Dry-reagent disposable dipstick test for visual screening of seven leukemia-related chromosomal translocations

We report the first dry-reagent, disposable, dipstick test for molecular screening of seven chromosomal translocations associated with acute and chronic leukemia. The dipstick assay offers about 10 times higher detectability than agarose gel electrophoresis and, contrary to electrophoresis, allows confirmation of the sequence of the polymerase chain reaction (PCR) product by hybridization within a few minutes without the need of instrumentation. Biotinylated amplified DNA is hybridized with a dA-tailed probe and applied to the strip, which contains oligo(dT)-conjugated gold nanoparticles in dry form. Upon immersion of the strip in the appropriate buffer, the solution migrates and the hybrids are captured by immobilized streptavidin at the test zone generating a characteristic red line. The excess nanoparticles are captured by oligo(dA) strands immobilized at the control zone of the strip producing a second red line. We studied the: t(9;22)(q34;q11), t(15;17)(q22;q21), t(11;17)(q23;q21), t(5;17)(q32;q21), t(11;17)(q13;q21), t(8,21)(q22;q22) and inv(16)(p13;q22) that generate the BCR-ABL, PML-RARa, PLZF-RARa, NPM-RARa, NuMA-RARa, AML1-ETO and CBFβ-MYH11 fusion genes, respectively. A single K562 cell was detectable amidst 106 normal leukocytes. A dipstick test was developed for actin, as a reference gene. The dipstick assay with appropriate probes can be used for identification of the fusion transcripts involved in the translocation. © 2007 Oxford University Press

Disease-related anemia in chronic lymphocytic leukemia is not due to intrinsic defects of erythroid precursors: A possible pathogenetic role for tumor necrosis factor-alpha

Background/Aims: Disease-related anemia in chronic lymphocytic leukemia (CLL) occurs when the obvious causes are excluded while its pathogenesis is still obscure. We investigated its underlying mechanisms in 56 untreated patients with CLL. Methods: Bone marrow (BM) lymphocytic infiltration was estimated in trephine biopsies. Serum erythropoietin (EPO) and tumor necrosis factor-α (TNF-α) levels were measured by ELISA. The potential of BM CD34+ to differentiate into erythroid cells was evaluated by methylcellulose-based assays and in liquid cultures supplemented with EPO, SCF, IL-3 ± TNF-α. The response of erythroid precursors to EPO ± TNF-α was assessed by detecting activated key proteins of EPO-EPO receptor signalling pathway using Western Blot and EMSA. Results: Bone marrow lymphocytic infiltration was not exclusively responsible for disease-related anemia and CD34+ cells were intrinsically capable of generating erythroid precursors. Also, no deficiency of serum erythropoietin (EPO) or defective intracellular response of erythroid precursors to EPO ± TNF-α stimulation was observed. Serum TNF-α levels were found increased in anemic CLL patients and TNF-α appeared to directly inhibit the erythroid development in early stages of erythropoiesis. Conclusion: We concluded that CLL-related anemia was not due to intrinsic defects of erythroid precursors, but might result from the direct suppressive effect of TNF-α on the erythroid production. Copyright © 2009 S. Karger AG

Global vasomotor dysfunction and accelerated vascular aging in β-thalassemia major

Background: Patients with β-thalassemia major (β-TM) demonstrate an increased incidence of vascular complications, which are thought to result from a procoagulant/proinflammatory environment. We investigated the arterial vasorelaxing capacity and sought for early carotid atherosclerosis and underlying pathophysiological correlates in these transfusion-dependent patients. Methods and results: The vasodilatory properties of the brachial artery and the carotid intima-media thickness (IMT) were examined with ultrasonography in 35 non-diabetic young adults with β-TM (patient group) and 35 control subjects (control group). Among thalassemic patients, both endothelium-dependent (FMD) and -independent dilatation (FID) as well as their ratio was impaired, whereas IMT was increased (p < 0.01). Patients on optimal, as compared with those on non-optimal chelation treatment had a non-significantly lower IMT. Vasodilatory capacity in the patient group was inversely correlated with IMT and independently associated either with the quality of chelation therapy (FMD) or serum ferritin levels (FID). Plasma concentrations of D-dimers, circulating markers of endothelial activation, inflammation and apoptosis were higher, while plasma cholesterol and fibrinogen levels were lower-than-normal in the patient group. Independent predictors of IMT among thalassemic patients were tumor necrosis factor-α levels and age. Conclusions: Young adults with β-TM exhibit both a global impairment of arterial vasorelaxation and early carotid atherosclerosis. A procoagulant/proinflammatory state in these transfusion-dependent patients may overwhelm atheroprotective mechanisms, including an optimal chelation regimen, and promote vascular injury and atherogenesis. © 2007 Elsevier Ireland Ltd. All rights reserved