Abstract. The aim of this paper was to study the elastic and electrical properties of lymphoid cells in patients with acute lymphoblastic leucosis (ALL, n = 15). The mechanical properties of the membrane of lymphoid cells was recorded by atomic force microscopy (AFM). The electrical properties of the lymphoid cell membranes were detected by the Kelvin method. The elastic and electrical membrane properties of lymphoid cells were recorded by incubation with doxorubicin, one of chemotherapy drugs. We used different concentrations and incubation time. It was shown that in the acute phase of the disease and the stage of stable remission the lymphoid cell clones with a reduced stiffness and increased cell surface charge were found. In the experiments in vitro was demonstrated that the increased cell membrane rigidity may be one of the factors determining the tumor cell resistance to the chemotherapy. It was found that if to use the highest concentration of drug in the incubation medium (0.5-1.0 mg/ml) and its longest time, then the surviving cells had more elastic membrane (0.25-1.0 Pa) and the positive potential of the membrane surface (15-29 mV). These obtained data may have a significant prognostic importance for the evaluation of drug resistance of tumor cells.

Introduction Intensive “pediatric oriented” treatment with heavy cytostatic load, incorporation of allogeneic HSCT is now considered a backbone approach in adult ALL therapy. Highly myelosuppressive treatment is more toxic and less reproducible, so RALL has initiated non-intensive but non- interruptive protocol “ALL-2009”and started a prospective multicenter trial for adult Ph-negative ALL based on: 1) the replacement of prednisolone (Pdn) 60 mg/m2 with dexamethazone (Dexa) 10 mg/m2 if blast cells are >25% in bone marrow after 7 days of prephase; 2) de-intensified but non-interruptive treatment with doses modification according to the myelosuppression with total treatment duration of 127 weeks; 3) prolonged implication of L-asparaginase (total proposed dose 590.000 IU/m2); 4) autologous hematopoietic stem cell transplantation (HSCT) after non-myeloablative BEAM conditioning followed by prolonged maintenance – for T-cell ALL patients. Allo-BMT was an option for high risk patients with sibling donors. The study is registered on the ClinicalTrials.gov public site; NCT01193933. Methods and patients From Jan 2009, till June 2014, 30 centers enrolled 250 pts: median age 30 years (15-60 years), 115f/135 m; in 2,4% phenotype was unknown (n=6), B-lineage ALL - 63,2% (n=158), T-lineage ALL - 34% (n=85), biphenotypic - 0,4% (n=1). Cytogenetics was available in 62,4% of patients (n=156) and 41% of them (n=64) had normal karyotype (NK). 25,2% of patients (n=63) were in the standard risk (SR) group (WBC <30 for B-lineage, <100 for T-lineage; EGIL BII-III, T-III; LDH < 2N; no late CR; t(4;11)-negative), 59,2% (n=148) - in the high risk (HR) group (WBC >30 for B-lineage, >100 for T-lineage; EGIL BI, T-I-II-IV; LDH > 2N; late CR; t(4;11)-positive), 39 patients were not qualified by risk group. The analysis was performed in June 2014. The median time of follow-up was 26,1 mo. Results Prednisolone was replaced with dexamethazone after prephase in 68,1% of patients (135 of 198). The portion of non-responders to PRD in SR and HR groups was 54% and 67%, respectively (p=0,06). CR rate in 228 available for analysis patients was 87% (n=198), induction death occurred in 10,5% (n=24), resistance was registered in 2,5% (n=6). The majority of CR patients (91%) achieved it after prephase (7,1%, n=16) and the 1st phase of induction (83,9%, n=164). Late responders constituted 9% (n=18). None of those factors (PRD sensitivity, initial risk group, immunophenotype, late response) influenced overall (OS) or disease-free survival (DFS). OS rate in older ALL patients (>30) was substantially less than in younger ones (52,7% vs 73,6%, p=0,0009). DFS was comparable - 61,2% vs 71,5%, p=0,1. 24 of 75 (32%) CR T-ALL patients underwent autologous BMT after BEAM conditioning at a median time of 6 mo from CR and proceeded to further maintenance. No relapses were registered in this group so far. Allogeneic BMT was performed only in 14 patients (Ò-ALL-7, B-ALL-7) on the protocol. Totally 47 patients (20,6%) relapsed (16 with T-lineage, 31 with B-lineage ALL). At 48 mo OS for the whole group constituted - 65,6%, DFS - 69,3%. OS and DFS differed in B-ALL patients with NK in comparison with abnormal karyotype: 80% vs 57%,(p=0,01) and 81% vs 61%, respectively (p=0,02), but not in T-ALL patients. Conclusions Our data demonstrate that the proposed treatment approach is rather effective and reproducible. OS and DFS did not depend on various common risk factors (initial risk group, WBC, LDH, immunophenotype, late response, PRD resistance). The only independent risk factor for OS was age (>30 y). In B-cell ALL abnormal karyotype became an independent adverse risk factor for OS, DFS, relapse incidence. Fig.1 Overall survival (A) according to age in the whole cohort and disease-free survival (B) in B-cell ALL according to karyotype Table 1 (A) OS in different age groups (B) DFS in B-cell ALL Figure Figure. (A) OS in different age groups Figure Figure. (B) DFS in B-cell ALL Disclosures No relevant conflicts of interest to declare.

Introduction It is postulated that the improvement in the overall treatment outcome in adult Ph-negative ALL came from the implementation of more aggressive pediatric-like protocols and higher portion of allogeneic HSCT. Here we report the results of the adult (15-55 yy) Ph-negative ALL protocol based on the opposite approaches: less intensive but non-interruptive treatment with low numbers of allo-HSCT. The study is registered on the ClinicalTrials.gov public site; NCT01193933. Patients and Methods The ALL-2009 is based on: (1) the replacement of prednisolone (Pdn) 60 mg/m2 with dexamethazone (Dexa) 10 mg/m2 if blast cells are >25% in b/m after prephase (7d); (2) de-intensified but non-interruptive 5 months induction/consolidation treatment (5 wks prd/dexa with 3 instead of 4 dauno/vncr pulses, 4 weeks of 6MP with 5 L-asp, 2 instead of 4 ARA-C blocks, 1 instead of 2 Cph injections during induction; induction-like 3 consolidations for 3wks, 2wks, 4wks-continuously without intervals), followed by (3) 2 late (at 6 mo) intensifications- with 1 day HD MTX and with 1 d HD ARA-C, both with L-asp and 3 ds dexa and (4) 2-yrs continuous 6MP/MTX maintenance with doses modification according to myelosuppression with monthly 3-days dexa/vncr/L-asp pulses (∑ L-asp = 590.000 IU/m2). The protocol was identical for all risk groups. Allo-HSCT was indicated only for extremely high-risk BCP-ALL (t(4;11),L>100). No central MRD monitoring was performed. Since Apr 2009 till June 2015 20 centers had recruited 168 BCP-Ph-negative ALL pts with a median age 28 years (15-54), 84f/84 m. Full cytogenetics was available in 67,3% (n=113), 43,4% of them (n=49) had normal karyotype (NK), 10% (n=9%) had no mitosis, 47,6% (n=54) - different abnormalities (hypoploid-1, hyperploid-12, t(11q23)/MLL-8, del11q23-2, t(1;19)-2, t(12;21)-1;others-28). 26,7% of pts (n=45) were in the standard risk (SR) group (WBC <30, EGIL BII-III, LDH < 2N; no late CR; t(4;11)-negative), 56,5% (n=95) - in the high risk (HR) group (WBC >30; EGIL BI, LDH > 2N; late CR; t(4;11)-positive), 28 patients (n=16,8%) were not qualified by the risk. The analysis was performed in June 2015. 158 pts were available for analysis. Results CR rate in 158 available for analysis pts was 87,7% (n=139), induction death occurred in 9,1% (n=14), resistance was registered in 3,2% (n=5). The majority of CR pts (87,8%) achieved it after prephase (12,2%, n=17) and the 1st phase of induction (75,6%, n=105). Late responders constituted 12,2% (n=17). Allogeneic BMT was performed only in 9 of 144 patients who survived induction (6,2%). Totally 31 pts (22,3%) had relapsed. At 60 mo OS for the whole group constituted - 50%, DFS - 51.3%. In a univariate analysis among various risk factors (age <> 30y, initial risk group, WBC, LDH, immunophenotype, late response >35d, PRD resistance) age (>30 y) became statistically significant for OS, DFS and relapse probability (RP) (pic.1), abnormal karyotype - for DFS (30% vs 68%, p=0,04) and RP (42% vs 19%, p= 0,04). In a multivariate analysis no common risk factors were significant. Conclusions Our data demonstrate that the proposed treatment approach is rather effective. We believe that constant non-interruptive treatment without intensive highly myelosuppressive consolidation courses and high portion of allogeneic HSCT may become an alternative and reproducible approach in adult Ph-negative ALL, though we have to stress that it should be very strict compliance of the pts to the protocol. All pts, mostly from the region hospitals who refused prolonged and constant treatment (~5%), relapsed. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.

In the investigation that was performed, the authors studied the structure and properties of lymphocytes' surfaces in patients with chronic lymphoblastic leukemia with application of atomic force microscopy technology. It was stated that development of chronic lymphoblastic leukemia is characterized with circulation of immature forms of lymphocytic series in peripheral bloodstream, for which increase of surface potential by 456% (p<0.05) as compared with control group, is typical. Surface relief of abnormal cells is characterized by abundance of globular structures with reduced height, which endows it with relief view. Stiffness of lymphocytes in patients with lymphoblastic leukemia is reduced by 51.4% (р<0.05) as compared with control group. Revealed peculiarities of morphological and functional properties of abnormal cell clones lead to microcirculatory embarrassment in vessels, which should be considered at providing standard treatment schemes.