scholarly journals CD20 up-regulation in pediatric B-cell precursor acute lymphoblastic leukemia during induction treatment: setting the stage for anti-CD20 directed immunotherapy

Blood ◽  
2008 ◽  
Vol 112 (10) ◽  
pp. 3982-3988 ◽  
Author(s):  
Michael N. Dworzak ◽  
Angela Schumich ◽  
Dieter Printz ◽  
Ulrike Pötschger ◽  
Zvenyslava Husak ◽  
...  

Abstract CD20 is expressed in approximately one- half of pediatric acute lymphoblastic leukemia (ALL) cases with B-cell precursor (BCP) origin. We observed that it is occasionally up-regulated during treatment. To understand the impact of this on the potential effectiveness of anti-CD20 immunotherapy, we studied 237 CD10+ pediatric BCP-ALL patients with Berlin-Frankfurt-Munster (BFM)–type therapy. We analyzed CD20 expression changes from diagnosis to end-induction, focusing on sample pairs with more than or equal to 0.1% residual leukemic blasts, and assessed complement-induced cytotoxicity by CD20-targeting with rituximab in vitro. CD20-positivity significantly increased from 45% in initial samples to 81% at end-induction (day 15, 71%). The levels of expression also increased; 52% of cases at end-induction had at least 90% CD20pos leukemic cells, as opposed to 5% at diagnosis (day 15, 20%). CD20 up-regulation was frequent in high-risk patients, patients with high minimal residual disease at end-induction, and patients who suffered later from relapse, but not in TEL/AML1 cases. Notably, up-regulation occurred in viable cells sustaining chemotherapy. In vitro, CD20 up-regulation significantly enhanced rituximab cytotoxicity and could be elicited on prednisolone incubation. In conclusion, CD20 up-regulation is frequently induced in BCP-ALL during induction, and this translates into an acquired state of higher sensitivity to rituximab. This study was registered at http://www.clinicaltrials.gov as #NCT00430118.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 906-906
Author(s):  
Andishe Attarbaschi ◽  
Angela Schumich ◽  
Georg Mann ◽  
Oskar A. Haas ◽  
Helmut Gadner ◽  
...  

Abstract CD20 is expressed in about one half of childhood acute lymphoblastic leukemia (ALL) cases with B-cell precursor (BCP) origin. We recently observed that this phenotypic marker is further up-regulated in some patients during remission induction treatment containing corticosteroids for up to 5 weeks. To understand the impact of this phenomenon on the potential effectiveness of anti-CD20 immunotherapy (i.e., Rituximab), we studied 237 CD10-positive childhood BCP-ALL patients consecutively enrolled onto the trial AIEOP-BFM-ALL 2000. The analysis included the assessment of CD20 expression changes from diagnosis to the end of induction therapy and complement-induced cytotoxicity by CD20-targeting with Rituximab in-vitro. CD20-positivity significantly increased from diagnosis to the end of induction therapy with respect to the number of positive cases as well as to the levels of expression. After completion of induction therapy, one half of cases showed ≥ 90% CD20pos. leukemic cells, as opposed to 5% at diagnosis and 20% after 2 weeks of chemotherapy. Notably, up-regulation occurred in viable cells sustaining chemotherapy, most probably as a consequence of steroid-induced modulation of gene expression. Rituximab-cytotoxicity was significantly enhanced by CD20 up-regulation and depended on high expression levels. Importantly, CD20 up-regulation was frequent in high-risk patients (mainly poor prednisone responders), patients with high minimal residual disease levels at the end of induction therapy, and patients who suffered later from relapse, but not in TEL/AML1-positive cases. In conclusion, CD20 up-regulation is frequently induced in BCP-ALL during induction therapy and this translates into an acquired state of higher sensitivity to Rituximab.


Blood ◽  
1987 ◽  
Vol 70 (1) ◽  
pp. 132-138 ◽  
Author(s):  
B Wormann ◽  
SR Mehta ◽  
AL Maizel ◽  
TW LeBien

Experiments were conducted to determine the effect of low mol wt B cell growth factor (L-BCGF) on B cell precursor acute lymphoblastic leukemia (ALL). L-BCGF induced a significant increase in 3H-TdR incorporation in 28 of 37 bone marrow aspirates from patients with B cell precursor ALL, with stimulation indices ranging from 2 to 129. Fluorescence-activated cell sorting confirmed that in five of seven patients the common acute lymphoblastic leukemia antigen (CALLA)/CD10 positive leukemic cells were responding directly to L-BCGF. L-BCGF was capable of inducing, in some patients, an increase in absolute viable cells and could also induce colony formation in vitro. The response of B cell precursor ALL was not attributable to beta IL 1, IL 2, or gamma interferon. These results indicate that the majority of B cell precursor ALL undergo a proliferative response to L-BCGF, suggesting a regulatory role for this lymphokine in the growth of B cell precursors.


Blood ◽  
1987 ◽  
Vol 70 (1) ◽  
pp. 132-138 ◽  
Author(s):  
B Wormann ◽  
SR Mehta ◽  
AL Maizel ◽  
TW LeBien

Abstract Experiments were conducted to determine the effect of low mol wt B cell growth factor (L-BCGF) on B cell precursor acute lymphoblastic leukemia (ALL). L-BCGF induced a significant increase in 3H-TdR incorporation in 28 of 37 bone marrow aspirates from patients with B cell precursor ALL, with stimulation indices ranging from 2 to 129. Fluorescence-activated cell sorting confirmed that in five of seven patients the common acute lymphoblastic leukemia antigen (CALLA)/CD10 positive leukemic cells were responding directly to L-BCGF. L-BCGF was capable of inducing, in some patients, an increase in absolute viable cells and could also induce colony formation in vitro. The response of B cell precursor ALL was not attributable to beta IL 1, IL 2, or gamma interferon. These results indicate that the majority of B cell precursor ALL undergo a proliferative response to L-BCGF, suggesting a regulatory role for this lymphokine in the growth of B cell precursors.


2020 ◽  
Vol 61 (11) ◽  
pp. 2665-2673 ◽  
Author(s):  
Nicola Gökbuget ◽  
Gerhard Zugmaier ◽  
Hervé Dombret ◽  
Anthony Stein ◽  
Massimiliano Bonifacio ◽  
...  

Blood ◽  
1992 ◽  
Vol 79 (7) ◽  
pp. 1781-1788
Author(s):  
E Privitera ◽  
MP Kamps ◽  
Y Hayashi ◽  
T Inaba ◽  
LH Shapiro ◽  
...  

The prognostically important 1;19 chromosomal translocation can alter the E2A gene on chromosome 19p13 in childhood B-cell precursor acute lymphoblastic leukemia (ALL), leading to formation of a fusion gene (E2A-PBX1) that encodes a hybrid transcription factor with oncogenic potential. It is not known whether this molecular alteration is a uniform consequence of the t(1;19) or is restricted to translocation events within specific immunologic subtypes of the disease. Therefore, we studied leukemic cells from 25 cases of B-cell precursor ALL, with or without evidence of cytoplasmic Ig mu heavy chains (cIg); 17 cases had the t(1;19) by cytogenetic analysis. Leukemic cell DNA samples were analyzed by Southern blotting to detect alterations within the E2A genomic locus; a polymerase chain reaction assay was used to identify expression of chimeric E2A-pbx1 transcripts in leukemic cell RNA; and immunoblotting with anti-Pbx1 antibodies was used to detect hybrid E2A- Pbx1 proteins. Of 11 cases of cIg+ ALL with the t(1;19), 10 had E2A- pbx1 chimeric transcripts with identical junctions and a characteristic set of E2A-Pbx1 hybrid proteins. Each of these cases had E2A gene rearrangements, including the one in which fusion transcripts were not detected. By contrast, none of the six cases of t(1;19)-positive, cIg- ALL had evidence of rearranged E2A genomic restriction fragments, detectable E2A-pbx1 chimeric transcripts, or hybrid E2A-Pbx1 proteins. Typical chimeric E2A-pbx1 transcripts and proteins were detected in one of eight cIg+ leukemias in which the t(1;19) was not identified by cytogenetic analysis, emphasizing the increased sensitivity of molecular analysis for detection of this abnormality. We conclude that the molecular breakpoints in cases of cIg- B-cell precursor ALL with the t(1;19) differ from those in cIg+ cases with this translocation. Leukemias that express hybrid oncoproteins such as E2A-Pbx1 or Bcr-Abl have had a poor prognosis in most studies. Thus, molecular techniques to detect fusion genes and their aberrant products should allow more timely and appropriate treatment of these aggressive subtypes of the disease.


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