Background: Chemotherapy-induced peripheral polyneuropathy is a major neurotoxicity of treatment for acute lymphoblastic leukemia (ALL) in children. Pathophysiological mechanisms of the injury of peripheral neural system are not fully investigated; however, some studies have shown the involvement of vascular endothelial growth factors.
Aim: To evaluate plasma levels of angiogenic growth factors in children with ALL and to identify their association with the development of vincristine-induced peripheral polyneuropathy.
Materials and methods: This single center prospective study included 41 patients with ALL aged 3 to 17 years. All patients were given the ALL-MB 2015 chemotherapy regimen. Depending on the vincristine-induced peripheral polyneuropathy, the patients were divided into two groups: the main group (n = 22) comprised of the patients with neurological signs and symptoms of peripheral neuropathy and the control group (n = 19), those without clinical signs of the peripheral nervous system involvement. The levels of angiogenic growth factors (VEGF-A, VEGF-D, PlGF-1, and PDGF-BB) were measured in plasma by multiparameter immunofluorescent analysis.
Results: During 3 months of the follow up the chemotherapy-induced signs of peripheral polyneuropathy developed in 53.6% (n = 22) of the children. In 72.7% (n = 16) of the patients the chemotherapy-induced peripheral polyneuropathy was characterized by a combination of neurologic abnormalities with prevailing motor symptoms. The comparative analysis of plasma angiogenic growth factors in children with ALL depending on the presence or absence of the vincristine-induced peripheral polyneuropathy showed that there was a significant decrease of the VEGF-A in those with chemotherapy-induced peripheral polyneuropathy, compared to those without (Me [Q1; Q3]: 178.20 [138.40; 228.45] and 558.50 [160.10; 650.0], respectively, p 0.017). This parameter had diagnostic sensitivity of 77.7% and specificity of 76.9%.
Conclusion: We have shown a high clinical value of plasma vascular endothelial growth factor (VEGF-A) level, which makes it possible to consider it as a significant biological marker of neurotoxicity in vincristine-induced peripheral polyneuropathy.
Acute megakaryoblastic leukemia (AMKL) is a rare subtype of acute myeloid leukemia, in which the bone marrow produce increased numbers of immature abnormal megakaryoblasts. AMKL is rare both in children and adults, but is the most frequent subtype of acute myeloid leukemia (AML) in children with Down syndrome. Morphological diagnosis of this disease could be complicated, thus flow cytometry plays a crucial role in the diagnostics of AMKL. The aim of the present study was to investigate the immunophenotypic characteristics of AMKL in children. The study was approved by the Independent Ethics Committee of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology, and Immunology. The study group included 103 patients with AMKL. Antigen expression profile was assessed by multicolor flow cytometry. We identified three groups of patients according to different levels of CD45 expression, and in majority of patients (74%) high level of CD45 expression was detected. Significant immunophenotypic differences between these groups were found. In 56% of patients trisomy of 21 chromosome was detected. Among these patients, 86% belonged to group of high CD45 expression. Moreover, children with trisomy 21 represented the majority in the group with high level of CD45 expression (64%). Also, there were found several significant differences between patients with and without trisomy 21 within the group of high CD45 expression. This study demonstrated the wide immunophenotypic heterogeneity of AMKL. In general, the revealed diversity obviously reflects the biological heterogeneity of this AML subtype.
We developed and implemented in multicenter setting the standardized approach for flow cytometric minimal residual disease (MRD) monitoring in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Participation of multicenter group reference laboratories in several ring trial studies demonstrated high concordance rate between participants. Successful integration of one additional laboratory in the multicenter group has shown good level of our approach reproducibility. These results will allow implementing MRD detection in stratification system of pediatric ALL treatment protocols of Russia-Belarus multicenter group.
Abstract Background Detection of bone marrow (BM) involvement in patients with neuroblastoma is crucial for staging and defining prognosis. Furthermore, the persistence of residual tumor cells in the BM is associated with an unfavorable outcome. Methods Expression of PHOX2B , TH , ELAVL4 , and B4GALNT1 (GD2‐synthase) was analyzed by quantitative polymerase chain reaction in neuroblastoma cell lines, control BM samples, and in BM samples from patients. The threshold level of expression for each gene was established through receiver operator characteristic analysis and used to determine the diagnostic test performance. The prognostic significance of BM involvement was assessed by survival rates calculations. The median of follow‐up time was 36.1 months. Results Neither PHOX2B nor TH expression was detected in control BM, while expression of ELAVL4 was found in 20 (76.9%) and GD2‐synthase in 15 (57.7%) of 26 samples. The overall correct predictive value for TH , ELAVL4 , and GD2‐synthase, based on thresholds levels, was 0.952, 0.828, and 0.767, respectively, whereas the overall correct predictive value for PHOX2B was 0.994. The PHOX2B/TH expression in diagnostic BM of patients with neuroblastoma corresponded with a decreased survival rate ( P < 0.001) in the total cohort and in different risk groups. Predominance of normalized expression of PHOX2B over TH > 1.68 in the diagnostic BM samples demonstrated an adverse prognostic effect ( P = 0.006). Persistence of PHOX2B / TH expression in the BM during and after induction chemotherapy resulted in dismal outcome ( P = 0.022 and P = 0.012). Conclusion PHOX2B and TH are the most optimal markers for detection of BM involvement, allowing identification of high‐risk patients. Predominance of PHOX2B expression over TH has a strong adverse prognostic impact.
Background & Aims. The diagnosis of chronic myeloid leukemia (CML) is confirmed in case of translocation t(9;22) (q34;q 11 ) is revealed by chromosomal banding analysis and/or BCR-ABL fusion gene transcript is detected by reverse-transcriptase polymerase chain reaction (RT-PCR). However, rare types of chimeric BCR-ABL transcript have been described and they may be overlooked. Moreover, timely CML diagnosing and detection of different types of BCR-ABL transcript are very important task, because the clinical course of the disease and efficacy of the therapy with tyrosine kinase inhibitors partly depend on the structure of BCR-ABL fusion. In some cases CML may be diagnosed without the chromosomal banding analysis and be confirmed by RT-PCR alone, so we consider it important to develop a diagnostic algorithm that allows to detect virtually all types of BCR-ABL fusion gene transcript. Methods. Over the period from January, 2004, till December, 2013, in the Molecular biology laboratory of Pediatric oncology and hematology center in Regional Chlildren’s Hospital # 1 (Yekaterinburg), the diagnosis of CML was confirmed in 1082 patients: 531 (49 %) males and 551 (51 %) females. The median age was 50 years (range 5-88 years). Chromosomal banding analysis and nested RT-PCR were performed in all patients. Reverse primers for nested RT-PCR are localized in exons 2 and 3 of ABL and are used for detection of all types of BCR-ABL transcript. Forward primes for typical e13a2 and e14a2 (M-bcr) transcripts are localized in exons 12 and 13 BCR gene, forward primes for e1a2 (m-bcr) transcript are complementary to exon 1 of BCR. While atypical amplicons are detected we performed Sanger sequencing with primers of the second round of RT-PCR and BigDye Terminator 3.1 kit. Results. Based on 1082 of confirmed CML cases we have developed a diagnostic strategy for detection of typical and atypical types of BCR-ABL fusion gene transcript in CML patients using RT-PCR. Proposed algorithm allowed to detect typical BCR-ABL transcript, e14a2 and e13a2, in 62.53 % and 35.89 % of cases, respectively. Atypical transcripts, e13a3, e14a3, e19a2, e1a2, e3a2, e6a2, and e8a2, were detected in 1.57 % of cases. Conclusion. Therefore, the proposed diagnostic algorithm proved to be effective for detection of typical and atypical types of BCR-ABL fusion gene transcripts in CML patients.
