Blast Cells In Peripheral Blood Research Articles

Prognostic relevance of circulating matrix metalloproteinase‐2 in acute myeloid leukaemia patients

Matrix metalloproteinases (MMPs) were postulated to have important implication in progression and invasiveness of many malignant disorders. On the other hand the biological role of MMP-2 in acute myeloid leukaemia (AML) is not fully clear. Serum samples from 37 adult patients with AML had been taken before chemotherapy was administered. In addition 20 out of the 37 patients were analysed again after achieving complete remission (CR). Ten samples from healthy volunteers were evaluated as the control. Total MMP-2 levels were measured using ELISA Kit obtained from R&D system. MMP-2 serum levels were significantly lower in pretreatment AML patients than that in the normal controls (p = 0.000) and in CR (p = 0.007). No significant correlations were detected between pretreatment sMMP-2 levels and FAB subtypes, peripheral blood blast cell counts, peripheral blood WBCs, bone marrow blast cell counts or blast cell distribution ratio. The prognostic value of MMP-2 was evaluated by dividing AML patients into high and low MMP-2 groups using the pretreatment median MMP-2 level of the AML group as the cut-off. The authors found that patients in the high group survived for a significantly shorter time than those patients in the lower MMP-2 group. High pretreatment levels of sMMP-2 among AML patients were associated with poor survival. Prospective studies are recommended to establish the clinical value of longitudinal sMMP-2 measurement.

Distinctive expression of myelomonocytic markers and down‐regulation of CD34 in acute myelogenous leukaemia with FLT3 tandem duplication and nucleophosmin mutation

Patients with acute myelogenous leukaemia (AML) show co-existing frequently internal tandem duplications of FLT3 (FLT3-ITD) and mutations of nucleophosmin (NPM1-Mt). We investigated the biological and clinical significance of FLT3-ITD and/or NPM1-Mt in this context. We analysed 89 AML patients according to whether NPM1 and FLT3-ITD were single mutants, double mutants, or wild type for both. FLT3-ITD was detected in 19 of 89 patients (21.3%), while NPM1-Mt was detected in 19 of 89 patients (21.3%); eight of 89 patients (9.0%) carried both FLT3-ITD and NPM1-Mt. By multivariate analysis, white blood cell count and peripheral blood blast cell count at diagnosis were significantly higher in patients with FLT3-ITD but not in those with only NPM1-Mt. NPM1-Mt was significantly related to female gender, normal karyotype, and M4 or M5 disease according to French-American-British criteria. In addition, leukaemic blast cells with NPM1-Mt, FLT3-ITD, or both expressed CD34 less frequently than wild-type blasts (P < 0.0001 and P = 0.005 respectively), while myelomonocytic markers such as CD11b and CD14 were expressed more frequently in patients with NPM1-Mt. FLT3-ITD may increase potential for cell proliferation to produce a leukaemic population; NPM1-Mt may cause cells to develop along the myelomonocytic lineage. Extensive analyses and detailed experiments will be required to clarify how NPM1 and FLT3 mutations interact in leukaemogenesis.

Fatal cerebral leucostasis in acute leukaemia with hyperleucocytosis

Acute leukaemia may present with extremely high blast counts, a phenomenon known as hyperleucocytosis. It is blood blast count greater than 100,000/cmm and occurs occasionally in Acute Myelogenous Leukaemias [1]. The risk of death is disproportionately high (20% to 40%) when acute hyperleucocytosis is present. Respiratory failure, intracranial haemorrhage and severe metabolic abnormalities occur frequently and are the primary determinants of high mortality. Risk of death due to haemorrhage in the central nervous system is higher in acute myeloblastic leukaemia, lymphoblastic leukaemia and blastic phase of chronic mylogenous leukaemia when thrombocytopenia and hyperleucocytosis are simultaneously present [2]. The management involves vigorous supportive measures and reducing the number of circulating leukaemic blast cells. Red cell transfusions should be minimized initially to avoid increasing viscosity. However platelet transfusions are needed to decrease risk of haemorrhage. Case Report A sixteen year-old boy reported to OPD with complaints of pain epigastric region, fever, nausea and vomiting of three days duration. Clinical examination admission revealed pulse=86/min, BP 140/106 mm Hg, Respiratory rate = 22/min, pallor present, axillary lymph nodes just palpable, no petechial haemorrhages or eccymosis seen. Systemic examination revealed tenderness in epigastric region, spleen tip palpable and hepatomegaly of 3cm. Laboratory reported a very high WBC count of 4,20,000/cmm predominantly with myeloblasts suggestive of AML (Fig 1). USG abdomen showed hepatomegaly with RMD grade I. Peripheral Blood smear-RBCs showed mild anisopoikilocytosis, predominantly microcytic hypochromic, No schistiocytes seen, myeloblasts 83%, promyelocytes 06%, myelocytes 03%, metamyelocytes 02%, stab forms 1%, lymphocytes 5%, granulocytes nil, Auer rods seen in some myeloblasts, myeloperoxidase negative, non-specific esterase negative, PAS faint staining positive in blast cells. Severe thrombocytopenia with platelet count of 30,000/cmm present. Diagnosis of Acute Myeloid Leukemia – FAB-M1 was made. Fig. 1 Photomicrograph showing Hyperleucocytosis due to blast cells in peripheral blood (x 10) Patient was treated with transfusion of one unit of packed red cells, two units of platelet concentrate and fresh frozen plasma was demanded. The same evening the patient became semiconscious, poorly responded to commands and passed urine in bed, plantars were extensors bilaterally. Urgent CT scan showed multiple intracranial haemorrhages, ventricular effacement, midline shift and cerebral oedema. Leukaemic infiltration due to cerebral leucostasis was suspected. Patient was treated with intravenous steroids, mannitol, lasix, antibiotics and metrogyl but his condition deteriorated and he succumbed the same day.

Clinical and Interphase-FISH Studies of Deletion of Derivative Chromosome 9 in Patients with Chronic Myelogenous Leukemia.

Objective: To determine the frequency of the deletion of derivative 9 [der(9)] among chronic myeloid leukemia (CML) patients with classic Ph translocation and variant Ph translocation, and to assess the association between this deletion and clinical prognosis.Methods: Cytogenetical analysis of bone marrow cells was performed by direct method and /or 24h culture method. RHG banding was used for karyotype analysis. Dual-color and dual-fusion DNA probe was used to perform interphase-FISH to investigate the deletion of der(9) in Ph+ CML patients and all patients were followed up.Result: Cytogenetical studies showed typical Ph translocation in 76/105 and variant Ph translocation in 29/105. Interphase-FISH studies showed deletion of der(9) in 12 cases(15.8%) of 76 patients with classic Ph translocation and in 4 cases (13.7%) of 29 patients with variant translocation. The frequency of deletion was similar in classic and variant translocations (P>0.9). This result is contrary to previous reports which suggested that deletions are much more common in variant Ph translocation than in classic Ph translocation. When the deletion was seen in a patient, it was present in all the Ph+ metaphases and nuclei. Three patients with heterogeneous cell populations mixed with cells with single 5′-ABL or 3′-BCR deletion and with both 5′-ABL and 3′-BCR deletion. It may suggest clone evolution in the progression of deletion. Complete clinical information was available in 54 patients. There were no significant difference in peripheral leukocyte count, platelet count, hemoglobin and percentage of peripheral blood blast cells between patients with and without der(9)deletion. However, the results of following up showed that the median survival time of patients with der(9) deletion was significantly shorter than those without der(9) deletion (34 months vs 76 months; P<0.05, log-rank Test).Conclusion: A deletion of der(9) is seen in about 1/6 Ph+ CML patients in china, with which Ph+ CML patients have shorter median survival time than those without it, indicating that it is a poor prognostic index. For evolution the prognosis of CML patients more precisely, it is best to perform cytogenetical analysis and FISH analysis for der(9) deletion simultaneously at diagnosis.

Acute monocytic leukaemia in a cat

A three-year-old cat with lymphadenopathy, non-regenerative anaemia and marked leucocytosis (171.3 x 10(9) white blood cells/l) was diagnosed with monocytic leukaemia and treated with a combination of anticancer drugs. A number of mature and immature monocyte-like cells were detected in the peripheral blood and bone marrow; they proved to be monocytic cells by cytochemical examination and an analysis of their cell surface phenotype, indicating that the cat suffered from acute myeloid leukaemia, subclassified as monocytic leukaemia (M5). Treatment with cytarabine, doxorubicin, vincristine and prednisolone greatly reduced the number of blast cells in the cat's peripheral blood and bone marrow. The cat was in partial remission for 67 days and survived for 95 days after it was first examined.

Soluble VEGF/sFLt1 ratio is an independent predictor of AML patient out come

Angiogenesis is the formation of new blood vessels and is controlled by a balance between positive and negative angiogenic regulatory factors. Soluble vascular endothelial growth factor receptors 1,2 (Flt-1, KDR) are the negative counterpoint to the vascular endothelial growth factor (VEGF) signaling pathway, which has been characterized as one of the most important endothelial regulator in human angiogenesis. In the present work, we tested the differential prognostic relevance of soluble vascular endothelial growth factor (VEGF), their receptors 1 (Flt-1), 2 (KDR), and the ratio between sVEGF/sFlt-1 in 43 patients with acute myeloid leukemia (AML). sVEGF and its soluble receptors were assessed using an ELISA. Soluble VEGF, sFLT-1 and sKDR concentration levels were significantly higher in AML patients at diagnosis when compared to the levels in normal controls. sVEGF, sFlt1 and the sVEGF/sFlt1 ratio were significantly higher in non responders when compared to responders (P < 0.001 for all). However, there was no significant difference regarding sKDR levels (P > 0.05). sVEGF, the sVEGF/sFlt1 ratio but not sFlt1 and sKDR levels were significantly elevated in those who did not survive, when compared to survivors. sVEGF, sFlt1 levels were significantly correlated to WBC counts (R = 0.93, P = 0.000, R = 0.56, P = 0.000, respectively); bone marrow blast cell counts (R = 0.92, P = 0.000; R = 56, P = 0.000, respectively); peripheral blood blast cell counts (R = 0.91, P = 0.000; R = 0.52, P = 0.000, respectively); sKDR was only correlated to peripheral blood blast cell counts(R=0.37,P=0.014). Cox regression analysis results with sVEGF, sFlt1, sKDR, sVEGF/sFlt1 ratio suggest that the most important predictor for AML outcome is the sVEGF/sFlt1 ratio. In conclusion, sVEGF/sVEGF ratio is independent predictor of AML patient out come, and its significance should be assessed when considering antiangiogenic therapy.

Antibody binding capacity for evaluation of MDR-related proteins in acute promyelocytic leukemia: Onset versus relapse expression.

Multidrug resistance (MDR) remains a major obstacle for successful treatment in cancer, in particular in acute leukemia. In acute promyelocytic leukemia (APL), the high sensitivity to anthracyclines appears to be attributable to the low frequency of MDR proteins overexpression at onset even if 30% of patients still relapse and become resistant to therapy. In attempt to explain different blast cell sensitivity, we studied the expression of PGP, MRP1, MRP2, and LRP in 45 cases of APL, comparing onset of disease with relapse. PGP, LRP, and MRP on bone marrow or peripheral blood blast cells were evaluated by flow cytometry using the MRK-16, LRP-56, MRP-m6, and MRP2 antibodies and results expressed by the mean fluorescence index (MFI). The antibody binding capacity (ABC) for each MDR protein was also calculated. At diagnosis, only 2 of 45 patients overexpressed PGP and 1 overexpressed LRP. PGP and LRP overexpressing cases significantly grew up during disease progression and at second relapse mean PGP MFI and mean LRP MFI were significantly higher than at onset (P = 0.001 and P = 0.008, respectively). By analyzing ABC, the same trend was more evident because a significant increment of PGP and LRP was observed at second (P = 0.002 and P = 0.002, respectively), but even at first relapse (P = 0.018 and P = 0.002, respectively). No changes were demonstrated in MRP1 and MRP2 expression in any phase of disease considered. Our data confirm the low expression at diagnosis of proteins related to development of drug resistance in APL. The evidence of a relative easy induction of PGP and LRP, but not of MRP, can be useful in choosing drugs to employ for consolidation or rescue therapy.

A Fetal Case of Transient Abnormal Myelopoiesis with Severe Liver Failure in Down Syndrome: Prognostic Value of Serum Markers

The authors recently encountered a lethal case of Down syndrome with transient abnormal myelopoiesis (TAM). Although the peripheral white blood cell count and blast cells had improved without specific treatment, the patient died of severe coagulopathy due to liver fibrosis when he was 5 years old. The prognosis of TAM with liver fibrosis was poor. The patient had high levels of N-terminal peptide of III procollagen, type IV collagen, and hyaluronic acid. These serum makers are noninvasive indicators of liver fibrosis and may be useful as prognostic indicators of TAM in Down syndrome.

Urokinase Plasminogen Activator Receptor and Soluble Matrix Metalloproteinase-9 in Acute Myeloid Leukemia Patients: A Possible Relation to Disease Invasion

Extracellular proteolytic enzymes of the urokinase-type plasminogen activator (uPA) and metalloproteinase (MMP) family play a crucial role in the matrix degradation and tissue remodeling process characteristic of malignant disorders. The receptor for urokinase plasminogen activator (uPAR) serves to localize and intensify the action of UPA and is expressed on the surface of malignant cells. Although the biological significance of MMP-9 and soluble urokinase receptor in growth and progression of lymphoid neoplasm is understood, its clinical significance in acute myeloid leukemia (AML) has not been fully elucidated. In this study, we determined the levels of soluble urokinase-type plasminogen activator receptor (suPAR), cellular uPAR and sMMP-9 in 43 newly diagnosed AML patients at diagnosis, before chemotherapy, and also studied 10 normal subjects served as a control group. After chemotherapy suPAR and MMP-9 were determined at remission and relapse. The levels of suPAR, cellular PAR were significantly higher (P=0.001, 0.001) and MMP-9 was significantly lower (P=0.001) in AML patients at diagnosis as compared to controls. suPAR and MMP-9 levels were significantly lower in AML patients who achieved complete remission (CR) as compared to those who did not (P=0.001 for both). Levels of suPAR and MMP-9 were significantly correlated to peripheral blood blast cells (r=0.88, P=0.001; r=0.65, P=0.001, respectively) and blast cell distribution ratio (BCDR, r=0.84, P=0.001; r=65, P=0.001, respectively). suPAR, cellular PAR and MMP-9 were significantly higher in patients with extramedullary infiltration as compared with those without (P=0.001, 0.001, <0.05). The suPAR, cellular uPAR, and MMP-9 levels were uneven in AML FAB subtypes being highest in M5(P<0.05 for all). MMP-9 and suPAR levels were correlated with the disease status. In AML survivors, MMP-9, cellular uPAR and suPAR were significantly lower as compared to non-survivors (P=0.001 for all).In conclusion, MMP-9 and suPAR levels might be used as a marker for disease activity and may contribute to blast cell dissemination. MMP-9 and suPAR may be target molecules in the strategy of treatment of AML.

Circulating myeloid colony-forming cells predict survival in myelodysplastic syndromes.

The growth characteristics and the prognostic value of cytokine-stimulated myeloid colony formation from peripheral blood mononuclear cells (PBMC) of patients with myelodysplastic syndromes (MDS) are largely unknown. In this study we have determined the number of myeloid colony-forming units (mCFUs) in semisolid medium from 112 MDS patients and correlated them with French-American-British (FAB) type, the international prognostic scoring system (IPSS), karyotype, peripheral blood (PB) and bone marrow (BM) blast cells, cytopenias, lactate dehydrogenase (LDH), and survival data. Concerning the FAB classification, lower median mCFUs were found in patients with refractory anemia (RA) and refractory anemia with ringed sideroblasts (RARS) compared to refractory anemia with excess of blast cells (RAEB) and refractory anemia with excess of blasts cells in transformation (RAEB-T). In vitro growth in MDS clearly correlated with the cytogenetic risk groups defined by the IPSS (30.5/10(5) PBMCs with favorable karyotypes, 191 in the intermediate prognostic group, 677 with unfavorable cytogenetics, p=0.015 favorable vs unfavorable). BM blast cells >5% (60.5 vs 255 colonies, p=0.032) as well as LDH levels above the normal limit (64.5 vs 425 colonies, p=0.045) were also associated with higher colony formation. Patients were stratified according to the number of circulating mCFUs into a low growth, intermediate growth and high growth group. Median survival was 343 days in the high growth, 1119 days in the low growth, and 2341 days in the intermediate growth group ( p=0.0002). Multivariate analyses revealed colony growth ( p=0.0056), PB blast cells ( p=0.0069), cytogenetic risk group ( p=0.024), and platelet count ( p=0.018) to predict survival in our patients. After inclusion of the IPSS risk categories, mCFU levels remained a highly predictive parameter for survival ( p=0.0056) and acute myeloblastic leukemia (AML) transformation ( p=0.0003).

The Potential Effect of Short-course High-dose Steroid on the Maturation and Apoptosis of Leukemic Cells in a Child with Acute Megakaryoblastic Leukemia

High-dose methylprednisolone (HDMP) treatment has been shown to induce differentiation of myeloid leukemic cells in children with acute promyelocytic leukemia and other subtypes (FAB AML M1-M2-M4) of acute myeloblastic leukemia. In the present study, a child with acute megakaryoblastic leukemia (AMKL) was given HDMP (30 mg/kg/day) orally in a single dose for the first 4 days of induction therapy. A marked decrease in peripheral blood blast cells and an increase in platelet count associated with a striking change in bone marrow (BM) morphology was observed following a short-course of HDMP treatment alone. BM cells developed distinct morphology characterized by cytoplasmic blebbing and some appeared as platelet producing micromegakaryocytes. Flow cytometric analysis of the BM cells 4 days after HDMP treatment demonstrated a decrease in the percentage of cells co-expressing CD34 and CD117 antigens and a marked increase in CD42a antigen. These changes in BM morphology and immunophenotype may suggest maturation effect of HDMP on megakaryocytic leukemic cells. In addition ultrastructural analysis of BM cells cultured with methylprednisolone (10 m 3 and 10 m 6 M) for 24 and 48 h showed numerous apoptotic cells. This was coincident with a significant increase in the percentage of annexin positive cells. These results suggest that HDMP treatment may induce differentiation and apoptosis of leukemic cells in a child with AMKL and it could be a promising agent for remission induction of patients with AMKL.

Low levels of ABCG2 expression in adult AML blast samples

Previous reports have suggested that the adenosine triphosphate-binding cassette protein ABCG2 (breast cancer resistance protein [BCRP], mitoxantrone resistance [MXR]) is associated with drug resistance in acute myeloid leukemia (AML). The aims of this study were to determine the level of ABCG2 mRNA expression necessary to produce drug resistance and to define the ABCG2 levels in normal bone marrow (BM), peripheral blood (PB), cord blood (CB), and adult AML blast cell populations. First, using transduced clonal cell lines expressing varying levels of ABCG2, we found that ABCG2 expression conferred resistance to mitoxantrone and topotecan, but not to idarubicin. Next, we developed a real-time reverse transcription-polymerase chain reaction assay for measuring ABCG2 mRNA expression levels in clinical samples. Normal BM and PB contained low levels of ABCG2 mRNA, while higher levels were measured in CB mononuclear cells, CD34(+), and Ac133(+) populations, consistent with the known stem cell enrichment in these populations. Next, we studied the ABCG2 mRNA levels in 40 specimens from newly diagnosed adult AML patients. Only 7% of these samples contained ABCG2 mRNA levels within the range of our drug-resistant clone, although another 78% were higher than normal blood and bone marrow. Flow cytometry revealed very small subpopulations of ABCG2-expressing cells in the cases we examined. Our data suggest that high levels of ABCG2 mRNA expression in adult AML blast specimens are relatively uncommon and that ABCG2 expression may be limited to a small cell subpopulation in some cases.

EFFECT OF SHORT-COURSE, HIGH-DOSE STEROID THERAPY IN A CHILD WITH MYELODYSPLASTIC SYNDROME

High-dose methylprednisolone (HDMP) has been shown to induce differentiation of myeloid leukemic cells with a remarkable antileukemic effect in children with various subtypes of acute myeloblastic leukemia (AML). Here the beneficial effect of short-course HDMP therapy in a child with myelodysplastic syndrome (MDS) is reported. Oral methylprednisolone sodium succinate (Prednol-L) was administered at a single daily dose of 30 mg/kg for 5 days to a 4-year-old girl with refractory anemia with excess of blasts and hypocellular bone marrow before the initiation of chemotherapy. In addition to dramatic clinical improvement, the patient's white blood cell count increased from 2.3 2 10 9 /L to 5.0 2 10 9 /L, and peripheral blood blast cells disappeared 4 days after HDMP treatment. Repeated bone marrow aspirate 1 week after the initiation of HDMP disclosed increased cellularity with no blasts. Furthermore, short-course HDMP treatment stimulated the increase in the number of peripheral blood lymphocytes and CD3 + , CD4 + , CD8 + , CD19 + , CD34 + , and NK cells. Results obtained with HDMP from the previous studies and the present case suggest that high-dose methylprednisoloneis a promising agent in the treatment of MDS and it is recommended as an initial treatment especially for MDS children with hypocellular bone marrow at presentation.

Chemotherapy and donor peripheral blood progenitor cells for acute leukemia in early relapse after allogeneic bone marrow transplantation.

Ten patients with acute leukemia (AL) in early relapse after allo-BMT were treated with a modified MEC (mitoxantrone, etoposide and Ara-C) regimen followed by donor PBPC collected after mobilization with G-CSF. Seven patients achieved CR or had normal hemopoietic reconstitution: two had an early relapse at days +53 and +48, two patients died from acute GVHD at days +31 and +96, one died of interstitial pneumonia at day +55, and two patients experienced long-term survival. One patient with refractory disease and nodal involvement who did not respond to the first BMT had overt expansion of the leukemia at day +36; one patient with Ph+ ALL and one with ANLL evolving from MDS, both with skin involvement, had blast cells in peripheral blood at day +27 and +26, respectively. Transient cytopenia occurred in all patients; a normal granulocyte and platelet count was achieved within 3 weeks in all patients but one; acute GVHD occurred in six patients, and four had chronic GVHD. This approach is feasible in patients in early relapse after allo-BMT. It assists prompt re-establishment of normal donor hematopoiesis avoiding the prolonged cytopenia observed after donor lymphocyte infusion in AL patients relapsed after allo-BMT.

In vitro growth in acute myeloblastic leukaemia: relationship with other clinico-biological characteristics of the disease.

The in vitro growth characteristics of a large series of acute myeloid leukaemia (AML) patients and their relationship with other clinical and biological disease characteristics were analysed. Patients with AML were studied, 181 with de novo AML and 45 with secondary AML (24 myelodysplastic syndrome, sAML-MDS, 21 myeloproliferative disorder, sAML-MPD). Leukaemic colony forming units (L-CFU) were assayed by plating peripheral blood (PB) blast cells in methyl-cellulose and using LCM-PHA as stimulant. In each case parallel cultures were made with and without stimulating factors. Plating efficiency (PE) was defined as the number of clusters plus colonies/10(5) cells plated. Autonomous growth (AG) was the number of colonies plus clusters growing without stimulant. The autonomous proliferative index (API) was calculated as the number of clusters + colonies without stimulating factor divided by the number of clusters + colonies with stimulating factor. No significant differences in the PE between de novo and secondary AML were found. Autonomous growth was significantly higher in sAML-MPD. The FAB subtype M3 leukaemias displayed a significantly greater PE and a significantly lower API when compared with the other FAB subgroups (P=0.0002). Upon analysing the relationship with the immunophenotype, only CD33 expression showed a significant relationship with the in vitro growth pattern; CD33+ cases displayed a higher PE (P=0.0002) and AG (P=0.0003) than CD33- cases. When patients were grouped according to the level of rh123 efflux (MDR1) it was observed that cases with >30% elimination showed a higher AG and API than those with <30% (P=0.03). Finally we found that patients with higher API (>0.05) displayed a significantly shorter overall survival as compared with patients with API<0.05 (P=0.04). The in vitro study properties of clonogenic cells produces relevant clinical information of leukaemic cell biology in AML patients.

Surface Marker Analysis in Acute Leukemias

We studied the expression of the cell surface antigen associated with myeloid and lymphoid leukemias on bone marrow or peripheral blood blast cells from 153 leukemic patients including 61 cases of acute myelogenous leukemias(AML), 46 of acute lymphocytic leukemias(ALL) and 12 of acute leukemias. They were analyzed by direct or indirect immunofluorescence method for reactivity with the monoclonal antibodies to B cells(CD10, CD19, SmIg), T cells(CD2, CD5, CD7, CD3, CD4, CD8), myeloid antigen(CD13, CD14, CD33, CD61) and a nonspecific antigen, HLA-DR. Lymphoid associated markers detected on AML is CD7 32.8%, CD10 14.8%, CD5 13.1%, CD2 6.6% and CD19 1.6%. TdT was positive in 4.9% of AMLs. Hybrid leukemias were 8 cases out 61 AML cases and were mainly composed of monocytic lineage, M4 and M5a. Myeloid markers detected in ALL were CD13 2.2% and CD33 2.2%. In this study, immunologically classified ALLs were composed of 65.2% of CALLA (+) B precursor type, 10.9% of CALLA (-) B precursor pattern, 8.7% of T cell type, 2.2% of B cell type, 4.5% of mixed lymphoid lineage(B&T), 2.2% of undifferentiated leukemia, and 6.5% of hybrid leukemia. Twelve cases of acute leukemias ware finally diagnosed to be 5 cases of hybrid leukemia, 3 cases of B lineage, 3 case of T lineage and 1 case of mixed lymphoid(B&T) leukemia. In summary, we think the best method for typing acute leukemias is by using a combination of FAB classification and immunophenotying.

Cytolytic Activity of Peripheral Blood Blast Cells from Patients with Acute Myeloid Leukemia

The results of the present study demonstrate that cells with the morphologic and phenotypic characteristics of blast cells that are obtained from the peripheral blood of patients with newly-diagnosed or recurrent acute myeloid leukemia (AML) can be stimulated by gamma interferon + lipopolysaccharide (IFN/LPS) to mediate in vitro cytolysis of an NK-insensitive hepatoma cell line. The conditions of IFN/LPS induction and subsequent assessment of cytotoxicity that were employed were identical to those used conventionally to test macrophage-mediated tumor cell cytotoxicity. What was totally unexpected was that these same blast cells, in the absence of stimulation with IFN/LPS, were also found to mediate high levels of spontaneous cytotoxicity against autologous bone marrow cells and against the U937 human promonocytic leukemia cell line in vitro. This high level of spontaneous cytotoxicity against autologous bone marrow or U937 promonocytic leukemia cells was not enhanced by IFN/LPS or MCSF under conditions that stimulated cytotoxic function in normal blood monocytes and was markedly reduced by pretreatment of the blast cells with IL2 under conditions that induced potent NK/LAK-mediated cytotoxicity. Neutralizing antibodies against TNFα and/or IL1α/β eliminated the cytolytic function of blast cells against autologous bone marrow or U937 promoncytic leukemia targets. These findings demonstrate the existence of a population of cells with the morphologic characteristics of blast cells in the peripheral blood of AML patients which has the capacity to mediate spontaneous cytolysis of autologous bone marrow cells or a promonocytic leukemia cell line. These cells may be an immature variant of normal precursors produced as a consequence of the disordered hematopoietic environment in the marrow of AML patients. Alternatively, this function may be mediated by a subset of the leukemic blasts themselves.

Influence of rhGM-CSF on Ara-C sensitivity of patients with acute myeloid leukemia in relapse: A flow cytometry study

Twenty-three patients with acute myelogenous leukemia (AML) in first relapse were treated with high-dose cytosine-arabinoside (Ara-C) and amsacrine or idarubicin. To prime the cells, the patients were given rhGM-CSF. We studied the influence of 48-h infusion of rhGM-CSF on proliferation and Ara-C sensitivity of leukemic cells both ex vivo and in vitro. We found that a 48-h infusion of rhGM-CSF increased both white blood cell counts and peripheral blood blast cell percentages. Using a Bromodeoxyuridine/DNA (BrdUrd/DNA) staining in flow cytometry, we found an non-constant increase in cells in the S-phase. Ex vivo 48-h culture of leukemic cells with or without rhGM-CSF, with or without other hematopoietic growth factors (HGFs), showed a greater increase of the cells in the S-phase with GF but no correlation with the ex vivo results. We used a method of quantitation of the DNA synthesis previously described (Lacombe F., et al. (1992) Cytometry 13, 730) to monitor the Ara-C sensitivity of the cells in S-phase before and after 48-h infusion with rhGM-CSF. We observed a great variation in the Ara-C sensitivity of the leukemic cells before and after infusion with rhGM-CSF from one patient to another. The BrdUrd/DNA method seems a convenient method to study the influence of HGFs on Ara-C sensitivity of the patients.

Effects of recombinant human granulocyte colony-stimulating factor on the growth potential of two murine myeloid leukemias

We investigated the in vitro and in vivo effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the proliferation of two murine leukemic cell lines. The rhG-CSF stimulated leukemic colony formation of the promyelocytic leukemic cell line L-8801 in methylcellulose culture and increased the number of L-8801 cells in liquid culture. However, rhG-CSF treatment prolonged the median survival period of mice implanted with L-8801 cells and the emergence of the leukemic blast cells in peripheral blood. Meanwhile, rhG-CSF had no influence on that of the megakaryoblastic leukemic cells L-8057 and failed to prolong the median survival period of L-8057 leukemic mice. Receptor binding analysis revealed that L-8801 cells expressed a G-CSF receptor ( Kd = 125 pM, 479 binding sites/cell) and L-8057 cells had no G-CSF receptors. Then, we examined the growth potential of these cells. The median survival period was longer for mice implanted with L-8801 cells cultured with rhG-CSF for 72 h in vitro than for cells grown without rhG-CSF. Furthermore, the median survival period of mice implanted with spleen cells from L-8801 leukemic mice treated with rhG-CSF was prolonged compared with those from leukemic mice without rhG-CSF. In contrast, there was no effect of rhG-CSF on the growth potential of the spleen from L-8057 leukemic mice. The results of our present study demonstrate that rhG-CSF reduced the growth of L-8801 leukemic cells in vitro and in vivo mediated through G-CSF receptors, thereby suppressing the development of leukemia.

Persistence of Circulating Blasts After 1 Week of Multiagent Chemotherapy Confers a Poor Prognosis in Childhood Acute Lymphoblastic Leukemia

Early response to therapy, typically assessed by bone marrow status, is predictive of outcome in childhood acute lymphoblastic leukemia (ALL). Less is known about the significance of early clearance of blast cells in peripheral blood. We reviewed medical records of all patients with ALL enrolled on St Jude Total Therapy Study XI (February 1984 to September 1988) to determine the presence of blast cells in peripheral blood at diagnosis and after 1 week of intensive induction therapy. Of the 358 patients, 59 lacked evidence of circulating blast cells at diagnosis, and data were unavailable for 2 patients. The prognostic significance of persistent circulating blast cells in the remaining 297 patients was assessed in a multivariate analysis that included known adverse prognostic factors. Persistent circulating leukemic blasts were present at day 8 in 41 patients (14%). Compared with the "blast-negative" group, these patients had a significantly higher frequency of several adverse clinical features (leukocyte count > 50 x 10(9)/L, mediastinal mass, central nervous system leukemia, T-cell phenotype, lack of CD10 expression, and L2 morphology) and a significantly poorer 5-year event-free survival (34% +/- 8% [SE] v 77% +/- 3%, P < .01). By multivariate analysis, blast cell persistence at week 1 was the most significant adverse feature in the overall cohort (relative risk, 2.9; 95% confidence interval, 1.8 to 4.8) and in an analysis limited to B-lineage cases (relative risk, 3.6; 95% confidence interval, 1.9 to 7.1). Patients identified by this simple, noninvasive measure may benefit from early modification of therapy.