Results of Molecular Monitoring in Posttransplant Period by Means of Series Investigation of WT1 Gene Expression in Patients with Acute Myeloid Leukemia

Aim. To demonstrate diagnostic and prognostic significance of series measurement of WT1 expression in patients with acute myeloid leukemia (AML) after allogenic hematopoietic stem cell transplantation (allo-HSCT). Materials & Methods. The clinical trial included 88 AML patients (38 females (43 %) and 50 males (57 %) aged 2–68, median 30 years). All the patients received allo-HSCT. Bone marrow was aspirated before (D0) and after HSCT (D+30, D+60, and D+100). Results. The univariate analysis showed statistically significant differences in 2-year overall survival with respect to the following factors: with and without remission at the moment of HSCT (p 250 copies before HSCT (p < 0.001) and at time points D+60 (p = 0.012), and D+100 (p < 0.001). Multivariate analysis revealed similar statistical significance of differences among patients transplanted in remission (p = 0.041) and with cGVHD (p = 0.03). In univariate analysis statistically significant differences in 2-year event-free survival (EFS) were found: a) in patients with allo-HSCT, either in remission or not (p < 0.001); b) using HSC, but not bone marrow, as transplant source (p < 0.026); c) with normal or high WT1 expression at the stage of HSCT (p < 0.001) and at time point D+100 (p < 0.001); d) using HSC from related or unrelated donor (p = 0.006); e) in patients with cGVHD (p = 0.05). In multivariate analysis independent positive effect on EFS was observed only in patients with normal WT1 expression at D+100 (p = 0.011) and with cGVHD (p = 0.038). Cumulative incidence of posttransplant relapse (PTR) in AML patients with normal or high WT1 expression at the stage of HSCT within the 2-year follow-up was significantly different (28.2 vs. 58.9 %; p = 0.002), also in measurements of this parameter at D+60 and D+100 (p = 0.015 and p < 0.001, respectively). In 1/4 of patients cytological relapses (cPTR) appeared considerably later than molecular relapses (mPTR), i.e. 13–489 days later (median 35 days), which is accounted for by early preventive therapy aimed at cPTR prophylaxis against the background of already recorded mPTR. According to our data, GVHD plays a crucial role in cPTR management. Conclusion. Phenomenon of WT1 expression normalization after allo-HSCT in AML patients proves to have a high diagnostic and prognostic significance. Introduction of this approach into clinical practice seems highly advisable for national oncohematological centers

Efficacy of Chemotherapy in Acute Leukemia Patients Resistant to Previous Standard Treatment According to the Series Measurement of WT1 Gene Expression

Aim. To estimate the efficacy of chemotherapy in acute leukemia patients resistant to previous standard treatment according to the series measurement of WT1 expression. Materials & Methods. The series measurement of WT1 expression formed the basis of the efficacy estimation of induction chemotherapy in 31 patients (15 men and 16 women aged from 3 months to 68 years; the median age was 28 years) with prognostically unfavourable variants of acute myeloid (AML) and lymphoblastic leukemia (ALL) (23 AML and 8 ALL patients). The WT1 gene expression was measured at baseline and 2–3 weeks after the treatment by the quantitative real-time PCR. The threshold level for detection was 250 copies of WT1/104 copies of ABL. The cytogenetic profile of leukemia cells was assessed by standard cytogenetics and FISH. Results. The baseline expression level of WT1 varied from 305 to 58,569 copies/104 copies of ABL. The expected reduction of WT1 expression after the first induction chemotherapy treatment was reported in 22/23 (96 %) AML patients and in 6/8 (75 %) ALL patients. According to our results WT1 expression reached the threshold in 13/31 (42 %) patients, including 9 AML patients and 4 ALL patients. After 11/31 (35 %) patients received the second course of treatment, WT1 expression level became normal in 8 cases (5 ALL and 3 AML patients). Despite high dose chemotherapy, HSCT and such agents as blinatumomab and gemtuzumab, an unfavourable outcome was observed in 18/31 (58 %) patients including 6 patients with complex karyotype (CK+) and 2 patients with monosomal karyotype (MK+). Once the MK+ and CK+ combination was observed, in another case the MK+ was combined with the prognostically unfavourable inv(3)(q21q26) inversion. Conclusion. Our results show that the molecular monitoring should be included as part of treatment of the prognostically unfavourable acute leukemia. The WT1 gene was shown to be the most appropriate marker. WT1 expression was shown to correlate with the common fusion genes allowing to estimate the blast cell count at the molecular level

Allogeneic Hematopoietic Stem Cell Transplantation in Myelofibrosis

Background & Aims. At present, the allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only treatment option with curative potential in patients with myelofibrosis (MF), especially in intermediate and high risk categories. The aim of the study is to perform a retrospective analysis of allo-HSCT outcomes in MF patients. Materials & Methods. Outcomes of allo-HSCT in 11 intermediate-2 (n = 3) and high (n = 6) risk patients (based on Dynamic International Prognostic Scoring Scale, DIPSSplus) performed in the R.M. Gorbacheva Scientific Research Institute of Pediatric Hematology and Transplantation over the period from 2005 till 2015 were analyzed in the study. Two more patients underwent allo-HSCT in MF blast phase. Two patients received ruxolitinib before allo-HSCT and 1 patient before and after allo-HSCT. Reduced intensity conditioning regimen was used in all cases. Results. Primary engraftment was documented in 8 patients. 72 % of patients achieved complete hematological remission. Molecular remission and myelofibrosis regression were confirmed in 5 patients. 5 of 11 patients were still with remission and followed-up by the date of the paper submission. The overall two-year survival was 46 %. Conclusion. Allo-HSCT is an effective treatment option for MF patients. Further trials are required to evaluate an optimal timing for allo-HSCT in MF patients and efficacy of Janus kinase (JAK) inhibitors as pre- and posttransplant therapy in MF