FLT3 overexpression in acute promyelocytic leukemia patients without detectable FLT3-ITD or codon 835-836 mutations: a pilot study.

BACKGROUND: Activating mutations of the FLT3 receptor tyrosine kinase are common in acute promyelocytic leukemia (APL) but have uncertain prognostic significance. Information regarding FLT3 expression levels in APL without FLT3 mutations is lacking. MATERIALS AND METHODS: Using RT-PCR, mutation analysis of the FLT3 gene, regarding internal tandem duplications (ITDs) and codon 835-836 point mutations, was performed and real-time PCR was carried out to determine the level of FLT3 expression in 11 APL patients at diagnosis and 5 in haematological remission with molecularly detectable disease. RESULTS: High levels of FLT3 transcript, at least a 10-fold increase compared to the normal controls, were found at diagnosis in all 3 mutated cases and in 2 patients without detectable FLT3 mutations. CONCLUSION: FLT3 overexpression can be documented in patients without FLT3 mutations. These patients might benefit from treatment using specific FLT3 tyrosine kinase inhibitors. Larger studies are needed to evaluate the clinical and biological significance of FLT3 overexpression in the absence of FLT3 mutations.

An unusual case of CD4+ CD7+ CD56+ acute leukemia with overlapping features of type 2 dendritic cell (DC2) and myeloid/NK cell precursor acute leukemia.

Type 2 dendritic cell (DC2) acute leukemia has been recently described. We report here an unusual case of a 17-yr-old adolescent with overlapping features of DC2 and myeloid/NK cell precursor acute leukemia as defined by Suzuki et al. The patient presented with lymphadenopathy and hepatosplenomegaly without extranodal manifestations in skin or elsewhere. The morphologic, cytochemical and immunophenotypic features were compatible with those described in DC2 acute leukemia, with co-expression of CD4, CD56 and CD123 antigens. The novel markers BDCA-4 and BDCA-2 considered specific for DC2s were co-expressed. However, bright CD7 positivity along with a dim expression of CD33 (57%) and CD117 (27%) were also noted. Additionally, there was bright expression of NG2 monoclonal antibody 7.1, a frequent finding in myeloid/NK cell precursor acute leukemia. The interpretation of the immunophenotypic profile leads to the hypothesis on the existence of borderline cases between DC2 and myeloid/NK cell precursor acute leukemia. Still, other hypotheses can not be overlooked, such as the possibility for a kind of variant monoblastic leukemia or of another rare entity of acute unclassified leukemia.

Behcet's disease in a patient with chronic myelogenous leukemia under hydroxyurea treatment: a case report and review of the literature.

Behcet's disease (BD) is a chronic, relapsing vasculitis of unknown etiology. Its association with chronic myelogenous leukemia (CML) is extremely rare, and typical manifestations of BD were observed in a very few patients with CML, mainly under interferon-alpha (IFN-alpha) treatment. Skin pathergy test, being positive in about 50% of patients with BD, is also positive in some IFN-alpha-treated patients with CML without any evidence of BD symptoms. We describe a 62-year-old woman with CML who developed characteristic features of BD, including a positive skin hyperactivity test, during treatment with hydroxyurea. Hydroxyurea has been implicated in the appearance of skin vasculitic ulceration, but this is the first case, according to our knowledge, where the development of BD was observed during hydroxyurea maintenance in the chronic phase of CML.

Cardiac involvement in thalassemia intermedia: a multicenter study.

Cardiac complications in 110 patients (mean age, 32.5 +/- 11.4 years) with thalassemia intermedia (TI) were studied. Sixty-seven (60.9%) of them had not been transfused or were minimally transfused (group A). The rest had started transfusions after the age of 5 years (mean, 15.1 +/- 10.1 years), initially on demand and later more frequently (group B). Overall mean hemoglobin and ferritin levels were 9.1 +/- 1.1 g/dL and 1657 +/- 1477 ng/mL, respectively. Seventy-six healthy controls were also studied. The investigation included thorough history taking, clinical examination, electrocardiography, chest radiograph, and full resting echocardiography. Of 110 patients, 6 (5.4%) had congestive heart failure (CHF), and 9 (8.1%) had a history of acute pericarditis. Echocardiography showed pericardial thickening, with or without effusion, in 34.5% of the patients. Valvular involvement included leaflet thickening (48.1%), endocardial calcification (20.9%), and left-sided valve regurgitation (aortic, 15.4%; mitral, 47.2%). All patients had normal left ventricular contractility (fractional shortening, 0.43 +/- 0.05), and high cardiac output (CO; 9.34 +/- 2.28 L/min). Pulmonary hypertension (PHT), defined as Doppler peak systolic tricuspid gradient greater than 30 mm Hg, developed in 65 patients (59.1%). PHT correlated positively with age and CO and did not differ significantly between groups. Cardiac catheterization in the 6 patients with CHF revealed severe PHT, increased pulmonary resistance (PVR), and normal capillary wedge pressure. It was concluded that in patients with TI, the heart is primarily affected by PHT, which is the leading cause of CHF. High CO resulting from chronic tissue hypoxia and increased PVR are the main contributing factors. Doppler tricuspid gradient measurement should be considered, in addition to other factors, when determining the value of transfusion therapy for patients with TI. (Blood. 2001;97:3411-3416)

Prognostic factors in advanced stage Hodgkin's lymphoma: the significance of the number of involved anatomic sites.

BACKGROUND: Advanced Hodgkin's lymphoma (HL) is curable by conventional chemotherapy in 60--70% of patients. The pretreatment identification of a sizeable subgroup of patients with sufficiently low failure-free survival (FFS) to be eligible for investigational treatment is necessary. OBJECTIVES: To determine the prognostic significance of the number of involved sites (NIS) in patients with advanced HL and its relationship to the International Prognostic Score (IPS). METHODS: A retrospective review of patients with advanced HL, defined as Ann Arbor stage (AAS) IB, IIB, III or IV, treated with anthracycline-based regimens. The end-point was FFS. RESULTS: We identified 277 patients with a median age of 32 yr (14--78), 57% of whom were males. AAS was I in 4% of patients, II in 29%, III in 38% and IV in 29%. B-symptoms were recorded in 81%. Most patients had nodular sclerosis (64%) and mixed cellularity (26%) histology. IPS was greater-than-or-equals 3 in 44% of 242 evaluable patients. The NIS was greater-than-or-equals 5 in 32% of the patients and 20% of all patients had both greater-than-or-equals 5 involved sites and IPS greater-than-or-equals 3. The 10-yr FFS was 67%, being 76% vs. 50% for patients with less-than-or-equals 4 vs. greater-than-or-equals 5 involved sites (P < 0.0001). The NIS (greater-than-or-equal 5), AAS IV and anemia were independent predictors of FFS in multivariate analysis. The NIS remained significant along with IPS, when the latter was included in the analysis. Patients with greater-than-or-equals 5 involved sites and IPS greater-than-or-equals 3 had 10-yr FFS overall, and relapse-free survival of 41%, 45% and 49%, respectively. CONCLUSIONS: The NIS was associated with FFS in advanced HL, was independent of IPS, and led to the identification of a sizeable subgroup of patients with 10-yr FFS of approximately 40%. This factor should be evaluated during the development of prognostic systems.

Trisomy 11 with loss of the Y chromosome and trisomy 13 in a case of de novo acute myeloid leukemia.

We report a man with de novo acute myeloid leukemia (M4 of the FAB classification) bearing two abnormal clones in the bone marrow cells. The clones showed trisomy 11 with loss of the Y chromosome and trisomy 13, respectively.

Reverse transcription polymerase chain reaction for the diagnosis and molecular monitoring of the PML/RAR alpha fusion gene in acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is characterized by a specific t(15;17) translocation and a high rate of response to all-trans retinoic acid. The translocation generates a PML/RAR alpha chimeric gene which is transcribed in a fusion PML/RAR alpha mRNA. In this study, by using RT-PCR, we examined 14 APL patients for PML/RAR alpha fusion gene transcripts. Eight patients were studied at diagnosis, 2 at relapse, 1 both at relapse and after reinduction, 1 both at diagnosis and after three cycles of consolidation chemotherapy, and 2 patients were examined for minimal residual disease (MRD) 4 months after completing treatment. A positive result was observed in all 14 cases. Two patients who were in complete hematologic remission had evidence of hematologic relapse soon after the positive test. We conclude that RT-PCR for APL yields important diagnostic and prognostic information for the APL patients.

Molecular basis and haplotype analysis of delta, beta-thalassemic chromosomes in Greece.

The molecular defect was defined in 38 delta beta-thalassemic chromosomes from 30 unrelated heterozygous and 4 homozygous patients of Greek origin. Restriction fragment beta-gene cluster haplotypes were studies in 23 delta beta-thalassemic chromosomes. The molecular lesion was identical in all studied cases and corresponds to the 'Sicilian' type of delta beta-thalassemia. Restriction haplotypes analysis has shown that, with one exception only, all Greek delta beta-thalassemic chromosomes bear the polymorphic sites which characterize haplotypes I or VII, the former being probable by indirect evidence. The striking similarities of the molecular lesion and the underlying haplotypes are consistent with two theories: (1) The deletion occurred once on a chromosome and spread all over Greece and the Mediterranean area thereafter; (2) the 5' subhaplotype +----favors the deletional event in the delta-beta gene area.

Reticulocyte counting in thalassemic and other conditions with the R-1000 Sysmex analyzer.

Precise reticulocyte counts are difficult to obtain by the manual method when their percentage in the blood is low or normal. In these instances, rapid reticulocyte counting by flow cytometry appears to offer more accuracy and precision. The purpose of this study was to establish reticulocyte counts in heterozygous beta-thalassemia for reference purposes and to evaluate the performance of the recently introduced apparatus R-1000 (Sysmex) in the very heterogeneous thalassemic and sickle-cell syndromes. We studied a total of 364 samples; 102 heterozygous beta-thalassemia carriers, 180 normal matched controls, 36 patients with thalassemia major or intermedia, and 46 patients with various sickle-cell syndromes. Reticulocyte counts (both as percentage and as total number) were higher in heterozygous beta-thalassemia than in normal controls (p less than 0.001) and showed an inverse correlation with the respective hemoglobin values (p less than 0.001). These results confirm the proposed slightly increased erythropoietic activity in heterozygous beta-thalassemia carriers. A drawback of the technique is that the reticulocyte-platelet discrimination error is signaled frequently in all conditions displaying a marked red cell heterogeneity, especially when these are associated with high reticulocyte numbers. This calls probably for readjustment of the corresponding algorithm. In addition, all these conditions show a significantly increased auramine-O mature red-cell nonspecific fluorescence.

alpha Interferon treatment of essential thrombocythaemia and other myeloproliferative disorders with excessive thrombocytosis.

The effect of recombinant interferon alfa-2b on platelet count, thrombocytosis-associated symptoms and marrow fibrosis was studied in 18 patients with myeloproliferative diseases and associated thrombocytosis (nine with essential thrombocythaemia, three with polycythaemia vera, three with myelofibrosis and three with chronic myelogenous leukaemia). A reduction of the platelet count below 600 x 10(9)/L was achieved in 94%, and below 400 x 10(9)/L in 77% of the patients within 8 to 330 days of treatment. The selective thrombocytosis-reducing effect of alpha interferon was maintained for long periods of time in most patients without serious side effects. Thrombocytosis-associated symptoms were relieved once the number of platelets was reduced to near normal levels. Marrow reticulin content was found to be reduced after treatment in two of the seven patients studied. Side effects of alpha interferon were flu-like symptoms, which usually subsided within 7 days of treatment.

[Anemia 2,3-DPG and tissue oxygenation in beta-thalassemia heterozygotes]. / Anémie, 2,3-DPG et oxygénation tissulaire chez les hétérozygotes de beta-thalassémie.

The levels of 2,3-DPG and the value of P50 were determined in unselected, clinically healthy, typical beta-thalassemia heterozygotes and normal controls. Values of 2,3-DPG in the heterozygotes are significantly elevated compared to normals (when expressed per gram of hemoglobin or per volume of red cells) and much higher than their mild hemoglobin deficit would explain; they are elevated even in selected heterozygotes presenting normal hemoglobins levels. These 2,3-DPG values, when expressed per number of erythrocytes, are within normal limits. In parallel, oxygen affinity is lower, as the P50 value is displaced to the right by 2 mmHg above the normal mean, thus assuring adequate tissue oxygenation. The findings suggest that the high 2,3-DPG values of the beta-thalassemia heterozygotes are not determined solely by anemic hypoxia; it is more likely that the microcytic erythrocytosis of heterozygous beta-thalassemia is the cause of this increase. The resulting lower oxygen affinity leads to a decreased stimulation of erythropoiesis and hence to its regulation at lower hemoglobin levels. Accordingly we suggest that the beta-thalassemia trait is a pseudo-anemia, because it is unlikely that these heterozygotes are unable to reach normal hemoglobin values by increasing erythrocyte output.