Boost Invariance and Multiplicity Dependence of the Charge Balance Functionin π+p\pi^{+}p and K+pK^{+}p Collisions at s=22\sqrt s= 22 GeV/c

Boost invariance and multiplicity dependence of the charge balance function are studied in \pi^{+}\rp and \rK^{+}\rp collisions at 250 GeV/$c$ incident beam momentum. Charge balance, as well as charge fluctuations, are found to be boost invariant over the whole rapidity region, but both depend on the size of the rapidity window. It is also found that the balance function becomes narrower with increasing multiplicity, consistent with the narrowing of the balance function when centrality and/or system size increase, as observed in current relativistic heavy ion experiments.Comment: 4 pages, 5 figures, Revte

Tyrosine Kinase Inhibitor Resistance in Patients with Chronic Myeloid Leukemia: A 10-Year Study of BCR-ABL Gene Mutation Profile in Russia (2006–2016)

Background. Kinase domain mutations of BCR-ABL gene is the most common cause of tyrosine kinase inhibitor resistance. Aim. To present the data on prognostic value of BCR-ABL mutation burden in Russian patients over the last 10 years. Materials & Methods. The study included 1885 chronic myeloid leukemia (CML) patients with tyrosine kinase inhibitor resistance who were followed up from 2006 to 2016. BCR-ABL point mutations in mRNA samples were analyzed by means of polymerase chain reaction and subsequent Sanger sequencing. Results. In 1257 CML patients with signs of tyrosine kinase inhibitor resistance BCR-ABL expression level was > 1 %. BCR–ABL mutations were detected in 31.8 % of patients. Total mutation count was 467 (70 mutation types). Total count of patients with mutation-associated tyrosine kinase inhibitor resistance decreased from 36.6 % (2006–2008) to 24.95 % (2013–2016) and to marked decrease of 23.12 % in 2014. Detection rate of imatinib-resistant mutations and F359V mutation was shown to decrease within the period from 2010–2011 to 2014–2015. F317L level, which is responsible for dasatinib resistance, considerably increased in 2015. T315I frequency was the highest in 2014, afterwards it was gradually decreasing. Mutation-associated resistance rates varied by region of the Russian Federation. Conclusion. The analysis of trends of mutation incidence in patients with CML can be of extreme significance in long-term prognosis of resistance development and in improvement of treatment planning

Prognostic Value of the PRAME Gene Expression in T-Cell Lymphoproliferative Disorders

Background. T-cell lymphomas (T-CL) represent a heterogeneous group of malignant lymphoproliferative disorders characterized by unfavorable prognosis. The cancer-testis PRAME gene is notable for its spontaneous expression in transformed cells as observed in solid tumors, B-cell lymphoproliferative and chronic myeloproliferative diseases. Activity and clinical significance of PRAME in T-CL was not studied before, which determines the relevance and provides ground for the present trial. Aim. To assess the clinical significance of the PRAME gene expression in T-CL. Materials & Methods. PRAME gene expression level was measured in samples of lymph nodes, blood, and bone marrow from 35 T-CL patients. Among them 3 patients received allogeneic hematopoietic stem cell transplantation, and 6 patients received autologous hematopoietic stem cell transplantation. A correlation was established between the PRAME expression in bone marrow and peripheral blood with morphological markers of disseminated disease with bone marrow lesions and leukemic blood. PRAME expression level was correlated with survival parameters and tumor proliferative activity (Ki-67). Results. PRAME activity was observed in 21 (60 %) patients. PRAME hyperexpression is associated with advanced stages of disease (p = 0.0734), bone marrow lesions (p = 0.0289), leukemic blood (p = 0.0187), worsening of the overall survival (OS) (p = 0.0787) and event-free survival (EFS) (p = 0.7185), also after hematopoietic stem cell transplantation (p = 0.2661 for OS and p = 0.0452 for EFS), and with a high Ki-67 expression level (p = 0.0155). Conclusion. PRAME expression in T-CL is often observed and related with unfavorable clinical prognosis

Expression of the BCR-ABL1 Gene in Patients with Chronic Myeloproliferative Diseases with Signs of Progression

Background. The V617F mutation of JAK2 is known to manifest in Ph-negative chronic myeloproliferative diseases (cMPD), such as polycythemia vera, thrombocythemia, and myelofibrosis. These diseases not infrequently advance into more aggressive forms up to acute leukemia. As the progression mechanism is still unknown, its study retains a high priority. JAK2 carrying the V617F mutation is believed to cause constant activation of V(D)J recombinase in myeloid tumor cells in cMPD patients. Aberrant activation of V(D)J recombinase in tumor cells in cMPD patients can lead to t(9;22)(q34;q11) chromosomal rearrangement. Aim. To study the expression of BCR-ABL1 resulting from translocation t(9;22)(q34;q11) in cMPD patients at the progression stage in order to test the suggested hypothesis. Materials & Methods. The BCR–ABL1 expression was assessed in peripheral blood granulocytes in cMPD patients by real-time PCR. The JAK2 V617F mutation was identified by quantitative allele-specific PCR. The JAK2 exon 12 mutations were determined using Sanger direct sequencing of PCR products. Results. The BCR-ABL1 expression was discovered in 29 % of patients with cMPD progression. The BCR-ABL1 expression in these patients correlated with hepatosplenomegaly and hyperleukocytosis. Conclusion. In a significant proportion of cMPD patients the disease progression can be associated with activation of the BCR-ABL expression