Melvyn F. Greaves

Antisera to acute lymphoblastic leukemia cells

Abstract Antisera to acute lymphoblastic leukemia cells have been raised in rabbits by injecting ALL cells coated in vitro with rabbit antibodies directed against normal lymphocyte antigens. The resultant antisera were absorbed with various normal tissues and tested by immunofluorescence for their ability to discriminate between ALL and other leukemias, and between ALL and normal cells. Fourteen out of 19 ALL patients at presentation had circulating cells reactive with the antisera. Three of these had a bone marrow diagnosis of ALL with no apparent abnormal cells in the peripheral blood. Of the five unreactive cases, three were the only T cell-like leukemias in the ALL group. Several patients considered to be in complete hematological remission had a small number of anti-ALL binding cells in their blood. Of several other types of leukemia and lymphoreticular cancers studied, the only other anti-ALL reactive cells were from two cases of acute undifferentiated leukemia, four out of five cases of chronic myeloid leukemia (CML) in blast crisis (CMLs at presentation were unreactive), and very weak reactivity in a proportion of cases of acute myeloid leukemia (AML). The reactivity of myeloid leukemic cells could be abolished by absorption with leukemic myeloblasts, leaving ALL reactivity intact. The only cells in normal fetal or adult tissues to show reactivity were a very small proportion of cells in bone marrow and spleen and a variable proportion of cells in fetal liver. Various control studies suggest that the antigen detected by anti-ALL sera is not a cell cycle, fetal, or cryptic “normal” antigen of lymphocytes. We conclude that antisera to ALL may define an antigen which may be restricted in expression to a large subgroup of ALL cases, and which offers considerable diagnostic and prognostic potential.

Immunologically defined subclasses of acute lymphoblastic leukaemia in children: their relationship to presentation features and prognosis.

Summary. Leukaemic cells from 542 patients under 21 years of age with a diagnosis of acute lymphoblastic leukaemia (ALL) were typed with immunological cell surface markers between June 1975 and December 1979; 379 of these patients entered into the trials up until December 1978 have been followed for more than 1 year. They were divided into four subgroups: common (c) ALL, T (thymic) ALL, ‘null’ (or ‘unclassified’) ALL and a rare lymphoma/leukaemia type B‐ALL. A T‐cell phenotype was found more frequently in boys and was usually but not invariably associated with a high white cell count at presentation. A mediastinal thymic mass was present in 53% of T‐ALL patients but was not observed in any unequivocal non‐T ALL. Clinical prognosis differed substantially between the three major phenotypic classes, remission induction rate and remission duration being lowest in T‐ALL, better in ‘null’ ALL, and highest in cALL (P trend < 0·0001; P=0·0002 for comparison of cALL versus T‐ALL). There was a much higher incidence of CNS involvement in the T‐ALL group than in the cALL group or ‘null’ ALL group and although this was strongly correlated with WBC count it was also significantly associated with T‐ALL independent of WBC count.

Acid Esterase in Human Lymphoid Cells and Leukaemic Blasts: a Marker for T Lymphocytes

A non‐specific acid alpha‐naphthyl‐acetate esterase activity was investigated in human lymphoid cell populations from tonsils, blood, thymus and in different leukaemias. Four patterns have emerged. (i) The vast majority of T lymphocytes (peripheral blood, tonsils) showed a localized, intense reaction product (‘T‐like’). (ii) A thymocyte subpopulation expressed faint, localized enzyme activity (‘Thy‐like’) but the majority of thymocytes showed no esterase activity. Some cells from acute lymphoblastic leukaemias with thymocyte surface characteristics had a ‘Thy‐like’appearance. (iii) Most B lymphocytes and cells from chronic lymphocytic leukaemias were esterase negative. No activity was seen in mitogen activated peripheral blood T and B lymphoblasts from peripheral blood and in leukaemic blasts from the common form of childhood acute ‘lymphoblastic’leukaemia. (iv) Myeloid cells, including peripheral blood monocytes, and blast cells from acute myeloblastic and chronic granulocytic leukaemias showed an intense, diffuse reaction product (M‐like).

Relation of “lymphoid” phenotype and response to chemotherapy incorporating vincristine-prednisolone in the acute phase of Ph1 positive leukemia

Forty‐four patients with Ph1 positive leukemia (36 developing blast crisis after chronic phase and eight presenting in acute leukemia) were classified into sub‐groups on the basis of reactivity of blasts with an anti‐serum made against non‐T,non‐B acute lymphoid leukemia (ALL+), levels of terminal transferase enzyme (TdT+) and morphology. Positivity with anti‐ALL serum was the most sensitive and reliable marker, and TdT was an important aid. The presence of “lymphoid” blasts in blast crisis of CML was related to the response to chemotherapy incorporating Vincristine and Prednisolone (VP). Patients with ALL+ blasts frequently (14 of 15 cases) responded to therapy while 21 of 25 patients who had no ALL+ blasts failed to respond. The clinical course of the ALL+ patients was variable: eight patients remitted with return to the appearances of the chronic phase; four patients demonstrated elimination of the Ph1 positive clone with hypoplasia and this was followed by normal (Ph1 negative) marrow regeneration in two. Subsequent relapse was of either the ALL+ “lymphoid” or the ALL− myeloid type. A regimen incorporating VP should be the treatment of choice in “lymphoid” blast crisis of CML. Cancer 43:426‐434, 1979.

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

SUMMARY. 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.

Elicitation of Selective T and B Lymphocyte Responses by Cell Surface Binding Ligands

One of the motivating forces in lymphocyte biology is the belief that the behaviour of lymphocytes, and more particularly their response to antigen, provides a unique opportunity to analyse the molecular and cellular events involved in the induction and expression of differentiation. A major advance in the realisation of this potential was the finding (Nowell 1960) that quiescent non-dividing small lymphocytes could be triggered into a derepressed state of active growth and proliferation in vitro by phytohaemagglutinin (PHA). The response observed involves parameters common to many systems in which cell growth and proliferation are occurring, e.g. tissue regeneration and embryogenesis, and includes enhanced glycolysis, lysosomal enzyme activity, enhanced nuclear template activity, histone acetylation, DNA polymerase enzyme activity, etc. More specific changes indicative of differentiated activities of lymphocytes, e.g. immunoglobulin synthesis, may also occur, as will be discussed in this review. Although precise quantitation of the number of responding cells has yet to be reported it is clear that the number of cells reacting to PHA and similar stimulants Is considerably greater than one would expect to observe with a classical immunological response in which antigen recognition by relatively small numbers of cells occurs (i.e. cional selection). The response to PHA and other mitogens (see below) is therefore generally considered to be non-specific, i.e. it is a polyclonal lymphocyte response initiated by

EXPRESSION OF HUMAN T AND B LYMPHOCYTE CELL-SURFACE MARKERS ON LEUKÆMIC CELLS

Abstract A panel of seven cell-surface markers that discriminate between T and B lymphocytes has been used to study the cell-surface characteristics of human leukaemic cells. Four out of 22 acute lymphoblastic leukaemias (A.L.L.) had T-cell surface phenotype, the remaining 18 lacked all seven markers. 1 out of 11 chronic lymphatic leukaemias studied expressed T-cell markers, 1 lacked all markers and the other 9 had B-cell surface characteristics. Myeloid leukaemic blasts did not react with six markers but did bind antibrain antibodies (anti-T-cell serum).

Epstein-Barr virus binding sites on lymphocyte subpopulations and the origin of lymphoblasts in cultured lymphoid cell lines and in the blood of patients with infectious mononucleosis☆

Abstract Binding of Epstein-Barr virus (EBV) to lymphocytes has been demonstrated by addition of extracts of virus-producing lymphoid cell lines (LCL) to suspension of human lymphocytes followed by fluoresceinated antibody to EBV. Combined tests for EBV binding and cell surface markers for T and B lymphocytes demonstrated that virtually all B lymphocytes have binding sites for EBV, whereas cells of the T developmental axis (thymus cells, T lymphocytes, T lymphoblasts) have no demonstrable receptors. This result was confirmed by analysis of purified T and B cell suspensions and by results with lymphocytes from children with selective immunodeficiencies. The relationship between lymphocytes bearing EBV binding sites, cell in LCL which carry the EBV genome, and atypical mononuclear cells in infectious mononucleosis (IM) have been investigated. Fifteen out of 16 LCL analyzed by a panel of seven cell surface markers were B cell-like and only one had the T cell surface phenotype. Atypical cells from IM were predominantly T lymphoblasts although some B lymphoblasts also appeared to be present.

Blast Crisis of Chronic Myeloid Leukaemia (CML): I. PRESENTATION SIMULATING ACUTE LYMPHOID LEUKAEMIA (ALL)

SUMMARY. Seven patients presenting as an acute leukaemia caused difficulty in diagnosis. The lymphoid appearance of the blast 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.

Terminal deoxynucleotidyl transferase in acute myeloid leukaemia

Between January 1980 and May 1981, 1966 marrow or blood samples from leukaemia patients were tested for terminal deoxynucleotidyl transferase (TdT) using nuclear immunofluorescence. The cells were also tested with a panel of immunological markers including monoclonal antibodies. Of 869 TdT positive cases detected, 555 were diagnosed as ALL and 32 as blast crisis of CGL; 226 were provisionally diagnosed as acute leukaemia and finally diagnosed as ALL partly on the basis of immunological data; 56 TdT+ cases were provisionally diagnosed as acute non-lymphocytic or myeloid leukaemia; 266 cases of AML and 177 cases of CGL in blast crisis were TdT negative. Eleven of the above AML cases were anti-cALL+ as well as TdT+ and were re-diagnosed and treated successfully as cALL. The remaining 45 were anti-cALL negative and finally diagnosed and treated, at least initially, as AML. Eleven of these cases had only 5-10% TdT+ cells which could have been normal, non-myeloid cells. Twenty cases had 11-50% TdT+ cells and 14 cases had 50-100% TdT+ cells. Of these latter two groups, details on 28 patients were available for evaluation. Three cases on review had no definitive myeloid cytochemistry and were haematologically AUL with a null-ALL phenotype (TdT+ DR+ cALL-). In 14 cases there was a large overlap (greater than 75%) of the proportion of cells with myeloid cytochemistry (Sudan black, peroxidase or esterases) and TdT; individual blast cells were therefore expressing these markers concurrently. In the remaining cases, mixtures of TdT negative myeloid and TdT+ (lymphoid?) cells may have coexisted although this was not proven unequivocally. Twenty-two cases of newly diagnosed TdT+ AML received induction chemotherapy for AML (DAT regime) and only six (37%) obtained a complete remission. It is concluded that TdT positive myeloid leukaemias do occur, albeit infrequently (approx. 5%) and may have a relatively poor prognosis.