Vol 6, No 1 (2011)

A t(8;21) is the most frequent abnormality in AML in children. Patients with this genetic abnormality are traditionally expected favorable prognosis with a probability of cure up to 80 %. Known additional cytogenetic abnormalities in AML with t(8;21) not affecting prognosis. These include loss of one sex chromosome and del(9q-). Prognosis impact of additional abnormalities involving chromosomes 7 and 11 in patients with t(8;21) is unknown. The purpose of this study was to analyse of additional anomalies, that occur in patients with t(8;21), and their influence on prognosis. During the study period 173 children with AML have received AML-MM-2000 treatment protocol in Russia and Belarus. Of these, in 33 patients (11 girls and 22 boys, median age — 10.5 years) t(8;21) was detected by chromosome banding or molecular-genetic analysis. In group with t(8;21) CNS leukemia in 8 patients was detected, extramedullary lesion — in 8 patients. In 4 patients CNS leukemia combined with presence of extramedullary lesions. These factors did not influence on therapy outcome. Overall survival of AML patients with t(8;21) was 0,67 ± 0,08 compared to 0,44 ± 0,04 in patients with AML without this translocation (p = 0,04). Special subgroup consist of 5 patients with t(8;21) and identified chromosomal abnormalities affecting chromosome 7 and 11, which were a poor prognostic factor: event-free survival in this subgroup of patients (n = 5) was 0,0 ± 0,0, compared to 0,34 ± 0,16 in patients with t(8;21) without additional anomalies (n = 28) (p = 0,027).

The article presents treatment results of 233 patients (children and adolescents under 19 years old; median — 8.76 years) with CD20-
positive non-Hodgkin lymphomas and B-cell acute leukemia (B-NHL/B-AL) received chemotherapy (BFM B-NHL 90–95 protocols) or combined chemo-immunotherapy with rituximab (B-NHL-2004mab protocol). Combined chemo-immunotherapy was used for patients with Burkitt lymphoma, diffuse large cells lymphomas stage III–IV and B-AL, and included cytoreductive phase, 6 polychemotherapy (PCT) courses and rituximab. PCT courses are similar to those of original BFM B-NHL90 protocol, except for the first 2 courses, where daily methotrexate dose was reduced from 5 to 1 g/m2/24 h. Rituximab infused IV 12 hours before the start of first 4 chemotherapy courses at a dose of 375 mg/m2. The data in the questionnaires form have been submitted from 28 pediatric specialized hospitals from 27 Russia regions over the past 5 years (2005–2009). Protocol with rituximab has proved to be more effective than chemotherapy alone. The authors discuss the possibility of using combined chemo-immunotherapy for the treatment of B-NHL/B-AL at regional hospitals and the prospects for further treatment results improvement in this group of tumors.

Introduction: Invasive fungal infections (IFI) remain an unresolved issue of hematology/oncology despite the introduction of methods of early diagnostic and invent of new highly active antimycotics. In etiologic structure of IFI the leading role belongs to candidiasis, the most frequent clinical form of which is candidemia. Candidemias in the pediatric hematology/oncology departments usually occur as sporadic cases, and epidemics are very rare. We describe an epidemic outbreak of candidemia caused by species of Candida non-albicans rarely reported in patients.

Results: Ten cases of candidemia were registered in the hematology/oncology department within one month. Candidemia was caused by C. guilliermondi in 4 patients (in 1 concomitantly with C. calliculosa), by С. parapsilosis – in 3 patients and by C. pelliculosa in another 3 patients. Contaminated intravenous 4 % KCl solution has been found to be the source of candidemia. In four patients granulocytes count was < 0.5  109/l at the time of positive blood cultures. Clinical manifestation of candidemia included fever > 38.5 in all patients and lung involvement in 2 patients. All patients received systemic antifungal therapy: 5 — monotherapy, 3 — combinations of 2 drugs and 2 — of 3 drugs. Central venous catheter was removed in 4 patients. Clinical and microbiological cure was achieved in all patients; the mortality rate was 0 %. In 2 patients candidemia relapsed 22 and 60 days after the first episode.

Conclusions: Outbreaks of systemic infections caused by unusual pathogens necessitate searching of a single infection source. Candidemia caused by a direct pathogen inoculation in the bloodstream, in the absence of multiple risk factors for invasive fungal infections follows a favorable course.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the standard curative therapy for juvenile myelomonocytic leukemia (JMML). Seventeen patients with JMML received myeloablative conditioning (busulfan-based — 15, treosulfan-based — 2). Donors included 5 matched related siblings, 8 — matched unrelated volunteer or cord blood (2), 4 — mismatched relatives. Primary engraftment was achieved in 75 %. The rate of acute GVHD grade II–IV was 58 %, grade III–IV — 23 %. Chronic GVHD occurred in 33 % of patients. Five JMML relapses occurred. Relapse-free survival is 66 ± 12 %. Four patients died of transplant-related complications. TRM was 28 ± 12 %.
Five patients died of disease progression. Overall survival is 38 ± 13 % with median follow-up of 13 months. A review of most important publications related to HSCT in JMML is provided.

This article provides an overview of research evolution of umbilical cord blood as a source of hematopoietic stem cells for transplantation. Phased developments of the technology of stem cells detection and selection, their proliferation, differentiation and function assessment using cultivation in vitro and in vivo in animal model was described. Differences of cord blood stem cells in comparison with those from other sources were described. The role of microenvironment for stem cells self-renewal and differentiation is shown. The possibility of stem cells biological properties modeling on example of using a vector based on HIV type 1 containing Notch genes, to regulate CD133+ and CD34+ cord blood stem cells proliferation is shown.