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HTIF1alpha, a transcription coactivator which is able to mediate RARalpha activity and functionally interact with PML, is encoded by a gene on chromosome 7q32-34, which is a critical region in acute myeloid leukemias (AML). With the assumption that this gene may be related to AML, we investigated the HTIF1alpha DNA structure and RNA expression in leukemic cells from 36 M1-M5 AML patients (28 "de novo" and eight "secondary" to myelodysplastic syndrome (MDS)). Abnormal HTIF1alpha DNA fragments were never found, whereas loss of HTIF1alpha DNA was observed in the patients with chromosome 7q32 deletion and translocation, and in one case without detectable chromosome 7 abnormality. HTIF1alpha RNA was found in acute myelocytic leukemic blasts, and was almost undetectable in normal mononuclear cells. The expression varied among the patients: higher in M1 to M3 subtypes, with the highest values in M1; low levels were constantly observed in M4 and M5 AML. In addition, HTIF1alpha was significantly overexpressed in MDS-related AML (MDR-AML), but not in MDS. We also found that HTIF1alpha expression was high in myeloid cell lines. In myeloblastic HL60 and promyelocytic NB4 cells, induced to differentiate along the monocytic-macrophage pathway by TPA or vitamin D3, HTIF1alpha expression decreased, whereas it was maintained at high levels on induction to granulocytic differentiation by RA or DMSO. In K562 cells, HTIF1alpha RNA levels did not change after hemin-induced erythroid differentiation. These results suggest that HTIF1alpha could play a role in myeloid differentiation, being distinctly regulated in hematopoietic lineages.

We studied the impact of cytogenetics and kind of induction/consolidation therapy on 848 adult acute myeloid leukemia (AML) patients (age 15-83). The patients received three types of induction/consolidation regimen: standard (daunorubicin and cytosine arabinoside (3/7); two cycles); intensive (idarubicin, cytosine arabinoside and etoposide (ICE), plus mitoxantrone and intermediate-dose Ara-C (NOVIA)); and low-dose (low-dose cytosine arabinoside). CR patients under 60 years of age, if an HLA-identical donor was available received allogeneic stem cell transplantation (allo-SCT); otherwise, as part of the program, they underwent autologous (auto)-SCT. CR rates significantly associated with 'favorable' (inv(16), t(8;21)), 'intermediate' ('no abnormality', abn(11q23), +8, del(7q)) and 'unfavorable' (del (5q), -7, abn(3)(q21q26), t(6;9), 'complex' (more than three unrelated cytogenetic abnormalities)) karyotypes (88% vs 65% vs 36%, respectively; P = 0.0001). These trends were confirmed in all age groups. On therapeutic grounds, intensive induction did not determine significant increases of CR rates in any of the considered groups, with respect to standard induction. Low-dose induction was associated with significantly lower CR rates. Considering disease-free survival (DFS), multivariate analysis of the factors examined (including karyotype grouping) showed that only age > 60 years significantly affected outcome. However, in cases where intensive induction was adopted, 'favorable' karyotype was significantly related to longer DFS (P = 0.04). This was mainly due to the favorable outcome of t(8;21) patients treated with intensive induction. Patients receiving allo-SCT had significantly longer DFS (P = 0.005); in particular, allo-SCT significantly improved DFS in the 'favorable' and 'intermediate' groups (P = 0.04 and P = 0.048, respectively). In conclusion our study could provide some guidelines for AML therapy: (1) patients in the 'favorable' karyotype group seem to have a longer DFS when treated with an intensive induction/consolidation regimen, adopted before auto-SCT instead of standard induction; this underlines the importance of reinforcement of chemotherapy, not necessarily based on repeated high-dose AraC cycles. Allo-SCT, independently of induction/consolidation therapy, should be considered an alternative treatment; (2) patients in the 'intermediate' karyotype group should receive allo-SCT; (3) patients in the 'unfavorable' karyotype group should be treated using investigational chemotherapy, considering that even allo-SCT cannot provide a significantly longer DFS, but only a trend to a better prognosis.

Diagnostic reproducibility of the FAB morphological subtypes of acute leukemia is a basic step in the assessment of the clinical outcome in multicenter trials. Unusual cytologic variables and slightly different interpretations of the FAB morphological criteria have been the most significant factors affecting the overall diagnostic concordance rate among the various centers. An evaluation of the diagnostic concurrence between 35 institutions of the Italian Cooperative Study Group GIMEMA and two reviewers of the ad hoc morphological committee has been performed on 377 patients entering the AML 8A and AML 8B GIMEMA protocols. Overall concordance rate was 62.6%. The most significant differences were observed for M2 vs M4, M4 vs M5, M1 vs M2, and M2 vs M5 subtypes. In order to minimize the impact of some diagnostic deviations on the mean cytologic concordance rate, a distinction between "major" and "minor" discrepancies in the diagnostic procedures has been proposed. When the results of the single institutions were corrected by considering the "major" discrepancies only, a mean diagnostic agreement of 78.1% was reached.

The cytogenetic features and the proliferative and differentiation capabilities of blast cell fractions purified on a density gradient were studied in one patient with chronic myeloid leukemia (CML) in blast crisis, both at the emergence and at relapse of the disease. The results show that relapse was due to the appearance of a new leukemic cell line that was characterized by peculiar chromosomal, growth, and differentiation features, which seemingly accounted for early refractoriness to therapy and disease progression.

Blastic crisis in chronic myeloid leukemia is characterized by several cytological alterations which may represent some abortive attempts to differentiate along various cell lines as a consequence of a maturation defect of the myelopoietic cells. These changes of the hematological picture are associated with alterations of the karyotype and with cytochemical abnormalities of the blast cells, possibly related to their metabolic anomalies. In this regard 14 patients with blastic crisis were investigated to achieve an evaluation of the composition of the cell population during the acute phase. A sequence of three cytochemical reactions applied consecutively on the same slide (alpha-naphthyl-acetate esterase + AS D-chloro-acetate esterase + PAS) proved to be useful for the detection of differently oriented blast cells. During the acute phase of chronic myeloid leukemia only about one half of the blast cells were expressing granuloblastic differentiation. The data may be important for some clinical and prognostic factors, since the heterogeneity of the blastic population may be associated with a particular resistance to therapy.