Programme for Harmonization to the International Scale in Latin America for BCR-ABL1 quantification in CML patients: findings and recommendations.

Objectives The quantitation of BCR-ABL1 mRNA is mandatory for chronic myeloid leukemia (CML) patients, and RT-qPCR is the most extensively used method in testing laboratories worldwide. Nevertheless, substantial variation in RT-qPCR results makes inter-laboratory comparability hard. To facilitate inter-laboratory comparative assessment, an international scale (IS) for BCR-ABL1 was proposed. Methods The laboratory-specific conversion factor (CF) to the IS can be derived from the World Health Organization (WHO) genetic reference panel; however, this material is limited to the manufacturers to produce and calibrate secondary reference reagents. Therefore, we developed secondary reference calibrators, as lyophilized cellular material, aligned to the IS. Our purpose was both to re-evaluate the CF in 18 previously harmonized laboratories and to propagate the IS to new laboratories. Results Our field trial including 30 laboratories across Latin America showed that, after correction of raw BCR-ABL1/ABL1 ratios using CF, the relative mean bias was significantly reduced. We also performed a follow-up of participating laboratories by annually revalidating the process; our results support the need for continuous revalidation of CFs. All participating laboratories also received a calibrator to determine the limit of quantification (LOQ); 90% of them could reproducibly detect BCR-ABL1, indicating that these laboratories can report a consistent deep molecular response. In addition, aiming to investigate the variability of BCR-ABL1 measurements across different RNA inputs, we calculated PCR efficiency for each individual assay by using different amounts of RNA. Conclusions In conclusion, for the first time in Latin America, we have successfully organized a harmonization platform for BCR-ABL1 measurement that could be of immediate clinical benefit for monitoring the molecular response of patients in low-resource regions.

Involvement of cAMP and calmodulin in endocytic yolk uptake during Xenopus laevis oogenesis.

The aim of the present study was to show the participation and physiological role of calmodulin (CaM) and cAMP during vitellogenin endocytic uptake in the amphibian Xenopus laevis. The results showed a differential distribution of CaM in the ovary follicles during oogenesis. The CaM intracellular localization was not affected by gap junction's downregulation and CaM inhibition did not completely abolished the endocytic activity of oocytes. We showed that cAMP was able to completely rescue the endocytic competence in follicles in which gap junctional communication had been disrupted by octanol. Moreover cAMP was capable of restoring oocyte endocytic capability in the presence of octanol and stelazine, a CaM inhibitor. We propose that, in Vtg uptake regulation, cAMP is upstream of CaM during the endocytic signalling pathway.

Foxo3 gene expression and oxidative status in beta-thalassemia minor subjects.

BACKGROUND: Oxidative stress may aggravate symptoms of hemolytic anemias such as beta-thalassemia. FoxO3 activation results in resistance to oxidative stress in fibroblasts and neuronal cell cultures. OBJECTIVE: The purpose of this research was to study FoxO3 gene expression and oxidative status in beta-thalassemia minor individuals. METHODS: Sixty-three subjects (42 apparently healthy individuals and 21 with beta-thalassemia minor) were analyzed at the Universidad Nacional de Tucumán, Argentina, between September 2013 and June 2014. A complete blood count, hemoglobin electrophoresis in alkaline pH and hemoglobin A2 levels were quantified. Moreover, thiobarbituric acid reactive species, erythrocyte catalase activity and iron status were evaluated. Beta-thalassemia mutations were determined by real-time polymerase chain reaction. FoxO3 gene expression was investigated by real-time reverse transcription-polymerase chain reaction using mononuclear cells from peripheral blood. RESULTS: Subjects were grouped as children (≤12 years), and adult women and men. The analysis of erythrocyte catalase activity/hemoglobin ratio revealed a significant difference (p-value <0.05) between healthy and beta-thalassemia minor adults, but no significant difference was observed in the thiobarbituric acid reactive species levels and FoxO3 gene expression (p-value >0.05). Thiobarbituric acid reactive species and the erythrocyte catalase activity/hemoglobin ratio were not significantly different on comparing the type of beta-thalassemia mutation (ß0 or ß+) present in carriers. CONCLUSIONS: The lack of systemic oxidative imbalance demonstrated by thiobarbituric acid reactive species is correlated to the observation of normal FoxO3 gene expression in mononuclear cells of peripheral blood. However, an imbalanced antioxidant state was shown by the erythrocyte catalase activity/hemoglobin ratio in beta-thalassemia minor carriers. It would be necessary to study FoxO3 gene expression in reticulocytes to elucidate the role of FoxO3 in this pathology.

Erythrocyte Catalase Activity in More Frequent Microcytic Hypochromic Anemia: Beta-Thalassemia Trait and Iron Deficiency Anemia.

Most common microcytic hypochromic anemias are iron deficiency anemia (IDA) and ß-thalassemia trait (BTT), in which oxidative stress (OxS) has an essential role. Catalase causes detoxification of H2O2 in cells, and it is an indispensable antioxidant enzyme. The study was designed to measure erythrocyte catalase activity (ECAT) in patients with IDA (10) or BTT (21), to relate it with thalassemia mutation type (ß (0) or ß (+)) and to compare it with normal subjects (67). Ninety-eight individuals were analyzed since September 2013 to June 2014 in Tucumán, Argentina. Total blood count, hemoglobin electrophoresis at alkaline pH, HbA2, catalase, and iron status were performed. ß-thalassemic mutations were determined by real-time PCR. Normal range for ECAT was 70,0-130,0 MU/L. ECAT was increased in 14% (3/21) of BTT subjects and decreased in 40% (4/10) of those with IDA. No significant difference (p = 0,245) was shown between normal and BTT groups, while between IDA and normal groups the difference was proved to be significant (p = 0,000). In ß (0) and ß (+) groups, no significant difference (p = 0,359) was observed. An altered ECAT was detected in IDA and BTT. These results will help to clarify how the catalase activity works in these anemia types.

Foxo3 gene expression and oxidative status in beta-thalassemia minor subjects

ABSTRACT Background: Oxidative stress may aggravate symptoms of hemolytic anemias such as beta-thalassemia. FoxO3 activation results in resistance to oxidative stress in fibroblasts and neuronal cell cultures. Objective: The purpose of this research was to study FoxO3 gene expression and oxidative status in beta-thalassemia minor individuals. Methods: Sixty-three subjects (42 apparently healthy individuals and 21 with beta-thalassemia minor) were analyzed at the Universidad Nacional de Tucumán, Argentina, between September 2013 and June 2014. A complete blood count, hemoglobin electrophoresis in alkaline pH and hemoglobin A2 levels were quantified. Moreover, thiobarbituric acid reactive species, erythrocyte catalase activity and iron status were evaluated. Beta-thalassemia mutations were determined by real-time polymerase chain reaction. FoxO3 gene expression was investigated by real-time reverse transcription-polymerase chain reaction using mononuclear cells from peripheral blood. Results: Subjects were grouped as children (≤12 years), and adult women and men. The analysis of erythrocyte catalase activity/hemoglobin ratio revealed a significant difference (p-value <0.05) between healthy and beta-thalassemia minor adults, but no significant difference was observed in the thiobarbituric acid reactive species levels and FoxO3 gene expression (p-value >0.05). Thiobarbituric acid reactive species and the erythrocyte catalase activity/hemoglobin ratio were not significantly different on comparing the type of beta-thalassemia mutation (β0 or β+) present in carriers. Conclusions: The lack of systemic oxidative imbalance demonstrated by thiobarbituric acid reactive species is correlated to the observation of normal FoxO3 gene expression in mononuclear cells of peripheral blood. However, an imbalanced antioxidant state was shown by the erythrocyte catalase activity/hemoglobin ratio in beta-thalassemia minor carriers. It would be necessary to study FoxO3 gene expression in reticulocytes to elucidate the role of FoxO3 in this pathology.