B-cell acute lymphoblastic leukaemia: clinical and biological aspects

Burkitt's acute lymphocytic leukemia (L3ALL) in adults

Burkitt's acute lymphocytic leukemia is a rare type of adult ALL, probably difficult to distinguish from disseminated Burkitt's lymphoma involving the bone marrow. This tumor is highly proliferative and tends to involve the CNS at diagnosis or early during the disease course. It shows rapid chemosensitivity, initially leading to the risk of severe acute tumor lysis syndrome. Principles of its treatment, by comparison with the other types of ALL, include: 1. A low-dose chemotherapy prephase to prevent acute tumor lysis syndrome. 2. Multiagent chemotherapy using high-dose cyclophosphamide, an anthracycline, high-dose MTX, high-dose ara-C, and probably VP16. A short and intensive treatment (6 to 8 months) without maintenance is indicated. 3. Early intensive CNS treatment, with multiple triple intrathecal injections, high-dose MTX, and high-dose ara-C, and possibly cranial irradiation. Autologous or allogeneic stem cell transplantation do not seem to be useful in first CR. Using such approaches, recent results suggest that about two thirds of L3ALL in adults can be cured, more than in any other type of adult ALL.

Secondary nonrandom chromosomal abnormalities of band 13q34 in Burkitt lymphoma-leukemia

Clonal abnormalities of the long arm of chromosome 13 were detected in 9 of 54 patients with Burkitt lymphoma-leukemia. All abnormalities involved band 13q34, in three patients as t(1;13). The 13q34 abnormalities are thus the second most frequent secondary chromosomal abnormalities, after those of chromosome I, in these lymphoid proliferations.

Cytogenetics and their prognostic value in childhood and adult acute lymphoblastic leukemia (ALL) excluding L3

Cytogenetic analysis was made at diagnosis in 174 cases of ALL (101 children less than 20 years and 73 adults), excluding Burkitt's ALL (L3). In 11 children (11 per cent) insufficient material was obtained. In the remaining 90, 50 (56 per cent) had a normal karyotype, 20 (22 per cent) a hyperdiploid karyotype, five (6 per cent) a hypodiploid karyotype, 12 (13 per cent) had a translocation (including seven cases of t(1;19] and three had a pseudodiploid karyotype without translocation. Ninety-eight per cent of patients reached complete remission (CR). Median actuarial CR duration was not attained, was 50 months, 13 months, and 11 months respectively in patients with hyperdiploid, normal, hypodiploid karyotype and in patients with a translocation, the difference between subgroups being significant. In a Cox model, cytogenetics were the strongest factor predicting CR duration (p = 0.03) followed by leukocytes (p = 0.04), whereas the presence of 'bulky disease' had a borderline value (p = 0.077). Of note was that 9/17 (53 per cent) patients with a hypodiploid karyotype or a translocation had no 'risk factors' before cytogenetic analysis. In adults, cytogenetic analysis was unsuccessful in 15 (20 per cent) of patients. In the remaining 58 cases, 19 (33 per cent) had a normal karyotype, 15 (26 per cent) had a hyperdiploid, one (2 per cent) had a hypodiploid karyotype, 19 (33 per cent) had a translocation (including 12 t(9;22], and four (7 per cent) had a pseudodiploid without translocation. 73 per cent patients reached CR. Median actuarial DFS was 12.5 months. No significant differences in CR rate and CR duration were seen between cytogenetic groups, but median CR duration was slightly longer in patients with a normal karyotype (17 months) and shorter in patients with t(9;22) (8.5 months). Only 3/12 of the latter had major risk factors before cytogenetic analysis. Cytogenetic analysis is important in ALL, especially in patients with otherwise standard risk factors, as it may reveal unexpected translocations or hypodiploidy, which may require a therapeutic reinforcement.

Artefactual low lymphocyte activity caused by platelet contamination in the mononuclear cell preparations

Platelet (PLT) contamination in preparations of mononuclear cells (MNC) produces a significant decrease (P less than 0.02) in lymphoproliferative activity and interleukin 2 (IL2) production. This effect was observed in MNC preparations from either healthy blood donors or polyglobulic patients. In a dose-response curve carried out with increasing PLT number per MNC, progressive inhibition was found, reaching to 62.6% and 49.5%, respectively, to phytohemagglutinin and IL2 lymphoproliferative response and 87.8% in IL2 production, at 80 PLTs/MNC.

Pre-B and 'common' lymphoblastic leukaemia of childhood compared

Consecutive children suffering from pre-B lymphoblastic leukaemia (pre-B ALL) were compared with those who had 'common' ALL (C-ALL) to assess any clinical and pathological differences between the two groups. Over 101 months 27 pre-B children were seen-an incidence in the population served of around 0.8/100,000 per year. There was some time-clustering and 12 of the 27 presented in one year (1987). The 51 patients with C-ALL who presented for comparison were distributed more evenly over the study period. Pre-B children had more basophilic blast cells with less periodic acid-Schiff positivity. They had higher presenting white cell counts and serum concentrations of lactic dehydrogenase; two variables which were correlated with each other. There was a trend towards pre-B children being younger and fewer had hyperdiploid blasts, but these differences were not statistically significant. No difference from 'common' ALL in response to therapy was apparent for the pre-B patients at a median follow up time of 17 months--too short a period for any conclusion to be drawn. Other than immunophenotype, pre-B ALL has no pathognomonic features, but there are differences from C-ALL in the distribution of some disease characteristics known to be associated with a worse prognosis.