scholarly journals Importance of Detection of Intracellular Myeloperoxidase, CD13, CD79a, CD22, CD3 and Terminal Deoxynucleotidyl Transferase By Flow Cytometry Diagnosis of Acute Leukemias

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5194-5194
Author(s):  
Aldair Sousa Paiva ◽  
Hugo Diogenes De Oliveira Paiva ◽  
Geraldo Barroso Cavalcanti ◽  
Frank Bahia ◽  
Rodrigo Villar Freitas ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Monoclonal Antibodies ◽  
Acute Leukemia ◽  
Lymphoblastic Leukemia ◽  
Lymphoid Cells ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Acute Leukemias ◽  
Cell Markers ◽  
Terminal Transferase

Abstract Background: The detection of Intracellular (IC) antigens by flow cytometry (FC) such as myeloperoxidase (MPO), cCD13, cCD79a, cCD22, cCD3 and Terminal deoxynucleotidyl Transferase (TdT) has become the useful tool in the differential diagnosis between acute myeloid leukemias (AML) and acute lymphoid leukemias (ALL). Through detection of myeloid antigens (MPO and cCD13), B cells precursors (cCD79a and cCD22) and precocity T-cells (cCD3) it has been possible to confirm the diagnosis of these acute leukemias. The detection of intracellular cell markers by FC usually requires previous permeabilization of fresh cell suspensions. TdT, also known as DNA nucleotidylexotransferase (DNTT) or terminal transferase, is a specialized DNA polymerase expressed in immature, pre-B, pre-T lymphoid cells, and acute lymphoblastic leukemia/lymphoma cells. TdT adds N-nucleotides to the V, D, and J exons of the TCR and BCR genes during antibody gene recombination, enabling the phenomenon of junctional diversity. In humans, terminal transferase is encoded by the DNTT gene. This antigen is expressed mostly in the nucleus cells from primary lymphoid organs, like the thymus and bone marrow. The TdT detection has also been shown to be useful in confirming the acute forms of B and T-lineage lymphoproliferative diseases by FC. The aim of this study was to demonstrate the importance of this cell markers' detection by FC in the differential diagnostic of acute leukemias. Methods: Bone marrow and/or peripheral blood leukemic cells from 50 cases of acute leukemia: 16 ALL and 36 AML. The cells were fixed and permeabilized in briefly exposed to Becton & Dickinson Lyse Solution at concentration of 10%, and subsequently labeled with monoclonal antibodies anti-MPO, TdT, CD3, CD13, CD22 and CD79a. Results: The MPO expression was observed in 35/36(97,22%) and cCD13 in all cases of AML and in none ALL patients. Three cases of MPO-positive ALL (FAB-L2) could be reclassified as M0-AML. These cases were CD34+;HLADR+;CD33-;CD13-;CD7+ and cCD13+. The intensity of TdT expression was observed in 15/16 (93.8%) of ALL and 5/36 (13.9%) of AML. The cCD22 and cCD79a were positive in 15/16 (93.8%) and all of pre-B ALL respectively and cCD3 was expressed in one case of Pre-T ALL that initial phenotype was CD34+/HLADR+/TdT+/CD7+ and sCD3-). Conclusions: These results indicate that monoclonal antibodies anti-MPO, cCD13, cCD79a, cCD22, cCD3 and TdT were excellent cell markers for the diagnosis and classification of acute leukemias and can be reliably detected by FC. This rapid and specific technique should be a valuable addition to routine immunophenotyping of acute leukemia. Disclosures No relevant conflicts of interest to declare.

Philadelphia chromosome and terminal transferase-positive acute leukemia: similarity of terminal phase of chronic myelogenous leukemia and de novo acute presentation.

1983 ◽  
Vol 1 (11) ◽  
pp. 669-676 ◽  
Author(s):  
K Jain ◽  
Z Arlin ◽  
R Mertelsmann ◽  
T Gee ◽  
S Kempin ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Leukemia ◽  
Chronic Myelogenous Leukemia ◽  
Lymphoblastic Leukemia ◽  
Allogeneic Bone Marrow Transplantation ◽  
Philadelphia Chromosome ◽  
Myelogenous Leukemia ◽  
Allogeneic Bone ◽  
Leukocyte Antigen ◽  
Terminal Transferase

Twenty-eight patients with Philadelphia chromosome (Ph1)--positive and terminal transferase (TdT)--positive acute leukemia (AL) were treated with intensive chemotherapy used for adult acute lymphoblastic leukemia (L-10 and L-10M protocols). Fifteen patients had a documented chronic phase of Ph1-positive chronic myelogenous leukemia preceding the acute transformation (TdT + BLCML) while the remaining 13 patients did not (TdT + Ph1 + AL). An overall complete remission (CR) rate of 71% was obtained with a median survival of 13 months in the responders. Clinical presentation, laboratory data, cytogenetics, response to treatment, and survivals of the two groups of patients are compared. These results appear to be similar, suggesting a common or closely related origin. Since the overall survival of those receiving chemotherapy maintenance is poor, three patients underwent allogeneic bone marrow transplantation (BMT) from histocompatibility leukocyte antigen--matched siblings after they achieved CR. One of them is a long-term survivor (35 + months) with a Ph1-negative bone marrow. New techniques such as BMT should be considered in young patients with a histocompatibility leukocyte antigen--compatible sibling once a CR has been achieved.

scholarly journals Expression of the three myeloid cell-associated immunoglobulin G Fc receptors defined by murine monoclonal antibodies on normal bone marrow and acute leukemia cells

Blood ◽  
1989 ◽  
Vol 73 (7) ◽  
pp. 1951-1956
Author(s):  
ED Ball ◽  
J McDermott ◽  
JD Griffin ◽  
FR Davey ◽  
R Davis ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Monoclonal Antibodies ◽  
Acute Leukemia ◽  
Cell Sorting ◽  
Lymphoblastic Leukemia ◽  
Mononuclear Phagocytes ◽  
Leukemic Cells ◽  
Leukemia Cells ◽  
Normal Bone Marrow ◽  
Normal Bone

Monoclonal antibodies (MoAbs) have been prepared recently that recognize the three cell-surface receptors for the Fc portion of immunoglobulin (Ig), termed Fc gamma RI (MoAb 32.2), Fc gamma R II (MoAb IV-3), and Fc gamma R III (MoAb 3G8) that are expressed on selected subsets of non-T lymphocyte peripheral blood leukocytes. In the blood, Fc gamma R I is expressed exclusively on monocytes and macrophages, Fc gamma R II on granulocytes, mononuclear phagocytes, platelets, and B cells, and Fc gamma R III on granulocytes and natural killer (NK) cells. We have examined the expression of these molecules on normal bone marrow (BM) cells and on leukemia cells from the blood and/or BM in order to determine their normal ontogeny as well as their distribution on leukemic cells. BM was obtained from six normal volunteers and from 170 patients with newly diagnosed acute leukemia. Normal BM cells were found to express Fc gamma R I, II, and III with the following percentages: 40%, 58%, and 56%, respectively. Cell sorting revealed that both Fc gamma R I and Fc gamma R II were detectable on all subclasses of myeloid precursors as early as myeloblasts. Cell sorting experiments revealed that 66% of the granulocyte-monocyte colony-forming cells (CFU-GM) and 50% of erythroid burst-forming units (BFU-E) were Fc gamma R II positive with only 20% and 28%, respectively, of CFU-GM and BFU-E were Fc gamma R I positive. Acute myeloid leukemia (AML) cells expressed the three receptors with the following frequency (n = 146): Fc gamma R I, 58%; Fc gamma R II, 67%; and Fc gamma R III, 26% of patients. Despite the fact that Fc gamma R I is only expressed on monocytes among blood cells, AML cells without monocytoid differentiation (French-American-British [FAB]M1, M2, M3, M6) were sometimes positive for this receptor. However, Fc gamma R I was highly correlated with FAB M4 and M5 morphology (P less than .001). Fc gamma R II was also correlated with FAB M4 and M5 morphology (P = .003). Cells from 11 patients with acute lymphoblastic leukemia were negative for Fc gamma R I, but six cases were positive for Fc gamma R II and III (not the same patients). These studies demonstrate that Ig Fc gamma R are acquired during normal differentiation in the BM at or before the level of colony-forming units. In addition, we show that acute leukemia cells commonly express Fc gamma R.

scholarly journals Expression of the three myeloid cell-associated immunoglobulin G Fc receptors defined by murine monoclonal antibodies on normal bone marrow and acute leukemia cells

Blood ◽  
1989 ◽  
Vol 73 (7) ◽  
pp. 1951-1956 ◽  
Author(s):  
ED Ball ◽  
J McDermott ◽  
JD Griffin ◽  
FR Davey ◽  
R Davis ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Monoclonal Antibodies ◽  
Acute Leukemia ◽  
Cell Sorting ◽  
Lymphoblastic Leukemia ◽  
Mononuclear Phagocytes ◽  
Leukemic Cells ◽  
Leukemia Cells ◽  
Normal Bone Marrow ◽  
Normal Bone

Abstract Monoclonal antibodies (MoAbs) have been prepared recently that recognize the three cell-surface receptors for the Fc portion of immunoglobulin (Ig), termed Fc gamma RI (MoAb 32.2), Fc gamma R II (MoAb IV-3), and Fc gamma R III (MoAb 3G8) that are expressed on selected subsets of non-T lymphocyte peripheral blood leukocytes. In the blood, Fc gamma R I is expressed exclusively on monocytes and macrophages, Fc gamma R II on granulocytes, mononuclear phagocytes, platelets, and B cells, and Fc gamma R III on granulocytes and natural killer (NK) cells. We have examined the expression of these molecules on normal bone marrow (BM) cells and on leukemia cells from the blood and/or BM in order to determine their normal ontogeny as well as their distribution on leukemic cells. BM was obtained from six normal volunteers and from 170 patients with newly diagnosed acute leukemia. Normal BM cells were found to express Fc gamma R I, II, and III with the following percentages: 40%, 58%, and 56%, respectively. Cell sorting revealed that both Fc gamma R I and Fc gamma R II were detectable on all subclasses of myeloid precursors as early as myeloblasts. Cell sorting experiments revealed that 66% of the granulocyte-monocyte colony-forming cells (CFU-GM) and 50% of erythroid burst-forming units (BFU-E) were Fc gamma R II positive with only 20% and 28%, respectively, of CFU-GM and BFU-E were Fc gamma R I positive. Acute myeloid leukemia (AML) cells expressed the three receptors with the following frequency (n = 146): Fc gamma R I, 58%; Fc gamma R II, 67%; and Fc gamma R III, 26% of patients. Despite the fact that Fc gamma R I is only expressed on monocytes among blood cells, AML cells without monocytoid differentiation (French-American-British [FAB]M1, M2, M3, M6) were sometimes positive for this receptor. However, Fc gamma R I was highly correlated with FAB M4 and M5 morphology (P less than .001). Fc gamma R II was also correlated with FAB M4 and M5 morphology (P = .003). Cells from 11 patients with acute lymphoblastic leukemia were negative for Fc gamma R I, but six cases were positive for Fc gamma R II and III (not the same patients). These studies demonstrate that Ig Fc gamma R are acquired during normal differentiation in the BM at or before the level of colony-forming units. In addition, we show that acute leukemia cells commonly express Fc gamma R.

scholarly journals Characterization of Thy-1 (CDw90) expression in CD34+ acute leukemia

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 60-65 ◽  
Author(s):  
JT Holden ◽  
RB Geller ◽  
DC Farhi ◽  
HK Holland ◽  
LL Stempora ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Acute Leukemia ◽  
Lymphoblastic Leukemia ◽  
Blast Crisis ◽  
Myelogenous Leukemia ◽  
Acute Leukemias ◽  
Hematopoietic Stem

Thy-1 (CDw90) is a phosphatidylinositol-anchored cell surface molecule which, when coexpressed with CD34 in normal human bone marrow, identifies a population of immature cells that includes putative hematopoietic stem cells. To date, the characterization of Thy-1 expression has been confined largely to normal tissues and cell lines. In this study, we evaluated the frequency and intensity of Thy-1 expression as defined by reactivity with the anti-Thy-1 antibody 5E10 in 38 cases of CD34+ acute leukemia (21 acute myelogenous leukemia [AML], 8 chronic myelogenous leukemia [CML] in blast crisis, and 9 acute lymphoblastic leukemia [ALL]). In 34 of 38 cases (89%) the CD34+ cells lacked expression of the Thy-1 antigen. High-density Thy-1 expression was found in 1 case of CML in lymphoid blast crisis, and low- density Thy-1 expression was identified on a portion of the leukemic cells in 2 cases of AML with myelodysplastic features, and 1 case of CML in myeloid blast crisis, suggesting a possible correlation between Thy-1 expression and certain instances of stem cell disorders such as CML and AML with dysplastic features. In contrast, the dissociation of Thy-1 and CD34 expression in the majority of acute leukemias studied suggests that the development of these leukemias occurs at a later stage than the hematopoietic stem cell. Characterization of Thy-1 expression in acute leukemia may eventually provide insights into the origin of the disease. In addition, separation of leukemic blasts from normal stem cells based on Thy-1 expression may prove useful in assessing residual disease, as well as in excluding leukemic blasts from stem cell preparations destined for autologous bone marrow or peripheral stem cell transplantation.

scholarly journals Phenotypic analysis of acute lymphoblastic leukemia (ALL) cells which are classified as non-T non-B and negative for common ALL antigen

Blood ◽  
1985 ◽  
Vol 66 (1) ◽  
pp. 47-52 ◽  
Author(s):  
K Kita ◽  
K Nasu ◽  
H Kamesaki ◽  
S Doi ◽  
H Tezuka ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Specific Antigen ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Acute Leukemias ◽  
Specific Antibodies ◽  
Myeloid Antigens ◽  
Human T Cell

Abstract When phenotypic marker analysis of acute lymphoblastic leukemia (ALL) cells (102 cases) was performed, a group of ALL cells (15 cases) classified as non-T non-B, and negative for common-ALL antigen (CALLA) was characterized in a focused manner. “Non-T non-B” was defined as negative for T cell properties such as E-rosetting or reactivity with anti-human T-cell monoclonal antibodies (T101, WT1), and absence of any B-cell characteristics (cell surface and/or cytoplasmic immunoglobulin and reactivity with B1 monoclonal antibody). Despite their marked heterogeneity, CALLA(-) non-T non-B ALL cells revealed three different phenotypic patterns in terms of presence of terminal deoxynucleotidyl transferase (TdT) and of reactivity with antimyeloid (MCS1) or myelomonocyte (MCS2 and OKM1) monoclonal antibodies. Four of 15 cases reacted with some myeloid-specific antibodies, but were negative for TdT. Six cases had both MCS2 antigen and TdT. The remaining five cases expressed no myeloid antigens, but were positive for TdT with some exceptions. These findings showed that acute leukemias with myeloid antigens might be involved in CALLA(-) non-T non-B ALL having no relationship to the presence of TdT, and, furthermore, that the blasts with simultaneous expression of TdT and myeloid-specific antigen (MCS2) might represent an immature stage in hematopoietic differentiation closely corresponding with the bifurcation of the lymphocyte/myeloid pathway. Alternatively, only five cases remained “unclassified leukemia.” We therefore think that the detailed examination of CALLA(-) non-T non-B ALL cells using myeloid specific antibodies is helpful in clarifying the characteristics of myeloid precursors and the common bipotential stem cell of lymphoid and myeloid progenitors.

scholarly journals Phenotypic analysis of acute lymphoblastic leukemia (ALL) cells which are classified as non-T non-B and negative for common ALL antigen

Blood ◽  
1985 ◽  
Vol 66 (1) ◽  
pp. 47-52
Author(s):  
K Kita ◽  
K Nasu ◽  
H Kamesaki ◽  
S Doi ◽  
H Tezuka ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Specific Antigen ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Acute Leukemias ◽  
Specific Antibodies ◽  
Myeloid Antigens ◽  
Human T Cell

When phenotypic marker analysis of acute lymphoblastic leukemia (ALL) cells (102 cases) was performed, a group of ALL cells (15 cases) classified as non-T non-B, and negative for common-ALL antigen (CALLA) was characterized in a focused manner. “Non-T non-B” was defined as negative for T cell properties such as E-rosetting or reactivity with anti-human T-cell monoclonal antibodies (T101, WT1), and absence of any B-cell characteristics (cell surface and/or cytoplasmic immunoglobulin and reactivity with B1 monoclonal antibody). Despite their marked heterogeneity, CALLA(-) non-T non-B ALL cells revealed three different phenotypic patterns in terms of presence of terminal deoxynucleotidyl transferase (TdT) and of reactivity with antimyeloid (MCS1) or myelomonocyte (MCS2 and OKM1) monoclonal antibodies. Four of 15 cases reacted with some myeloid-specific antibodies, but were negative for TdT. Six cases had both MCS2 antigen and TdT. The remaining five cases expressed no myeloid antigens, but were positive for TdT with some exceptions. These findings showed that acute leukemias with myeloid antigens might be involved in CALLA(-) non-T non-B ALL having no relationship to the presence of TdT, and, furthermore, that the blasts with simultaneous expression of TdT and myeloid-specific antigen (MCS2) might represent an immature stage in hematopoietic differentiation closely corresponding with the bifurcation of the lymphocyte/myeloid pathway. Alternatively, only five cases remained “unclassified leukemia.” We therefore think that the detailed examination of CALLA(-) non-T non-B ALL cells using myeloid specific antibodies is helpful in clarifying the characteristics of myeloid precursors and the common bipotential stem cell of lymphoid and myeloid progenitors.

Dynamics of Bcl-2, Bax and ACE Expression In CD34+ Cells of Peripheral Blood and Bone Marrow In Patients with Acute Leukemia During Induction Therapy

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4840-4840
Author(s):  
Elena E. Khodunova ◽  
Elena N. Parovichnikova ◽  
Irina V. Galtzeva ◽  
Sergey M. Kulikov ◽  
Valentin G. Isaev ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Drug Resistance ◽  
Acute Leukemia ◽  
Induction Therapy ◽  
Peripheral Blood ◽  
Acute Leukemias ◽  
Healthy Donors ◽  
Cd34 Cells ◽  
Blast Cells

Abstract Abstract 4840 The causes of drug resistance in acute leukemias (AL) have been studied very intensively and the key research was done on Bcl-2 family proteins. Last studies have showed that high level Bcl-2 expression in acute leukemia is really associated with drug resistance andpoor prognosis [Haematologica 2007, U. Testa]. It was demonstrated that lower Bax/Bcl-2 ratio (<0,3) was associated with FAB M0-M1 classes (p=.00001), poor-risk cytogenetics and poor prognosis [Blood 2003, G. Poeta]. But there were no studies on the dynamic evaluation of Bcl2 and Bax expression on CD34+ cells during chemotherapy. Renin-angiotensin system and angiotensin concertin enzyme (ACE) influence on leukogenesis is extensively investigated. It was reported that ACE expression on blast cells is high [Leuk Lymphoma 2006, S. Aksu]. Recent publications indicate that primitive hematopoietic precursors have different characteristics regarding ACE: CD34+ACE+cells transplanted into NOD/SCID mice contribute 10-fold higher numbers of multilineage blood cells than their CD34+ACE- counterparts and contain a significantly higher incidence of SCID-repopulating cells than the unfractionated CD34+ population [Blood 2008, V. Jokubaitis]. But it's still unknown how CD34+ACE+ cells in AL behave on and after chemotherapy. We have studied the dynamics of Bcl-2 and Bax expression by flow cytometry in CD34+ cells of peripheral blood (PB) and bone marrow (BM) in pts with AL. PB and BM samples were collected before treatment, on days +8, +36, only PB - on day + 21. Bcl-2 and Bax were detected on CD34+ cells by flow cytometry using specific monoclonal antibodies: CD34 (8G12, BD), Bcl-2 (100, BD), Bax (2D2, Santa Cruz). ACE (9B9, BD) expression was also evaluated. We calculated 10 000 cells in each sample. 10 pts were included in the study: 4 AML, 6 ALL. The control group comprised 4 healthy donors. At time of diagnosis CD34+ cells number in BM was 38,7%± 9,75, in PB - 38,3%± 8,14 in AL pts, not differing much in AML and ALL, and indicating blast cells population. CD34+ cells numbers in BM and PB of healthy donors were 1,35% and 0,23%, respectively. After induction therapy and WBC recovery (days +36-38) CD34+ cells number in AL pts decreased dramatically in BM to 3,83%±1,51 (p=0,001) and in PB to 0,98%± 0,29 (p=0,0001), indicating the efficacy of chemotherapy. The dynamics of Bcl-2, Bax and ACE expression on CD34+ cells of BM and PB in AL pts are presented in fig.1-6 As seen in the fig.1,2 CD34/Bcl-2 expression in BM is significantly higher (p=0,04) and in PB is similar in AL pts at the diagnosis comparing with donors. It's also worth to note that BM and PB CD34+ cells in donors had different expression characteristics of Bcl-2 demonstrating much higher level of antiapoptotic marker in PB cells. On the contrast CD34+ AL cells in BM and PB had similar characteristics regarding CD34/Bcl-2 expression. This expression level decreased substantially in BM at day +36 comparing with day 0 (p=0,04), but it never reached the donors level remaining extremely high and supposing the persistence of antiapoptotic activity in CD34+ cells in AL pts. It did not change at all during chemotherapy in PB cells, being identical to donors characteristics. The fig.2,3 demonstrate that, CD34/Bax expression in BM is almost 3-times higher (p=0,14) and in PB is twice lower (p=0,02) in AL pts in comparison with donors. It's interesting that CD34/Bax expression in leukemic BM and PB cells looks very similar, when in donors we had very low expression in BM and high - in PB. This fact demonstrates the heterogeneity of donor CD34+cells in BM and PB and points that leukemia CD34+cells in BM and PB are rather similar in Bax expression. Chemotherapy caused the significant augmentation of CD34/Bax expression in PB on day +8 (p=0,01) and near significant on day +21 (p= 0,09) showing the increased level of “dieing” cells in PB after cytostatic influence. The fig. 5,6 show that CD34/ACE coexpression in BM cells of AL pts and donors did not differ much at any time of evaluation. But CD34/ACE expression in PB cells of AL pts was much lower (p=0,02) than in donors and substantially increased at day +36 almost reaching the donor level. We may conclude that Bcl-2, Bax, ACE expression on CD34+ cells in AL pts and donors significantly differs, the dynamics of expression in AL while chemotherapy shows critical changes in CD34/Bcl-2 expression in BM, CD34/Bax and CD34/ACE in PB. Disclosures: No relevant conflicts of interest to declare.

VEGFR-1 (FLT-1) activation modulates acute lymphoblastic leukemia localization and survival within the bone marrow, determining the onset of extramedullary disease

Blood ◽  
2006 ◽  
Vol 107 (4) ◽  
pp. 1608-1616 ◽  
Author(s):  
Rita Fragoso ◽  
Teresa Pereira ◽  
Yan Wu ◽  
Zhenping Zhu ◽  
José Cabeçadas ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Migration ◽  
Acute Lymphoblastic Leukemia ◽  
Acute Leukemia ◽  
Actin Polymerization ◽  
Lymphoblastic Leukemia ◽  
Leukemia Cells ◽  
Acute Leukemias ◽  
Extramedullary Disease

The presence of persistent circulating leukemia cells, or engrafted into extramedullary tissues, is a bad prognostic factor for patients with acute leukemia. However, little is known about the mechanisms that regulate the exit of leukemia cells from the bone marrow (BM) microenvironment. We reveal that vascular endothelial growth factor receptor 1 (FLT-1) modulates acute leukemia distribution within the BM, along VEGF and PlGF gradients, regulating leukemia survival and exit into the peripheral circulation. FLT-1 activation on acute lymphoblastic leukemia (ALL) cells results in cell migration and proliferation in vitro, whereas in vivo FLT-1-overexpressing cells accumulate in the BM epiphysis of nonobese diabetic-severe combined immunodeficient (NOD-SCID) recipients and are detected in circulation 2 weeks after inoculation. In turn, FLT-1 neutralization affects leukemia localization (now in the BM diaphysis), increases leukemia apoptosis, and impedes the exit of ALL cells, prolonging the survival of inoculated mice. We demonstrate further that FLT-1-induced cell migration involves actin polymerization and lipid raft formation. Taken together, we show that FLT-1 regulates the BM localization of ALL cells, determining their survival and exit into the circulation and ultimately the survival of inoculated recipients. FLT-1 targeting on subsets of acute leukemias may delay the onset of extramedullary disease, which may be advantageous in combinatorial therapeutic settings.

scholarly journals Immunophenotypic Aberrancies in Acute Leukemia: A Tertiary Care Centre Experience

2021 ◽  
Vol 36 (1) ◽  
pp. e218-e218
Author(s):  
Monika Gupta ◽  
Lovekesh Monga ◽  
Dimple Mehrotra ◽  
Sonia Chhabra ◽  
Shivani Singhal ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Leukemia ◽  
Peripheral Blood ◽  
Tertiary Care ◽  
Flow Cytometric Analysis ◽  
Antigen Expression ◽  
Molecular Techniques ◽  
Acute Leukemias ◽  
Simultaneous Application

Objectives: Acute leukemias (AL) are a heterogeneous group of hematological malignancies with the presence of 20% or more blasts in the peripheral blood or bone marrow. Malignant cells display characteristic patterns of surface antigenic expression. Aberrant phenotypes are defined as patterns of antigen expression on neoplastic cells different from the process of normal hematopoietic maturation. We sought to evaluate the occurrence of aberrant phenotypes in newly diagnosed cases of AL. Methods: The study included 100 patients in whom both bone marrow aspiration and flow cytometry were performed. Patients with blasts > 20% of all ages were included in the study. Flow cytometric analysis was done using the monoclonal antibody panel of peripheral blood/bone marrow. Results: Out of 100 cases, 53 were categorized as acute myeloid leukemia (AML), 43 as acute lymphoid leukemia (ALL), and four cases of mixed phenotypic acute leukemia (MPAL). ALL were subcategorized based on immunophenotyping into B-ALL and T-ALL, which comprised 88.4% and 11.6%, respectively, of total ALL (43.0%) cases. Cluster of differentiation 33 (CD33) and CD13 were the most commonly expressed antigens in AML, with CD7 being the most common aberrancy. CD19 was expressed in all B-ALL cases followed by cCD79a, CD10, Tdt (86.8%) with CD13 being the most common aberrancy. cCD3, CD7, and CD5 were expressed in all T-ALL cases with aberrant antigen expression in 80.0% of T-ALL cases. MPAL cases showed expression of B/myeloid antigens. Conclusions: The diagnosis and classification of leukemia rely on the simultaneous application of cytomorphology, cytochemistry, flow cytometry, cytogenetics, and molecular techniques. Flow cytometry is of great help in the diagnosis of AL, particularly in ALL for lineage assignment and in classifying MPAL. It also helps in detecting aberrant antigen expression and assisting in minimal residual disease detection.

Sign in / Sign up

Export Citation Format

Share Document