Sickle cell disease has a great variability of clinical and biological expression that depends on modulatory and environmental genetic factors. This variability in clinical and biological expression encourages us to look for predictors of severity. Hemoglobin F and its genetic determinants are influencing prognostic factors. The objectives of this study were to: determine the prevalence of the Senegal haplotype in homozygous sickle cell patients, study the relationship between this haplotype and the hemoglobin F level and evaluate its influence on the complications of the disease. This is a cross-sectional prospective study that included 100 homozygous sickle cell patients aged over 15 years. A questionnaire was used to collect epidemiological, clinical and biological variables. The hemoglobin F level was measured by capillary method and the analysis of point mutations by restriction fragment length polymorphism (RFLP). These data were collected and analyzed with the software Epi-info 7.2. A value p ≤ 0.05 was considered significant. The Senegal haplotype was found in 90% of patients, of whom 58% were homozygous for this mutation and 32% were heterozygous. The hemoglobin F level averaged 9.5% ± 8.3% and correlated statistically significantly with the allelic frequency. However, only bilary lithiasis correlated with the Senegal haplotype (p <0.005). This study confirms the homogeneity of the Senegal haplotype in the Senegalese sickle cell population and its influence on the synthesis of hemoglobin F. On the other hand, it revealed the existence of a relationship between the Senegal haplotype and bilary lithiasis suggesting the role of this haplotype in the protection against polymerization and hemolysis globally.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common worldwide enzymopathy with approximately 400 million individuals affected. This inherited disease is sex-linked recessive inheritance. The high prevalence of certain variants of G6PD in different populations and ethnic groups increases the likelihood of finding associations with other pathologies. Sickle cell disease and thalassemia are the most common pathologies associated with G6PD deficiency. The aim of this study was firstly to study the prevalence of glucose-6-phosphate dehydrogenase deficiency (A-376/202) by molecular analysis in homozygous sickle cell patients, and secondly to study the influence of this association on the clinical severity of the disease. In a cross-sectional study, 100 patients aged 15 years with homozygous sickle cell disease in the stationary phase regularly monitored in a National Center for Blood Transfusion were included over a six-month period stretching from September 2015 to February 2016. An EDTA sampling tube was taken from each patient for the study of hematological parameters and a molecular study for the detection of mutations 376 and 202. Clinical, epidemiological and biological variables were collected using a questionnaire. Data was analyzed using Epi-info 7.2. The results of the study showed that the variant A-characterized by a double mutation (376/202) was found with a frequency of 13% (13/100) with a clear male predominance (p ˂ 0.006). Variant Awas statistically significantly associated with cholelithiasis (p˂0.031). This study is of therapeutic interest since the recognition of G6PD-deficient sickle cell disease would make it possible to take adequate preventive measures with respect to the taking of oxidizing drugs.

No abstract

No abstract

No abstract

The association between hyperuricemia and metabolic syndrome (MS) has been reported in many studies. The authors performed this cross-sectional study to determine the association between hyperuricemia and the MS among diabetic patients in Dakar. Type 2 diabetic patients received as part of their follow-up at the Marc Sankalé Center of Abass Ndao Hospital in Dakar were enrolled. For each patient, blood samples and 24 h urine collection were performed. Hyperuricemia was defined for uric acid concentrations > 416 µmol/l in men and > 357 µmol/l in women and the MS was evaluated according to WHO criteria. Statistical analysis was done using the XLSTAT 2019 software. A total of 153 type 2 diabetic patients were included with an average age of 56.63 years. Thirty-one percent (31%) of patients had metabolic syndrome and 32% of them had hyperuricemia. Significant correlations were found between serum uric acid and some components of the MS including triglyceride levels (r = 0.25, p = 0.002), microalbuminuria (r = 0.19, p = 0.018), and fasting glucose (r = -0.22, p = 0.005). The authors found that hyperuricemia is frequent in patients with MS and this could be considered as a biomarker associated with the presence of this syndrome.

High levels of hemoglobin F (HbF) could reduce the severity of sickle cell disease (SCD) by inhibiting hemoglobin S (HbS) polymerization. HbF expression is modulated by the Quantitative Trait Loci (QTLs) located on the HBS1L-MYB intergenic region (HMIP) (rs28384513) and intron 2 of the B-cell lymphoma/leukemia 11A (BCL11A) gene (rs4671393, rs1427407). To assess the impact of QTLs of HbF on clinical and biological parameters associated with the severity of sickle cell disease in a Senegalese pediatric population, 301 children with SCD not treated with hydroxyurea were recruited. The numbers of hospitalizations and VOC were estimated over 2 years. HbF levels were determined by HPLC. Three QTLs of HbF were genotyped by High Resolution Melting (HRM), two single nucleotide polymorphisms (SNPs) of BCL11A and one SNP of HMIP. Data analysis was performed using SPSS. The mean frequency of hospitalizations was 0.84 ± 1.29. The mean number of vaso-occlusive crises (VOC) episodes was 2.73 ± 1.98. The mean Hb concentration was 7.76 ± 1.05 g/dl. The mean HbS was 82.28 ± 4.78% and the mean HbF was 9.49 ± 5.12%. BCL11A (rs1427407) was associated with fewer hospitalizations. Both BCL11A SNPs were associated with increased HbF levels. BCL11A SNPs were associated with increased HbF levels, decreased HbS levels, and decreased hospitalizations (rs1427407). However, no association was noted between these SNPs and the number of VOC episodes. Thus, HbF QTLs are not the only genetic factors modulating the clinical severity of sickle cell disease, which suggests the involvement of other genetic factors such as alpha-thalassemia.

La Société française de biologie clinique « Marqueurs biochimiques de COVID-19 » a constitué un groupe de travail ayant pour but premier de faire le point, d'analyser, de suivre l'évolution des prescriptions biologiques en fonction du parcours de soins du patient et de rechercher des marqueurs d'évolutivité et de gravité de la maladie. Cette étude recouvre tous les secteurs publics et privés de la biologie médicale situés en France métropolitaine et ultra-marine et s'étend également à la francophonie. Dans cet article, sont présentés les témoignages et données obtenus pour le sous-groupe de travail « Outre-mer et francophonie » composé de 45 correspondants volontaires, répartis dans 20 régions du monde. Au vu d'une propagation décalée du virus SARS-CoV-2, les régions d'Outremer et les régions francophones ont bénéficié des retours d'expériences des premiers territoires confrontés au COVID-19. Ainsi, l'entrée du virus ou sa propagation sous forme épidémique ont pu être évitées grâce à la fermeture rapide des frontières. Les territoires ultramarins dépendent très fortement des liaisons aériennes et/ou maritimes avec la métropole ou avec le continent voisin. L'isolement de ces pays est responsable de difficultés d'approvisionnement en réactifs et a nécessité des commandes en urgence et la mise en place de stocks de plusieurs mois, afin d'éviter les pénuries et de maintenir une prise en charge adéquate des patients. De plus, dans les pays situés en zones tropicales ou intertropicales, le diagnostic de COVID-19 est compliqué par la présence de diverses zoonoses (dengue, Zika, paludisme, leptospirose, etc.).