[Withdrawal syndrome after tyrosine kinase inhibitors discontinuation in patients with chronic myeloid leukemia].

BACKGROUND: Withdrawal syndrome (WS) a musculoskeletal pain after discontinuation of tyrosine kinase inhibitors (TKI) in patients with chronic myeloid leukemia (CML) has been described in the treatment-free remission (TFR) studies. The pathophysiological mechanisms and predisposing factors of WS have not been well established. AIM: Our aim was to evaluate clinical features and factors associated with WS in the Russian cohort of CML patients who discontinued TKI therapy. MATERIALS AND METHODS: WS was evaluated in total of 183 CML patients with chronic phase and sustained deep molecular response (DMR). WS was defined as a musculoskeletal pain newly observed after TKI cessation or as a worsening of previously observed symptoms. RESULTS: DMR loss free survival at 36 months was 49% and 43% in prospective and retrospective groups respectively (p=0.96) with mеdian (Me) time of observation 33 months (range 1136). WS was observed in 49 (27%) patients: grade 12 was in 45 (92%) patients, grade 3 in 4 (8%) patients. Me time to WS occurrence was 2 months (range 17), Ме duration of WS was 5 months (range 135). WS was resolved in 14 of 15 patients with molecular relapse after 13 months of TKI re-initiation and was decreased in 1 patient. WS was completely resolved in 31 of 34 patients who continued remained in TFR and decreased in 3 patients. WS was resolved spontaneously or with nonsteroidal anti-inflammatory drugs in 14 (45%) and 17 (55%) patients accordingly. Older age (p0.0001), longer duration of TKI therapy (p0.0001) and presence of locomotion system diseases (p=0.022) were observed in patients with WS. No WS was observed in pregnant patients (р0.001). Survival without DMR loss at 12 months after TKI stop was 66 and 42% in patients with and without WS accordingly (р=0.095). CONCLUSION: The rate of WS was 27% that is in a good concordance with the data of the other TFR studies. A longer period of TKI exposure, older age and the history of locomotion system diseases were associated with the development of the WS. We found for the first time that WS was not observed in patients with pregnancy. There was no association of WS development and the rate of molecular relapses.

Changes in Bone Marrow Stromal Progenitor Cells in Patients with Hematoblastosis at the Onset of the Disease.

Multipotent mesenchymal stromal cells (MSC) are the key regulators of hematopoiesis. We studied changes in MSC characteristics in patients with myeloid leukemia and patients with lymphoproliferative diseases. MSC were obtained from the bone marrow of patients at the time of diagnostic puncture using a standard technique. Their proliferative potential and expression of genes associated with differentiation and regulation of hematopoiesis were studied. The total cell production of MSC in patients with leukemia at the onset of the disease did not differ from that in the group of healthy donors. The relative expression of the IL6, TGFb1 and TGFb2, PPARG genes was similar in all patients. The relative expression of the JAG1, LIF, IGF1, CSF1, IL1b, and IL1bR1 genes in MSC of patients with leukemia was enhanced and the relative expression of SDF1 was unchanged in comparison with MSC from donors. MSC from patients with leukemia were characterized by enhanced relative expression of PDGFRA and PDGFRB, and reduced expression of SOX9. Changes functions of the stromal microenvironment in patients with hemoblastoses attested to the role of stromal cells in the maintenance and spread of tumor cells.

[Successful use of long-term follow-up in patients with chronic myeloid leukemia with a deep molecular response at reduced doses of 2nd generation tyrosine kinase inhibitors: clinical cases and literature review].

Therapy with tyrosine kinase inhibitors (TKI) allows to achieve a deep molecular response in 6070% of patients with chronic myeloid leukemia (CML). According to the current guidelines CML patients receive a long-term treatment with TKI in standard dose. The frequently observed adverse effects (AE) of TKI therapy are mostly dose-dependent. A new treatment approach with TKI use in reduced dose is desirable for the CML patients with existing AE or with a high risk of AE occurrence. We report the two cases of successful long-term treatment of CML patients with reduced doses of second generation TKIs. The aim of the TKI dose reduction was to reduce the clinical manifestations of drug toxicities and to prevent the AE.

Multipotent Mesenchymal Stromal Cells in Patients with Chronic Myeloid Leukemia before Discontinuation of Tyrosine Kinase Inhibitors.

We analyzed changes in multipotent mesenchymal stromal cells of patients with chronic myeloid leukemia before discontinuation of tyrosine kinase inhibitors. Withdrawal syndrome was significantly more common in patients who have been taking tyrosine kinase inhibitors for a longer time and in patients of older age and with lower body weight. In patients with withdrawal syndrome, the total production of mesenchymal stromal cells and expression of FGFR2 and MMP2 genes were significantly lower; loss of deep molecular response was also less frequent in this group of patients. At the same time, the expression of genes important for the maintenance of stem cells (SOX9, PDGFRa, and LIF) was significantly lower in the mesenchymal stromal cells of patients with withdrawal syndrome and loss of deep molecular response. We observed a clear-cut relationship between the development of withdrawal syndrome and the loss of deep molecular response. The decrease in the expression of FGFR2 and MMP2 genes in the mesenchymal stromal cells of patients with chronic myeloid leukemia before discontinuation of treatment can be a predictor of withdrawal syndrome, while simultaneous decrease in the expression of SOX9, PDGFRa, and LIF in these cells attests to undesirability of therapy discontinuation at the moment.

[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.

[A rare case of myeloproliferative disease with t(8;13)(p11;q12) associated with eosinophilia and lymphadenopathy]. / Redkii sluchai mieloproliferativnogo zabolevaniya s t(8;13)(p11;q12), protekayushchego s eozinofiliei i limfadenopatiei.

Myeloproliferative disease associated with FGFR1 rearrangement (8p11), which is included in the 2008 WHO Classification of Myeloid Neoplasms, is a rare and extremely aggressive abnormality. The paper describes a clinical case of a 39-year-old female patient who was detected to have leukocytosis (as high as 47.2·109/l), absolute eosinophilia (as high as 3.1·109/l), and enlarged peripheral lymph nodes during her visit to a doctor. The bone marrow (BM) showed the changes typically encountered in myeloproliferative disease with eosinophilia. The patient was found to have t(8;13)(p11;q12) translocation associated with the rearrangement of the FGFR1 gene located at the 8p11 locus. Molecular and cytogenetic examinations failed to reveal BCR-ABL chimeric transcript, Jak2 V617F mutation, and deletions and translocations involving PDGFRA (4q12) and PDGFRB (5q32-33). The similar changes in the karyotype were also found in the lymph node cells. The undertaken treatment with hydroxyurea and the tyrosine kinase inhibitor dasatinib turned out to be ineffective. The patient underwent allogeneic BM transplantation from a HLA-identical sibling. Graft rejection occurred 6 months later. Allogeneic BM transplantation from the same donor (100% donor chimerism; FGFR1/8р11 translocation was not detected), which was complicated by the development of chronic graft-versus-host reaction, was performed again in March 2015. The patient is being followed up and continues to receive immunosuppressive therapy.

[Efficiency of interferon therapy in patients with essential thrombocythemia or polycythemia vera]. / Effektivnost' interferonoterapii u bol'nykh essentsial'noi trombotsitemiei i istinnoi politsitemiei.

AIM: To evaluate the efficiency of interferon (IFN) therapy in patients with essential thrombocythemia (ET) and polycythemia vera (PV). SUBJECTS AND METHODS: A total of 61 patients (41 with ET and 20 with PV) were examined. Prior to study enrolment, 44 (72%) patients with ET or PV received one or other therapy (aspirin was not taken into account). The mean Jak2V617F mutant allele at baseline was 23% (6-54%) in the patients with ET and 40% (11-88%) in those with PV. The median time from diagnosis to enrollment was 49 months. RESULTS: The paper presents the clinical and molecular findings of long-term INF-α therapy in patients with ET or PV. The median follow-up was 52 months. Recombinant IFN-α2 showed its ability to induce complete hematologic remission (ET (76%), PV (70%)) and a complete molecular response. 22 (69%) out of 32 patients were noted to have a smaller number of cells with the Jak2V617F mutation. In the patients with PV and in those with ET, the relative reduction in the proportion of cells with the Jak2V617F mutant gene averaged 85% and 56% of the baseline values, respectively. There was a reduction in the proportion of cells expressing the Jak2V617F mutation in both the ET (from 12 to 2.2%; p=0.001) and PV (from 32.7% to 3.2%) groups (р=0.001). Ten (31%) patients achieved a deep molecular remission (≤2% Jak2V617F allele); among them, 5 patients were not found to have Jak2V617F mutation. The obtained molecular response remained in 7 of the 10 patients untreated for 11 to 86 months. The long-term treatment with IFN-α led to normalization of the morphological pattern of bone marrow in 5 of the 7 PV or ET patients. CONCLUSION: Significant molecular remissions achieved by therapy with recombinant interferon-α2 confirm the appropriateness of this treatment option in in the majority of patients with ET or PV.

The EUTOS population-based registry: incidence and clinical characteristics of 2904 CML patients in 20 European Countries.

This population-based registry was designed to provide robust and updated information on the characteristics and the epidemiology of chronic myeloid leukemia (CML). All cases of newly diagnosed Philadelphia positive, BCR-ABL1+ CML that occurred in a sample of 92.5 million adults living in 20 European countries, were registered over a median period of 39 months. 94.3% of the 2904 CML patients were diagnosed in chronic phase (CP). Median age was 56 years. 55.5% of patients had comorbidities, mainly cardiovascular (41.9%). High-risk patients were 24.7% by Sokal, 10.8% by EURO, and 11.8% by EUTOS risk scores. The raw incidence increased with age from 0.39/100,000/year in people 20-29 years old to 1.52 in those >70 years old, and showed a maximum of 1.39 in Italy and a minimum of 0.69 in Poland (all countries together: 0.99). The proportion of Sokal and Euro score high-risk patients seen in many countries indicates that trial patients were not a positive selection. Thus from a clinical point of view the results of most trials can be generalized to most countries. The incidences observed among European countries did not differ substantially. The estimated number of new CML cases per year in Europe is about 6370.

[FIP1L1-PDGFRА-positive myeloproliferative disease with eosinophilia: A rare case with multiple organ dysfunction and a response to tyrosine kinase inhibitor therapy].

The described case of FIP1L1-PDGFRА-positive myeloproliferative disease is characterized by an atypical aggressive course to develop severe specific complications as injuries to the brain, heart, lung, and intestine. Pathogenetic therapy with imatinib could stabilize a patient's state, but failed to produce a complete hematological response. Switching from imatinib to dasatinib could produce sustained clinical, hematological, and molecular remissions.

[Incidence of chronic myeloid leukemia in 6 regions of Russia according to the data of the 2009-2012 population-based study].

AIM: To assess the main epidemiological characteristics of chronic myeloid leukemia (CML) in the Russian Federation. SUBJECTS AND METHODS: A planned epidemiological prospective study was conducted in 2009-2012 in 6 Russian regions with the total number of 10.1 million inhabitants, which notified all new CML cases. RESULTS: The unstandardized (unnormalized, baseline) recorded incidence of CML in the examined regions was 0.58 per 100,000 annually. Its standardized (normalized) incidence was 0.70 for the WHO standard population and 0.72 for the European standard population. The regional variations in the incidence were 0.44 to 0.69. The structural analysis of the incidence in the age strata indicated that the overall morbidity was less due to the decreased rate of registration in old age groups. The morbidity rates in patients aged less than 60 years were nearly similar to the European rates; those in patients aged over 70 years were almost 10 times lower. The lower rate of detection and screening diagnosis of CML in pensioners in primary health care is discussed. CONCLUSION: The data obtained in this study may serve as the starting point for monitoring the CML epidemiological situation.

[Synchronous and metachronous myeloid and lymphoid tumors].

AIM: To determine the clinical features of multiple primary tumors (MPT) in patients with hemoblastoses, to develop treatment policy for synchronous and metachronous tumors, and to determine the impact of chemotherapy for one disease on the course and prognosis of another one. SUBJECTS AND METHODS: The investigation included 20 patients with multiple primary synchronous and metachronous myeloid and lymphoid tumors, who had been followed up at the Outpatient Department of the Hematology Research Center, Ministry of Health of the Russian Federation. The distribution of patients by nosological entities was as follows: 17 (85%) patients with myeloproliferative diseases (MPDs) concurrent with lymphoproliferative diseases (LPDs) and 3 (15%) with two types of MPD. A special group comprised 3 patients who successively developed 3 malignant diseases: cancer/B-cell chronic lymphocytic leukemia (B-CLL)/Ph-positive chronic myeloid leukemia (Ph+CML); cancer/polycythemia vera (PCV)/B-CLL; cancer/essential thrombocythemia (ETC)/multiple myeloma (MM). RESULTS: The Outpatient Department of the Hematology Research Center, Ministry of Health of the Russian Federation, followed up 20 patients with synchronous and metachronous tumors in 1996 to 2013. The patients' age was 42 to 82 years (64 years). The female/male ratio was 1:1.2. Metachronous tumors were 1.5-fold higher than synchronous ones. The time to detection of secondary hemoblastosis averaged 3.3 years; the longest interval was 14 years; the mean coexistence of 2 tumors was 4.8 years (1-11 years). The total length of the follow-up was 8 years (1-19 years). Among them, there were 17 (85%) patients with 2 chronic hematologic tumors with a myeloid or lymphoid phenotype; 3 (15%) of the 20 patients had 3 malignant diseases (cancer/ B-CLL)/Ph+CML, cancer/PCV/B-CLL, cancer/ETC/MM. In the group of 17 patients, 13 (76%) were diagnosed as having Ph-negative MPDs (PCV in 4 patients, primary myelofibrosis in 4, ETC in 4, undifferentiated MPD in1) and 4 (24%) patients had Ph+CML. This patient group was found to have the following LPDs: CLL in 5 (30%), hairy cell leukemia in 1 (5%), paraproteinemic hemoblastoses in 11 (65%). MPD preceded LPD in 8 (47%) patients; the development interval between two tumors averaged 6 years (1 to 14 years). LPD preceded MPD in 3 (18%) patients; the interval averaged 5 years (2 to 17 years). MPD and LPD appeared synchronously in 6 (35%) patients. CONCLUSION: The fact that 2 malignancies or more may occur in one patient determines the need for a careful follow-up of patients with blood system diseases. The activity of one hematologic disease or another is a leading criterion for choosing a therapeutic tactic.

[Therapeutic strategy for chronic myeloid leukemia: possibilities and prospects].

Over the past decade the clinical introduction of agents that directionally blocks the activity of BCR-ABL tumor tyrosine kinase (TK) has changed the prognosis of chronic myeloid leukemia. A significant malignant Ph'-positive clone inhibition and durable remissions have made it possible to increase overall and relapse-free survival. Due to their higher life expectancy, the number of patients is on the increase and their quality of life and working capacity remain good. According to the All-Russian Register of Chronic Myeloid Leukemia, there were more than 6500 cases in the Russian Federation in 2012. Of them, 93.1% were diagnosed with the chronic phase of the disease, 6.4 and 0.4% with its accelerated phase and blast crisis, respectively. Among the BCR-ABL TK inhibitors (TKI) registered in the Russian Federation and recommended for the treatment of chronic myeloid leukemia, there are 3 medications: imatinib, nilotinib, and dasatinib. The efficiency and safety of TKI therapy have been well studied. The most important principle of treatment is to permanently affect the Ph'-positive tumor cell clone by the long-term daily use of TKls. Regular cytogenetic and molecular genetic monitoring allows adequate estimation of the leukemic clone volume and it is essential in evaluating the therapeutic effectiveness. To choose a TKI for each specific patient with regard for its best tolerability and maximum efficiency permits individualized treatment. The prospect of therapy discontinuation can be discussed only in individual patients with a durable and stable complete molecular response and only within clinical trials.

[A rare complication of imatinib mesylate therapy: drug-induced pneumonitis].

The use of imatinib mesylate (Glivec) (Novartis Pharma AG, Switzerland) that is the drug of choice in treating patients with chronic myeloid leukemia (CML) has increased 7-year survival and improved the prognosis of the disease. The drug is generally tolerated well; the proportion of patients in whom imatinib treatment results in the development of toxic complications is small. Drug-induced interstitial pneumonitis associated with imatinib therapy is a rare complication that requires timely differential diagnosis, discontinuation of an inductor (imatinib), and altered further treatment policy.

[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.

Cell Regulation of Proliferation and Differentiation ex vivo for Cells Containing Ph Chromosome in Chronic Myeloid Leukemia.

Cell regulation of Ph(+)cell proliferation and differentiation has been studied ex vivo in various chronic myeloid leukemia (CML) patients. The regulation is provided by alternation of effective stages of proliferation and maturation with inhibition of Ph(+) cell proliferation by accumulating neutrophils under apoptosis blockage. The alternation of stages consists of switching stage 1 (effective proliferation) to stage 2 (effective maturation) and proceeds according to the 1/2 -1/2/1 or 2/1-2/1/2/1 schemes. The kinetic plots of alternations pass through control points of crossing plots, where the parameters of proliferation and maturation are equal. The indices of P/D efficiency (ratio of proliferation and maturation rates) are 1.06±0.23 and don't depend on time, alternation order, or sources of Ph(+) cells - CML patients. During stages alternation, conversely, the parameters of Ph+ cell proliferation and maturation vary. The proliferation stages are characterized by increased proliferating cells content, a decreased number of neutrophils, and apoptosis induction. At the maturation stages, conversely, apoptosis is inhibited, the number of mature neutrophils increases, while immature Ph(+) cells decrease. High content neutrophils inhibit the proliferation of Ph(+) cells and impair their own maturation by inversion of maturation order, probably through a feedback mechanism. The regulation differences ex vivo reveal three types of Ph(+) cells from various individual CML patients, distinguished by the number and duration of alternating stages of proliferation and maturation. Ph(+) cells types 1 and 2 have one prolonged stage of effective proliferation or effective maturation with efficiency indices P/D(1) = 1-20 or P/D(2) ⇐ 1. At the same time period, the proliferation and differentiation of the Ph(+) cells type 3 proceeds with repeated alternations of stages with P/D(1) = 1-4 or P/D(2) ⇐ 1. Type 1 Ph(+) cells (~20%) were isolated from patients in advanced stages of CML, while Ph(+) cells types 2 and 3 (30 and 50% correspondingly) were isolated from CML chronic phase patients sensitive to chemotherapy.

Role of P-glycoprotein in evolution of populations of chronic myeloid leukemia cells treated with imatinib.

Imatinib mesylate (imatinib) is a new generation preparation that is now successfully used for treatment of cancer, particularly for chemotherapy of chronic myeloid leukemia (CML). Imatinib inhibits the activity of chimeric kinase BCR-ABL, which is responsible for the development of CML. The goal of this study was to investigate the role of a multidrug resistance protein, P-glycoprotein (Pgp), in the evolution of CML treated with imatinib. We demonstrate here that although imatinib is a substrate for Pgp, cultured CML cells (strain K562/i-S9), overexpressing active Pgp, do not exhibit imatinib resistance. Studies of CML patients in the accelerated phase have shown variations in the number of Pgp-positive cells (Pgp+) among individual patients treated with imatinib. During treatment of patients with imatinib for 6-12 months, the number of Pgp-positive cells significantly increased in most patients. The high number of Pgp+ cells remained in patients at least for 4.5 years and correlated with active Rhodamine 123 (Rh123) efflux. Such correlation was not found in the group of imatinib-resistant patients examined 35-60 months after onset of imatinib therapy: cells from the imatinib-resistant patients exhibited efficient Rh123 efflux irrespectively of Pgp expression. We also compared the mode of Rh123 efflux by cells from CML patients who underwent imatinib treatment for 6-24 months and the responsiveness of patients to this therapy. There were significant differences in survival of patients depending on the absence or the presence of Rh123 efflux. In addition to Pgp, patients' cells expressed other transport proteins of the ABC family. Our data suggest that treatment with imatinib causes selection of leukemic stem cells characterized by expression of Pgp and other ABC transporters.

[Recovery of polyclonial hemopoiesis in females with chronic myeloid leukemia with a complete cytogenetic response].

AIM: To study feasibility of hemopoiesis clonality determination in assessment of remission completeness in patients with chronic myeloid leukemia (CML) using polymerase chain reaction (PCR HUMARA). MATERIAL AND METHODS: We have examined 28 patients with newly diagnosed CML, 10 CML patients with a complete cytogenetic response (CCR) to therapy with imatinib mesilate and/or alpha-interferon, 24 healthy control females. Twelve patients with untreated CML were homozygous by HUMARA gene (human androgenic receptor gene) and were withdrawn from the study. Leukocytes of peripheral blood from all the patients were investigated with PCR HUMARA for mono- or polyclonal hemopoiesis. Clonality was defined as allele proportion (a/p) of polymorphic loci of HUMARA gene. Remission completeness was confirmed cytogenetically and by molecular methods. RESULTS: The value a/p in 10 patients with CCR varies from 0.69 to 1.33 and is similar to those in the control group. CONCLUSION: The PCR HUMARA technique adequately assesses reduction of Ph-positive clone in CML patients with CCR and points to polyclonal hemopoiesis.

[Prognosis factors in imatinib mesilate therapy in patients with a chronic phase of Ph-positive chronic myeloid leukemia: data from a multicenter non-randomized trial in Russia].

AIM: To reveal prognostically significant factors affecting efficacy of glivek therapy in untreated (duration of the disease < or = 6 months) and pretreated (duration of the disease > 6 months) patients with chronic myeloid leukemia (CML) in a chronic phase. MATERIAL AND METHODS: A total of 338 patients (64 untreated and 274 pretreated) with a chronic-phase CML on glivek therapy entered the trial. RESULTS: Five-year survival on glivek was high (89, 98 and 88% in untreated and pretreated patients, respectively). Incidence of transformation in the acceleration phase and blast crisis was low both in untreated and pretreated patients (1.6 and 11%, respectively) and correlated with the rate of a complete cytogenetic response (CCR). Untreated patients had no factors affecting treatment efficacy negatively, CCR probability was 96%. Blastemia, thrombocytosis and splenomegaly reduced CCR probability significantly in pretreated patients. Slow reduction of the tumor mass, late achievement of a complete hematological response and a cytogenetic response decreased probability of CCR. CONCLUSION: Glivek is a drug of choice for patients with chronic-phase CML. High probability of CCR both in untreated and pretreated patients lowers the risk of the disease transformation into the phase of acceleration/blast crisis and raises overall survival in both groups.

[Monitoring of minimal residual disease in patients with chronic myeloleukemia: clinical value of real-time polymerase chain reaction].

AIM: To quantitatively determine minimal residual disease (MRD) by real-time polymerase chain reaction (PCR) in patients with a chronic phase (CP) of chronic myeloid leukemia (CML). MATERIALS AND METHODS: A molecular response was analyzed in 53 CML CP patients with incomplete and complete cptogenetic response (ICR and CCR) during imatinib therapy (median follow-up 36 months). BCR-ABL gene type p210 expression was quantitatively determined by real-time PCR under the TaqMan technology (an ICycler IQ device). The beta2 microglobulin (beta2M) gene was used as a reference gene. The results were expressed as the ratio: the number of BCR-ABL copies to that of beta2M x 10(5), as well as the difference of the common logarithm (lg) of the baseline expression level (BEL) and the result obtained: CEL lg-result lg. RESULTS: The study revealed a correlation of the results of real-time PCR with those of cytogenetic analysis and showed it possible to study not only bone marrow, but also peripheral blood. Some negative real-time PCR results were checked using more sensitive PCR techniques. MRD was identified in most CML patients showing ICR and CCR during imatinib therapy. The reduction in BCR-ABL transcript levels by less than 2 lg (as compared to BEL) was associated with a cytogenetic recurrence and that by less than 3 lg was associated with a permanent high cytogenetic response. In patients with a cytogenetic recurrence, the median of BCR-ABL transcript levels was higher than that in patients with a permanent stable or unstable cytogenetic response. An elevation of BCR-ABL transcript levels over time antedated the development of a cytogenetic recurrence. CONCLUSION: Quantitative monitoring by real-time PCR gives additional information on the dynamics of MRD in CML patients treated with glivec and permits improvement of study protocols for patients with CML at complete clinicohematological and cytogenetic remission.