Angela Vecchi

Cytogenetic conversion in a case of polycythaemia vera treated with interferon-alpha.

Summary Polycythaemia vera is a clonal disorder of the haemopoietic stem cell causing a pathologic expansion of the erythroid and sometimes the megakaryocytic and myeloid elements. In order to avoid the possible mutagenic effects of radioactive phosphorus, alkylating agents and hydroxyurea, since 1988 α‐IFN has been used for the treatment of PV and has been shown to induce and maintain haematological remission. We describe a 24‐year‐old PV patient with chromosomal abnormalities who achieved not only a reduction of the proliferation of erythroid elements and reticulin content in the bone marrow, but also a complete cytogenetic remission after IFN treatment.

A prospective comparison between treatment with phlebotomy alone and with interferon-alpha in patients with polycythemia vera

SummaryInterferon alpha (α-IFN) is increasingly used for the treatment of patients affected by polycythemia vera (PV). As prior studies are difficult to interpret in view of the lack of appropriate controls, we undertook a randomized comparison of lymphoblastoid α-IFN (α n−1 IFN) treatment against venesection treatment alone. In a crossover trial, we treated 22 PV patients alternatively for 5 months each with 3 MU/day sc of α n−1 IFN and phlebotomy alone. During IFN treatment, red blood cell count and hematocrit level were well controlled in both trial groups, reducing or eliminating the need for phlebotomy in all patients; furthermore, platelet number and white blood cell count declined during α-IFN therapy. In addition, the number of symptomatic patients was greatly reduced, and in six patients a reduction in splenic size was observed. Finally, the only patient with chromosomal abnormalities showed a complete cytogenetic conversion after 5 months of α-IFN therapy. Thus, for the first time, our results provide the unequivocal demonstration that α-IFN is superior to phlebotomy in controlling the pathologic expansion of erythroid elements and all the clinical aspects of this disease.

Progression of Essential Thrombocythemia to Blastic Crisis Via Idiopathic Myelofibrosis

We report a 61-year-old man with essential thrombocythemia (ET) whose clinical course was followed for 12 years. The ET evolved into true idiopathic myelofibrosis (IM) 6 years after the initial diagnosis and progressed to myeloid blastic transformation 6 years later. The cytogenetic analysis showed a normal karyotype during the ET phase but subsequent analysis revealed an abnormal karyotype during the IM phase which evolved clonally at blastic crisis with constant involvement of chromosome 13q and chromosome 7. The close monitoring of essential events, using clinical, morphologic, immunologic and cytogenetic parameters, allowed us to carefully identify the transition from one chronic myeloproliferative disease (MPD) to another. This is only the second case reported showing a clinical evolution of this nature. The clinical and biological aspects of the disease are briefly discussed.

Interferon alpha-2b in the long-term treatment of essential thrombocythemia

SummaryWe treated 35 patients affected with essential thrombocythemia (ET) with interferon (IFN) alpha-2b. Our treatment scheme consisted of (a) a 6-month induction phase and (b) a continuous maintenance phase. During the induction phase, our results showed that using 21 million units (mu) of IFN weekly platelet counts fell below 600×109/l in about 90% of patients. These data demonstrate that well-tolerated doses of IFN can rapidly correct excessive thrombocytosis. During the continuous maintenance phase, 61% of patients required 3 mu three times a week, 15% once a week, and 24% daily. Thus the minimal IFN doses able to maintain platelet count below 600×109/l varied between 3 and 21 mu per week. During long-term treatment, subjective side effects were tolerable, especially using 3 mu three times a week. We conclude that IFN alpha-2b is an effective drug in the long-term treatment of ET.

Sustained complete hematological remission in essential thrombocythemia after discontinuation of long-term α-IFN treatment

SummaryIn essential thrombocythemia patients α-IFN rapidly reduces platelet count, and it is also able to maintain a low count during long-term treatment. In order to verify if long-term IFN treatment can produce sustained remission in selected patients, we decided to suspend IFN treatment in two subsets of 21 patients on long-term α-IFN treatment: (a) all six patients who had shown a platelet count below 450×109/l for at least 2 months with 3 MU once a week; (b) three patients who had shown the same platelet count for at least 2 months with 3 MU three times a week. After withdrawal of α-IFN treatment, a rapid increase in the platelet count was observed in all three patients requiring 3 MU three times a week. Three of the six patients treated with 3 MU once a week are still free of symptoms and have been in complete hematological remission (platelet count below 450×109/l) for 9+, 13+, and 14+ months, respectively. As far as the three remaining cases are concerned, one was not assessable because of loss to follow-up, while the other two relapsed after 1 and 2 months. We believe that the three cases of sustained remission might be the result of a long-term tumor load reduction produced by the α-IFN treatment. Finally, the factor best able to predict sustained, unmaintained remission seems to be the clinical response to a low dose of α-IFN during the maintenance phase, rather than disease features prior to treatment.

SINUS HISTIOCYTOSIS WITH MASSIVE LYMPHADENOPATHY - IMMUNOLOGICAL, CYTOGENETIC AND MOLECULAR STUDIES

SummaryWe describe a case of “sinus histiocytosis with massive lymphadenopathy” (SHML) studied by immunohistochemical, cytogenetic and molecular analysis. The immunophenotyping showed that the lymph node histiocytes were strongly positive for the S-100 protein and MoAb LeuM3, OKM5, KP1 and DRC-1; a portion of these cells was also positive for OKT6 and Leu3A, suggesting a possible relationship with the veiled cells, which represent an intermediate step in the pathway from the Langerhans cell to the interdigitating reticulum cell. Cytogenetic analysis showed a normal prevalent clone and a small hypodiploid clone and the molecular study showed no detectable involvement of the c-fms proto-oncogene, which is related to monocyte/macrophages. Unfortunately all these data do not seem sufficient to define the benign or neoplastic nature of the disease. Further investigations, immunophenotypical, cytogenetic and molecular, are needed to elucidate the pathogenesis of the disease, especially for more aggressive cases or for cases with unfavorable evolution.

Extramedullary Pleural Blast Crisis in Chronic Myelogenous Leukemia Cytogenetic and Molecular Study

Two patients with Ph1-positive chronic myelogenous leukemia with pleural blastic transformation occurring before medullary involvement are presented. The clonal origin of the pleural cells identified as unclassified blasts in 1 patient and as erythroid blasts in the other was confirmed by the presence of the t(9;22) translocation and their clonal evolution by the presence of duplicated Ph1 and additional chromosome alterations. DNA obtained from the pleural blasts and peripheral blood cells of 1 patient showed an identically rearranged bcr configuration, indicating the origin of the pleural blasts from the CML clone and suggesting that this genomic event is not directly linked with the progression of disease.

P-GLYCOPROTEIN EXPRESSION IN ACUTE MYELOBLASTIC-LEUKEMIA ANALYZED BY IMMUNOCYTOCHEMISTRY AND FLOW-CYTOMETRY

Using the APAAP technique, we assessed the reactivity of five monoclonal antibodies, JSB1, C219, Mab 57, 2F8 and MRK16, to gp 170 in 60 cases of de novo acute myeloid leukemia (AML) and 13 relapses. Reactivity, varied between the five antibodies, and positivity was obtained with 2F8 > JSB1 > MRK16 > Mab57 > C219. Sixteen of the 60 cases were also studied by flow cytometry. In 10 cases, the results with the two techniques corresponded, in the other 6 cases, flow cytometry proved more sensitive than APAAP in detecting small amounts of gp170. In the flow cytometry analysis, the cells fixed in methanol and paraformaldehyde were more fluorescent than unfixed samples or those fixed in paraformaldehyde or methanol alone. Our results thus reveal that positivity for gp 170 depends on various factors, including the specificity of the monoclonal antibodies, the techniques used and the preservation of the samples. This suggests the need for a clear standardization of the methods to detect gp170.

Incidence of lymphoid markers in acute myeloid leukemia : alkaline phosphatase-antialkaline phosphatase versus immunofluorescence

The aim of the present study was to compare the immunofluorescence technique (IF) with the immunoenzymatic (IE) alkaline phosphatase-antialkaline phosphatase method for the evaluation of the presence of lymphoid antigens (Ag) in 46 cases of acute myeloid leukemia (AML). The first technique allows detection of Ag expressed on the cytoplasmic membrane of living cells, whilst the second shows the presence of intracytoplasmic Ag on fixed cells. In general, the percentages of lymphoid Ag expression on AML cells are relatively low with both IE (15.2%) and IF (17.4%). We found a good correlation between the two methods for CD2 (4/4), CD7 (4/5), CD20 (1/1) and CD4 (2/2). The Ag CD19, CD21 and CD8 were negative in all cases, both with IE and with IF. CD3 (2 cases) and CD22 (1 case) were only evident with IE. CD10 was seen in 1 case with IF, whilst it was found more frequently with IE. For this reason, demonstration of CD10 with IF is more specific for the classification of acute leukemia.

In vivo biological response following low-dose interleukin-2 in complete remission B-cell non-Hodgkin's lymphoma patients

Abstract: The aim of the present study is to verify whether recombinant interleukin‐2 (rIL‐2) at low doses is well tolerated in aggressive lymphoma in complete remission (CR), and if there may be a biological justification for its use as a remission‐maintenance therapy able to reduce the percentage of relapses. We treated 6 patients with B‐cell non‐Hodgkins lymphoma (B‐NHL) in CR following PM‐Cytabom with rIL‐2 3 IMU s.c. x 5 d per wk, every other wk for 8 wk. Our results show that this treatment provokes statistically significant changes in the absolute number of lymphocytes, eosinophils, CD25+ and CD122+ cells and soluble IL‐2 receptors; these doses, however, are not sufficient to modify CD3+, CD16+ and CD56+ cell values or natural killer and lymphokine activated killer cell activity. Thus these findings do not appear to constitute a biological rationale for the use of rIL‐2 at this dose and schedule as a remission‐maintenance therapy in B‐cell NHL. Nevertheless, the results are a valid basis for further study of the use of the same rIL‐2 doses for a longer period of time in combination with other cytokines, in the hope that the biological effects can be augmented without increasing the toxic side effects.