Clinical relevance of mutant NPM1 and CEBPA in patients with acute myeloid leukaemia - preliminary report.

AIM OF THE STUDY: Mutant NPM1 and CEBPA have been reported in patients with acute myeloid leukaemia (AML) and intermediate cytogenetic risk, and they appear to be associated with characteristic demographic and laboratory data, as well as clinical outcome. The objective of the study was to assess the clinical relevance of NPM1 and CEBPA mutations in AML. MATERIAL AND METHODS: This retrospective analysis was based on 60 newly diagnosed patients with AML and normal/no metaphases karyotype and known mutation status, who were treated in our centre between 2008 and 2011 according to the PALG (Polish Adult Leukaemia Group) study protocol. Pretreatment bone marrow samples were studied by G-banding analysis, and NPM1, CEBPA, and FLT3-ITD mutations were detected by polymerase chain reaction (PCR). RESULTS: NPM1 mutations were detected in 21 AML patients (35%). In the NPM1-positive subgroup, the FLT3-ITD mutation was observed in 3 cases (14%), which was significantly less frequent than in the NPM1-negative patients, where FLT3-ITD was detected in 16 cases (41%; p = 0.04). Among the CEBPA-positive population (n = 11; 18%), none of the studied patients had FLT3-ITD mutation, whereas it was detected in 19 CEBPA-negative patients (0% vs. 38%; p = 0.01). The highest complete remission rate was reported for the NPM1-positive/FLT3-ITD-negative group (n = 18; 88%) and the CEBPA-positive/FLT3-ITD-negative group (n = 8; 73%). For OS, multivariable analysis revealed NPM1-positive/FLT3-ITD-negative (HR: 0.18, 95% CI: 0.19-0.63) and CEBPA-positive/FLT3-ITD-negative (HR: 0.35, 95% CI: 0.19-0.63) as favourable prognostic factors. The presence of the NPM1-negative/FLT3-ITD-positivecombination predicted adverse overall survival (HR: 2.03, 95% CI: 1.13-3.66). CONCLUSIONS: NPM1 and CEBPA mutations are associated with clinical outcome in AML patients.

Characteristics and clinical outcome of patients with hypereosinophilia of undetermined significance.

The term "hypereosinophilia of undetermined significance" (HEus) previously known as idiopathic, benign eosinophilia relates to patients who have a long-lasting, unexplained and asymptomatic blood HE. These patients have not been studied so far in terms of demographic characteristics and clinical outcome. The aim of this study was to present the clinical characteristics and outcome of HEus patients. This is a retrospective, single-center study of 40 patients with HEus. All patients underwent the basic and specialized evaluations in order to rule out the most common causes of blood HE, but no abnormalities were detected. Twelve patients with at least moderate blood hypereosinophilia (defined as greater than 3.0 × 10(9)/L) for more than 1-year duration were treated with corticosteroids (CS) to avoid end-organ damage. Twenty-one patients (52 %) had an increased leukocyte count at diagnosis. Median blood eosinophilia was 4.2 × 10(9)/L (range 1.5-55.4). HE > 3.0 × 10(9)/L was demonstrated in 17 patients. 65 % of studied population had an increased serum IgE levels, whereas only 2 % demonstrated an increased serum vitamin B12 levels. A median bone marrow infiltration by eosinophils was 30.5 % (range 11-78.2). All treated patients responded promptly to CS and remained in complete remission while receiving low doses of CS (20 mg/day to 5 mg every 2-day). One patient developed hypereosinophilic syndrome (HES) after 11 years of follow-up. Further studies are needed to define risk factors of HES development. The use of CS for HEus patients is controversial and should be individualized.

Chronic eosinophilic leukemia-not otherwise specified has a poor prognosis with unresponsiveness to conventional treatment and high risk of acute transformation.

Chronic eosinophilic leukemia-not otherwise specified (CEL-NOS) is a rare disorder with hypereosinophilia and an increased number of blood or marrow blast (<20%) or an evidence of eosinophil clonality.We evaluated the clinical outcome of 10 patients with CEL-NOS. Seven males and three females at a median age of 62 years (range, 23­73) were included. The median leukocyte count at diagnosis was 33.4 3109/l (range, 9.3­175.0) with a median eosinophil count of 15.6 3 109/l (range, 1.5­136.0). Median hemoglobin and platelets were 11.0 g/dl (range, 8.3­13.3) and 158 3 109/l (range, 31.0­891.0), respectively. Clinical manifestations included splenomegaly (n 5 7), hepatomegaly (n 56), cardiac failure (n 5 2), and lung infiltrations (n 5 1). Median survival from diagnosis to death for entire cohort was 22.2 months (range,2.2­186.2). Five of the 10 studied patients developed acute transformation(AT) after median of 20 months from diagnosis (range, 1.6­41.9).None of patients with AT is alive at the time of last follow-up. Median time from AT to death was 2 months (range, 1.0­6.1). Among five patients who did not develop AT, three died in active disease. Two patients are alive in complete remission; first underwent allogeneic stem-cell transplantation preceding by intensive induction chemotherapy;the second remains on imatinib with hydroxyurea. Except the latter patient, imatinib was ineffective in our study population. CEL-NOS is a rare and aggressive disease with high rate of AT and resistance to conventional treatment.

Imatinib mesylate may induce long-term clinical response in FIP1L1-PDGFRα-negative hypereosinophilic syndrome.

The idiopathic hypereosinophilic syndrome (HES) comprises a heterogenous group of disorders characterized by marked blood eosinophilia with eosinophilia-associated organ damage. Eight patients with a median age at diagnosis of 42 years (range 19-67) received imatinib mesylate (IM) for FIP1L1-PDGFRα-negative HES resistant to previous conventional treatment. Median number of prior therapies was 3 (range 2-4). Median time from diagnosis to IM initiation was 112 months (range 2-293). Four patients were treated daily with 100 mg IM, whereas the remaining four patients were treated daily with 400 mg IM. Four male patients (50%) achieved complete haematologic response (CHR) after median of 7 days (range 3-150) using 100 mg daily IM (n = 2) and 400 mg (n = 2). Median duration of IM treatment for IM responders was 18 months (range 2-88). No adverse events were reported throughout the treatment duration. Two patients maintained CHR while on 100 mg weekly IM. Four patients (2 men and 2 women) failed IM treatment. Median duration of IM for non-responding patients was 3 weeks (range 3-12). Non-responding HES patients were significantly older and had lower percentage of blood eosinophilia when compared with IM responders. Our results suggest that IM, even at lower than conventional doses, may induce and maintain long-term remission for FIP1L1-PDGFRα-negative HES.