acid-phosphatase and Leukemia--Myelogenous--Chronic--BCR-ABL-Positive

Acute megakaryoblastic leukemia (AMKL) has two peaks in distribution of incidence (in adults and children 1 to 2 years of age) and is frequently seen in children with Down syndrome. The current study was undertaken to disclose whether there were any differences between these groups.. Electron microscopic and ultrastructural cytochemical features of 49 children and adults with a AMKL or chronic myelogenous leukemia (CML) in megakaryoblastic crisis were compared.. Blast cells from children with AMKL, including those with and without Down syndrome, had immature features lacking typical alpha granules and a demarcation membrane system (DMS). However, blast cells from patients with AMKL with Down syndrome had more theta, electron-lucent, and basophil-like granules, suggesting that the blast cells had more potential to differentiate into other cell lines than megakaryocytes. The AMKL blast cells of adult patients showed a higher percentage of platelet peroxidase (PPO) positivity than other subgroups, and they occasionally contained typical alpha granules and DMS. This indicated that the blast cells of adults with AMKL were more mature than those of children and CML in megakaryoblastic crisis.. By electron microscopic analysis, leukemic megakaryoblasts differed between children with AMKL with and without Down syndrome, adults with AMKL, and patients with CML in megakaryoblastic crisis.

Topics: Acid Phosphatase; Adolescent; Adult; Age Factors; Aged; Blast Crisis; Blood Platelets; Child; Child, Preschool; Cytoplasmic Granules; Down Syndrome; Histocytochemistry; Humans; Infant; Intracellular Membranes; Leukemia, Megakaryoblastic, Acute; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Megakaryocytes; Microscopy, Electron; Middle Aged; Peroxidase; Peroxidases

Cytoplasmic protein from peripheral blood myeloid cells of chronic myelogenous leukemia (CML) patients altered the electrophoretic mobility of complexes formed between nuclear proteins and interferon-inducible transcriptional enhancers. Immature myeloid marrow cells (blasts and promyelocytes) have a higher level of this activity than do mature myeloid marrow cells (bands and polys). This activity, which is not detectable in the peripheral blood cells of normal individuals, is at least 50-fold higher in CML marrow blasts and promyelocytes than that found in marrow blasts and promyelocytes of normal individuals. This activity was inhibited by in vivo incubation of immature myeloid cells with the phosphatase inhibitor, sodium orthovanadate (0.2 mM), and by adding orthovanadate (20 mM) directly to cytoplasmic proteins of myeloid cells. Interferon-alpha (1,000 U/ml) reduced the effects of the CML myeloid cell cytoplasmic protein on the electrophoretic mobility of nuclear protein-DNA complexes. These data suggest that a unique phosphatase may be involved in the abnormalities in CML which are modulated by interferon-alpha.

Topics: Acid Phosphatase; Base Sequence; Bone Marrow; Electrophoresis; Enhancer Elements, Genetic; Gene Expression Regulation, Neoplastic; Humans; Interferon Type I; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Molecular Sequence Data; Nuclear Proteins; Temperature; Transcription, Genetic

Stromal cell numbers from subjects with no haematological disease and those with acute myeloid leukaemia (AML), chronic granulocytic leukaemia (CGL), acute lymphatic leukaemia (ALL) and non-Hodgkin's lymphoma (NHL) were compared to determine their role in malignancy. Frozen sections of trephine biopsy specimens from iliac crests were stained for endogenous alkaline phosphatase activity, endogenous acid phosphatase activity, and, using immunocytochemical methods, for endothelial cells (anti-factor-VIII related antigen) and macrophages and related cells (EBM/11). In granulocytic malignancies, whether acute or chronic, alkaline phosphatase positive reticulum cells (AL-RC) and vascular endothelial cells were generally increased. In lymphoid malignancies, the numbers of AL-RC were generally reduced. Numbers of vascular endothelial cells seemed to be normal in ALL but reduced in foci of NHL. Macrophages are numerous in normal marrow, and their numbers seemed to be normal in granulocytic lesions but were more variable and sometimes reduced in ALL and NHL. Lymphoid malignancies, therefore, have a destructive effect on some stromal elements; granulocytic malignancies are associated with normal or increased numbers of stromal cells. A possible consequence of depleted stromal cells might be slower reconstitution of normal haemopoiesis after treatment. The large numbers in granulocytic malignancies raises the possibility of synergistic stimulation between stromal and neoplastic cells.

Topics: Acid Phosphatase; Adult; Aged; Alkaline Phosphatase; Bone Marrow; Cell Count; Endothelium, Vascular; Female; Humans; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid; Lymphoma, Non-Hodgkin; Macrophages; Male; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma