Target cell in chronic myeloid leukaemia and its relationship to acute lymphoid leukaemia

On the basis of membrane marker analysis with an antiserum made against acute lymphoblastic leukaemia and other immunological markers it is suggested that some chronic myeloid leukaemias (C.M.L.) and some acute lymphoblastic leukaemias (A.L.L.) originate in a common target cell or precursor. This is possibly a pluripotential stem cell or a closely related derivative. These leukaemic cells retain their undifferentiated membrane characteristics C.M.L. patients in blast crisis who are A.L.L.-antigen-positive and have terminal transferase enzyme activity might benefit from therapy usually given in typical Philadelphia-chromosome-negative A.L.L.

Blast crisis of chronic myeloid leukaemia (CML). I. Presentation simulating acute lymphoid leukaemia (ALL)

Seven patients presenting as an acute leukaemia caused difficulty in diagnosis. The lymphoid appearance of the balst cells either initially or during treatment suggested acute lymphoid leukaemia (ALL). In each case the Philadelphia chromosome was shown to be present thus suggesting that these cases were examples of chronic myeloid leukaemia (CML) presenting in blast crisis without a detectable chronic phase. The implications of these findings are discussed and the difficulty in achieving a precise diagnosis in the acute leukaemias is emphasised. Cytogenetic analysis should be carried out whenever the type of acute leukaemia present is of critical importance.

Blast crisis of chronic myeloid leukaemia (CML). II. Cell surface marker analysis of "lymphoid" and myeloid cases

Fourteen cases of philadelphia chromosome (Ph1) positive chronic myeloid leukaemia in blast transformation have been investigated using cell surface markers. Morphologically eight cases were lymphoid and the remainder myeloid in appearance. All cases were negative with surface markers for thymocytes and T and B lymphocytes. Five of the lymphoid cases reacted with an antiserum specific for acute lymphoid leukaemia )ALL) of non-T non-B type and were also weakly reactive with a lymphocyte reactive antiserum. A sixth patient, whose blast cells were anti-ALL negative (ALL-) at presentation, subsequently developed central nervous system leukaemia with anti-ALL positive (ALL+) blast cells in the CSF. In all cases the leukaemic blast cells showed greatly diminished expression of cholera toxin receptors when compared to granulocytic cells from the chronic phase of CML. This parallels weak or negligible expression of the cholera toxin receptor in ALL and AML. These results suggest that the blastic phase of CML may involve different cellular derivatives of a pluripotential stem cell in which the primary malignant/genetic changes reside. The blast crisis of CML can therefore be heterogeneous with respect to cellular expression and in a significant proportion of patients involves a cell which is by membrane markers and morphological criteria indistinguishable from that seen in the common form of ALL. In these cases the Philadelphia chromosome may be the only distinguishing cellular characteristic.

Studies on the glycolipids of sheep thymus and of normal and concanavalin A-stimulated sheep peripheral lymphocytes

The neutral glycolipids and gangliosides of sheep thymus and of sheep peripheral lymphocytes were compared. The patterns of both of these major classes of glycolipids were more complex in thymus than in the lymphocytes. The incorporation of radioactivity from D-[1-14C]galactose into the individual glycolipids of control and concanavalin A-stimulated sheep peripheral lymphocytes was also studied. A marked enhancement of incorporation into trihexosylceramide and an alteration of the pattern of incorporation into gangliosides were noted in the mitogen-treated cells. The results suggest that significant alterations of glycolipid composition and metabolism may occur during at least certain stages of lymphocyte differentiation.

Virus 'receptors' on lymphocytes

This paper gives a review of the field of virus-lymphocyte interactions and virus receptors on lymphocytes as well as the use of viruses as markers for various lymphocyte populations.

Detection of monocyte specific antigen on human acute leukaemia cells

Heteroantisera with specificity for human monocyte and macrophage antigens (HuMa) have been tested for activity against peripheral blood cells from patients with acute leukaemia. Using indirect immunofluorescence, blast cells from 25/27 patients with acute myelomonocytic leukaemia were reactive with anti-HuMa antisera, whereas blasts from 19/20 patients with acute myeloblastic leukaemia and 13/13 patients with acute lymphoblastic leukaemia were not reactive. The F(ab1)2 fragment of the antibody retained specific activity. Activity of whole serum against myelomonocytic blast cells was specifically removed by absorption with macrophages. These observations indicate that circulating blast cells from patients with acute myelomonocytic leukaemia may carry differentiation antigens characteristic of monocytes and macrophages.

Identification of cells with monocyte markers in panhypogammaglobulinaemia

Nonphagocytic cells bearing receptors for complement and IgGFc in blood samples from four boys with panhypogammaglobulinaemia who lacked B lymphocytes were positively stained for human macrophage antigen (HuMA) and intracellular peroxidase. Similar non-T, non-B cells were found in adult blood preparations but in lower numbers than in the four boys above and in two of three other boys with various immunodeficiencies. Because of their monocyte characteristics, it is improbable that these cells are B-lymphocyte precursors; this is consistent with our view that there is a central failure of B-cell induction in boys with panhypogammaglobulinaemia who lack lymphocytes with surface immunoglobulin.

A surface antigen marker for human monocytes

Antisera have been raised in rabbits aginst human peritoneal macrophages. After absorption with tonsil cells the sera reacted, by direct and indirect immunfluorescence, with phagocytic mononuclear cells from a variety of tissues and, in addition, stained a small population of nonphagocytic non-T, non-B mononuclear cells present in blood, spleen, and marrow but absent or very rare in tonsil and thymus. The antisera may define a human monocyte-macrophage cell surface differentiation antigen (HuMA) and can be used to deplete or enrich reactive cell population.

Lymphocyte activation. VI. A re-evaluation of factors affecting the selectivity of polyclonal mitogens for mouse T and B cells

In the culture and assay systems described here the majority of mouse spleen cells stimulated by soluble concanavalin A and phytohaemagglutinin have been shown to be T cells, whereas bacterial endotoxin (LPS) stimulates B cells almost exclusively. These observations appear to be independent of the tissue source, the length of the culture period, and the presence of supernatants from other cultured T cells. Pokeweed mitogen (PWM) is capable of stimulating both T and B cells, the relative numbers of each probably being affected by the length of the culture period and variability between different PWM samples. Preliminary evidence is presented for mature LPS-responsive cells being able to persist for long periods in the mouse peripheral lymphoid system. The importance of using culture conditions that allow selective stimulation of T and B cells is discussed, especially in relation to their accurate quantitation.