Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 110
Filter
1.
Hematol Transfus Cell Ther ; 46(2): 167-175, 2024.
Article in English | MEDLINE | ID: mdl-38182466

ABSTRACT

INTRODUCTION: Hemoglobinopathy Sß-thalassemia (HbSß-thal) has a wide range of clinical and laboratory severity. There is limited information on the natural history of HbSß-thal and its modulating factors. We described the molecular, hematological, and clinical characteristics of a cohort of children with HbSß-thal and estimated its incidence in Minas Gerais, Brazil. METHODS: Laboratory and clinical data were retrieved from medical records. Molecular analysis was performed by HBB gene sequencing, PCR-RFLP, gap-PCR, and MLPA. RESULTS: Eighty-nine children were included in the study. Fourteen alleles of ß-thal mutations were identified. The incidence of HbSß-thal in the state was 1 per 22,250 newborns. The most common ßS-haplotypes were CAR and Benin. The most frequent ßthal-haplotypes were V, II, and I. Coexistence of 3.7 kb HBA1/HBA2 deletion was present in 21.3 % of children. ß-thalassemia mutations were associated with several clinical and laboratory features. In general, the incidence of clinical events per 100 patient-years was similar for children with HbSß0-thal, IVS-I-5 G>A, and IVS-I-110 G>A. Children with HbSß+-intermediate phenotypes had a more severe laboratory and clinical profile when compared with those with HbSß+-mild ones. ßS-haplotypes and α-thalassemia did not meaningfully influence the phenotype of children with HbSß-thal. CONCLUSION: The early identification of ß-thalassemia alleles may help the clinical management of these children.

3.
Hematol., Transfus. Cell Ther. (Impr.) ; 44(4): 478-484, Oct.-dec. 2022. tab, ilus
Article in English | LILACS | ID: biblio-1421534

ABSTRACT

ABSTRACT Background: Stroke is a serious complication of sickle cell anemia (SCA). The transcranial Doppler (TCD) is the risk-screening tool for ischemic strokes. The objective of the study was to describe the clinical progression of children with SCA who presented with high risk for stroke by TCD or relevant changes by magnetic resonance angiography (MRA) and underwent the regular transfusion program (RTP) and/or hydroxyurea (HU) treatment between 2007 and 2018. Method: This was a neonatal retrospective/prospective cohort study with children born between 1999 and 2014 with the homozygotic form (HbSS) or Sβ0-thalassemia who underwent TCD at least once. Results: Of the 718 children screened during this period, 675 had HbSS and 43 Sβ0-thalassemia. In 54 children (7.5%), all with HbSS, a high-risk TCD (n = 45) or, when the TCD was inconclusive, an MRA with cerebral vasculopathy (n = 9) was used for detection. Of these, 51 started the RTP and the families of three refused treatment. Of the 43 children with a highrisk TCD who initiated the RTP, 29 (67.4%) reverted to low risk. In 18 of them (62%), HU was started at the maximum tolerated dose (MTD) before transfusion discontinuation. None of these 29 patients had a stroke. Eight children (18.6%) maintained a high-risk TCD, even using the RTP/HU and two had a stroke. Conclusions: The TCD was confirmed as a viable tool for tracking patients with a risk for stroke. The RTP was effective in preventing the primary event. New strategies are necessary to prevent stroke using HU and new drugs, in addition to bone marrow transplantation.


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Ischemic Stroke , Anemia, Sickle Cell , Primary Prevention , Child , Ultrasonography, Doppler, Transcranial , Stroke , Hydroxyurea
4.
J Hum Genet ; 67(12): 701-709, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36167770

ABSTRACT

Single nucleotide polymorphisms (SNPs) of BCL11A gene and HBS1L-MYB intergenic region (named HMIP-2) affect both fetal hemoglobin (HbF) concentration and clinical outcomes in patients with sickle cell anemia (SCA). However, no previous study has examined the interaction among these SNPs in the regulation of HbF. We examined whether HbF-boosting haplotypes combining alleles of functional SNPs of BCL11A and HMIP-2 were associated with clinical outcomes and hematological parameters, and whether they interact to regulate HbF in a cohort of Brazilian children with SCA. The minor haplotype of BCL11A ("TCA", an allele combination of rs1427407, rs766432, and rs4671393) was associated with higher HbF, hemoglobin and lower reticulocytes count compared to reference haplotype "GAG". The minor haplotype of HMIP-2 ("CGC", an allele combination of rs9399137, rs4895441, and rs9494145) was associated with higher HbF and hemoglobin compared to reference haplotype "TAT". Subjects carrying minor haplotypes showed reduced rate of clinical complications compared to reference haplotypes. Non-carriers of both minor haplotypes for BCL11A and HMIP-2 showed the lowest HbF concentration. Subjects carrying only the minor haplotype of BCL11A showed significantly higher HbF concentration than non-carriers of any minor haplotype, which showed no significant difference compared to subjects carrying only the minor haplotype of HMIP-2. Interestingly, subjects carrying both minor haplotypes of BCL11A ("TCA") and HMIP-2 ("CGC") showed significantly higher HbF levels than subjects carrying only the minor haplotype of BCL11A. Our novel findings suggest that HbF-boosting haplotypes of BCL11A and HMIP-2 can predict clinical outcomes and may interact to regulate HbF in patients with SCA.


Subject(s)
Anemia, Sickle Cell , Fetal Hemoglobin , Child , Humans , Fetal Hemoglobin/genetics , Haplotypes , DNA, Intergenic , Anemia, Sickle Cell/genetics , Cohort Studies , Transcription Factors , Polymorphism, Single Nucleotide , Repressor Proteins/genetics
5.
Hematol Transfus Cell Ther ; 44(4): 478-484, 2022.
Article in English | MEDLINE | ID: mdl-34210619

ABSTRACT

BACKGROUND: Stroke is a serious complication of sickle cell anemia (SCA). The transcranial Doppler (TCD) is the risk-screening tool for ischemic strokes. The objective of the study was to describe the clinical progression of children with SCA who presented with high risk for stroke by TCD or relevant changes by magnetic resonance angiography (MRA) and underwent the regular transfusion program (RTP) and/or hydroxyurea (HU) treatment between 2007 and 2018. METHOD: This was a neonatal retrospective/prospective cohort study with children born between 1999 and 2014 with the homozygotic form (HbSS) or Sß0-thalassemia who underwent TCD at least once. RESULTS: Of the 718 children screened during this period, 675 had HbSS and 43 Sß0-thalassemia. In 54 children (7.5%), all with HbSS, a high-risk TCD (n = 45) or, when the TCD was inconclusive, an MRA with cerebral vasculopathy (n = 9) was used for detection. Of these, 51 started the RTP and the families of three refused treatment. Of the 43 children with a high-risk TCD who initiated the RTP, 29 (67.4%) reverted to low risk. In 18 of them (62%), HU was started at the maximum tolerated dose (MTD) before transfusion discontinuation. None of these 29 patients had a stroke. Eight children (18.6%) maintained a high-risk TCD, even using the RTP/HU and two had a stroke. CONCLUSIONS: The TCD was confirmed as a viable tool for tracking patients with a risk for stroke. The RTP was effective in preventing the primary event. New strategies are necessary to prevent stroke using HU and new drugs, in addition to bone marrow transplantation.

6.
Ann Hematol ; 99(7): 1453-1463, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32447424

ABSTRACT

Fetal hemoglobin (HbF) ameliorates clinical severity of sickle cell anemia (SCA). The major loci regulating HbF levels are HBB cluster, BCL11A, and HMIP-2 (HBS1L-MYB). However, the impact of noncoding single-nucleotide polymorphisms (SNPs) in these loci on clinical outcomes and their functional role on regulating HbF levels should be better elucidated. Therefore, we performed comprehensive association analyses of 14 noncoding SNPs in five loci with HbF levels and with clinical outcomes in a cohort of 250 children with SCA from Southeastern Brazil, and further performed functional annotation of these SNPs. We found SNPs independently associated with HbF levels: rs4671393 in BCL11A (ß-coefficient = 0.28), rs9399137 in HMIP-2A (ß-coefficient = 0.16), and rs4895441 in HMIP-2B (ß-coefficient = 0.15). Patients carrying minor (HbF-boosting) alleles for rs1427407, rs93979137, rs4895441, rs9402686, and rs9494145 showed reduced count of reticulocytes (p < 0.01), while those carrying the T allele of rs9494145 showed lower white blood cell count (p = 0.002). Carriers of the minor allele for rs9402686 showed higher peripheral saturation of oxygen (p = 0.002). Patients carrying minor alleles in BCL11A showed lower risk of transfusion incidence rate ratio (IRR ≥ 1.3; p < 0.0001). This effect was independent of HbF effect (p = 0.005). Carriers of minor alleles for rs9399137 and rs9402686 showed lower risk of acute chest syndrome (IRR > 1.3; p ≤ 0.01). Carriers of the reference allele for rs4671393 showed lower risk of infections (IRR = 1.16; p = 0.01). In conclusion, patients carrying HbF-boosting alleles of BCL11A and HMIP-2 were associated with milder clinical phenotypes. Higher HbF concentration may underlie this effect.


Subject(s)
Anemia, Sickle Cell/diagnosis , Anemia, Sickle Cell/genetics , Fetal Hemoglobin/metabolism , GTP-Binding Proteins/genetics , Genes, myb , Polymorphism, Single Nucleotide , Repressor Proteins/genetics , Alleles , Anemia, Sickle Cell/blood , Anemia, Sickle Cell/epidemiology , Brazil/epidemiology , Child , Child, Preschool , Cohort Studies , Female , Fetal Hemoglobin/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Infant , Infant, Newborn , Male , Prognosis , Retrospective Studies
8.
Cytokine ; 125: 154800, 2020 01.
Article in English | MEDLINE | ID: mdl-31442679

ABSTRACT

Sickle cell anemia (SCA) is an important cause of chronic kidney disease, but its pathophysiology is not completely understood. The aim of this study was to compare inflammatory biomarkers in urine samples of SCA children with and without albuminuria, and to explore correlations with renin-angiotensin system (RAS) molecules. A cross-sectional study of 213 children selected from the Minas Gerais state cohort were assigned to two groups: Group 1-89 children with SCA who had albuminuria; Group 2-124 children with SCA and normal albuminuria matched by age and sex with group 1. A subset of 89 children was prospectively followed for a median time of 1.1 year. Inflammatory biomarkers (chemokines and cytokines) in urine were measured using cytometric beads array, and RAS molecules were measured by ELISA. Children with albuminuria had significantly higher urinary levels of IP-10/CXCL10, MCP-1/CCL2, MIG/CXCL9, IL-8/CXCL8, IL-12p70, TNF, IL-10, and IL-6 than patients with normal albuminuria. In the correlation analysis, albumin/creatinine ratio was significantly and positively correlated with IP-10/CXCL10, MCP-1/CCL2, MIG/CXCL9, IL-8/CXCL8, TNF, IL-10, and IL-6. Significant correlations were found between inflammatory and RAS molecules. In the prospective analysis, cumulative risk of persistent albuminuria was higher for children with urinary levels of IP-10/CXCL10 or IL-6 above the 50th percentile. Our data showed that inflammatory markers and RAS molecules might contribute to the occurrence of albuminuria in children with SCA, suggesting that both pathways interact in sickle cell nephropathy.


Subject(s)
Albuminuria/metabolism , Anemia, Sickle Cell/metabolism , Chemokines/urine , Cytokines/urine , Kidney Diseases/metabolism , Renin-Angiotensin System , Adolescent , Biomarkers/metabolism , Chemokine CCL2/metabolism , Chemokine CXCL10/metabolism , Chemokine CXCL9/metabolism , Child , Child, Preschool , Cross-Sectional Studies , Female , Follow-Up Studies , Humans , Infant , Inflammation/metabolism , Interleukin-10/metabolism , Interleukin-12/metabolism , Interleukin-6/metabolism , Interleukin-8/metabolism , Male , Prospective Studies , Tumor Necrosis Factor-alpha/metabolism , Young Adult
9.
J Med Screen ; 27(3): 115-120, 2020 09.
Article in English | MEDLINE | ID: mdl-31801038

ABSTRACT

OBJECTIVE: The prevalence of biotinidase deficiency and the frequency of biotinidase gene variants in Brazil are not documented. We aimed to determine the incidence of partial and profound biotinidase deficiency in the state of Minas Gerais, Brazil, and to calculate the frequency of biotinidase gene variants in the newborn screening program of Minas Gerais. METHODS: Neonates (1,168,385) were screened from May 2013 to June 2018. Those detected with abnormal biotinidase activity based on semi-quantitative assays underwent confirmatory serum tests. The biotinidase gene was sequenced in all confirmed cases. RESULTS: The combined incidence of partial and profound biotinidase deficiency was estimated at 1:13,909 live births (95% confidence limit 1:11,235-1:17,217), much higher than the incidence rates reported in other populations worldwide. The most frequent biotinidase gene variants were p.D444H (allele frequency, 0.016), haplotype c.1330G>C;c.511G>A (p.D444H;A171T), p.D543E, c.310-15delT (intronic), p.V199M, and p.H485Q. Together these accounted for 74.6% of the alleles analysed. CONCLUSION: Newborn screening for biotinidase deficiency, which revealed a higher incidence in Minas Gerais, is feasible and plays a critical role in the early identification of affected neonates and prevention of symptoms and irreversible sequelae. Biotinidase gene sequencing is a useful tool to confirm the diagnosis, and also provides valuable information about genetic variability among different populations.


Subject(s)
Biotinidase Deficiency/genetics , Biotinidase/genetics , Mutation , Neonatal Screening , Biotinidase/blood , Biotinidase Deficiency/diagnosis , Biotinidase Deficiency/epidemiology , Brazil/epidemiology , Female , Gene Frequency , Humans , Incidence , Infant, Newborn , Male
10.
Hematol., Transfus. Cell Ther. (Impr.) ; 41(3): 236-243, July-Sept. 2019. tab, graf
Article in English | LILACS | ID: biblio-1039923

ABSTRACT

ABSTRACT Objectives: To describe cytogenetic and molecular abnormalities observed in children and adolescents with acute myeloid leukemia (AML), classify AML according to the World Health Organization (WHO) classifications from 2008 and 2016, and evaluate the prognosis according to clinical characteristics and cytogenetic abnormalities. Methods: A retrospective longitudinal study was performed on a population of 98 patients with AML, aged up to 16 years, seen in a single hospital from 2004 to 2015. Results: Among the 80 patients for whom it was possible to analyze the karyotype, 78.7% had chromosomal changes, the most frequent being t(15;17)(q22;q21). Of the 86 patients for whom we had cytogenetic or molecular data, making it possible to classify their AML according to the WHO classification, 52.3% belonged to the group with recurrent genetic abnormalities, 22% to the "AML not otherwise specified" group, 18.6% to the group with myelodysplasia-related cytogenetic changes, and 7% to the group with Down syndrome-related leukemia. Five-year overall survival (OS) for the whole group was 49.7% ± 5.2%. In the univariate and multivariate analyses, patients with myelodysplasia-related cytogenetic changes (OS 28.1% ± 12.2%) and those with "AML not otherwise specified" (OS 36.1% ± 11.2%) had an unfavorable prognosis when compared to patients with AML with recurrent genetic abnormalities (OS 71% ± 5.8%) and patients with Down syndrome-related AML (OS 83% ± 15.2%, p = 0.011). Conclusions: The results corroborate the importance of cytogenetic abnormalities as a prognostic factor and indicate the need for cooperative and prospective studies to evaluate the applicability of the WHO classification in the pediatric population.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Prognosis , Leukemia, Myeloid, Acute , Cytogenetic Analysis , Child
11.
J. pediatr. (Rio J.) ; 95(4): 451-457, July-Aug. 2019. tab, graf
Article in English | LILACS | ID: biblio-1040345

ABSTRACT

Abstract Objective: To evaluate the cognitive abilities of children and adolescents with sickle cell anemia diagnosed through neonatal screening and to compare them with healthy controls, adjusting the results to their socioeconomic status. Methods: Cognitive assessment was performed with the Wechsler WISC-III scale in 64 children and adolescents with sickle cell anemia and in 64 controls matched by gender and age, without the disease and without neurological impairment; socioeconomic status was measured by the Criterion Brasil. Results: All cognitive scores were lower in the group of patients. The mean overall IQ, Verbal IQ, and Performance IQ were, respectively, 90.95 for the group of patients and 113.97 for the controls (p < 0.001); 91.41 for the group of patients and 112.31 for the controls (p < 0.001); 92.34 for the group of patients and 113.38 for the controls (p < 0.001). Scores for processing speed, distraction resistance, and perceptual organization were also significantly lower in patients. A direct and significant correlation was detected between socioeconomic status and cognitive scores. In the multivariate analysis, for the same socioeconomic status, a child with sickle cell anemia had an average IQ of 21.2 points lower than the mean IQ observed for the controls (p < 0.001), indicating that the disease, adjusted for the socioeconomic effect, is a strong predictor of the overall IQ. Conclusion: The cognitive impairment of children with sickle cell anemia is severe and manifests even when the disease effect is adjusted to the socioeconomic status. In the authors' view, such impairment requires an early preventive approach in order to avoid this cognitive damage.


Resumo Objetivo: Avaliar os sistemas cognitivos de crianças e adolescentes com anemia falciforme provenientes de triagem neonatal e compará-las com controles sadios, ajustando-se os resultados para o nível socioeconômico. Método: A avaliação cognitiva foi feita com a escala de Wechsler WISC-III em 64 crianças e adolescentes com anemia falciforme e em 64 controles pareados por sexo e idade, sem a doença e sem comprometimento neurológico; o nível socioeconômico foi aferido pelo Critério Brasil. Resultados: Todos os escores cognitivos foram inferiores no grupo de pacientes. As médias de QI Total, QI Verbal e QI de Execução foram respectivamente 90,95 para o grupo de pacientes e 113,97 para os controles (p < 0,001); 91,41 para o grupo de pacientes e 112,31 para os controles (p < 0,001); 92,34 para o grupo de pacientes e 113,38 para os controles (p < 0,001). Os escores de velocidade de processamento, de resistência à distração e de organização perceptual foram, também, significativamente mais baixos nos pacientes. Detectou-se correlação direta e significativa entre o nível socioeconômico e os escores cognitivos. Em análise multivariada, para um mesmo nível socioeconômico, uma criança com anemia falciforme teve QI total, em média, 21,2 pontos mais baixo do que a média dos controles (p < 0,001), indicou que a doença, ajustada para o efeito socioeconômico, é forte fator preditivo do QI total. Conclusão: Os prejuízos cognitivos das crianças com anemia falciforme são intensos e se manifestam mesmo quando o efeito da doença é ajustado para o nível socioeconômico, o que, a nosso ver, requer abordagem preventiva precoce para tentar evitar tais prejuízos.


Subject(s)
Humans , Male , Female , Child , Adolescent , Cognition Disorders/etiology , Anemia, Sickle Cell/complications , Socioeconomic Factors , Wechsler Scales , Brazil , Case-Control Studies , Cross-Sectional Studies , Cognition Disorders/prevention & control , Intelligence Tests , Neuropsychological Tests
12.
Hematol Transfus Cell Ther ; 41(3): 236-243, 2019.
Article in English | MEDLINE | ID: mdl-31085153

ABSTRACT

OBJECTIVES: To describe cytogenetic and molecular abnormalities observed in children and adolescents with acute myeloid leukemia (AML), classify AML according to the World Health Organization (WHO) classifications from 2008 and 2016, and evaluate the prognosis according to clinical characteristics and cytogenetic abnormalities. METHODS: A retrospective longitudinal study was performed on a population of 98 patients with AML, aged up to 16 years, seen in a single hospital from 2004 to 2015. RESULTS: Among the 80 patients for whom it was possible to analyze the karyotype, 78.7% had chromosomal changes, the most frequent being t(15;17)(q22;q21). Of the 86 patients for whom we had cytogenetic or molecular data, making it possible to classify their AML according to the WHO classification, 52.3% belonged to the group with recurrent genetic abnormalities, 22% to the "AML not otherwise specified" group, 18.6% to the group with myelodysplasia-related cytogenetic changes, and 7% to the group with Down syndrome-related leukemia. Five-year overall survival (OS) for the whole group was 49.7%±5.2%. In the univariate and multivariate analyses, patients with myelodysplasia-related cytogenetic changes (OS 28.1%±12.2%) and those with "AML not otherwise specified" (OS 36.1%±11.2%) had an unfavorable prognosis when compared to patients with AML with recurrent genetic abnormalities (OS 71%±5.8%) and patients with Down syndrome-related AML (OS 83%±15.2%, p=0.011). CONCLUSIONS: The results corroborate the importance of cytogenetic abnormalities as a prognostic factor and indicate the need for cooperative and prospective studies to evaluate the applicability of the WHO classification in the pediatric population.

13.
J Pediatr (Rio J) ; 95(4): 451-457, 2019.
Article in English | MEDLINE | ID: mdl-29957246

ABSTRACT

OBJECTIVE: To evaluate the cognitive abilities of children and adolescents with sickle cell anemia diagnosed through neonatal screening and to compare them with healthy controls, adjusting the results to their socioeconomic status. METHODS: Cognitive assessment was performed with the Wechsler WISC-III scale in 64 children and adolescents with sickle cell anemia and in 64 controls matched by gender and age, without the disease and without neurological impairment; socioeconomic status was measured by the Criterion Brasil. RESULTS: All cognitive scores were lower in the group of patients. The mean overall IQ, Verbal IQ, and Performance IQ were, respectively, 90.95 for the group of patients and 113.97 for the controls (p<0.001); 91.41 for the group of patients and 112.31 for the controls (p<0.001); 92.34 for the group of patients and 113.38 for the controls (p<0.001). Scores for processing speed, distraction resistance, and perceptual organization were also significantly lower in patients. A direct and significant correlation was detected between socioeconomic status and cognitive scores. In the multivariate analysis, for the same socioeconomic status, a child with sickle cell anemia had an average IQ of 21.2 points lower than the mean IQ observed for the controls (p<0.001), indicating that the disease, adjusted for the socioeconomic effect, is a strong predictor of the overall IQ. CONCLUSION: The cognitive impairment of children with sickle cell anemia is severe and manifests even when the disease effect is adjusted to the socioeconomic status. In the authors' view, such impairment requires an early preventive approach in order to avoid this cognitive damage.


Subject(s)
Anemia, Sickle Cell/complications , Cognition Disorders/etiology , Adolescent , Brazil , Case-Control Studies , Child , Cognition Disorders/prevention & control , Cross-Sectional Studies , Female , Humans , Intelligence Tests , Male , Neuropsychological Tests , Socioeconomic Factors , Wechsler Scales
14.
Hematol Transfus Cell Ther ; 40(2): 166-181, 2018.
Article in English | MEDLINE | ID: mdl-30057991

ABSTRACT

Cerebrovascular disease, particularly stroke, is one of the most severe clinical complications associated with sickle cell disease and is a significant cause of morbidity in both children and adults. Over the past two decades, considerable advances have been made in the understanding of its natural history and enabled early identification and treatment of children at the highest risk. Transcranial Doppler screening and regular blood transfusions have markedly reduced the risk of stroke in children. However, transcranial Doppler has a limited positive predictive value and the pathophysiology of cerebrovascular disease is not completely understood. In this review, we will focus on the current state of knowledge about risk factors associated with ischemic stroke in patients with sickle cell disease. A search of PubMed was performed to identify studies. Full texts of the included articles were reviewed and data were summarized in a table. The coinheritance of alpha-thalassemia plays a protective role against ischemic stroke. The influence of other genetic risk factors is controversial, still preliminary, and requires confirmatory studies. Recent advances have established the reticulocyte count as the most important laboratory risk factor. Clinical features associated with acute hypoxemia as well as silent infarcts seem to influence the development of strokes in children. However, transcranial Doppler remains the only available clinical prognostic tool to have been validated. If our understanding of the many risk factors associated with stroke advances further, it may be possible to develop useful tools to detect patients at the highest risk early, improving the selection of children requiring intensification therapy.

15.
Hematol., Transfus. Cell Ther. (Impr.) ; 40(2): 166-181, Apr.-June 2018. tab
Article in English | LILACS | ID: biblio-953827

ABSTRACT

ABSTRACT Cerebrovascular disease, particularly stroke, is one of the most severe clinical complications associated with sickle cell disease and is a significant cause of morbidity in both children and adults. Over the past two decades, considerable advances have been made in the understanding of its natural history and enabled early identification and treatment of children at the highest risk. Transcranial Doppler screening and regular blood transfusions have markedly reduced the risk of stroke in children. However, transcranial Doppler has a limited positive predictive value and the pathophysiology of cerebrovascular disease is not completely understood. In this review, we will focus on the current state of knowledge about risk factors associated with ischemic stroke in patients with sickle cell disease. A search of PubMed was performed to identify studies. Full texts of the included articles were reviewed and data were summarized in a table. The coinheritance of alpha-thalassemia plays a protective role against ischemic stroke. The influence of other genetic risk factors is controversial, still preliminary, and requires confirmatory studies. Recent advances have established the reticulocyte count as the most important laboratory risk factor. Clinical features associated with acute hypoxemia as well as silent infarcts seem to influence the development of strokes in children. However, transcranial Doppler remains the only available clinical prognostic tool to have been validated. If our understanding of the many risk factors associated with stroke advances further, it may be possible to develop useful tools to detect patients at the highest risk early, improving the selection of children requiring intensification therapy.


Subject(s)
Cerebrovascular Disorders , Risk Factors , Ultrasonography, Doppler, Transcranial , Stroke , Anemia, Sickle Cell
16.
Rev Bras Hematol Hemoter ; 39(2): 108-114, 2017.
Article in English | MEDLINE | ID: mdl-28577646

ABSTRACT

BACKGROUND: The etiology of stroke, a severe complication of sickle cell anemia, involves inflammatory processes. However, the pathogenetic mechanisms are unknown. The aim of this study was to evaluate the influence of interleukin-10 polymorphisms and haplotypes on the risk of acute cerebral ischemia and high-risk transcranial Doppler in 395 children with sickle cell anemia from the state of Minas Gerais, Brazil. METHODS: Interleukin-10 haplotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and sequencing. The outcomes studied were acute cerebral ischemia and high-risk transcranial Doppler. Clinical data were retrieved from the children's records. RESULTS: There was no statistically significant difference in the frequencies of polymorphisms and haplotypes between children with and without acute cerebral ischemia or children with or without high-risk transcranial Doppler. These data are consistent with a previous report that showed an absence of association between interleukin-10 plasma levels and high-risk transcranial Doppler velocity in children with sickle cell anemia. CONCLUSION: Interleukin-10 haplotypes were not associated with the risk of acute cerebral ischemia or high-risk transcranial Doppler velocity in children with sickle cell anemia from the state of Minas Gerais, Brazil.

17.
Rev. bras. hematol. hemoter ; 39(2): 108-114, Apr.-June 2017. tab, graf
Article in English | LILACS | ID: biblio-898907

ABSTRACT

ABSTRACT Background: The etiology of stroke, a severe complication of sickle cell anemia, involves inflammatory processes. However, the pathogenetic mechanisms are unknown. The aim of this study was to evaluate the influence of interleukin-10 polymorphisms and haplotypes on the risk of acute cerebral ischemia and high-risk transcranial Doppler in 395 children with sickle cell anemia from the state of Minas Gerais, Brazil. Methods: Interleukin-10 haplotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and sequencing. The outcomes studied were acute cerebral ischemia and high-risk transcranial Doppler. Clinical data were retrieved from the children's records. Results: There was no statistically significant difference in the frequencies of polymorphisms and haplotypes between children with and without acute cerebral ischemia or children with or without high-risk transcranial Doppler. These data are consistent with a previous report that showed an absence of association between interleukin-10 plasma levels and high-risk transcranial Doppler velocity in children with sickle cell anemia. Conclusion: Interleukin-10 haplotypes were not associated with the risk of acute cerebral ischemia or high-risk transcranial Doppler velocity in children with sickle cell anemia from the state of Minas Gerais, Brazil.


Subject(s)
Humans , Male , Female , Child , Polymorphism, Genetic , Interleukin-10 , Ultrasonography, Doppler, Transcranial , Stroke , Anemia, Sickle Cell , Brain Ischemia , Child
18.
Pediatr Hematol Oncol ; 34(2): 53-65, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28548878

ABSTRACT

This study aimed at evaluating the use of immunophenotyping (IMP) in the identification of blast cells in the cerebrospinal fluid (CSF) of children and adolescents with acute lymphoblastic leukemia (ALL). Sixty-seven patients aged 18 years or younger were included. Fifty-five CSF samples were analyzed at initial diagnosis and 17 at the time of relapse. A cytological analysis (CA) was performed in all 72 samples, while IMP was done in 63. Blasts were identified in only three samples by CA, whereas all three samples were found negative by IMP, one of which had no isolation of nucleated cells after centrifugation. Among the samples analyzed by IMP, 11 showed a positive blast count, two of which had been inconclusive using CA. No equivalence was found between CA and IMP results (p = 0.55). CSF IMP positivity was not associated with other risk factors for ALL relapse. Among the 55 patients included at the time of diagnosis of ALL, eight relapsed during follow-up. Considering the cases of central nervous system (CNS) relapse, one of the patients belonged to the CSF IMP-positive group (11%) at diagnosis, and the other two cases, to the IMP-negative (5%) group. Detection of CSF blast cells using IMP was associated with a worse overall (p < 0.0001) and event-free survival (p < 0.0001). These results show that CSF IMP may be a useful additional method to conventional CA in the diagnosis of CNS involvement in ALL, and for the identification of high-risk subgroups that would benefit from an intensified therapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Blast Crisis , Immunophenotyping , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Adolescent , Blast Crisis/cerebrospinal fluid , Blast Crisis/diagnosis , Blast Crisis/therapy , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Infant , Male , Precursor Cell Lymphoblastic Leukemia-Lymphoma/cerebrospinal fluid , Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy , Prognosis
19.
Paediatr Int Child Health ; 37(1): 56-62, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27077628

ABSTRACT

BACKGROUND: The incidence of sickle cell disease (SCD) in newborns in Minas Gerais, Brazil is 1:1400, and is a considerable public health problem. Care for SCD at the primary level is still in its early stages and has not even been assessed even worldwide. AIM: To evaluate the effectiveness of a training programme about childhood SCD aimed at primary care professionals. METHODS: Assessment of a SCD training course for 263 community health agents of the Family Health Programme was conducted using pre- and post-testing of knowledge related to epidemiological and clinical issues and management of children with SCD. In one of the three municipalities evaluated, the group that participated in the training (n = 82) was compared with a control group (n = 75). Active methods that consider trainees as the key protagonists of the educational programme were used throughout. The control group did not receive any training on SCD during the period. RESULTS: There was a significant increase in correct answers to questions after the intervention in the three municipalities (P < 0.001). This increase was significant in all the domains of the questionnaire. In a multivariate analysis, professionals in the intervention group showed a post- and pre-test score difference that was 8.7 times higher than that in the control group (95% CI 7.8-9.6). The length of employment as a community health worker had a modest positive effect on the difference in scores (P = 0.046). CONCLUSION: The educational intervention proved effective in increasing health care providers' knowledge.


Subject(s)
Anemia, Sickle Cell/diagnosis , Anemia, Sickle Cell/therapy , Community Health Workers/education , Education, Medical , Health Knowledge, Attitudes, Practice , Nursing Staff/education , Primary Health Care , Adult , Brazil , Female , Humans , Male , Young Adult
20.
Ann Hematol ; 95(11): 1869-80, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27520094

ABSTRACT

Stroke is a severe clinical manifestation of sickle cell anemia (SCA). Despite the prognostic relevance of transcranial Doppler (TCD), more accurate tools to assess stroke risk in children with SCA are required. Here, we describe the effect of clinical, laboratory, and molecular features on the risk of stroke and high-risk TCD in children from the newborn cohort of Minas Gerais, Brazil. Outcomes studied were acute cerebral ischemia and high-risk TCD. Clinical and hematological data were retrieved from children's records. Genetic markers, which were known for their association with stroke risk, were genotyped by polymerase chain reaction/restriction fragment length polymorphism and sequencing. The cumulative incidence of acute cerebral ischemia by the age of 8 years was 7.4 % and that of high-risk TCD by the age of 11.5 years was 14.2 %. The final multivariate model for acute cerebral ischemia risk included high white blood cell count and reticulocyte count, acute chest syndrome rate, and the single nucleotide polymorphisms (SNPs) TEK rs489347 and TNF-α rs1800629. The model for high-risk TCD included high reticulocyte count and the SNPs TEK rs489347 and TGFBR3 rs284875. Children with risk factors should be considered for intensive risk monitoring and for intervention therapy.


Subject(s)
Anemia, Sickle Cell/complications , Brain Ischemia/blood , Reticulocyte Count , Acute Chest Syndrome/etiology , Acute Disease , Brain Ischemia/diagnostic imaging , Brain Ischemia/etiology , Child , Female , Follow-Up Studies , Haplotypes , Humans , Incidence , Infant, Newborn , Leukocyte Count , Male , Polymorphism, Single Nucleotide , Proteoglycans/genetics , Receptor, TIE-2/genetics , Receptors, Transforming Growth Factor beta/genetics , Risk , Risk Factors , Tumor Necrosis Factor-alpha/genetics , Ultrasonography, Doppler, Transcranial , beta-Globins/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...