-lymphocytes in peripheral blood, bone marrow and secondary lymphoid organs. Apoptotic processes have been shown to be altered in leukemic B cells, however, the role of apoptosis in the mechanisms of disease progression remains unclear. Recent studies suggest that the clonal excess of B-cells is caused not only by a decrease in cell death but also by increased cell proliferation. We have recently reported on a high rate of apoptosis leukemic B cells in peripheral blood (PB) of advanced stage patients and that apoptosis of PB lymphocytes from advanced-stage (III–IV acc. Rai) patients is higher than that in early-stage (0–II acc. Rai) patients. However the spontaneous apoptosis in B-CLL patients was significantly lower compared to the healthy controls that confirmed the defective apoptosis as one of the mechanisms of leukemic lymphocytes accumulation in B-CLL. Continuing our research, in the presented study we measured apoptosis of B and T cells in peripheral blood and bone marrow in correlation with the stage of B-CLL and prognostic factors. Materials and methods: Peripheral blood and bone marrow (BM) samples were obtained from 120 previously untreated B-CLL patients. An analysis of apoptosis within the B and T cells population was performed using flow cytometer and chloromethyl-X-rosamine staining (Mito Tracker Red CMXRos). CMXRos was used to detect disruptions in the mitochondrial membrane potential (ΔΨm), which is one of the earliest events in the apoptotic pathway and allow finding apoptotic cells when there are still in PB and BM. We found that ex vivo lymphocyte apoptosis was higher in BM compared to PB (p&lt;0.05). Moreover, both B-cell and T-cell apoptosis in BM was higher than in PB (p&lt;0.0001 and p&lt;0.001, respectively). When compared, ex vivo apoptosis of T cells was found higher than that of B cells, both in BM (p&lt;0.0001) and PB (p&lt;0.0001). The percentage of apoptotic leukemic B cells correlated negatively with Bcl-2/Bax ratio in CD19+ B cells (p&lt;0.05). Similarly, the percentage of apoptotic CD3+ cells correlated negatively with Bcl-2/Bax ratio in CD3+ cells (p&lt;0.01). We also found that the percentage of apoptotic leukemic B cells correlated positively with the expression of proapoptotic protein Par-4 (prostate apoptosis response-4) in CD19+ B cells (p&lt;0.01). The expression of Par-4 protein in CD19+ B cells correlated positively with the percentage of CD38+ cells (p&lt;0.05), and it was higher in patients with CD38+ and ZAP-70+/CD38+ phenotypes (p&lt;0.05 and p&lt;0.01, respectively). There was a positive correlation between the expression of Par-4 protein and the lactate dehydrogenase (LDH) and β2-microglobulin serum concentrations (p&lt;0.01 and p&lt;0.05, respectively). Furthermore, the percentage of apoptotic CD19+ cells correlated positively with the LDH serum level (p&lt;0.05). These data indicate that high amount of apoptotic leukemic cells in PB and BM might be considered as poor prognosis factor. Higher rate of B and T cells apoptosis in BM than in PB suggest the influence of bone marrow microenviroment on this process. Our results indicate also that high rate of T cells apoptosis might be responsible for immune dysfunction including both impaired anti-infection immunity as well as impaired anti-cancer response resulting in disease progression.

scholarly journals Early generated B1 B cells with restricted BCRs become chronic lymphocytic leukemia with continued c-Myc and low Bmf expression

2016 ◽  
Vol 213 (13) ◽  
pp. 3007-3024 ◽  
Author(s):  
Kyoko Hayakawa ◽  
Anthony M. Formica ◽  
Joni Brill-Dashoff ◽  
Susan A. Shinton ◽  
Daiju Ichikawa ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Cell Subset ◽  
Lymphocytic Leukemia ◽  
Transgenic Expression ◽  
Bcr Signaling ◽  
B Cell Subsets ◽  
A Minor ◽  
B1 B Cells

In mice, generation of autoreactive CD5+ B cells occurs as a consequence of BCR signaling induced by (self)-ligand exposure from fetal/neonatal B-1 B cell development. A fraction of these cells self-renew and persist as a minor B1 B cell subset throughout life. Here, we show that transfer of early generated B1 B cells from Eμ-TCL1 transgenic mice resulted in chronic lymphocytic leukemia (CLL) with a biased repertoire, including stereotyped BCRs. Thus, B1 B cells bearing restricted BCRs can become CLL during aging. Increased anti-thymocyte/Thy-1 autoreactive (ATA) BCR cells in the B1 B cell subset by transgenic expression yielded spontaneous ATA B-CLL/lymphoma incidence, enhanced by TCL1 transgenesis. In contrast, ATA B-CLL did not develop from other B cell subsets, even when the identical ATA BCR was expressed on a Thy-1 low/null background. Thus, both a specific BCR and B1 B cell context were important for CLL progression. Neonatal B1 B cells and their CLL progeny in aged mice continued to express moderately up-regulated c-Myc and down-regulated proapoptotic Bmf, unlike most mature B cells in the adult. Thus, there is a genetic predisposition inherent in B-1 development generating restricted BCRs and self-renewal capacity, with both features contributing to potential for progression to CLL.

Effects Of Bendamustine Plus Rituximab On The Distribution Of Normal Peripheral Blood Leucocyte Populations In Advanced-Stage Chronic Lymphocytic Leukemia (CLL)

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5289-5289 ◽  
Author(s):  
Georgiana Grigore ◽  
Martin Perez-Andres ◽  
Susana Barrena ◽  
Rosa Ana Rivas ◽  
Marcos González ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Lymphocytic Leukemia ◽  
Cd4 T Cell ◽  
Advanced Stage ◽  
Time Point

Abstract Introduction Management of B-cell chronic lymphocytic leukemia (CLL) is currently undergoing profound changes. Accordingly, new treatment options with an expected less toxicity than standard regimens are been explored. Recent results show that chemoimmunotherapy may improve the life expectancy of CLLpatients and has proven to be more efficient than chemotherapy alone in depleting malignant cells. Despite its efficacy, little is known about its precise immunomodulatory effects. Aim To evaluate the effects of chemoimmunotherapy with bendamustine plusrituximab (BR) on the distribution of normal residual leucocyte populations in peripheral blood (PB) from advanced-stage CLL patients, with special emphasis on maturation-associated B-cell subsets (immature, naïve, memory IgM/IgG/IgA and plasma cells). Material and Methods Distribution of PB neoplastic cells and residual normal immune cell subpopulations were analyzed in 72 CLL patients with advanced disease (Binet B/C), before therapy (M0) and after 1 course of BR (M1). The same analysis was repeated 3 months after completing treatment (M3) in 31/72 patients. PB leucocyte cell subsets were identified at each time-point by 8-color flow cytometry with monoclonal antibody reagents against CD3, CD4, CD5, CD8, TCRgd, CD19, CD20, CD27, CD38, CD45, CD56, sIgM, sIgA, sIgG, sIgLambda and sIgKappa. Results After the first BR course, absolute counts of all PB myeloid subsets were significantly decreased as compared to time M0, including neutrophils (2,744±1,830 vs 4,764±2,906 cells/uL, p<0.001), eosinophils (132±185 vs 215±245 cells/uL; p<0.001), basophils (37±28 vs 59±47 cells/uL, p<0.001), monocytes (334±280 vs 504±424 cells/uL, p=0.001) and dendritic cells (DCs, 41±40 vs 89±168 cells/uL, p=0.02), as well as NK cells (120±147 vs 550±599 cells/uL, p<0.001). At M3, all these populations remained decreased when compared to M0, but at similar levels to M1 (except for the absolute number of DCs, found to be increased vs. M1 -74±46 vs 41±40 cells/uL, p=0.008- and closer to M0). In turn, total T cells were reduced in M1 as compared to M0 values (818±655 vs 3,905±2,375 cells/uL, p<0.001), due to decreased numbers of CD4+ (424±376 vs 1,573±1,204 cells/uL, p<0.001), CD8+ (342±330 vs 1,334±1,218 cells/uL, p<0.001) and TCRgd (21±28 vs 141±289 cells/uL, p=0.001) T cells, leading to an increased CD4/CD8 ratio (1.8±1.3 vs 1.4±0.8, p=0.004). Also, decreased levels of CD4 (222±156 cells/uL), CD8 (501±544 cells/uL) and TCRgd (21±40 cells/uL) T cells were observed at time M3 vs. baseline values. No changes (p>0.05) were observed for CD8 and TCRgd for M3 vs. M1, while CD4+ T-cell numbers were significantly reduced (p=0.006), resulting in an inverted CD4/CD8 ratio (0.9±1.0 vs. 1.8±1.3, p=0.005) at the M3 time-point. As regards B cells, the absolute count of both neoplastic and normal B lymphocytes were significantly decreased at time M1 vs. M0 (3,363±9,353 vs 53,521±56,602 CLL cells/uL and 2±6 vs 58±107 normal B-cells/uL, p=0.006 and p<0.001, respectively). Within the normal residual B-cell compartment, we found significantly decreased numbers of immature (0.07±0.22 vs 6.55±21.64 cells/uL, p=0.01) and memory (1.3±14.7 vs 35.1±43.6 cells/uL, p<0.001) B cells -including sIgM (0.5±2.3 vs 14.5±24.8 cells/uL, p<0.001), sIgG (0.2±1.0 vs 11.5±17.2 cells/uL; p<0.001) and sIgA (0.6±3.1 vs 9.5±12.5 cells/uL, p<0.001) memory B cells-. At time M3, decreased (p<0.01) naïve (0.46±2.58 cells/uL) and memory B-cells (1.34±6.75 cells/uL), including IgM (0.46±2.58 cells/uL), IgG (0.34±1.69 cells/uL) and IgA (0.09±0.31 cells/uL), but not immature cells (2.28±8.84 cells/uL, p=0.9), were observed as compared to time M0. Differences did not reach statistical significance when comparing M3 vs. M1. The number of circulating plasma cells did not significantly vary during treatment. Conclusions All PB leucocyte subsets are affected by BR treatment in advanced-stage CLL. Interestingly, at time M3 the CD4+ T-cell subset continues to be decreased, while the other T-cell compartments seem to remain stable. Also, normal B cells are affected by BR treatment, and the depletion induced after one course therapy is maintained even three months after finishing BR therapy, except for immature B cells, that seem to be the first to recover in PB. Further studies will offer a more accurate insight into the biology of cell recovery during and after BR therapy in CLL patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Cellular origin and pathophysiology of chronic lymphocytic leukemia

2012 ◽  
Vol 209 (12) ◽  
pp. 2183-2198 ◽  
Author(s):  
Marc Seifert ◽  
Ludger Sellmann ◽  
Johannes Bloehdorn ◽  
Frederik Wein ◽  
Stephan Stilgenbauer ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Cell Subset ◽  
Variable Region ◽  
Lymphocytic Leukemia ◽  
Independent Evidence ◽  
Cellular Origin ◽  
Germinal Center B Cell ◽  
B Cell Subsets

The cellular origin of chronic lymphocytic leukemia (CLL) is still debated, although this information is critical to understanding its pathogenesis. Transcriptome analyses of CLL and the main normal B cell subsets from human blood and spleen revealed that immunoglobulin variable region (IgV) gene unmutated CLL derives from unmutated mature CD5+ B cells and mutated CLL derives from a distinct, previously unrecognized CD5+CD27+ post–germinal center B cell subset. Stereotyped V gene rearrangements are enriched among CD5+ B cells, providing independent evidence for a CD5+ B cell derivation of CLL. Notably, these CD5+ B cell populations include oligoclonal expansions already found in young healthy adults, putatively representing an early phase in CLL development before the CLL precursor lesion monoclonal B cell lymphocytosis. Finally, we identified deregulated proteins, including EBF1 and KLF transcription factors, that were not detected in previous comparisons of CLL and conventional B cells.

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