Clinical, hematological, and molecular characterization of sickle cell anemia pediatric patients from two different cities in Brazil

Lyra, Isa Menezes; Gonçalves, Marilda Souza; Braga, Josefina Aparecida Pellegrini; Gesteira, Maria de Fátima Malvar; Carvalho, Maria Helena; Saad, Sara Teresinha Olalla; Figueiredo, Maria Stella; Costa, Fernando Ferreira

doi:10.1590/s0102-311x2005000400032

Cited by 33 publications

(23 citation statements)

References 7 publications

(8 reference statements)

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“…The lower percentage of severe proliferative retinopathy found among HBSS patients when compared to HBSC patients could be attributed to auto infarction or a spontaneous regression of proliferative retinopathies, a phenomenon described in sickle cell disease. (21) A milder disease phenotype was previously described among these patients, (22,23) protecting against the early vessel occlusion described in HBSS 1 and contributing to proliferative lesion development among the older patients. In addition, the age-related variation in proliferative lesions observed in HBSC patients could be related to more severe anemia, resulting in a decrease in blood viscosity.…”

Section: Discussionmentioning

confidence: 74%

Ocular lesions in sickle cell disease patients from Bahia, Brazil

Cury

Boa‐Sorte

Lyra³

et al. 2010

Rev. bras.oftalmol.

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Objective: The present study aims to describe ocular alterations in sickle cell disease patients in Bahia, a Northeast state, with the highest prevalence of the disease in Brazil. Methods: We carried out a cross-sectional study in a group of 146 (292 eyes) sickle cell disease patients (90 HBSS and 56 HBSC). Ophthalmologic examination including indirect binocular ophthalmoscopy was performed. Examination was completed by fluorescein angiography to detect retinal lesions. Results: The most frequent ocular lesions identified were "vascular tortuosity" and "black sunburst". Proliferative retinopathy was found in 22 (12.2%) eyes of HBSS patients and 25 (22.3%) eyes of HBSC patients (OR=2.06; CI95%: 1.5-4.06, p=0.022); Its frequency was higher among HBSS patients aged 20-39 years, while in HBSC patients, it peaked after 40 years (35.7% and 42.8%) and dropped sharply afterwards. Conclusion: Proliferative retinopathy was described as early as 10 years of age in both patients groups. Proliferative sickle retinopathy can result in blindness and the knowledge of the most prevalent ocular alterations and age risk will be important to establish a protocol of ophthalmologic follow-up, in order to prevent a severe visual loss and increase patient's life quality.

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Section: Discussionmentioning

confidence: 74%

Ocular lesions in sickle cell disease patients from Bahia, Brazil

Cury

Boa‐Sorte

Lyra³

et al. 2010

Rev. bras.oftalmol.

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“…In Brazil, 700 to 1000 infants with SCD are estimated to be born each year (1). Even with the same inherited DNA mutation within the ß-globin gene, patients present a notorious clinical heterogeneity.…”

Section: Introductionmentioning

confidence: 99%

The clinical impact of MTHFR polymorphism on the vascular complications of sickle cell disease

Neto¹,

Lourenço²,

Noguti³

et al. 2006

Braz J Med Biol Res

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Sickle cell disease (SCD) is one of the most common inherited diseases in the world and the patients present notorious clinical heterogeneity. It is known that patients with SCD present activation of the blood coagulation and fibrinolytic systems, especially during vaso-occlusive crises, but also during the steady state of the disease. We determined if the presence of the factor V gene G1691A mutation (factor V Leiden), the prothrombin gene G20210A variant, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism may be risk factors for vascular complications in individuals with SCD. We studied 53 patients with SCD (60% being women), 29 with SS (sickle cell anemia; 28 years, range: 13-52 years) and 24 with SC (sicklehemoglobin C disease; 38.5 years, range: 17-72 years) hemoglobinopathy. Factor V Leiden, MTHFR C677T polymorphism, and prothrombin G20210A variant were identified by PCR followed by further digestion of the PCR product with specific endonucleases. The following vascular complications were recorded: stroke, retinopathy, acute thoracic syndrome, and X-ray-documented avascular necrosis. Only one patient was heterozygous for factor V Leiden (1.8%) and there was no prothrombin G20210A variant. MTHFR 677TT polymorphism was detected in 1 patient (1.8%) and the heterozygous form 677TC was observed in 18 patients (34%, 9 with SS and 9 with SC disease), a prevalence similar to that reported by others. No association was detected between the presence of the MTHFR 677T allele and other genetic modulation factors, such as α-thalassemia, ß-globin gene haplotype and fetal hemoglobin. The presence of the MTHFR 677T allele was associated with the occurrence of vascular complications in SCD, although this association was not significant when each complication was considered separately. In conclusion, MTHFR C677T polymorphism might be a risk factor for vascular complications in SCD.

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“…Diferentes estudios en Colombia muestran una prevalencia de hasta 10 % de hemoglobina S en población infantil (11,19,28,29), y la forma heterocigota (AS) es la presentación más común, igual que en otros países de América, como México, Venezuela, Costa Rica y Brasil (27,(30)(31)(32)(33).…”

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