Myeloperoxidase Expression in B-Lymphoblastic Leukemia by Immunohistochemistry as a Diagnostic Confounder

Abstract Background B-lymphoblastic leukemia (BLL) is a B lineage neoplasm that expresses typical immature B cell markers, but may also express myeloid-associated antigens. Myeloperoxidase (MPO) is a heme-containing peroxidase, which has been used as the single most specific myeloid marker when assigning lineage to acute leukemia. MPO positivity by immunohistochemistry (IHC) in BLL has been historically described in a subset of patients; however, further detailed comparison of IHC to flow cytometry and IHC methodology is described herein. Design The University of Washington pathology database was searched for new or relapsed adult BLL from 2011–2019. Cases with blasts >30% of marrow cellularity by morphology were selected. MPO IHC was performed using the Dako, polyclonal antibody (rabbit) on a Ventana instrument with streptavidin-biotin (SB) detection method. MPO IHC SB positive cases were also stained using the same antibody and platform, but a different detection method, multimer-optiview (MO). MPO IHC was called positive when >10% of neoplastic blasts showed expression. MPO positive blast percentage, staining intensity and pattern were assessed. Intensity: 0=negative, 1=mild, 2=moderate, 3=bright/same level as myeloids. Cytoplasmic pattern: homogenous or granular. Concurrent flow cytometry results and cytogenetic and/or molecular studies were reviewed. Results 35 cases were identified. Positive MPO IHC expression was present in 7/35 cases by SB method, with the percentage of MPO positive blasts ranging from 20–90% (majority >70%), all ranged from 1 - 2+ intensity and most (5/7) were homogenous pattern. 4/5 MPO SB positive cases were negative by MO detection method. MPO evaluation by flow cytometry was negative in 3 of 3 cases and myeloid associated antigens were negative or low on a subset. 2/8 BLL, BCR-ABL1 cases were MPO IHC positive by SB. Conclusion MPO staining by IHC in BLL is present in 17% of cases, often present in the majority of blasts, and positive using the SB detection system. This aberrant staining can be negated in most cases with the MO detection system. MPO expression by flow cytometry in MPO IHC SB positive cases were negative (3/3) and were low to absent for other myeloid antigens. We agree with prior studies that MPO IHC using the SB method can be a confounder for lineage assignment in acute leukemia.

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Different Minimal Residual Disease Levels between Childhood Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia Detected with Multi-Parameter Flow Cytometry.

Blood ◽

10.1182/blood.v104.11.4410.4410 ◽

2004 ◽

Vol 104 (11) ◽

pp. 4410-4410

Author(s):

Yongmin Tang ◽

Hongqiang Shen ◽

Hua Song ◽

Shilong Yang ◽

Shuwen Shi ◽

...

Keyword(s):

Flow Cytometry ◽

Acute Leukemia ◽

Residual Disease ◽

Lymphoblastic Leukemia ◽

Disease Recurrence ◽

Free Survival ◽

B Lineage ◽

Childhood Acute Leukemia ◽

Minimal Residual

Abstract Minimal residual diseases (MRD) are the problem of disease recurrence for childhood acute leukemia. Different levels of MRD determined with multi-parameter flow cytometry (MP-FCM) have been revealed prognostic for both adult and childhood acute leukemia in several recent studies. However, the MRD levels at the time of complete remission and the various check point during further treatment have not been reported. Methods: 122 cases (Male 73, Female 49, aged 2 month to 15yrs with a median of 6.5yrs) with childhood acute leukemia treated in our hospital from 2001.3 ~ 2004.7 were enrolled into this study. A total of 610 BM samples were detected with three or four color MP-FCM based on individualized leukemia-associated aberrant immunophenotypes (LAIP) in each patient according to their initial complete immunophenotypic profiles (B lineage ALL: 79 cases, T lineage ALL: 11 cases; AML: 32 cases). A total of 99 LAIPs (B lineage ALL: 48, T lineage ALL: 16, AML: 31, HAL: 4) were identified and single LAIP was used in most patients, but some patients needed more than one (2 or 3) LAIPs to detect their MRDs. At least 100,000 events were collected for each analysis. ALL and AML patients were treated with Chinese Childhood Cancer Study Group (CCCSG) ALL-protocol-1998 and AML-protocol-1998, respectively. Results: The CR rates for B lineage ALL, T lineage ALL and AML were 99.3%, 94.7% (overall ALL 98.8%) and 89.1%, respectively. The 1 yr/2 yrs of event free survival (EFS) for the three types of leukemia was 92.5%/85.2%, 78.3%/68.9% and 68.3%/56.4%, respectively. At the time of first CR after induction therapy, MRD level of B lineage ALL (79 cases) was 0.166%±0.057% (mean ± SE), significantly lower than those of T lineage ALL (11 cases, 0.783%±0.328%, t = 3.1926, P = 0.002) and AML (32 cases, 1.191%±0.257, t = 5.5177, P < 0.00001), respectively. No significance was identified between the MRD levels of T lineage ALL and AML (t = 0.8488, P = 0.40). The MRD level of the overall ALL (T + B lineage: 90 cases) was also significantly lower than that of AML (32 cases) (t = 5.0249, P < 0.00001). With further detection of MRD following the continuous consolidation and maintenance therapy, some patients relapsed and were excluded the study, and some had not reached the time for detection. At the time of 6 months after first CR, the MRD level of B lineage ALL (53 cases, 0.224%±0.065%) was not statistically different from that of T lineage ALL (7 cases, 0.627% ± 0.276%, t = 1.767, P = 0.083), while it was significantly higher than that of AML (16 cases, 0.966%±0.347%, t =3.334, P = 0.0014). At the time of 1 yr after CR, the MRD level in ALL (50 cases, 0.347%±0.090%) was not significantly different from that of AML (7 cases, 0.094%±0.072, t = 1.043, P = 0.31). At the time of 2 yrs after CR, the MRD level in ALL (49 cases, 0.302%±0.105%) was also not significantly different from that of AML (8 cases, 0.485%±0.246%, t = 0.6599, P = 0.51). Conclusions: MRD level of B lineage ALL is significantly lower than those of T lineage ALL and AML at the time of first CR, being true at the time of 6 months after CR. The differences are lost at 12 and 24 months after CR indicating that MRD detection with MP-FCM are well associated with the prognosis of childhood acute leukemia. Continuous follow-up to accumulate more cases is now underway.

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Human acute leukemia cell line with the t(4;11) chromosomal rearrangement exhibits B lineage and monocytic characteristics

Blood ◽

10.1182/blood.v65.1.21.21 ◽

1985 ◽

Vol 65 (1) ◽

pp. 21-31 ◽

Cited By ~ 194

Author(s):

RC Stong ◽

SJ Korsmeyer ◽

JL Parkin ◽

DC Arthur ◽

JH Kersey

Keyword(s):

Acute Leukemia ◽

Cell Line ◽

Lymphoblastic Leukemia ◽

Leukemia Cell ◽

Leukemic Cells ◽

Leukemia Cell Line ◽

Terminal Deoxynucleotidyl Transferase ◽

Immunoglobulin Gene ◽

A Cell ◽

B Lineage

Abstract A cell line, designated RS4;11, was established from the bone marrow of a patient in relapse with an acute leukemia that was characterized by the t(4;11) chromosomal abnormality. The cell line and the patient's fresh leukemic cells both had the t(4;11)(q21;q23) and an isochromosome for the long arm of No. 7. Morphologically, all cells were lymphoid in appearance. Ultrastructurally and cytochemically, approximately 30% of the cells possessed myeloid features. The cells were strongly positive for terminal deoxynucleotidyl transferase. They were HLA-DR positive and expressed surface antigens characteristic for B lineage cells, including those detected by anti-B4, BA-1, BA-2, and PI153/3. Immunoglobulin gene analysis revealed rearrangements of the heavy chain and kappa chain genes. The cells lacked the common acute lymphoblastic leukemia antigen and antigenic markers characteristic of T lineage cells. The cells reacted with the myeloid antibody 1G10 but not with other myeloid monoclonal antibodies. Treatment with 12-O-tetradecanoyl- phorbol-13-acetate induced a monocyte-like phenotype demonstrated by cytochemical, functional, immunologic, and electron microscopic studies. The expression of markers of both early lymphoid and early myeloid cells represents an unusual phenotype and suggests that RS4;11 represents a cell with dual lineage capabilities. To our knowledge, RS4;11 is the first cell line established from t(4;11)-associated acute leukemia.

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Acute leukemia of childhood: A single institution's experience

Archives of Biological Sciences ◽

10.2298/abs0501011s ◽

2005 ◽

Vol 57 (1) ◽

pp. 11-17 ◽

Cited By ~ 1

Author(s):

Bojana Slavkovic ◽

Marija Guc-Scekic ◽

Gordana Bunjevacki ◽

S. Djuricic ◽

Aleksandra Krstic ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Acute Leukemia ◽

Childhood Leukemia ◽

Lymphoblastic Leukemia ◽

Chromosomal Rearrangements ◽

Age Distribution ◽

Normal Karyotype ◽

Mediterranean Countries ◽

B Lineage ◽

Childhood Acute Leukemia

The aim of this study was to investigate distribution of immunophenotypic and cytogenetic features of childhood acute leukemia (AL) in the cohort of 239 newly diagnosed patients registered at the leading pediatric oncohematology center in the country during a six-year period (1996-2002). With approximately 60-70% of all childhood AL cases in Serbia and Montenegro being diagnosed and treated in this institution the used data represent a valid research sample to draw conclusions for entire country. On the basis of five phenotypic markers, the distribution of immunological subtypes was as follows: 169 (70.7%) expressed B-cell marker CD19 (137 were CD10 positive and 32 CD10 negative), 37 (15.5%) belonged to T-lineage acute lymphoblastic leukemia (T-ALL) (cyCD3 positive), and 33 (13.8%) were acute myeloblastic leukemia (AML) (CD13 positive and/or CD33 positive in the absence of lymphoid-associated antigens). The ratio of males and females was 1.5:1. Most of the cases were between the ages of 2 and 4, and were predominantly B-lineage acute lymphoblastic leukemia (B-ALL) cases. Another peak of age distribution was observed at the age of 7. The frequency of T-ALL (18% of ALL) was similar to that reported for Mediterranean countries: France (19.4%), Greece (28.1%), Southern Italy (28.3%), and Bulgaria (28.0%). Cytogenetic analyses were performed in 193 patients: 164 ALL and 29 AML. Normal karyotype was found in 57% of ALL and in 55% of AML patients, while cytogenetic abnormalities including structural, numerical, and complex chromosomal rearrangements were found in 43% of ALL and in 45% of AML patients. Our results represent a contribution to epidemiological aspects of childhood leukemia studies.

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The Reliability and Specificity of c-kit for the Diagnosis of Acute Myeloid Leukemias and Undifferentiated Leukemias

Blood ◽

10.1182/blood.v92.2.596 ◽

1998 ◽

Vol 92 (2) ◽

pp. 596-599 ◽

Cited By ~ 134

Author(s):

M.C. Bene ◽

M. Bernier ◽

R.O. Casasnovas ◽

G. Castoldi ◽

W. Knapp ◽

...

Keyword(s):

Acute Leukemia ◽

De Novo ◽

Lymphoblastic Leukemia ◽

Cell Lineage ◽

Specific Marker ◽

Acute Leukemias ◽

Routine Basis ◽

Immunological Classification ◽

B Lineage ◽

Acute Myeloid

Abstract We document findings on c-kit (CD117) expression in 1,937 pediatric and adult de novo acute leukemia cases, diagnosed in five single European centers. All cases were well characterized as to the morphologic, cytochemical, and immunologic features, according to the European Group for the Immunological Classification of Leukemias (EGIL). The cases included 1,103 acute myeloid leukemia (AML), 819 acute lymphoblastic leukemia (ALL), 11 biphenotypic acute leukemia (BAL), and 4 undifferentiated (AUL). c-kit was expressed in 741 (67%) AML cases, regardless of the French-American-British (FAB) subtype, one third of BAL, all four AUL, but only in 34 (4%) of ALL cases. The minority of c-kit+ ALL cases were classified as: T-cell lineage (two thirds), mainly pro-T–ALL or T-I, and B lineage (one third); cells from 62% of these ALL cases coexpressed other myeloid markers (CD13, CD33, or both). There were no differences in the frequency of c-kit+ AML or ALL cases according to age being similar in the adult and pediatric groups. Our findings demonstrate that c-kit is a reliable and specific marker to detect leukemia cells committed to the myeloid lineage, and therefore should be included in a routine basis for the diagnosis of acute leukemias to demonstrate myeloid commitment of the blasts. c-kit expression should score higher, at least one point, in the system currently applied to the diagnosis of BAL, as its myeloid specificity is greater than CD13 and CD33. Findings in ALL and AUL suggest that c-kit identifies a subgroup of cases, which may correspond to leukemias either arising from early prothymocytes and/or early hematopoietic cells, both able to differentiate to the lymphoid and myeloid pathways.

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A Randomised Phase II Study of Pegylated Liposomal Doxorubicine in Elderly Patients with Acute Lymphoblastic Leukemia (ALL): The GRAALL-SA1 Study.

Blood ◽

10.1182/blood.v112.11.918.918 ◽

2008 ◽

Vol 112 (11) ◽

pp. 918-918

Author(s):

Mathilde hunault-Berger ◽

Thibaut Leguay ◽

Xavier Thomas ◽

Ollivier Legrand ◽

Francoise Huguet ◽

...

Keyword(s):

Elderly Patients ◽

Lymphoblastic Leukemia ◽

Philadelphia Chromosome ◽

Patient Characteristics ◽

Cranial Irradiation ◽

Incidence Rates ◽

Aberrant Expression ◽

Myeloid Antigens ◽

B Lineage ◽

Induction Failure

Abstract The GRAALL-SA1 study aimed to randomly compare the efficacy and toxicity of liposomal pegylated doxorubicin (Peg-Dox) vs continuous infusion doxorubicin (CI-Dox) in elderly patients with Philadelphia chromosome-negative ALL. Induction chemotherapy, supported by G-CSF, comprised either CI-Dox 12 mg/m2/d and CI-VCR 0.4 mg/d on d1-4 or Peg-Dox 40 mg/m2 IV and standard VCR 2 on d1, in combination with dexamethasone. A second cycle, reinforced by cyclophosphamide 1 g/m2, was started at d28. Consolidation included two additional cycles using reduced doses of CI-Dox (12mg/m2/d d1-3) or Peg- Dox (30 mg/m2 d1) with VCR in both treatment arms (5 minutes infusion on d1,8,15) alternating with two cyclophosphamide (650 mg/m2 d1) /thioguanine (60 mg/m2 d2- d15) /cytarabine (75 mg/m2/d4-7 and d11-14) cycles. Maintenance included 6-MP and methotrexate for 2 years. CNS prophylaxis was based on 6 triple ITs and cranial irradiation. From March 2002 to October 2006, 60 patients aged 55 years or more from 26 centers were enrolled in this multicenter study. The median age was 66 years (range 55–80), 17% had initial WBC 3 30 x109/l, 2 patients had CNS leukemia and 6.6% had mediastinal involvement. Immunophenotyping showed 85% B-lineage ALL, 12% T-ALL, and 3% aberrant expression of myeloid antigens. Patient characteristics were comparable in the two randomization groups except for a small unbalance with more T-ALL and more steroids resistant leukemia in the Peg-Dox group (6/29 vs 1/31, P = .05 and 5/29 vs 1/31, P = .1, respectively). Tolerance was improved in the Peg-Dox arm with less Grade 3–4 infectious events during induction (27% vs 48%; P = .04), less Gram negative bacteriemia during induction (1 vs 9, P = .02) and consolidation courses (2 vs 7, P = .07) and less cardiac toxicities (1/29 vs 6 /31, P = .12). Duration of neutropenia was reduced from 7 days in the CI-Dox arm to 6 days in the Peg-Dox arm (P= .06). RBC units transfused were reduced from 7.2 to 4.5 during induction (P= .02) and from 2.9 to 1.1 during consolidation course (P= .003). Days with platelets < 50.109/L were reduced from 13.4 to 6.4 (P=0.03). After the 2 induction cycles, CR rate was 82%, with 10% failures and 8% induction deaths. With a median follow-up of 40 months, median OS for the entire population was 10 months and 19% of the patients were alive in CR at 3 years (95% CI, 9–30). Despite the better tolerance, there was a trend for a worse 2-year OS in the Peg-Dox arm (11 vs 27% ; P=0.07), due to higher induction failure (17 vs 3%) as well as relapse incidence rates (62 vs 39%). Younger age, B-lineage, and steroid sensitivity were the three factors identified for a higher CR rate in multivariate analysis. The decreased toxicity of Peg-Dox over CI-Dox was thus offset by a decreased efficacy. Further studies should evaluated higher doses of pegylated versus conventional formulations of anthracycline in patients with ALL.

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CHILDHOOD Biphenotypic ACUTE LEUKEMIA with High Incidence of Basophilic Differentiation: The CONTRIBUTION of Ultrastructural Methods to Diagnosis.

Blood ◽

10.1182/blood.v114.22.4698.4698 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4698-4698

Author(s):

Peretz Resnitzky ◽

Drorit Luria ◽

Dina Shaft ◽

Gali Avrahami ◽

Marta Jeison ◽

...

Keyword(s):

Flow Cytometry ◽

Acute Leukemia ◽

Nuclear Membrane ◽

Conflicts Of Interest ◽

Medical Center ◽

Leukemic Cells ◽

Ultrastructural Studies ◽

High Incidence ◽

B Lineage ◽

Biphenotypic Acute Leukemia

Abstract Abstract 4698 The diagnosis of Biphenotypic Acute Leukemia (BAL) is still a challenge in clinical hematology. In spite of the use of the score formulation of the European Group for the Immunological Classification of Leukemias (EGIL) there are still cases difficult to define. We assessed the contribution of ultrastructural morphology and cytochemistry to the diagnosis of BAL in pediatric leukemic patients. Twenty six patients diagnosed at Schneider Children's Medical Center of Israel between the years 1989 to 2004 have been classified as BAL in a retrospective analysis evaluated by various combinations of light-microscopy (LM) morphology, immunophenotype flow-cytometry, cytogenetics and electron-microscopy (EM) including myeloperoxidase (MPO) and platelet peroxidase (PPO) reaction. The identification of myeloid features by EM was based on the presence of 1) MPO positive granules and MPO reactivity in the nuclear membrane, profiles of endoplasmic reticulum (ER) and in the membranes of the Golgi system; 2) PPO reaction in the nuclear membrane and profiles of ER, and 3) the presence of primary basophilic granules in the cytoplasm of the blasts. The EGIL scoring system has been used with the addition of the ultrastructural findings for the definition of BAL. In 24 cases the morphologic appearance and cytochemistry by LM of the leukemic cells were that of undifferentiated blasts. By cytogenetic evaluation abnormal karyotypes were detected in 16 patients, normal in 4 and unknown in 6 patients. Out of 26 patients 15 had the combination of T-ALL with myeloid phenotype and 11 had the B-lineage with myeloid features. Unexpectedly the blasts of 9 of the 26 BAL patients had basophilic differentiation as indicated by the presence of typical primary basophilic granules with MPO reactivity in a scattered pattern as previously reported in basophylic leukemia. Interestingly 7 of these 9 cases had a T lymphoid component. By contrast among 15 patients who had FAB M0, 9 had the B lineage markers. The remaining 2 patients had M1 and M7 features with T lymphoid phenotype. The contribution of EM studies enabled to establish the diagnosis of BAL in 11 out of 26 patients, in other 6 patients it allowed for the refinement of the AML subgroup such as basophilic leukemia and in the remaining 9 patients EM confirmed the diagnosis of BAL as defined by flow cytometry. Conclusions Our study identified a subgroup of children with acute leukemia in whom BAL could be suggested only by the addition of ultrastructural studies. EM could further refine and confirm the diagnosis of BAL in all the other cases. Of interest is the high incidence of basophylic differentiation among BAL pediatric patients, and its association with T lymphoid phenotype. Disclosures: No relevant conflicts of interest to declare.

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Childhood acute lymphoblastic leukemia with chromosomal breakpoints at 11q23

Blood ◽

10.1182/blood.v73.6.1627.bloodjournal7361627 ◽

1989 ◽

Vol 73 (6) ◽

pp. 1627-1634 ◽

Cited By ~ 2

Author(s):

SC Raimondi ◽

SC Peiper ◽

GR Kitchingman ◽

FG Behm ◽

DL Williams ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Lymphoblastic Leukemia ◽

Leukemic Cells ◽

Chromosome 11 ◽

Myeloid Antigens ◽

Hla Dr ◽

Chromosomal Breakpoints ◽

Leukocyte Counts ◽

Structural Chromosomal Abnormality ◽

B Lineage

Twenty-one (5.7%) of 368 cases of acute lymphoblastic leukemia (ALL), studied fully for karyotype and immunophenotype, had breakpoints in the q23 region of chromosome 11. This abnormality resulted from reciprocal translocation in 17 cases [with chromosomes 4 (n = 5), 10 (n = 2), and variable chromosomes (n = 10)], from deletions in three cases, and from a duplication in one case. The 17 children with 11q23 translocations had higher leukocyte counts (P less than .01) and were more likely to be black (P less than .01) and younger (P = .08) as compared with each of the following non-11q23 translocation groups: t(1;19), t(9;22), random translocations, and cases without translocations. Event-free survival at 3 years for the 11q23 translocation group did not differ significantly from that of the t(1;19), t(9;22), or random translocation groups. Leukemic cells from ten of the 21 patients with an 11q23 structural chromosomal abnormality had an immunophenotype indicative of B-lineage ALL (HLA-DR+, CD19+, CD2-, CD3-); this was confirmed by the presence of rearranged immunoglobulin heavy-chain genes in seven cases. In eight of these ten B-lineage cases, the blasts were negative for expression of the CD10 antigen, indicating a primitive stage of B-cell development. Four cases were classified as T- cell ALL, and seven others were characterized by blasts that failed to react with our panel of lineage-associated monoclonal antibodies (MoAbs). Myeloid antigens were expressed by leukemic cells in three of the cases that were tested. The initial clinical features associated with translocations involving the 11q23 chromosomal region may define a distinct subtype of ALL. Whether the constellation of findings relates to a breakpoint at 11q23 per se or to the specific translocation will require further study.

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Elevation of Normal B Cells in Children with ALL Can Predict Relapse.

Blood ◽

10.1182/blood.v104.11.4445.4445 ◽

2004 ◽

Vol 104 (11) ◽

pp. 4445-4445

Author(s):

Joseph Kapelushnik ◽

Itai Levi ◽

Tikva Yermoau ◽

Asher Moser ◽

Atamma Haj-Yhia ◽

...

Keyword(s):

Flow Cytometry ◽

B Cells ◽

Acute Leukemia ◽

Reference Values ◽

Predictive Marker ◽

Multiparametric Flow Cytometry ◽

Flow Cytometric ◽

Immature B Cells ◽

B Lineage ◽

Relapsed Disease

Abstract Flow cytomerty analysis of bone marrow (BM) is performed routinely in children with acute leukemia in different phases of chemotherapy. The aim of flow cytometric monitoring is to measure the amount of residual blasts and to evaluate the efficacy of chemotherapy. Multiparametric flow cytometry may be also used to evaluate normal hematopoisis in BM of patients with acute leukemia in different phases of chemotherapy. The aim of this study was to study normal lymphopoiesis in patients with relapsed disease. Twenty-two pediatric patients with ALL were enrolled in the protocol of study. Patients were treated in accordance with BFM-98 protocol. Eighteen children were in complete remission during follow-up period, while 4 children relapsed. Three of the relapsed children had B-lineage ALL, and one had T-cell ALL. Using multiparamertic flow cytometry we measured normal pro-B cells (CD19+CD34+), immature B (CD19+CD10+CD20+ and CD19+CD10−CD20+) and mature B (CD19+CD10−CD20+) cells in BM of relapsed patients in different phases of chemotherapy. Amounts or different subsets of B cells were compared with reference values determined in patients with relapse-free disease. Reference values were expressed as mean ± confidence interval for each subset of B cells and for each phase of chemotherapy. Elevation of immature normal B-cells was determined in all 4 patients who relapsed.Three during chemotherapy. Increased amount of mature B cells was determined 3 mo before the diagnosis of relapse in the patient who relapsed after the end of chemotherapy.This event was not observed in patient who did not relapse We conclude that elevation of normal immature B cells in BM of patient with ALL can be a predictive marker for eventual relapse.

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Prognostic Significance of Minimal Residual Disease in Adult Patients with B-Lineage Acute Lymphoblastic Leukemia by 8-Color Flow Cytometry

Blood ◽

10.1182/blood.v120.21.4789.4789 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4789-4789

Author(s):

Xiang-Qin Weng ◽

Yang Shen ◽

Yan Sheng ◽

Bing Chen ◽

Jing-han Wang ◽

...

Keyword(s):

Flow Cytometry ◽

Acute Lymphoblastic Leukemia ◽

Treatment Response ◽

Minimal Residual Disease ◽

Residual Disease ◽

Lymphoblastic Leukemia ◽

Prognostic Significance ◽

Color Flow ◽

B Lineage ◽

Minimal Residual

Abstract Abstract 4789 Monitoring of minimal residual disease (MRD) in patients with acute lymphoblastic leukemia (ALL) by immunophenotyping and/or molecular techniques provides a way to precisely evaluate early treatment response and predict relapse. In this study, we have investigated the prognostic significance of MRD in adult patients with B-lineage acute lymphoblastic leukemia (B-ALL) by 8-color flow cytometry. A cohort of 106 patients with B-ALL who had achieved a complete remission (CR) and at least 1 LAIP characteristics were enrolled to perform MRD assessment at the end of induction and 1 cycle of consolidation. LAIPs were identifiable in 96% of the patients by 8-color flow cytometric assay, in which, most cases (90.6%) containing 2 or more LAIPs had a sensitivity as high as identifying 1 leukemic blast among 1×105 BM nucleated cells. MRD negative status could clearly predict a favorable 1 year relapse free survival (RFS) and 2 year overall survival (OS) when a cut-off level of 0.01% was used to define MRD positivity at the point of achieving CR (P=0.000 and 0.000, respectively) and after 1 cycle of consolidation (P=0.000 and 0.000, respectively), respectively. In multivariate analysis including cytogenetic abnormalities, clinical factors and MRD status, late CR (P=0.046), MRD status at the points of obtaining CR (P=0.016) and 1 consolidation (P=0.007) were associated with RFS independently, while only MRD status after 1 course of consolidation was independent prognostic factor for OS (P=0.000). Of note, in exploring the fewer patients with MRD negative status experienced recent relapse, we have identified that most of such patients had a MRD level of 10−4−10−5 comparing to undetectable MRD level. Furthermore, our evidences showed that MRD assessed by flow cytometry and by RQ-PCR assay targeting to BCR-ABL fusion gene yielded concordant results in the vast majority of cases (90%). In conclusion, immunophenotypic evaluation of MRD by 8-color flow cytometry could work as an important tool to assess the treatment response and prognosis precisely in adult B-ALL. Disclosures: No relevant conflicts of interest to declare.

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Aneuploidy and percentage of S-phase cells determined by flow cytometry correlate with cell phenotype in childhood acute leukemia

Blood ◽

10.1182/blood.v60.4.959.bloodjournal604959 ◽

1982 ◽

Vol 60 (4) ◽

pp. 959-967 ◽

Cited By ~ 1

Author(s):

AT Look ◽

SL Melvin ◽

DL Williams ◽

GM Brodeur ◽

GV Dahl ◽

...

Keyword(s):

Flow Cytometry ◽

T Cell ◽

Acute Leukemia ◽

Dna Content ◽

Lymphoblastic Leukemia ◽

Leukemia Cell ◽

S Phase ◽

Cell Surface Expression ◽

Phase Cell ◽

Cell Phenotype

Cellular DNA content distributions of propidium-iodide-stained bone marrow blasts were determined by flow cytometry (FCM) for 225 untreated children with acute leukemia and were correlated with leukemia cell phenotype and karyotype. Aneuploidy of the primary malignant stem line was detected in 54 cases (24%): 51 hyperdiploid and 3 hypodiploid. A second stem line with approximately twice the DNA content of the primary stem line was recognized by FCM in 28 cases (23 ALL, 5 ANLL) and may be an important source of leukemia cell heterogeneity. The degree of DNA content abnormality detected by FCM was highly correlated (r = 0.98) with the number of whole chromosome gains or losses in the leukemia karyotype. Aneuploidy detectable by FCM was more frequent in acute lymphoblastic leukemia (ALL) (52 of 173, 30.1%) than in acute nonlymphoblastic leukemia (2 of 52, 3.8%) (p less than 0.001). In the ALL group, aneuploidy was significantly correlated with the cell surface expression of common ALL antigen: 46 of 127 antigen-positive cases were aneuploid compared to 6 of 46 antigen-negative cases (p less than 0.003). Only 2 of 21 cases of T-cell ALL without common ALL antigen had detectable aneuploidy, which was significantly less than in the common ALL group (p = 0.02). The median percentage of cells in S- phase was significantly greater for B-cell and erythrocyte rosette- positive T-cell ALL, than for the other phenotypic subgroups. We conclude that aneuploidy and S-phase cell percentage are correlated with the state of leukemia cell differentiation. The biologic basis for the correlation is not established, but may be linked to the process of malignant transformation.

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