The applicability of simple blood and bone marrow variables in prediction of acute leukaemia in patients with acquired bi- or pancytopenia

Prognostic significance of some clinical, morphological and cytogenetic findings in refractory anaemia (RA) and RA with sideroblasts

In 27 patients initially diagnosed as refractory anaemia (RA) or RA with sideroblasts (RA-S) according to the FAB-classification a number of clinical, morphological and cytogenetic parameters were correlated for prognostic significance. From these correlations it emerged that severe cytopenia is centrally positioned with regard to clinical course in RA and RA-S. Positive correlations were found to initial diagnosis, clonal cytogenetic abnormalities, progression to RA with an excess of blasts (RAEB) or acute myeloid leukaemia (AML), the percentage of bone marrow blast cells and prolonged half life for radioactively labeled iron. The degree of peripheral blood granulocytopenia, alone, was correlated to bone marrow hypoplasia. Moreover, the frequency of abnormal karyotypes was inversely correlated to bone marrow cellularity and proportional to the frequency of bone marrow blast cells. From these relationships it may be proposed that chromosome abnormalities are associated with prolonged blast cell generation times and inhibition of blast cell maturation resulting in reduced marrow cellularity and blast cell accumulation, and, in the peripheral blood, falling percentages of neutrophil granulocytes. With the blast cell accumulation the bone marrow cellularity again becomes hyperplastic and the preleukaemic condition is transformed into RAEB or AML.

Prediction of survival in adults with acquired Bi- or pancytopenia

In a retrospective study of 44 adults with acquired bi- or pancytopenia without evidence of any causal disorder, the survival curve suggested the existence of a subgroup of short survivors, mainly with aplastic anaemia, with death within 4 months. The initial values of 14 single clinical, blood and bone marrow variables were significantly associated with survival less than 4 months. Stepwise multiple logistic regression analyses identified 2 combinations of variables displaying significant simultaneous associations with short survival: (i) increased % of non-myeloid bone marrow cells and haemorrhagic manifestations initially; (ii) increased % of non-myeloid marrow cells, circulating erythroblasts and no history of any drug exposure. The predictive capacities of a resulting estimate of the probability of short survival and of previously introduced prognostic indices were approximately equal. The frequency of a correct prediction of a survival shorter than 4 months was in the range of 0.71-0.78 and that of longer survival in the range of 0.74-0.94.

Natural killer (NK)-cell activity and antibody-dependent cellular cytotoxicity (ADCC) in primary preleukemic syndrome

In 13 patients with a multi-parameter based diagnosis of primary acquired preleukemic syndrome (PPS), natural killer (NK) cell activity and antibody-dependent cellular cytotoxicity (ADCC) were investigated on peripheral blood mononuclear cell (MNC) fractions. In all but two patients a defective NK activity was found. Lymphocyte-monocyte mixture experiments demonstrated that this was not due to suppressor monocytes. Furthermore, NK activity was defective when both myeloid and non-myeloid target cell lines were used. Addition of human leukocyte interferon to the NK cultures augmented the cytotoxicity, which exhibited the same kinetics as that of normal controls, but NK activity levels remained subnormal. These data strongly indicate that the decreased NK activity seen in the patients is due to a decreased number of circulating NK cells. In contrast ADCC was within the normal range both when MNC suspensions as well as when purified peripheral blood lymphocytes were used as effector cells thus ruling out subnormal lymphocyte ADCC masked by the presence of monocyte ADCC. These results demonstrate that PPS patients have a selective NK defect with an intact lymphocyte ADCC function. Whether this defect will prove to be valuable in the assessment of a malignant transformation in a given patient will await further longitudinal NK studies and clinical follow-up of the patients.