Elevated erythroferrone distinguishes erythrocytosis with inherited defects in oxygen-sensing pathway from primary familial and congenital polycythaemia.

Congenital erythrocytoses represent a heterogenous group of rare defects of erythropoiesis characterized by elevated erythrocyte mass. We performed molecular-genetic analysis of 21 Czech patients with congenital erythrocytosis and assessed the mutual link between chronic erythrocyte overproduction and iron homoeostasis. Causative mutations in erythropoietin receptor (EPOR), hypoxia-inducible factor 2 alpha (HIF2A) or Von Hippel-Lindau (VHL) genes were detected in nine patients, including a novel p.A421Cfs*4 EPOR and a homozygous intronic c.340+770T>C VHL mutation. The association and possible cooperation of five identified missense germline EPOR or Janus kinase 2 (JAK2) variants with other genetic/non-genetic factors in erythrocytosis manifestation may involve variants of Piezo-type mechanosensitive ion channel component 1 (PIEZO1) or Ten-eleven translocation 2 (TET2), but this requires further research. In two families, hepcidin levels appeared to prevent or promote phenotypic expression of the disease. No major contribution of heterozygous haemochromatosis gene (HFE) mutations to the erythrocytic phenotype or hepcidin levels was observed in our cohort. VHL- and HIF2A-mutant erythrocytosis showed increased erythroferrone and suppressed hepcidin, whereas no overproduction of erythroferrone was detected in other patients regardless of molecular defect, age or therapy. Understanding the interplay between iron metabolism and erythropoiesis in different subgroups of congenital erythrocytosis may improve current treatment options.

Increased blood reactive oxygen species and hepcidin in obstructive sleep apnea precludes expected erythrocytosis.

Obstructive sleep apnea (OSA) causes intermittent hypoxia during sleep. Hypoxia predictably initiates an increase in the blood hemoglobin concentration (Hb); yet in our analysis of 527 patients with OSA, >98% did not have an elevated Hb. To understand why patients with OSA do not develop secondary erythrocytosis due to intermittent hypoxia, we first hypothesized that erythrocytosis occurs in these patients, but is masked by a concomitant increase in plasma volume. However, we excluded that explanation by finding that the red cell mass was normal (measured by radionuclide labeling of erythrocytes and carbon monoxide inhalation). We next studied 45 patients with OSA before and after applying continuous positive airway pressure (CPAP). We found accelerated erythropoiesis in these patients (increased erythropoietin and reticulocytosis), but it was offset by neocytolysis (lysis of erythrocytes newly generated in hypoxia upon return to normoxia). Parameters of neocytolysis included increased reactive oxygen species from expanded reticulocytes' mitochondria. The antioxidant catalase was also downregulated in these cells from hypoxia-stimulated microRNA-21. In addition, inflammation-induced hepcidin limited iron availability for erythropoiesis. After CPAP, some of these intermediaries diminished but Hb did not change. We conclude that in OSA, the absence of significant increase in red cell mass is integral to the pathogenesis, and results from hemolysis via neocytolysis combined with inflammation-mediated suppression of erythropoiesis.

Hemoglobinopathies.

This article summarize molecular-genetic basis of hemoglobinopathies, their classification and phenotypic manifestations. The description of individual subgroups is supplemented with a case reports of patients diagnosed in the Czech population. This paper provides an overview of 14 types of α-thalassemic mutations, 34 ß-thalassemic alleles, 4 δß-thalassemic alleles and 22 hemoglobin variants identified in the Czech population in 876 persons from 579 families. In more detail are described hemoglobinopathies, that have been diagnosed and described as novel: ß-thalassemic mutation CD 38/39 (-C); Hb Olomouc; Hb Hana; Hb Hradec Kralove and 18.3 kb deletion downstream of α-globin cluster leading to a new mechanism of α-thalassemia-2. The fact that until the end of 2017 hemoglobinopathies were diagnosed in nearly 900 patients shows that they are not rare in the Czech Republic. This brings increased demands for their diagnostics, including prenatal diagnosis. Key words: hemoglobinopathies - hemoglobinopathy with high affinity to oxygen - sickle cell anemia - thalassemia - thalassemic hemoglobinopathy - unstable hemoglobins.

Molecular Characterization of ß-Thalassemia in the Czech and Slovak Populations: Mediterranean, Asian and Unique Mutations.

ß-Thalassemia (ß-thal) is considered rare in Central Europe. As in other malaria-free regions, the presence of ß-thal in Central Europe reflects historical and recent immigration, and demographic changes that have influenced the genetic variability of the current populations living in this area. This study assesses the frequency and spectrum of mutations on the ß-globin gene in Czech and Slovak subjects with clinical symptoms of thalassemia. The results of the initial part of this research were published more than two decades ago; the aim of this study was to update these original reports. During the period from 2002 to 2015, 400 cases from Czech and Slovak hematological centers were analyzed. Twenty-nine ß-thal mutations, identified in 356 heterozygotes from 218 unrelated families, involve five unique mutations including a recently described insertion of a transposable L1 element into the ß-globin gene. One mutation described here is reported for the first time. Most of the mutations were of Mediterranean origin and accounted for 82.0% of cases. All but one case studied were heterozygous carriers, manifesting ß-thal minor, with rare exceptions represented by the rare (ß(0)) codons 46/47 (+G) (HBB: c.142_142dupG) mutation associated with an α-globin gene quadruplication and by dominantly inherited ß-thal with a more severe phenotype. One double heterozygous ß-thal patient was a recent immigrant from Moldavia. The list of δß-thal alleles (26 carriers, 16 families) contains Hb Lepore and two types of δß(0)-thal deletions. In the past, genetic drift and migration as well as recent immigrations were responsible for the introduction of Mediterranean alleles, while several mutations described in single families were of local origin.

Iron status in patients with pyruvate kinase deficiency: neonatal hyperferritinaemia associated with a novel frameshift deletion in the PKLR gene (p.Arg518fs), and low hepcidin to ferritin ratios.

Pyruvate kinase (PK) deficiency is an iron-loading anaemia characterized by chronic haemolysis, ineffective erythropoiesis and a requirement for blood transfusion in most cases. We studied 11 patients from 10 unrelated families and found nine different disease-causing PKLR mutations. Two of these mutations - the point mutation c.878A>T (p.Asp293Val) and the frameshift deletion c.1553delG (p.(Arg518Leufs*12)) - have not been previously described in the literature. This frameshift deletion was associated with an unusually severe phenotype involving neonatal hyperferritinaemia that is not typical of PK deficiency. No disease-causing mutations in genes associated with haemochromatosis could be found. Inappropriately low levels of hepcidin with respect to iron loading were detected in all PK-deficient patients with increased ferritin, confirming the predominant effect of accelerated erythropoiesis on hepcidin production. Although the levels of a putative hepcidin suppressor, growth differentiation factor-15, were increased in PK-deficient patients, no negative correlation with hepcidin was found. This result indicates the existence of another as-yet unidentified erythroid regulator of hepcidin synthesis in PK deficiency.

ß-Thalassemia due to intronic LINE-1 insertion in the ß-globin gene (HBB): molecular mechanisms underlying reduced transcript levels of the ß-globin(L1) allele.

We describe the molecular etiology of ß(+)-thalassemia that is caused by the insertion of the full-length transposable element LINE-1 (L1) into the intron-2 of the ß-globin gene (HBB). The transcript level of the affected ß-globin gene was severely reduced. The remaining transcripts consisted of full-length, correctly processed ß-globin mRNA and a minute amount of three aberrantly spliced transcripts with a decreased half-life due to activation of the nonsense-mediated decay pathway. The lower steady-state amount of mRNA produced by the ß-globin(L1) allele also resulted from a reduced rate of transcription and decreased production of full-length ß-globin primary transcripts. The promoter and enhancer sequences of the ß-globin(L1) allele were hypermethylated; however, treatment with a demethylating agent did not restore the impaired transcription. A histone deacetylase inhibitor partially reactivated the ß-globin(L1) transcription despite permanent ß-globin(L1) promoter CpG methylation. This result indicates that the decreased rate of transcription from the ß-globin(L1) allele is associated with an altered chromatin structure. Therefore, the molecular defect caused by intronic L1 insertion in the ß-globin gene represents a novel etiology of ß-thalassemia.

Current survival measures reliably reflect modern sequential treatment in CML: correlation with prognostic stratifications.

Using the data of 723 chronic myeloid leukemia (CML) patients in the chronic phase, we analyzed the prognostic value of the Sokal, Euro, and EUTOS scores as well as the level of BCR-ABL1 and the achievement of complete cytogenetic response (CCgR) at 3 months of imatinib therapy in relation to the so-called current survival measures: the current cumulative incidence (CCI) reflecting the probability of being alive and in CCgR after starting imatinib therapy; the current leukemia-free survival (CLFS) reflecting the probability of being alive and in CCgR after achieving the first CCgR; and the overall survival. The greatest difference between the CCI curves at 5 years after initiating imatinib therapy was observed for the BCR-ABL1 transcripts at 3 months. The 5-year CCI was 94.3% in patients with BCR-ABL1 transcripts ≤ 10% and 57.1% in patients with BCR-ABL1 transcripts > 10% (P = 0.005). Therefore, the examination of BCR-ABL1 transcripts at 3 months may help in early identification of patients who are likely to perform poorly with imatinib. On the other hand, CLFS was not significantly affected by the considered stratifications. In conclusion, our results indicate that once the CCgR is achieved, the prognosis is good irrespective of the starting prognostic risks.

Infectious complications of induction treatment for acute myeloid leukaemia using the "7 + 3" protocol without antibiotic prophylaxis - 15 years of experience of one clinical site.

BACKGROUND: Infectious complications during induction chemotherapy of acute myeloid leukaemia are very common. Prophylactic use of antibiotics however is an ongoing challenge in this situation due to bacterial multi-drug resistance. The aim of this study was to provide a comprehensive overview of the incidence of infectious complications in patients with AML undergoing induction therapy using the "7+3" protocol without routine antibiotic prophylaxis at one clinical site providing specialised haematological care in the Czech Republic, over a period of 15 years. The study also evaluates the aetiological spectrum of causative agents and the development of antibiotic resistance in the context of the use of the various classes of antibiotics. The analysis includes evaluation of the importance of risk factors for infectious complications and their impact on treatment of the underlying disease. The data are compared with published figures for similar cohorts of patients. PATIENTS AND METHODS: This study presents a retrospective analysis of infectious complications in 242 patients with acute myeloid leukaemia undergoing the first cycle of induction therapy without routine antibiotic prophylaxis in one clinical site in Czech Republic during years 2006-2020. RESULTS: A total of 363 febrile episodes (FE) were recorded. At least 1 FE during the induction was detected in 229 (94.6%) patients. Clinically defined infection was the cause in 96 (26.4%) FEs and blood stream infection in 69 (19.0%) FEs. Both complications occurred simultaneously in 29 (8.0%) FEs. 169 (46.6%) FEs were evaluated as fever of unknown origin (FUO). The achievement of complete remission had a significant effect on the duration of the FE (6 vs. 9 days, P=0.0005) and on the overall survival duration (79.3 vs. 6.5 months, P<0.0001). Patients diagnosed with infection or FUO at diagnosis were significantly more likely to suffer from colonisation by multi-drug resistant bacterial strains at discharge (29.2% vs. 16.3%, P=0.022). This group of patients used antibiotic therapy for a significantly longer time (35 vs. 23 days, P<0.0001). Infection was a contributing cause of death in 18 (7.4%) patients. Mortality was significantly related to the failure to achieve complete remission (P<0.0001). CONCLUSION: Infectious mortality during induction treatment without routine antibiotic prophylaxis was comparable to the published cohorts with prophylaxis. Regular microbiology surveillance with adequate initial antibiotic treatment can compensate routine antibiotic prophylaxis with slower development of antibiotic resistance.

Value of infliximab (Remicade®) in patients with low-risk myelodysplastic syndrome: final results of a randomized phase II trial (EORTC trial 06023) of the EORTC Leukemia Group.

Tumor-necrosis factor alpha activity has been correlated to ineffective erythropoiesis in lower risk myelodysplastic syndromes. Infliximab (Remicade(®)) is an anti-tumor necrosis factor alpha chimeric antibody that is used in the treatment of patients with rheumatoid arthritis or Crohn's disease. Forty-six patients with myelodysplastic syndromes and a relatively low risk of developing acute leukemia were included in a randomized phase II study assessing the therapeutic activity of two dosages of infliximab administration (3 mg/kg vs. 5 mg/kg). The primary end point was the response rate. Responses were observed in 3 of 22 patients (13.1%) randomized to the 3 mg/kg arm, versus 0 of 21 patients randomized in the 5 mg/kg arm. According to the statistical design of the current study, neither of the two infliximab dose schedules tested showed sufficient activity as a single agent in this cohort of unselected patients with early myelodysplastic syndrome.

Imatinib trough plasma levels do not correlate with the response to therapy in patients with chronic myeloid leukemia in routine clinical setting.

Association of trough imatinib plasma levels (IPL) with cytogenetic or molecular response to treatment in patients with chronic myeloid leukemia (CML) was repeatedly reported. We analyzed their value in the routine clinical setting in 131 patients with chronic phase CML in whom imatinib was applied as first- or second-line treatment. A total of 1,118 measurements were obtained by ultra-performance liquid chromatography-tandem mass spectrometry assay in patients treated with daily dose of imatinib ranging from 100 to 800 mg. Samples were obtained from 1 to 96 h after drug ingestion. High inter (36%) and intraindividual variability (9-33%) of IPL was observed. For analysis of correlation of IPL with treatment response, two sets of samples were selected according to the European LeukemiaNet (ELN) criteria. The first set consisted of 241 samples taken 24 ± 2 h after dosing in 54 patients, and the second one consisted of 329 samples taken 24 ± 4 h after imatinib ingestion in 84 patients. In both sets, only patients treated with 400 mg imatinib once daily for at least 18 months were included. From multiple measurements in individual patients, mean IPL were used. In both sets, we were not able to demonstrate a statistically significant correlation between IPL and response to treatment according to the ELN. We believe that this was due to the differences in patients' compliance, leukemia biology, and other variables that are difficult to eliminate in the routine clinical practice. The use of IPL for prognostic estimation in CML treatment outside the clinical trials is probably limited.

Standardised uptake value of 18F-FDG on staging PET/CT in newly diagnosed patients with different subtypes of non-Hodgkin's lymphoma.

OBJECTIVES: Positron emission tomography using 2-[fluorine-18]-fluoro-2-deoxy-D-glucose ((18) F-FDG) is considered to be the most beneficial imaging method for staging patients with non-Hodgkin's lymphoma (NHL). The intensity of (18) F-FDG accumulation may be determined by calculating the so-called standardised uptake value (SUV). The study aimed at assessing the benefit of SUV(max) determination in staging (18) F-FDG PET/CT in untreated patients with NHL. METHODS: One hundred and forty-nine initial staging (18) F-FDG PET/CT scans performed in patients with NHL between January 2007 and August 2009 were assessed, and the SUV(max) was determined. RESULTS: The highest mean and median values of SUV(max) were observed in patients with diffuse large B-cell lymphoma (DLBCL), the lowest mean and median values were found in small lymphocytic lymphoma. The overlap in SUV(max) < 10 between DLBCL and the other subgroups of NHL was very significant. Statistically, no correlation was found between the lactate dehydrogenase and SUV(max) values. On the other hand, a correlation of the Ki-67 proliferative index of tumour cells and SUV(max) was revealed (r = 0.409, P < 0.001). The geometric mean of SUV(max) in patients with Ki-67 ≤ 60 and those with Ki-67 > 60 was 8.8 and 14.3, respectively (P < 0.001). CONCLUSIONS: The results confirm that SUV(max) is not beneficial for making a more precise diagnosis in most patients with NHL. Correlation of SUV(max) with the Ki-67 values suggests that SUV(max) might have a prognostic values in NHL.

Treatment of consecutive patients with chronic myeloid leukaemia in the cooperating centres from the Czech Republic and the whole of Slovakia after 2000--a report from the population-based CAMELIA Registry.

BACKGROUND: Most results on the treatment of chronic myeloid leukaemia (CML) with imatinib were obtained from clinical trials that may differ from the routine practice. We report the results of treatment of consecutive patients with CML at ten major centres during 2000-2008. PATIENTS AND METHODS: Data reporting was retrospective in 2000-2004 and prospective from 2005 on. A total of 661 patients [301 women and 360 men; median age 51 (range, 15-83)] with Ph+CML were registered. The median follow-up was 46.1 months (0-122.2). RESULTS: Most patients were treated with first- (379; 57.3%) or second-line (193; 29.2%) imatinib; some of the patients underwent allogeneic hematopoietic stem cell transplantation (AHSCT) (83; 12.6%), but 6.1% were treated with other modalities [40 patients; median age 66 (range, 32-83)]. The probability of overall survival (OS) at 5 years, according to Kaplan and Meier, was 88.9%, 77.5% and 68.7% for chronic-phase patients treated with first-line imatinib, second-line imatinib and first-line AHSCT, respectively, but only 25.2% for patients receiving other modalities. The OS was dependent on the disease phase and Sokal, Hasford and European group for blood and marrow transplantation (EBMT) risk scores (P<0.001; each). Only 46.2% of deaths in patients treated with other modalities were attributable to CML. Elderly patients over 65 years achieved similar response rates and progression-free survival to the younger ones. There was a trend for inferior results of AHSCT performed after the failure of imatinib (P=0.075), probably as a result of differences in EBMT risk scores (P<0.001). CONCLUSIONS: The ability to achieve results comparable to those of previous clinical studies in our CML cohort was influenced by centralised care. Decisions not to initiate imatinib or to delay AHSCT may have a negative impact on OS, but comorbidities may limit the treatment potential of imatinib in the elderly.

The role of new technologies in myeloproliferative neoplasms: Application of next-generation sequencing in myelofibrosis.

INTRODUCTION: Driver mutations in Philadelphia chromosome-negative myeloproliferative neoplasms are well known. In the past, whole-genome sequencing identified nondriver mutations in other genes, potentially contributing to evolution of malignant clones. METHODS: Next-generation sequencing was used to assess the presence of any mutations in 14 candidate genes at the point of diagnosis and the resultant impact on the clinical course of the disease. RESULTS: The study analysed 63 patients with myelofibrosis (MF). Nondriver mutations were detected in 44% of them. The most frequently affected genes were ASXL1 (27%), TET2 (11%) and SF3B1 (6%). The frequency of such mutations was highest in primary MF (59%) and lowest in the prefibrotic phase of primary MF (21%). Patients with prognostically unfavourable sequence variants in genes had significantly worse overall survival (53 vs 71 months; HR = 2.77; 95% CI 1.17-6.56; P = .017). CONCLUSION: In our study, multivariate analysis proved DIPSS to be the only significant factor to predict patient survival. DIPSS contains all of the important clinical and laboratory factors except genetic changes. Stratification of patients according to DIPSS is still beneficial although there are newer and improved scoring systems like GIPSS or MIPSS70. Assessing subclonal mutations in candidate genes during diagnosis may aid in the identification of high-risk MF patients and is therefore relevant for making a prediction for overall survival more accurate.

Outcome of HLA-matched related allogeneic hematopoietic stem cell transplantation for patients with acute leukemia in first complete remission treated in Eastern European centers. Better results in recent years.

The goal of this study was to analyze results and to determine factors affecting outcome of HLA-matched hematopoetic stem cells transplantation (MRD-HSCT) for patients with acute leukemia transplanted in first complete remission in Eastern European countries. Six hundred forty HSCT were performed between 1990 and 2006 for adults with acute myeloid (n = 459) and lymphoblastic (n = 181) leukemia. Two-year leukemia-free survival (LFS), nonrelapse mortality (NRM), and relapse incidence were 58 +/- 2%, 19 +/- 2%, and 23 +/- 2%, respectively. The cumulative incidence of NRM decreased from 22 +/- 2% for patients treated between 1990 and 2002 to 15 +/- 3% for transplantations performed between 2003 and 2006 (p = 0.02), despite increasing recipient age. In a multivariate analysis, time of HSCT affected both NRM and LFS. Among other prognostic factors, the use of TBI decreased relapse incidence and increased the LFS rate. We conclude that results of MRD-HSCT for acute leukemia in Eastern Europe improved over time as a consequence of decreased NRM. The use of TBI containing regimens appears advantagous.

Precursor T-lymphoblastic lymphoma as a secondary malignancy in a young patient after successful treatment of acute promyelocytic leukemia.

BACKGROUND: Acute promyelocytic leukemia (APL) is a relatively rare subtype of acute myeloid leukemia. It has become the best curable subtype of acute leukemias in adults due to the inclusion of all-trans-retinoic acid (ATRA) in the treatment. Despite the efficacy of ATRA, chemotherapy must be added in APL patients in order to maintain durable complete remission. However, chemotherapy administration is inevitably related to many complications, including the risk of secondary malignancies. T-lymphoblastic lymphoma (T-LBL) is an infrequent disease that belongs to the group of highly aggressive lymphomas. CASE REPORT: The authors describe the case of a 25-year-old woman who was treated for APL in 2002 and developed precursor T-LBL 5 years later. CONCLUSION: Several cases of secondary acute lymphoblastic leukemias in 'cured' APL patients have been described, but probably no patient with secondary precursor T-LBL. Secondary malignancy has become one of the topics discussed (not only) in APL patients. It is apparently related to the excellent treatment outcomes and long-term survival. Better tailored treatment based on relevant prognostic factors allowing chemotherapy reduction or omission in some patients is needed.

Prevalence and spread of pseudomonas aeruginosa and Klebsiella pneumoniae strains in patients with hematological malignancies.

The aim of the study was to determine the prevalence of Pseudomonas aeruginosa and Klebsiella pneumoniae strains in patients with acute leukemias, to assess their clinical significance, and to define the sources and ways of their spread using genetic analysis. Thirty-four patients were investigated during the observed period. Twenty-one strains of Pseudomonas aeruginosa and 35 strains of Klebsiella pneumoniae were isolated from patient samples. In the case of Pseudomonas aeruginosa, 47.6% of strains were identified as pathogens and caused infection. By contrast, only 4 isolates (11.4%) of Klebsiella pneumoniae could be regarded as etiological agents of bacterial infection. Based on the obtained results, Klebsiella pneumoniae strains are assumed to be of mostly endogenous origin. In the case of Pseudomonas aeruginosa strains, the proportion of identical strains detected in various patients was higher and exogenous sources were more significant. In addition, our results confirmed the ability of Pseudomonas aeruginosa strains to survive on a particular site in the hospital for a longer time.

Granulocyte transfusions collected after steroid priming for severe infections during neutropenia: A single center experience.

BACKGROUND: There is no universally accepted opinion on the use of granulocyte transfusions collected using apheresis (GTA) in neutropenic patients and severe infection. PATIENTS AND METHODS: The efficacy and safety of GTAs transfused at a single center over 10 years were analyzed retrospectively. GTAs were harvested from voluntary unrelated donors after priming with methylprednisolone using continuous apheresis and hydroxyethylstarch as sedimentation agent. RESULTS: 41 patients with neutropenia and hematologic malignancy (15 females and 26 males aged 22-69 (median 45.5)) were given a median 3.5 GTAs per patient (range: 1-17) containing a median 1.39×1010 granulocyte/GTA (range: 0.65-2.81). The indications for GTA use were soft tissue inflammation, sepsis, and pneumonia in 30, 22, and 14 cases, respectively. After GTA complete (30 patients: 73.2%) or partial (6 patients: 14.6%) healing of the infection was achieved. The success rate was 91.7% in soft tissue infections, 66.7% in invasive fungal infections, and 68% in sepsis. Septic shock (documented in 12 cases) was associated with a poor response (P<0.03; Chi-square test). Clinical worsening was observed in six cases (14.6%); four patients died. No significant short-term side effects of GTA treatment were recorded. CONCLUSIONS: In our study GTAs collected after steroid priming and used for the treatment of infection during severe neutropenia have shown comparable efficacy with several previously reported trials. However retrospective fashion of our study and inhomogeneous group of patients do not allow any firm conclusions. Prospective studies (including patients' registries) are needed for the better clarification of the role and the dose of GTAs necessary for the successful infection management during neutropenia.

First-line imatinib in elderly patients with chronic myeloid leukaemia from the CAMELIA registry: Age and dose still matter.

We retrospectively evaluated the role of age and dosage in 372 CML patients (170 women, 202 men) treated with first-line imatinib (IMA) from the records of the CAMELIA registry. The median follow-up of the patients was 82.3 (18.0-177.3) months. The treatment results of 80 elderly patients aged over 65 years at diagnosis were compared in analysis "A" with those of 292 younger patients and in analysis "B" with those of 90 patients younger than 40 and 202 patients aged 40-64. The elderly patients had statistically adverse values of the Sokal, ELTS, and ECOG scores and Charlson comorbidity index in both analyses (p from = 0.012 to ≤ 0.001). Despite a more frequent use of a daily dose lower than 400 mg - in 31 elderly patients (38.8%) than in 45 younger ones (15.4%) (p < 0.001), there were no statistically significant differences in the achievement of optimal haematological, cytogenetic, and molecular responses according to the ELN criteria in both the analyses, A and B. The comparisons of overall survival with CML-related death (OSCML) and event-free survival (EFS) were insignificant inanalysis A (p = 0.07 and 0.396, respectively) but progression-free survival (PFS) differed significantly (p = 0.007). In analysis B OSCML and PFS differed significantly (p = 0.027 and 0.003) but EFS was similar (p = 0.351). Elderly patients with a sustained dose of IMA of 400 mg/day have insignificantly better OS, PFS, and EFS compared to patients treated with a lower dosage of IMA. The results in the treatment of the elderly CML patients were comparable with those of the younger ones in terms of the probabilities of the achievement of optimal ELN responses. However, the results for the survival probabilities were influenced by age and the IMA dosage.