scholarly journals Spurious E rosette formation in B cell chronic lymphocytic leukemia due to monoclonal anti-sheep RBC antibody

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 270-274 ◽  
Author(s):  
LE Mills ◽  
JF O'Donnell ◽  
PM Guyre ◽  
PJ LeMarbre ◽  
JD Miller ◽  
...  

Abstract The apparent simultaneous presence of surface markers characteristic of both B and T cells is a phenomenon being described with increasing frequency in patients with chronic lymphocytic leukemia (CLL). We describe a patient with CLL whose B lymphocytes possessed surface immunoglobulin reactive with neuraminidase-treated sheep erythrocytes (SRBCs) and produced E rosette formation. Cytofluorography using monoclonal antibodies demonstrated the B cell nature of these cells and the absence of the SRBC receptor. Further documentation that the binding of SRBCs was mediated through immunologic reaction included E rosette formation inhibition by monospecific antisera and hemagglutination of SRBCs by a paraprotein isolated from the patient's serum. Fusion of the CLL cells with a human hypoxanthine-aminopterin- thymidine-sensitive plasma cell line resulted in the production of human hybridomas that secreted the SRBC-reactive IgM antibody. An analysis of clinical histories of CLL patients whose cells exhibited this phenomenon from both immunologic and clinical perspectives is presented.

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 270-274
Author(s):  
LE Mills ◽  
JF O'Donnell ◽  
PM Guyre ◽  
PJ LeMarbre ◽  
JD Miller ◽  
...  

The apparent simultaneous presence of surface markers characteristic of both B and T cells is a phenomenon being described with increasing frequency in patients with chronic lymphocytic leukemia (CLL). We describe a patient with CLL whose B lymphocytes possessed surface immunoglobulin reactive with neuraminidase-treated sheep erythrocytes (SRBCs) and produced E rosette formation. Cytofluorography using monoclonal antibodies demonstrated the B cell nature of these cells and the absence of the SRBC receptor. Further documentation that the binding of SRBCs was mediated through immunologic reaction included E rosette formation inhibition by monospecific antisera and hemagglutination of SRBCs by a paraprotein isolated from the patient's serum. Fusion of the CLL cells with a human hypoxanthine-aminopterin- thymidine-sensitive plasma cell line resulted in the production of human hybridomas that secreted the SRBC-reactive IgM antibody. An analysis of clinical histories of CLL patients whose cells exhibited this phenomenon from both immunologic and clinical perspectives is presented.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3309-3309
Author(s):  
Cristina Gattazzo ◽  
Andrea Visentin ◽  
Alberto Pavan ◽  
Veronica Martini ◽  
Federica Frezzato ◽  
...  

Abstract INTRODUCTION B-cell chronic lymphocytic leukemia (B-CLL) is a disorder characterized by the accumulation of clonal CD5+ B lymphocytes, due to uncontrolled growth and resistance to apoptosis. Although the prognosis and clinical outcome has dramatically improved by recent innovative therapies, B-CLL still remains an incurable disease. Since signaling events downstream the BCR engagement are important for the progression of B cells, BCR signaling has been investigated in B-CLL in order to design new agents to specifically treat this disease. We demonstrated that Lyn, one of the first kinases involved in BCR signaling pathway, is overexpressed, constitutively active and anomalously distributed in malignant B cells, as compared to normal B lymphocytes. The Focal adhesion kinase (FAK), a non-receptor protein tyrosine kinase, is the primary enzyme involved in the engagement of integrins and assembly of Focal Adhesion. FAK is regulated primarily through tyrosine phosphorylation by Lyn after BCR engagement and was found to be overexpressed in many kinds of human cancers. However, a downmodulation of FAK expression and its association to poor prognosis have also been reported. The aim of this study was to investigate the role of FAK in CLL patients. METHODS Blood samples were collected from 5 controls and 50 B-CLL patients. Informed consent was obtained according to the Declaration of Helsinki. Untouched peripheral blood B cells were purified using the RosetteSep for human B cells isolation kit. The samples that were used had at least 95% of normal CD19+ or neoplastic CD5+/CD19+ cells, as assessed by flow-cytometry. Level of FAK protein was evaluated by Western blotting (Wb) and Flow Cytometry assay (FC). Levels of FAK were correlated to clinical parameters of patients. RESULTS We observed that FAK was downmodulated in 56% of analyzed patients with respect to healthy subjects (respectively, Wb: 0.28±0.25 vs 0.85±0.32, p<0.001; FC: 35%±29 vs 60%±16, p<0.05). We also identified that lower levels of FAK expression were related to the prognostic markers of poor outcome (the expression of ZAP70, CD38 and an unmutated-IGHV genes status, p<0.05) and to a shorter Treatment Free Survival (p<0.05). Moreover, patients (n=6) who had an indolent course and were responsive to the standard treatment, showed normal expression of this kinase already at diagnosis. In contrast, patients (n=6) with a more aggressive disease, had a lower expression of FAK, that was further downmodulated during the progression of disease, irrespective of how the patients were treated. CONCLUSIONS From the data presented in this report we propose that FAK downmodulation could be considered as a new marker of poor prognosis and as a putative predictor for high-risk subgroups of CLL, even in early-stage disease. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
1994 ◽  
Vol 84 (10) ◽  
pp. 3440-3446 ◽  
Author(s):  
R Silber ◽  
B Degar ◽  
D Costin ◽  
EW Newcomb ◽  
M Mani ◽  
...  

Abstract Chemosensitivity of B lymphocytes, obtained from 65 patients with B- cell chronic lymphocytic leukemia (B-CLL), Rai stages 0 through IV, was determined using the MTT assay. The results were expressed by the drug concentration required for 50% inhibition of cell viability (IC50). The cytotoxicity of chlorambucil (CLB) was compared with that of fludarabine and the DNA topoisomerase I inhibitors, camptothecin, 9- aminocamptothecin, 10,11-methylenedioxy-20(S)-camptothecin (10,11-MDC) and 9-amino-10,11-methylenedioxy-20(S)-campthothecin (9-A-10,11-MDC), and topotecan. Considerable heterogeneity in sensitivity to CLB was observed, with a median IC50 of 40.5 mumol/L in untreated patients. B- CLL cells from patients treated with CLB had a significantly higher median IC50 of 86.0 mumol/L (P < .01). Untreated as well as CLB-treated patients were divided into two subsets. For the purpose of this study, B-CLL lymphocytes with an IC50 CLB of less than 61.0 mumol/L were designated as “sensitive” and those with an IC50 CLB of > or = 61.0 mumol/L were designated as “0resistant.” After baseline assays, 15 untreated patients received CLB; after treatment, the IC50 increased in B-CLL lymphocytes from 13 of 15 patients. The response to CLB treatment, determined by its effect on the absolute lymphocyte count and by the Eastern Cooperative Oncology Group clinical criteria, was significantly better in patients whose lymphocytes had an IC50 CLB of less than 61.0 mumol/L before therapy (P < .01). B-CLL lymphocytes also had a variable degree of sensitivity in vitro to each of the other drugs. There was significant cross-resistance between CLB and fludarabine (P < 0.01). Whereas only 29% of CLB-resistant B-lymphocyte specimens obtained from individual patients were sensitive to fludarabine in vitro, 52% and 67% of CLB-resistant lymphocyte samples were sensitive to 10,11-MDC and 9-A-10,11-MDC, respectively. We have previously reported that p53 gene mutations were associated with aggressive B-CLL and a poor prognosis. B lymphocytes from seven patients with these mutations were resistant to CLB, and five of six were resistant to fludarabine. Lymphocytes from four of seven were resistant to 10,11-MDC, and three of four were resistant to 9-A-10,11- MDC. This study implies that the MTT assay may be useful in identifying subsets of CLL patients resistant to conventional chemotherapy. However, definitive conclusions can not be drawn in view of the small number of patients studied prospectively. In addition, these results suggest the potential of camptothecin-based therapy for patients unresponsive to standard treatment.


1992 ◽  
Vol 88 (2-3) ◽  
pp. 151-153
Author(s):  
Caterina Musolino ◽  
Enrico Di Cesare ◽  
Andrea Alonci ◽  
Alessandro Allegra ◽  
Annunziata Orlando ◽  
...  

Blood ◽  
1994 ◽  
Vol 84 (10) ◽  
pp. 3440-3446 ◽  
Author(s):  
R Silber ◽  
B Degar ◽  
D Costin ◽  
EW Newcomb ◽  
M Mani ◽  
...  

Chemosensitivity of B lymphocytes, obtained from 65 patients with B- cell chronic lymphocytic leukemia (B-CLL), Rai stages 0 through IV, was determined using the MTT assay. The results were expressed by the drug concentration required for 50% inhibition of cell viability (IC50). The cytotoxicity of chlorambucil (CLB) was compared with that of fludarabine and the DNA topoisomerase I inhibitors, camptothecin, 9- aminocamptothecin, 10,11-methylenedioxy-20(S)-camptothecin (10,11-MDC) and 9-amino-10,11-methylenedioxy-20(S)-campthothecin (9-A-10,11-MDC), and topotecan. Considerable heterogeneity in sensitivity to CLB was observed, with a median IC50 of 40.5 mumol/L in untreated patients. B- CLL cells from patients treated with CLB had a significantly higher median IC50 of 86.0 mumol/L (P < .01). Untreated as well as CLB-treated patients were divided into two subsets. For the purpose of this study, B-CLL lymphocytes with an IC50 CLB of less than 61.0 mumol/L were designated as “sensitive” and those with an IC50 CLB of > or = 61.0 mumol/L were designated as “0resistant.” After baseline assays, 15 untreated patients received CLB; after treatment, the IC50 increased in B-CLL lymphocytes from 13 of 15 patients. The response to CLB treatment, determined by its effect on the absolute lymphocyte count and by the Eastern Cooperative Oncology Group clinical criteria, was significantly better in patients whose lymphocytes had an IC50 CLB of less than 61.0 mumol/L before therapy (P < .01). B-CLL lymphocytes also had a variable degree of sensitivity in vitro to each of the other drugs. There was significant cross-resistance between CLB and fludarabine (P < 0.01). Whereas only 29% of CLB-resistant B-lymphocyte specimens obtained from individual patients were sensitive to fludarabine in vitro, 52% and 67% of CLB-resistant lymphocyte samples were sensitive to 10,11-MDC and 9-A-10,11-MDC, respectively. We have previously reported that p53 gene mutations were associated with aggressive B-CLL and a poor prognosis. B lymphocytes from seven patients with these mutations were resistant to CLB, and five of six were resistant to fludarabine. Lymphocytes from four of seven were resistant to 10,11-MDC, and three of four were resistant to 9-A-10,11- MDC. This study implies that the MTT assay may be useful in identifying subsets of CLL patients resistant to conventional chemotherapy. However, definitive conclusions can not be drawn in view of the small number of patients studied prospectively. In addition, these results suggest the potential of camptothecin-based therapy for patients unresponsive to standard treatment.


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