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.

Detection of CD55- and/or CD59-deficient red cell populations in patients with lymphoproliferative syndromes.

INTRODUCTION: Paroxysmal nocturnal hemoglobinuria is an acquired clonal stem cell disorder characterized by the decrease or absence of glycosylphosphatidylinositol-anchored molecules from the surface of the affected cells, such as CD55 and CD59, resulting in chronic intravascular hemolysis, cytopenia and increased tendency to thrombosis. PNH-phenotype has been described in various hematological disorders, mainly in aplastic anemia and myelodysplastic syndromes, while it has been reported that complete deficiency of CD55 and CD59 has also been found in patients with lymphoproliferative syndromes, like non-Hodgkin's lymphomas. MATERIALS AND METHODS: The presence of CD55- and/or CD59-defective red cell populations was evaluated in 217 patients with lymphoproliferative syndromes. The study population included 87 patients with NHL, 55 with HD, 49 with CLL, 22 with ALL and four with hairy cell leukemia. One hundred and twenty-one healthy blood donors and seven patients with PNH were also studied as control groups. The sephacryl gel microtyping system was performed for the detection of CD55- and CD59-deficient red cell populations. Ham and sucrose lysis tests were also performed in all samples with CD55 or CD59 negative populations. RESULTS: Red cell populations deficient in both CD55 and CD59 molecules were detected in 9.2% of patients with lymphoproliferative syndromes (more often in ALL and nodular sclerosis type of HD) and in all PNH patients. CD55-deficient red cell populations were found in 8.7% of LPS patients (especially in low grade B-cell NHL), while CD59-deficient populations were found in only two patients with low grade B-cell NHL. CONCLUSION: These data indicate a possible association between paroxysmal nocturnal hemoglobinuria phenotype and lymphoproliferative syndromes, while further investigation is necessary to work out the mechanisms and the significance of the existence of this phenotype in these patients.

Sjögren's syndrome associated with multiple myeloma.

Sjögren's syndrome (SS) is a chronic autoimmune disease of unknown etiology characterized by lymphocytic infiltration of the exocrine glands and a polyclonal B-cell activation; it is demonstrated by the presence of multiple autoantibodies against organ- and non-organ-specific autoantigens. SS is associated with malignant lymphomas, Waldenstrom's macroglobulinemia and benign monoclonal gammopathy, while its relationship with multiple myeloma is extremely rare. The association between multiple myeloma and rheumatoid arthritis and other autoimmune diseases has been established, but it is not clear why a B-cell proliferation like myeloma occurs more rarely than other B-cell disorders in patients with SS. We describe a patient who presented with multiple myeloma and SS that might have existed for at least 2 years prior to the appearance of myeloma.

Inflammatory pseudotumor of the spleen: a case report and review of the literature.

Inflammatory pseudotumor of the spleen is a benign tumorous lesion of unknown etiology and pathogenesis that has been described in only a few cases in the literature. Recognition of this rare entity is important, as the clinical manifestations and imaging features could be indistinguishable from a lymphoproliferative disorder or another malignancy of the spleen. We report a new case and review the clinical presentation, laboratory findings, pathological and immunohistochemical studies, treatment, and prognosis of the previously reported cases of inflammatory pseudotumor of the spleen.

Association of neutrophil alkaline phosphatase activity and glycosylated haemoglobin in diabetes mellitus.

We determined neutrophil alkaline phosphatase (NAP) activity in diabetic patients in conjunction with HbA1c levels. NAP was estimated using semiquantitative cytochemical technique, and we studied its activity in different groups of diabetic patients. We found that NAP score is correlated with the HbA1c level. Non-diabetic patients were used as controls, in whom NAP score and HbA1c were found normal. In diabetic patients the NAP activity and the HbA1c level were altered similarly during the various phases of the disease. Our findings indicate that NAP score could be used as a simple new parameter for diabetes. The pathophysiologic mechanism of our observations needs further investigation.

Systemic lupus erythematosus presenting as myelofibrosis.

Myelofibrosis is not frequent in systemic lupus erythematosus (SLE). A review in the literature reveals that the co-incidence is rather rare since there are only a few papers reporting this combination. The female patient described hereby, presented with thrombocytopenia; following investigation, the diagnosis of SLE was established and bone marrow examination revealed an increase of marrow reticulin. Treatment with steroids reversed both thrombocytopenia and bone marrow fibrosis.

Detection of CD55 and/or CD59 deficient red cell populations in patients with aplastic anaemia, myelodysplastic syndromes and myeloproliferative disorders.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal stem cell disorder characterized by intravascular haemolysis, venous thrombosis, marrow hypoplasia, frequent episodes of infection, and rarely leukaemic conversion. At the cellular level, PNH is characterized by the decrease or absence of glycosylphosphatidylinositol (GPI)-anchored molecules, such as CD55 and CD59, from the cell surface. PNH-like clones have been described in various haematological disorders. The link between PNH and aplastic anaemia (AA) has been established but the relationship of PNH with myelodysplastic syndromes (MDS) or myeloproliferative disorders (MPD) remains unclear. In this study, the presence of CD55 and/or CD59 defective (PNH-like) red cell populations was evaluated in 21 patients with AA, 133 with MDS, 197 with MPD, 7 with PNH and in 121 healthy blood donors using the Sephacryl Gel Test microtyping system. Red cell populations deficient in both molecules CD55 and CD59 were detected in 33.3% of AA patients, in 16.5% of MDS patients (50% with hypoplastic bone marrow), in 14.2% of MPD patients (more often in essential thrombocythemia, 21.2%) and in all PNH patients. CD55 deficient red cell populations were found in 14.2% of patients with AA, 12.7% of patients with MDS and 21.3% of patients with MPD. CD59 deficient populations were found in 9.5% of AA patients, 2.2% of MDS patients and 2% of MPD patients. These results indicate an association between PNH, AA and MDS or even between PNH and MPD. Further investigation is necessary to work out the mechanisms of this association, and to define classification criteria for borderline cases, where diagnosis is difficult.

Fetal Erythropoiesis after Allogeneic Bone Marrow Transplantation Estimated by the Peripheral Blood Erythrocytes Containing Hemoglobin F (F-cells).

During bone marrow engraftment following BMT there is a re-establishment of fetal erythropoiesis, expressed by the increase of F-cells. This seems to depend on several factors such as underlying disease, conditioning before therapy and other mechanisms concerning both the donor and the recipient bone marrow. The aim of this work was to study the factors influencing F-cell production during bone marrow engraftment following transplantation. We studied 28 patients who underwent allogeneic bone marrow transplantation, for various hematological malignancies (CML, AML, ALL, CMML and SAA). F-cells were estimated on peripheral blood smears by indirect immunofluorescence. Overall, there was an F-cell increase after BMT in comparison with values before BMT; this increase was significant on days 15-50 (p <.01). F-cell on days 18, 25, 32 and 40 following transplantation were significantly higher (p <.01) in patients who have had increased F-cell numbers post-chemotherapy before BMT, compared with the patients who did not show any increase of the F-cell number post chemotherapy. During the first month following transplantation (day 7 to day 40) patients who were transplanted from high F-cell donors failed to show any significant differences in their F-cell numbers in comparison to those transplanted from low F-cell donors. However, the F-cell increase became significantly higher in the former group between days 50 and 120. This observation implies that the stressed erythropoiesis of the initial phase does not allow revealing the varying F-cell production of the capacities donor bone marrow, while later, when the graft has settled, the high F-cell donors reveal this property of the host.