Angela Tassinari

Cytogenetic analyses in 89 patients with secondary hematologic disorders—Results of a cooperative study

Eighty-nine patients who developed a secondary hematologic disorder and were studied with chromosome analysis were collected from nine institutions. The results of the study confirmed previous findings, in particular, -5/5q-, -7/7q-, -17, and +21 were the most frequently encountered aberrations. Moreover, a t(1;7)(p11;p11) was reported in four cases and consistent chromosome abnormalities were observed in a small group of patients who had been treated only with surgery, but not with chemo- or radiotherapy for a previous tumor.

Close association between antibodies to cytoskeletal intermediate filaments, and chronic graft-versus-host disease

Chronic graft-versus-host disease can mimic various autoimmune disorders, although autoantibodies are rarely detected in the sera of affected patients. Antibodies to cytoskeleton are a frequent finding in patients affected by autoimmune disorders. In all the sera of 16 patients who were submitted to allogeneic bone marrow transplantation, we have found antibodies against cytoskeletal intermediate filaments. Moreover, the titer of such antibodies is quite elevated when compared with those reported in autoimmune disorders. A statistically significant difference between the titers found in patients without and with cGVHD (median 1:40 vs. 1:256, P<0.05) has been found. This would suggest that such antibodies might be relevant in monitoring clinical course. Furthermore, since certain cytoskeleton antigens have been shown to be expressed also on cell membrane, antibodies against intermediate filaments might also play a more important role by interfering with such surface structures.

ABL proteins in Philadelphia-positive acute leukaemias and chronic myelogenous leukaemia blast crises

Summary. The Philadelphia chromosome (Ph1) is present in 95% of chronic myelogenous leukaemias (CML) and 15% of acute lymphoblastic leukaemias (ALL). This cytogenetic marker is due to a t(9;22) translocation, which causes a rearrangement of the ABL oncogene. In order to better define the relationship between type of genomic rearrangement, variant ABL protein expressed and haematological phenotype, a series of Phl‐positive acute leukaemias, both myeloblastic (AML) and lymphoblastic, and several CML lymphoid blast crises have been analysed at the DNA and protein level.

Cytoskeleton organization of normal and neoplastic lymphocytes and lymphoid cell lines of T and B origin

Summary An anomalous organization of the cytoskeleton has been described in lymphocytes from chronic lymphatic leukaemia and in only few cell lines. We have now studied normal and neoplastic lymphocytes and lymphoid cell lines of both T and B lineage in order to detect morphological differences in the expression of microfilaments and intermediate filaments. Microfilaments appear to be well expressed by all the B cells, whereas a rich network of intermediate filaments is present in T cells and plasma cells. Most prominent changes occur in the latter system, which is almost lacking in cells of B chronic lymphatic and hairy cell leukaemia. Although the significance of the present findings is not yet clear, one might speculate that such alterations account for some of the aberrant functions and peculiar biologic properties of neoplastic lymphocytes.

CYTOGENETIC AND MOLECULAR ANALYSES IN PHILADELPHIA CHROMOSOME POSITIVE ACUTE LYMPHOBLASTIC LEUKAEMIA

Lestas, A.N., Kai, L.A. & Bellingham. A.J. (1987) Red cell 3phosphoglycerate level as a diagnostic aid in pyruvate kinase deficiency. British Journal of Haematology, 67, 485-488. International Committee for Standardization in Haematology ( 1 979) Recommended methods for the characterization of red cell pyruvate kinase variants. British Iournal of Haematology. 43,275-286. Staal. G.E.J., Jansen, G. & Roos. D. (1984) Pyruvate kinase and the ‘high ATP syndrome’. Iournal of Clinical Investigation, 74, 23 1235.

Role of target and effector cell structures in natural killer-mediated cytotoxicity

SummaryAn analysis of target and effector cell structures involved in thein vitro natural killer (NK)-mediated cytotoxicity has been performed. The degree of surface expression of transferrin receptor (TR) was only in part correlated with that of cell lysis. Moreover, the lysis could not be blocked by treating target cells with two anti-TR monoclonal antibodies. Finally, cell lines poorly affected by NK cells express TR only at the cytoplasmic level. As to the effector cells, the integrity of cytoskeleton components (especially microtubules) was found to be essential for the occurrence of cell lysis. In fact, vinblastine, an anti-microtubule agent, was able to significantly reduce the percentage cell lysis. This effect was not due to a selective depletion in NK cells induced by the drug. It is concluded that the mechanisms underlying NK activity are complex and involve both target and effector cell structures.

Phenotypic Characterization of Adult Acute Lymphoblastic Leukaemia: Are Cytoplasmic Immunoglobulins Related to Prognosis?

Donatella Raspadori, Angela Tassinari, Pier Luigi Tazzari, Michele Baccarani, Institute of Haematology ‘L. e A. Seràgnoli’, University of Bologna, S. Orsola’s Hospital, I-40138 Bologna (Italy) The detection of cytoplasmic immunoglobulins (Cylg), the positivity to several early B cell lineage-specific monoclonal antibodies (MoAb), and the demonstration of immunoglobulingene rearrangements, provide evidence that common (CALLA+) acute lymphoblastic leukaemia (ALL) blast cells belong to, or differentiate along the B-cell lineage [1-3]. Only a few cases of ALL arrive to express a mature, surface membrane immunoglobulin positive (Smlg+) B cell phenotype, that is invariably associated with a very poor prognosis either in adults or in children [3, 4]. Therefore also early B cell differentiation markers can have an important relationship with prognosis. In fact, a pediatric oncology group [5] reported that the 1st complete remission length was significantly shorter in children with CALLA+ Cylg+ leukaemia than in children with CALLA+ Cylgdisease. That finding alerted on the possibility that the expression of early-B-lineage markers is also associated with a poorer prognosis. In adults, the frequency of Cylg+ ALL seems to be the same as in children (32% vs. 27%) [5,6] but a comparison between Cylg+ and Cylgcases has not yet been attempted. Over the last 4 years, we have studied the phenotype of the cells of 41 consecutive adult patients (more than 15 years old) with ALL, by contemporary detection of Smlg and Cylg [1,7] and by means of a panel of MoAb, including anti-la (Ortho Ph. C), anti-CALLA (Vil-Al kindly provided by Dr. W. Knapp; or J5, Coulter Clone), OKT6 and OKT11 (Ortho Ph. C), and RFT1 and RFT2 (kindly provided by Dr. G.Janossy). Anti-BAl and Anti-BA2 MoAb (Hy-britech) were tested in 18 cases. Other MoAb were used whenever appropriate. Twentyseven patients (66%) were negative for any T markers and for Smlg, and were CALLA+. Ten of these 27 cases (37%) were Cylg+, i.e., they had 15-70% Cylg+ cells (mean and median = 40%). All patients were treated according to the L17M protocol with arm B consolidation, without implantation of an Ommaya reservoir [8]. The median time at risk is 25 months for Cylgpatients and 29 months for Cylg+ ones. A comparison between Cylg+ and Cylgpatients is shown in table I. The two groups are quite similar, with regard to presenting features and treatment outcome. Numbers are small, so that the probability of not detecting an existing difference is high. However, a big difference such Table I. Presenting features and outcome of therapy of Cylg-and Cylg + adult patients

Variant Breakpoint Positions on Chromosome 22 in Ph′-Positive Chronic Myelogenous Leukemias

As a consequence of the molecular events associated with the presence of a Philadelphia (Ph′) chromosome, two different types of abnormal c-abl proteins, termed P210 and P190 according to their molecular weight, have been found in Ph′ positive leukemic cells [1, 2]. P210, expressed in almost all chronic myelogenous leukemias (CML) and in approximately half of the Ph′ positive acute lymphoblastic leukemias (Ph′+ ALL), is codified by a hybrid gene arising from a rearrangement between the 5′ of c-abl oncogene and a restricted region called (“m-bcr” — major breakpoint cluster region) of a gene on chromosome 22, also denominated bcr [3–5]. By contrast, P190, present in the remaining half of the Ph′+ ALLs, derives from a rearrangement involving the same two genes, but with a different breakpoint on chromosome 22, mapping more 5′ and within the first large intron of the bcr gene [6, 7].

Significance of the Philadelphia chromosome in acute leukemias: variable correlation with rearrangements involving the c-abl and bcr genes.

The Philadelphia chromosome (Phl), present in the leukemic cells of over 90% of the chronic myelogenous leukemia (CML) patients, derives from a reciprocal translocation between chromosomes 9 and 22, which moves the human proto-oncogene c-abl from its normal position at band 9q24 of chromosome 9 to band 22ql1 of chromosome 22.’** The breakpoints on chromosome 22 cluster in a very short region of about 5 Kb defined as “breakpoint cluster region” (bcr).’ This is part of a transcribed gene, whose normal function is still to be defined. By contrast, the breakpoint position on chromosome 9 is more variable mapping 5’ to the c-abl proto-oncogene or within its first intron, more than 100 Kb long ( I Kb 10 base pairs). As a consequence, the Phl chromosome translocation generates a hybrid bcr/c-abl gene transcribed in a new 8.5-Kb mRNA, which contains sequences derived from both 5’ bcr and 3‘c-abl exons.‘ An abnormal p2 10 c-abl protein bearing a strong protein kinase activity has been identified in CML leukemic cells and represents the translation product of the fused