Sandra Saemi Nakashima

Mutational Profiling of JAK2V617F vs. CALR mutated Primary Myelofibrosis

Background: The median survival of patients with primary myelofibrosis (PMF) is 5 to 7 years after diagnosis. In the majority of patients with PMF somatic mutations were detected either in Janus Kinase 2 (JAK2; in 60% of patients), Calreticulin (CALR; in 25% of patients) or MPL (in 5% of patients) genes. Neither mutation was detected 5% to 10% of PMF patients. Patients with mutated JAK2 are known to have a more aggressive disease compared to patients with mutated CALR. However patients with mutated JAK2 and high allele burden have a favorable outcome compared to patients with a low mutated JAK2 burden. Aim: To develop a model that uses genetic information to predict survival outcome of patients with PMF. Patients and Methods: Bone marrow samples were collected from 344 patients with PMF that were followed at MD Anderson Cancer Center between 2000 and 2013 (157 months). All samples were screened for JAK2 and for mutations in CALR. Patients who did not have a mutation in either gene were also screened for mutations in MPL. Results: In 226 patients (66%) JAK2 was detected and in 43 (13%) CALR was mutated. Of the 75 patients who did not have JAK2 or CALR mutations, 16 (21%) had mutated MPL. In 59 patients (17%), none of those mutations was detected. In the 226 patients who harbored the JAK2 mutation, a cut-point of 50% dichotomized patients into those with a high JAK2 burden and a favorable overall survival (OS; median OS: 80 months) and those with a low JAK2 burden and an adverse OS (median OS: 50 months). Age (above 65 years) and mutation status (low JAK2 burden or triple-negative) were independent risk factors. Patients with a favorable mutation status and age below 65 had a median survival of 126 months (n 1⁄4 82). Patients with either one risk factor, age above 65 (n 1⁄4 88) or adverse mutation status (n 1⁄4 87) had intermediate survival expectancy. The two risk factors were additive and patients age > 65 years and adverse mutation status (n 1⁄4 87) had a median survival of 35 months. Conclusions: Age and mutation status are independent predictors of survival in patients with PMF and stratify patients into 4 groups of equal size with very different survival outcome. 703 Mutational Profiling of JAK2V617F vs. CALR mutated Primary Myelofibrosis Fabio Santos, Renato Puga, Bianca Lisboa, Welbert Pereira, Mariana Miyagi, Evelyn Mata, Tarcila Datoguia, Isabel Bello, Michelli Diniz, Sandra Nakashima, Guilherme Perini, Ricardo Helman, Nelson Hamerschlak, Paulo Campregher Hematology/Oncology, Hospital Israelita Albert Einstein

Iron overload in Brazilian thalassemic patients.

UNLABELLED ABSTRACTObjectives:To evaluate the use of magnetic resonance imaging in patients with β-thalassemia and to compare T2* magnetic resonance imaging results with serum ferritin levels and the redox active fraction of labile plasma iron. METHODS We have retrospectively evaluated 115 chronically transfused patients (65 women). We tested serum ferritin with chemiluminescence, fraction of labile plasma iron by cellular fluorescence and used T2* MRI to assess iron content in the heart, liver, and pancreas. Hepatic iron concentration was determined in liver biopsies of 11 patients and the results were compared with liver T2* magnetic resonance imaging. RESULTS The mean serum ferritin was 2,676.5 +/- 2,051.7 ng/mL. A fraction of labile plasma iron was abnormal (> 0,6 Units/mL) in 48/83 patients (57%). The mean liver T2* value was 3.91 ± 3.95 ms, suggesting liver siderosis in most patients (92.1%). The mean myocardial T2* value was 24.96 ± 14.17 ms and the incidence of cardiac siderosis (T2* < 20 ms) was 36%, of which 19% (22/115) were severe cases (T2* < 10 ms). The mean pancreas T2* value was 11.12 ± 11.20 ms, and 83.5% of patients had pancreatic iron deposition (T2* < 21 ms). There was significant curvilinear and inverse correlation between liver T2* magnetic resonance imaging and hepatic iron concentration (r= -0.878; p < 0.001) and moderate correlation between pancreas and myocardial T2* MRI (r = 0.546; p < 0.0001). CONCLUSION A high rate of hepatic, pancreatic and cardiac impairment by iron overload was demonstrated. Ferritin levels could not predict liver, heart or pancreas iron overload as measured by T2* magnetic resonance imaging. There was no correlation between liver, pancreas, liver and myocardial iron overload, neither between ferritin and fraction of labile plasma iron with liver, heart and pancreas T2* values.