[Results of following up patients with chronic myeloid leukemia and a deep molecular response without tyrosine kinase inhibitor therapy]. / Rezul'taty nabliudeniia bol'nykh khronicheskim mieloleikozom s glubokim molekuliarnym otvetom bez terapii ingibitorami tirozinkinaz.

AIM: To assess the results of following up patients with chronic myeloid leukemia (CML) and a deep molecular response (MR) without tyrosine kinase inhibitor (TKI) therapy. SUBJECTS AND METHODS: The reasons for TKI discontinuation in 70 patients with CML and a deep MR of more than 1 year's duration were adverse events, pregnancy, and patients' decision. Information was collected retrospectively and prospectively in 2008-2016. RESULTS: The median follow-up after TKI therapy discontinuation was 23 months (2 to 100 months). At 6, 12 and 24 months after TKI therapy discontinuation, the cumulative incidence of major MR (MMR) loss was 28, 41 and 48%, respectively; the survival rates without TKI therapy were 69, 50, and 39%, respectively. MMR loss was noted in 28 (88%) patients at 12 months; it was not seen without TKI therapy at 2-year follow-up. Deaths due to CML progression were absent. The Sokal risk group was a reliable factor influencing MMR loss (p ≤ 0.05). The cumulative recovery rate for deep MR after resumption of TKI use was 73 and 100% at 12 and 24 months, respectively, with a median follow-up of 24 months (1 to 116 months). Deep MR recovered at a later time when the therapy was resumed more than 30 days after MMR loss. CONCLUSION: Safe follow-up is possible in about 50% of the patients with CML and stable deep MRs without TKI therapy. The introduction of this approach into clinical practice requires regular molecular genetic monitoring and organizational activities. Biological factors in maintaining remission after TKI discontinuation need to be separately studied.

[Trisomy of chromosome 8 in Ph-negative cells of the bone marrow in patients with chronic myeloid leukemia treated with inhibitors of BCR-ABL tyrosine kinases].

AIM: To analyse clinical implications of chromosome 8 trisomy in Ph-negative cells of the bone marrow in patients with chronic myeloid leukemia (CML) treated with inhibitors of tyrosinkinases (ITK). MATERIAL AND METHODS: A total of 386 patients with CML (chronic phase--288, acceleration phase--77) received imatinib (400-800 mg/day). Because of resistance and/or intolerance some patients were switched to ITK II (nilotinib, dasatinib, bozutinib). This study included 8 CML patients (7 in a chronic phase, 1 in acceleration phase) treated with BCR-ABL ITK inhibitors of the first (imatinib) and the second line (ITK-II). The standard cytogenetic examination, on demand--investigation of the interphase nuclei with FISH, in some cases morphological, cytochemical and histological examinations of the bone marrow were made. RESULTS: The existence of a Ph-negative clone with trisomy of chromosome 8 had no negative effect on the course of the disease. The patients showed a stable hematological and cytogenetic response and no need in changing treatment policy. In long-term follow-up Ph-negative clone with trisomy of the chromosome 8 persisted without a clear trend to rise in most patients. CONCLUSION: Detection of a Ph-negative clone with chromosome 8 trisomy at early stages suggests parallel existence of Ph-positive and Ph-negative clones. None of the patients had myelodisplasia.

[Dasatinib treatment of imatinib-resistant and imatinib-intolerant patients with chronic myeloid leukemia in a chronic phase].

AIM: To analyse resistance to imatinib therapy, efficacy and safety of dasatinib. MATERIAL AND METHODS: A total of 18 patients with chronic myeloid leukemia (CML) in a chronic stage received dasatinib for 9-30 months (median 30 months) to September 2008. RESULTS: Lethal outcomes during dasatinib treatment were absent. To September 2008, 16 (89%) patients were alive, 2 (11%) patients died of the disease progression after dasatinib discontinuation. A complete clinicohematological response was observed in all the patients. Major cytogenetic, complete cytogenetic, major molecular, complete molecular responses were achieved in 12 (67%), 10 (55%), 7 (39%) and 5 (28%) patients, respectively. Hematological and non-hematological toxicity occurred in 9 (50%) patients. Now 12 (67%) patients continue dasatinib treatment, in 6 (33%) patients the drug was discontinued. CONCLUSION: The results from trials in Russian Hematological Research Center are the same as in the international study. Dasatinib is effective and well tolerated therapeutic option for imatinib-resistant patients with a chronic phase of CML.

[Biotransformation of nitrogen-containing compounds in the process of the continuous final purification of effluents from swine-breeding farms by immobilized cells]. / Biotransformatsiia azotsoderzhashchikh soedinenii v protsesse neprepyvnoi doochistki stokov svinokompleksov immobilizovannymi kletkami.

After their two-step purification in aeration tanks, effluents from a swine-breeding farm were subjected to final purification in a flow bioreactor with immobilized cells derived from activated sludge. The dynamics of nitrogen compounds were studied at the reactor inlet and outlet at three flow rates. The use of a simple mathematical model of the nitrogen balance allowed the rates of nitrogen assimilation-mineralization two nitrification stages, and nitrogen fixation-denitrification to be estimated. The first stage of nitrification was found to proceed intensely and produce high nitrite concentrations (up to 100 mg N/l, accounting for about half of the total N at the inlet). The second nitrification stage was inhibited, and nitrate was only produced after 3-4 weeks of continuous operation. The strategy of the final purification of effluents from nitrogen compounds is discussed on the basis of the known regulatory mechanisms of microbial activities in activated sludge.