Uroš Mlakar

Effects of molgramostim, filgrastim and lenograstim in the treatment of myelokathexis

Abstract Myelokathexis is a very rare form of chronic hereditary neutropenia resulting from impaired neutrophil releasing mechanism in the bone marrow. The recombinant human granulocyte-macrophage (molgramostim) and granulocyte (filgrastim, lenograstim) colony stimulating factors release the mature granulocytes from the bone marrow. We describe a 43-year-old woman suffering from myelokathexis, with the absolute neutrophil count ranging between 0.03 and 1.35 × 109/L. In the period before the introduction of cytokines, the patient had more than 80 major infectious episodes. Since 1991, infections in this patient have been treated with cytokines, given in conjunction with antibiotics. Initially, she received molgramostim in a daily dose of 5 μg/kg subcutaneously, which stimulated the release of granulocytes from her bone marrow, thereby allowing successful treatment of infection. After the development of hypersensitivity, molgramostim was substituted with filgrastim. Finally, lenograstim was given a trial. With all three cytokines, the patient’s neutrophil count always attained normal values already 4 hours after subcutaneous application of the drug in a dose of 5 μg/kg, the highest neutrophil levels were measured at 24 hours post-injection, and the neutrophil count was again close to the baseline value 72 hours after the treatment. A slight neutropenia was present 48 hours after the application of filgrastim. We believe that all three cytokines are equally effective in increasing the neutrophil count in venous blood of patients with myelokathexis.

Serum thrombopoietin levels in acute myeloid leukaemia

Abstract To improve our understanding of the regulation of circulating platelet counts (PC) by thrombopoietin (TPO), we studied serum TPO levels and PC before and after myelosuppressive chemotherapy in 12 patients with acute myeloid leukaemia (AML). Serum TPO levels were measured by the quantitative sandwich enzyme-linked immunosorbent assay (Quantikine, RD Systems). At the start of the induction chemotherapy, the patients had a median serum TPO level of 199 pg/ml (range 120-2150 pg/ml), while 10 to 12 days after the end of chemotherapy, their TPO levels were substantially increased, the median value being 1907 pg/ml (range 1049-4194 pg/ml). The correlation between PC and TPO was statistically significant prior to chemotherapy (p<0.03) and insignificant after chemotherapy. As a result of chemotherapy, the patients developed aplasia; after the administration of platelet transfusions, their median PC increased to 21 × 109/l (range 5-55 × 109/l), while the median TPO value decreased by 300 pg/ml (range 11-1125 pg/ml). Our results suggest that platelet mass directly regulates serum TPO levels in acute leukaemia patients prior to chemotherapy and after the administration of platelet transfusions. Serum TPO levels may also be influenced by the cytokine response during complicating infections in patients with chemotherapy-induced cytopenia.

Indices of iron status in patients treated by chronic haemodialysis.

Abstract Iron deficiency in patients with end stage renal disease (ESRD) treated by haemodialysis (HD) is difficult to diagnose. The reticulocyte hemoglobin content (CHr) and the percentage of hypochromic red cells (%hypo) are sensitive novel assays for the detection of functional iron deficiency in patients treated with erithropoietin (EPO). In our study thirty-nine chronically hemodialyzed patients were evaluated to determine the value of these two parameters in comparison to the conventional biochemical indicators of iron metabolism. There were significant correlations between CHr and transferrin saturation, CHr and weekly dosage of EPO, and also between %hypo and weekly dosage of EPO. Our data represent superior value of %hypo and CHr to the transferrin saturation and ferritin concentration in detecteng of iron deficiency in HD patients.

Treatment of acute myeloid leukemia in adults in the period 2008–2011 at the University medical centre Ljubljana

Background: Retrospective analyses of unselected patients with acute myeloid leukaemia (AML), treated at individual centres, provide an estimate of treatment success in real world, in contrast to artificially designed conditions in clinical trials. We analysed the treatment outcome of adult patients with AML at the University Medical Centre of Ljubljana over the last four years. Results: From year 2008 to 2011, 222 patients with AML were treated at our centre. Out of the 222 treated patients, 19 patients had acute promyelocytic leukaemia (APL) and they received a combination of tretinoin and anthracycline based chemotherapy. Four patients died in the period of induction therapy, while the remaining patients reached molecular remission, which still lasts. In the group of 203 non-APL patients, 129 patients (of these 76 younger and 53 older than 59 years) received intensive chemotherapy. Non-intensive treatment was given to 74 patients. The intensive treatment included daunorubicin-cytarabine- based induction therapy (DA3+10). In 22 % of younger patients the time from diagnosis to the beginning of intensive treatment lasted more than 5 days. The percentage of early deaths (less than 33 days after the beginning of treatment) was 12 % for younger, and 19 % for older patients. The remission rate was 67 % in younger and 47 % in older patients. The estimated median of overall survival was 13 months and relapsefree survival was 12.5 months. Three-year survival rate was 31 %. Allogeneic stem-cell transplantation was performed in 36 patients; in 10 of these patients transplantation was induction treatment. Remission was achieved in a half of the patients , 8 patients died and of these only 2 survived more than a year. Allogeneic stem cell transplantation was a part of consolidation treatment in 26 patients. In four cases AML relapsed and 10 patients died (38 %). Relapse of the disease was the cause of death in two cases only . Conclusions: The remission rate in our study is comparable with the reports of several randomized trials. For survival analysis, if we are critical, the duration of follow-up in our study might be too short. Suggested measures for the improvement of treatment outcome are: once a diagnosis of APL is suspected, treatment with tretinoin (and blood products) should be started immediately, in younger patients with AML the time from diagnosis to treatment initiation should be under 5 days, patient-specific and leukaemia-associated factors should be analysed carefully before the treatment decisions, especially in older patients.

The thrombopoietin receptor W515L and W515k mutations detection in patients with essential thrombocythemia

Background: The aim of the study was to investigate the frequency of the thrombopoietin receptor (MPL) W515L and W515K mutations in our cohort of essential thrombocythemia (ET) patients negative for the somatic JAK2 V617F mutation, and to compare the results to those published in the literature. Methods: Seventy-seven ET patients (59 female, 18 male), median age 48 (range from 18 to 89 years) and negative for JAK2 V617F mutation were included in the study. Granulocytes were isolated from patients’ venous blood samples by Ficoll density gradient centrifugation followed by red blood cell lysis procedure. DNA was isolated from granulocytes by QIAamp DNA Mini Kit from Qiagen (USA). The detection of MPL W515L/K mutations was carried out by test designed by Ipsogen (France) using the fluorescence-based quantitative real-time PCR (qPCR) and allelic discrimination method. Results: MPL W515L and MPL W515K mutations in our cohort of patients with ET and negative for the somatic JAK2 V617F mutation was found in 4 % (N = 3) and 2 % (N = 1), respectively. Both mutations were found in 5 % of ET patients included in the study (N = 77). Conclusions: We have found out that the frequency of MPL W515L/K mutation was similar to those published in the literature and was 5 %. The MPL W515L mutation frequency was higher than MPL W515K. The assay is suitable for the routine detection of MPL W515L/K mutations in patients with ET and negative for the somatic JAK2 V617F mutation.