[Prevalence of hemoglobin S in the State of Paraná, Brazil, based on neonatal screening]

Sickle Cell Anaemia Prevalence Among Newborns in the Brazilian Amazon-Savanna Transition Region

Sickle cell anaemia is one of the most common hemoglobinopathies worldwide and an important public health problem in Brazil. This study evaluated the prevalence of sickle cell anaemia and its traits in newborns from the Amazon-Savanna Transition Region in the state of Maranhão, Brazil. A cross-sectional study was carried out, based on data from neonatal screening tests performed in 2013-2015 in Maranhão. The Hardy-Weinberg theorem was applied to analyse the frequency of expected homozygotes based on HbSS phenotype. A spatial-temporal distribution analysis was performed to delimit the regions with the greatest number of newborn cases with sickle cell anaemia. Of 283,003 newborns, 162 were found to have sickle cell anaemia, while 10,794 had a sickle cell trait, with a prevalence of 0.05% and 3.8%, respectively. The prevalence of expected homozygotes was higher in the North Region and in the state capital of Maranhão. This study may contribute to existing social and public health actions or the creation of new strategies for sickle cell disease in endemic areas in Brazil to improve the quality of life.

Prevalence of anemia in schools of the metropolitan region of Curitiba, Brazil

Background

Anemia during childhood is one of the biggest public health problems worldwide, including Brazil. Insufficient or abnormal production of hemoglobin, loss of iron and excessive destruction of red blood cells are the most common causes of anemia. Among the reasons of anemia, iron deficiency accounts for 50% of anemia cases in developing countries. Affected individuals present a wide range of clinical problems, including delayed neuropsychomotor progression, impaired cellular immunity and reduction of intellectual capacity. This study aimed to evaluate the prevalence of anemia in children attending public schools in the metropolitan region of Curitiba, Paraná, Brazil.

Method

A retrospective study was conducted of 409 children aged 8–12 years old included in an extension project of the Universidade Federal do Paraná. The results of complete blood count and hemoglobin electrophoresis of all children were evaluated. Anemia was considered when the hemoglobin levels were <11.5 g/dL.

Results

The prevalence of anemia was found to be 2.2% of the population studied, with hypochromic microcytic anemia being the most common type. Seven children had sickle cell trait and one had β-thalassemia.

Conclusion

The prevalence of anemia in this study was considered normal according the World Health Organization classification, which is different from the data found in other Brazilian regions.

Clinical and laboratory profile of patients with sickle cell anemia

OBJECTIVE

This study aimed to describe and analyze clinical and laboratory characteristics of patients with sickle cell anemia treated at the Hemominas Foundation, in Divinópolis, Brazil. Furthermore, this study aimed to compare the clinical and laboratory outcomes of the group of patients treated with hydroxyurea with those patients that were not treated with hydroxyurea.

METHODS

Clinical and laboratorial data were obtained by analyzing medical records of patients with sickle cell anemia.

RESULTS

Data from the medical records of 50 patients were analyzed. Most of the patients were female (56%), aged between 20 and 29 years old. Infections, transfusions, cholecystectomy, splenectomy and systemic arterial hypertension were the most common clinical adverse events of the patients. The most frequent cause of hospitalization was painful crisis. The majority of patients had reduced values of hemoglobin and hematocrit (8.55±1.33g/dL and 25.7±4.4%, respectively) and increased fetal hemoglobin levels (12±7%). None of the clinical variables was statistically significant on comparing the two groups of patients. Among hematological variables only hemoglobin and hematocrit levels were statistically different between patients treated with hydroxyurea and untreated patients (p-value=0.005 and p-value=0.001, respectively).

CONCLUSION

Sickle cell anemia requires treatment and follow-up by a multiprofessional team. A current therapeutic option is hydroxyurea. This drug reduces complications and improves laboratorial parameters of patients. In this study, the use of the drug increased the hemoglobin and hematocrit levels of patients.

Evaluation of a neonatal screening program for sickle-cell disease

OBJECTIVE

Evaluate the Neonatal Screening Program of the Health Secretariat of the State of Santa Catarina for sickle-cell disease, from January 2003 to December 2012, regarding program coverage and disease frequency.

METHODS

Descriptive, observational, cross-sectional study with retrospective data collection. The variables analyzed were: number of live births in the State of Santa Catarina; number of screened children; number of children diagnosed with sickle-cell trait and sickle-cell disease; type of sickle-cell disease diagnosed; age at the time of sample collection, ethnicity/skin color, gender, and origin of children with sickle-cell disease. Descriptive measures and frequency tables were used for data analysis.

RESULTS

During the study period, there were 848,833 live births and 730,412 samples were screened by the program, resulting in a coverage of 86.0%. There were 6173 samples positive for sickle-cell trait and 39 for sickle-cell disease. Among children with sickle-cell disease, the median age at the time of sample collection was 6 days. Regarding the ethnicity/skin color, 25 (64.1%) children were white, seven were black, and seven others were not specified. The Midwest and the Highland (Planalto Serrano) of Santa Catarina were the regions with the highest incidence of sickle-cell disease.

CONCLUSION

Coverage by the Neonatal Screening Program of Santa Catarina is good, but did not demonstrate an improvement trend over the years. The frequency of sickle-cell disease is low and lower than in the North, Northeast, and Midwest regions. The median age in days at the time of collection is older than the age recommended by the Ministry of Health.

Prevalence of β(S)-globin gene haplotypes, α-thalassemia (3.7 kb deletion) and redox status in patients with sickle cell anemia in the state of Paraná, Brazil

The aim of this study was to determine the frequency of beta S-globin gene (β^S globin) haplotypes and alpha thalassemia with 3.7 kb deletion (−α^3.7kb thalassemia) in the northwest region of Paraná state, and to investigate the oxidative and clinical-hematological profile of β^S globin carriers in this population. Of the 77 samples analyzed, 17 were Hb SS, 30 were Hb AS and 30 were Hb AA. The β^Sglobin haplotypes and −α^3.7kb thalassemia were identified using polymerase chain reaction.Trolox equivalent antioxidant capacity (TEAC) and lipid peroxidation (LPO) were assessed spectophotometrically. Serum melatonin levels were determined using high-performance liquid chromatography coupled to coulometric electrochemical detection. The haplotype frequencies in the SS individuals were as follows: Bantu- 21 (62%), Benin - 11 (32%) and Atypical- 2 (6%). Bantu/Benin was the most frequent genotype. Of the 47 SS and AS individuals assessed, 17% (n = 8) had the −α^3.7kb mutation. Clinical manifestations, as well as serum melatonin, TEAC and LPO levels did not differ between Bantu/Bantu and Bantu/Benin individuals (p > 0.05). Both genotypes were associated with high LPO and TEAC levels and decreased melatonin concentration. These data suggest that the level of oxidative stress in patients with Bantu/Bantu and Bantu/Benin genotypes may overload the antioxidant capacity.

Stroke in sickle cell anemia patients: a need for multidisciplinary approaches

Sickle cell anemia (SCA) is an autosomal recessive disorder, with Mendelian inheritance pattern, caused by a missense mutation in the β-polypeptide chain of the hemoglobin B. SCA preferentially affects populations in countries where malaria was/is present (e.g. Africa, USA, Brazil). Thereby, in USA, the incidence of SCA is relatively high, around 1/500, and the prevalence is about 1/1000. In Brazil, SCA represents a major public health problem with an incidence ranging from 1/2000 to 1/600 depending on the regions. Homozygotic patients present more severe medical conditions and reduced life expectancy than heterozygous individuals who generally are asymptomatic. Eventually, this life-threatening disease displays a complex etiology owing to heterogeneous phenotypes and clinical outcomes, subsequently affecting the management of the patients. One of the most critical complications associated with SCA is stroke, a leading neurologic cause of death and disability. About 24% of SCA patients have a stroke by the age of 45 and 11% by the age of 20. From the general population, twin and familial aggregation studies as well as genome-wide association studies (GWAS), mostly in pediatric populations with ischemic stroke, showed that the risk of stroke has a substantial genetic component. Nevertheless, to fully characterize genomic contributors of stroke and permit reliable personalized medicine, multidisciplinary studies incorporating knowledge from clinical medicine, epidemiology, genetics, and molecular biology, are required. In this manuscript, stroke in SCA patients is extensively reviewed with emphasis to the US and Brazilian populations. Recent advances in genomics analysis of stroke in SCA patients are highlighted.

Protective effect of flavonoids against reactive oxygen species production in sickle cell anemia patients treated with hydroxyurea

OBJECTIVE

The aim of this study was to evaluate the protective effects of quercetin, rutin, hesperidin and myricetin against reactive oxygen species production with the oxidizing action of tert-butylhydroperoxide in erythrocytes from normal subjects and sickle cell anemia carriers treated with hydroxyurea.

METHODS

Detection of intracellular reactive oxygen species was carried out using a liposoluble probe, 2',7'-dichlorfluorescein-diacetate (DCFH-DA). A 10% erythrocyte suspension was incubated with flavonoids (quercetin, rutin, hesperidin or myricetin; 30, 50, and 100 µmol/L), and then incubated with tert-butylhydroperoxide (75 µmol/L). Untreated samples were used as controls.

RESULTS

Red blood cell exposure to tert-butylhydroperoxide resulted in significant increases in the generation of intracellular reactive oxygen species compared to basal levels. Reactive oxygen species production was significantly inhibited when red blood cells were pre-incubated with flavonoids, both in normal individuals and in patients with sickle cell anemia. Quercetin and rutin had the highest antioxidant activity, followed by myricetin and hesperidin.

CONCLUSION

Flavonoids, in particular quercetin and rutin, showed better antioxidant effects against damage caused by excess reactive oxygen species characteristic of sickle cell anemia. Results obtained with patients under treatment with hydroxyurea suggest an additional protective effect when associated with the use of flavonoids.

Prevalence of sickle cell disease and sickle cell trait in national neonatal screening studies

Sickle cell anemia is the best known hereditary blood disorder; there are serious complications associated with the condition. Diagnosis and early intervention reduce morbidity and mortality. These benefits have resulted in the widespread use of newborn screening education programs. In Brazil, the National Neonatal Screening Program established by decree 822/01 included sickle cell disease in the list of diseases tested in the so called "heel prick test". Since then, national studies of the results of this program have been periodically published. To review the literature in order to assess the prevalence of sickle cell trait and sickle cell anemia from data of national neonatal screening studies on hemoglobin S (Hb S). A bibliographic review was carried out using the key words: sickle cell anemia & hemoglobinopathies & neonatal screening & Brazil in the Bireme and SciELO databases. Original Brazilian studies presenting data on prevalence of the sickle cell trait (Hb AS) and sickle cell anemia (Hb SS) based on neonatal screening for Hb S were analysed. Twelve original national studies were identified with prevalences varying from 1.1% to 9.8% for the sickle cell trait and from 0.8 to 60 per 100,000 live births for sickle cell disease in different Brazilian regions. Conclusion: Neonatal screening for Hb S is a very useful method to assess the prevalence of sickle cell trait (Hb AS) and sickle cell anemia (Hb SS) in Brazil. There is a heterogeneous distribution of this disease with the highest prevalence in the northeastern region and the lowest prevalence in the south.

Neonatal screening for hemoglobinopathies: results of a public health system in South Brazil

AIM

The aim of this study was to estimate the prevalence of hemoglobinopathies in South Brazil.

METHODS

Samples of dried blood spots collected by heel prick in neonates were evaluated by isoeletric focusing and/or high-performance liquid chromatography techniques. All variants were characterized at the molecular level.

RESULTS

A total of 437,787 samples were evaluated. Among these, 6391 showed an abnormal hemoglobin pattern. These included 48 cases (0.01%) of sickle cell disorders (33 hemoglobin SS [Hb SS], 7 Hb SC, 7 Hb S/beta thalassemia, 1 Hb SD), 1 neonate who was homozygous for beta thalassemia, 6272 (1.4%) newborns who were heterozygous for Hb S, C, or D, and 71 (0.02%) neonates who were carriers for rare hemoglobin variants. Most of these rare variants were identified for the first time in Brazil.

CONCLUSIONS

Comparing these results with those obtained in other Brazilian regions, we observe a highly heterogeneous distribution. This knowledge is useful in healthcare planning and allocation of resources, as well as identifying at-risk couples, which will assist with disease prevention.

[Prevalence of sickle cell trait and sickle cell anemia among newborns in the Federal District, Brazil, 2004 to 2006]

To determine the prevalence of sickle cell trait and sickle cell anemia among newborns in the Federal District, Brazil, a cross-sectional prevalence study covering the years 2004 to 2006 was conducted. Test results reported from the Neonatal Screening Program in the Federal District Health Department from 2004 to 2006 were analyzed, and prevalence rates were calculated. Neonatal blood samples were tested by isoelectric focalization. From January 2004 to December 2006, 116,271 newborns were tested for hemoglobinopathies, corresponding to 85% of all live births from mothers residing in the Federal District. The study identified 3,760 newborns with sickle cell trait (Hb AS) and 109 with sickle cell anemia (Hb SS). The prevalence rates were 323 (Hb AS) and 9 (Hb SS) per 10,000 live births. The high prevalence of sickle cell trait highlights the importance of neonatal screening in the Federal District to support work by health managers and professionals for planning educational measures and reducing the morbidity associated with sickle cell disease.