Pollution of water in Africa: a review of contaminants and fish as biomonitors and analytical methodologies-the case of Senegal.

Environmental pollution is one of the major problems facing human health, ecosystems, and biodiversity. This is particularly the case for water quality in Senegal. Fish can be used as a biomonitor of pollution by accumulating pollutants from the environment through their tissues. Fish is an indispensable element in the assessment of the quality of the environment due to the diversity of biological cycles and their position in the food chain. Fish, which is very sensitive to chemical and bacterial pollution, concentrates pollutants and is a good indicator of water quality. This review presents water pollution in Senegal and the possibility of using fish as an ideal monitoring matrix for marine environments, to detect the concentration of heavy metals and organic pollutants. The different extraction and analytical techniques used for fish biomonitoring will be also described.

Biomarkers of sickle cell nephropathy in Senegal.

Sickle cell anemia (SCA) is caused by a single point variation in the ß-globin gene (HBB): c.20A> T (p.Glu7Val), in homozygous state. SCA is characterized by sickling of red blood cells in small blood vessels which leads to a range of multiorgan complications, including kidney dysfunction. This case-control study aims at identifying sickle cell nephropathy biomarkers in a group of patients living with SCA from Senegal. A total of 163 patients living with SCA and 177 ethnic matched controls were investigated. Biological phenotyping included evaluation of glycemia, glucosuria, albuminuria, proteinuria, tubular proteinuria, serum creatinine, urine creatinine, urine specific gravity and glomerular filtration rate. Descriptive statistics of biomarkers were performed using the χ2 -test, with the significance level set at p<0.05. Patients living with SCA had a median age of 20 years (range 4 to 57) with a female sex frequency of 53.21%. The median age of the control participants was 29 years (range: 4-77) with a female sex frequency of 66.09%. The following proportions of abnormal biological indices were observed in SCA patients versus (vs.) controls, as follows: hyposthenuria: 35.3%vs.5.2% (p<0.001); glomerular hyperfiltration: 47.66%vs.19.75% (p<0.001), renal insufficiency: 5.47%vs.3.82% (p = 0.182); microalbuminuria: 42.38%vs.5.78% (p<0.001); proteinuria: 39.33%vs.4.62% (p<0.001); tubular proteinuria: 40.97%vs.4.73% (p<0.001) and microglucosuria: 22.5%vs.5.1% (p<0.001). This study shows a relatively high proportion of SCA nephropathy among patients living with SCA in Senegal. Microglucosuria, proteinuria, tubular proteinuria, microalbuminuria, hyposthenuria and glomerular hyperfiltration are the most prevalent biomarkers of nephropathy in this group of Senegalese patients with SCA.

Application of the QuEChERS method for the determination of pesticides, PAHs and PCBs in fish in Senegal.

Pollution of water by persistent organic pollutants is well described; however, little is known about the accumulation of these pollutants by aquatic organisms. For this reason, a method based on QuEChERS extraction and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) was developed for the determination of pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in the muscles of five fish species from the bay of Soumbedioune (Dakar, Senegal). This method shows good recoveries of extraction (68.2-98.1% for pesticides, 83.87-98.10% for PAHs and 81.30-98.15% for PCBs), precision (% RSD ≤ 1%), sensitivity (LODs between 0.001 and 0.079 ng g-1), linearity (R2 ≥ 0.99) and repeatability and reproducibility, evaluated for three concentration levels (10 ng g-1, 200 ng g-1 and 500 ng g-1), ≤ 15% for the majority of pollutants under study except for alachlor, atrazine, acetochlor, dicofol, deltamethrin and dichlorvos where a RSD ≥ 20% was determined for the 10 ng g-1 concentration. Organic pollutants have been detected in fish from the Soumbedioune coast demonstrating the necessity of a regular survey of water and fish in order to protect the populations.

Effects of Senegal haplotype (Xmn1-rs7412844), alpha-thalassemia (3.7kb HBA1/HBA2 deletion), NPRL3-rs11248850 and BCL11A-rs4671393 variants on sickle cell nephropathy.

OBJECTIVE: Sickle cell anemia (SCA) can cause substantial kidney dysfunction resulting in sickle cell nephropathy, which may be affected by the presence of modifier genes. This study evaluates the effects of some modifier genes on sickle cell nephropathy. METHODS: Patients living with SCA were recruited. Alpha-thalassemia (3.7kb HBA1/HBA2 deletion) was genotyped using gap PCR multiplex. Senegal haplotype (Xmn1-rs7412844), BCL11A-rs4671393 and NPRL3-rs11248850 were genotyped using Mass Array. The effects of variants on kidney dysfunction were then evaluated using multivariate analysis. RESULTS: The number of patients living with SCA included in this study was 162 with a median age of 20 years [minimum-maximum: 4-57] and a female frequency of 53.21%. Senegal haplotype, BCL11A-rs4671393 variant were protective factors against albuminuria stage A2 with an odds ratio (OR) of 0.22 (95% CI 0.05-0.90) and 0.27 (95% CI 0.08-0.96) respectively. The combination NPRL3-rs11248850 variant - 3.7kb HBA1/HBA2 deletion was a protective factor against albuminuria stage A2 (OR = 0.087, 95% Cl 0.01-0.78) but it was a risk factor for glomerular hyperfiltration (OR = 17.69, 95% CI 1.85-169.31). CONCLUSIONS: All four variants displayed a protective effect against albuminuria stage A2. The combination alpha-thalassemia - NPRL3-rs11248850 variant is a risk factor for glomerular hyperfiltration.

Estimating the risk of child mortality attributable to sickle cell anaemia in sub-Saharan Africa: a retrospective, multicentre, case-control study.

BACKGROUND: Many children with sickle cell disease living in sub-Saharan Africa die before reaching age 5 years. We estimate the child mortality associated with sickle cell anaemia using an indirect approach to overcome the absence of systematic screening at birth. METHODS: We did a retrospective, multicentre, case-control study in five countries in sub-Saharan Africa (Burkina Faso, Democratic Republic of the Congo, Côte d'Ivoire, Mali, and Senegal). Women with at least one child with a confirmed SS haemoglobin phenotype (sickle cell anaemia) and who had at least three (alive or deceased) children from the same father born more than 5 years ago were recruited at an outpatient consultation in a sickle cell disease care centre. Women who had children without sickle cell disease (control group) were recruited from the same area, with inclusion criteria of being a neighbour or relative of one of the mothers included in the study who had a child with sickle cell anaemia, having no child or other first-degree relative with major sickle cell syndrome, having at least three children (alive or deceased) born more than 5 years ago, and having a confirmed haemoglobin AA phenotype. During the mothers' interview, we collected data concerning the mortality of siblings from the same father of a child with sickle cell anaemia and characteristics of the family, such as age at the time of the survey and the level of education of both parents. Mortality rates were calculated for children younger than 1, 5, and 10 years using the Kaplan-Meier method after excluding the index children. We assumed, as per Mendel law, that in families who have a child with sickle cell anaemia and healthy heterozygous parents, 25% of children born on average have sickle cell anaemia. A multivariate Cox model was used to describe socioeconomic and geographical factors associated with mortality. FINDINGS: Between Sept 1, 2017, and Nov 30, 2020, 1563 women who had at least one child with sickle cell anaemia and 4972 women from the same neighbourhood who had children without sickle cell disease were assessed for eligibility. Of 1563 women, 248 were excluded because the genotype of the index child was SC or S ß-thalassaemia. 1315 families with cases of sickle cell anaemia and 1243 control families were included in the study. The median age of children (alive) was 14 years (IQR 8-20) in control families and 13 years (8-19) in families with cases of sickle cell anaemia. 5532 [50·6%] of 10 924 children were male. Mortality rates were 15·3% (95% CI 13·3-17·3) for children with sickle cell anaemia younger than 1 year, 36·4% (33·4-39·4) for those younger than 5 years, and 43·3% (39·3-47·3) for those younger than 10 years. Multivariate Cox survival analysis showed that belonging to a family with sickle cell anaemia (hazard ratio [HR] 2·23, 95% CI 1·96-2·54), living in the Democratic Republic of the Congo (HR 1·64, 1·34-2·01), having an older parent (father or mother age had similar effect; HR 1·12, 1·05-1·19 per 10 years of age), or a significantly higher global Multidimensional Poverty Index (HR 1·09, 1·03-1·14), independently increased the risk of mortality. Whereas, living in Senegal (HR 0·70, 95% CI 0·57-0·86) or having a mother with higher education (high school HR 0·66, 0·55-0·80 or advanced HR 0·41, 0·28-0·61) independently decreased the risk of mortality. INTERPRETATION: Although higher than in high-income countries and affected by non-specific socioeconomic factors, the estimated mortality in children with sickle cell anaemia living in sub-Saharan African cities was substantially lower than previous estimates, suggesting an improvement of sickle cell anaemia care in this setting. FUNDING: Fondation Pierre Fabre. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Polymorphisms in Inflammatory Genes Modulate Clinical Complications in Patients With Sickle Cell Disease.

Sickle cell disease (SCD), the most common monogenic disease worldwide, is marked by a phenotypic variability that is, to date, only partially understood. Because inflammation plays a major role in SCD pathophysiology, we hypothesized that single nucleotide polymorphisms (SNP) in genes encoding functionally important inflammatory proteins might modulate the occurrence of SCD complications. We assessed the association between 20 SNPs in genes encoding Toll-like receptors (TLR), NK cell receptors (NKG), histocompatibility leukocyte antigens (HLA), major histocompatibility complex class I polypeptide-related sequence A (MICA) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), and the occurrence of six SCD clinical complications (stroke, acute chest syndrome (ACS), leg ulcers, cholelithiasis, osteonecrosis, or retinopathy). This study was performed in a cohort of 500 patients. We found that the TLR2 rs4696480 TA, TLR2 rs3804099 CC, and HLA-G, rs9380142 AA genotypes were more frequent in patients who had fewer complications. Also, in logistic regression, the HLA-G rs9380142 G allele increased the risk of cholelithiasis (AG vs. AA, OR 1.57, 95%CI 1.16-2.15; GG vs. AA, OR 2.47, 95%CI 1.34-4.64; P = 0.02). For SNPs located in the NKG2D loci, in logistic regression, the A allele in three SNPs was associated with a lower frequency of retinopathy, namely, rs2246809 (AA vs. GG: OR 0.22, 95%CI 0.09-0.50; AG vs. GG: OR 0.47, 95%CI 0.31-0.71; P = 0.004, for patients of same origin), rs2617160 (AT vs. TT: OR 0.67, 95%CI 0.48-0.92; AA vs. TT: OR 0.45, 95%CI 0.23-0.84; P = 0.04), and rs2617169 (AA vs. TT: OR 0.33, 95%CI 0.13-0.82; AT vs. TT: OR 0.58, 95%CI 0.36-0.91, P = 0.049, in patients of same SCD genotype). These results, by uncovering susceptibility to, or protection against SCD complications, might contribute to a better understanding of the inflammatory pathways involved in SCD manifestations and to pave the way for the discovery of biomarkers that predict disease severity, which would improve SCD management.

Influence of Oxidative Stress Biomarkers and Genetic Polymorphisms on the Clinical Severity of Hydroxyurea-Free Senegalese Children with Sickle Cell Anemia.

Oxidative stress would play a role in the pathophysiology of sickle cell anemia (SCA). We tested the impact of common SCA genetic modifiers (alpha-thalassemia, G6PD deficiency, HbF quantitative trait loci; QTL) and pro/antioxidant genes polymorphisms (SOD2 rs4880, XO rs207454, MPO rs233322) on oxidative stress biomarkers (AOPP, MDA, MPO, XO, MnSOD, CAT, GPx) and clinical severity in 301 Senegalese SCA hydroxyurea-free children at steady-state (median age 9.1 years, sex ratio H/F = 1.3). Plasma oxidative stress biomarkers were compared with those of a control group (AA). CAT activity, AOPP, and MDA levels were higher in SCA than in AA individuals while XO, GPX, and MnSOD activities were lower. The presence of alpha-thalassemia decreased MDA level and MPO activity but no effect of the HbF QTL or G6PD deficiency was observed. SCA children who experienced their first hospitalized complication before 3 years old had higher MnSOD and CAT activities than the other children while those with no hospitalized VOC in the previous 2 years presented higher GPX activity. Age of the first hospitalized complication and AOPP levels were affected by the MPO rs2333227 SNP. Our results suggest that alpha-thalassemia modulates oxidative stress in SCA, presumably because of a reduction in the MPO activity.

Iconic Visualization of Sickle Cell Patients Current and Past Health Status.

Rapid access to patient overall health status is essential for a physician during a medical consultation. The use of a HIS for the management of neonatal screening and follow-up of sickle cell disease patients at CERPAD in the Saint-Louis region of Senegal leads the patient electronic records growing in volume and complexity. To facilitate access to relevant information and shortens the time required to analyze and understand these clinical data, an original solution is to set up a data visualization system. In this article, we propose the integration of two iconic visualization tools into the SIMENS-CERPAD module designed for sickle cell screening and healthcare. The two tools use the VCM iconic language and consist of a simplified anatomical schema showing the current health status of the patient and a timeline to visualize its temporal evolution.

SIMENS-LIS4SC, a Laboratory Information System for Biological Tests of Sickle Cell Screening and Healthcare.

Neonatal screening and ongoing follow-up of children with sickle cell disease are essential to reduce the mortality caused by this disease. To ensure care continuity, it is essential to include in the patient's record the history and details of biological tests. Thus, it is necessary to provide a Laboratory Information System for electronic management of biological test prescription and results, and the laboratory system must integrate well with Health Information Systems. In this paper, we propose a Laboratory Information System for the management of biological tests for the neonatal screening and healthcare of sickle cell disease in Senegal.

Combined and differential effects of alpha-thalassemia and HbF-quantitative trait loci in Senegalese hydroxyurea-free children with sickle cell anemia.

BACKGROUND: Our objective was to investigate the combined and differential effects of alpha-thalassemia -3.7 kb deletion and HbF-promoting quantitative trait loci (HbF-QTL) in Senegalese hydroxyurea (HU)-free children and young adults with sickle cell anemia (SCA). PROCEDURE: Steady-state biological parameters and vaso-occlusive crises (VOC) requiring emergency admission were recorded over a 2-year period in 301 children with SCA. The age of the first hospitalized VOC was also recorded. These data were correlated with the alpha-globin and HbF-QTL genotypes. For the latter, three different genetic loci were studied (XmnI, rs7482144; BCL11A, rs1427407; and the HBS1L-MYB region, rs28384513) and a composite score was calculated, ranging from zero (none of these three polymorphisms) to six (all three polymorphisms at the homozygous state). RESULTS: A positive clinical impact of the HbF-QTL score on VOC rate, HbF, leucocytes, and C-reactive protein levels was observed only for patients without alpha-thalassemia deletion. Conversely, combination of homozygous -3.7 kb deletion with three to six HbF-QTL was associated with a higher VOC rate. The age of the first hospitalized VOC was delayed for patients with one or two alpha-thalassemia deletions and at least two HbF-QTL. CONCLUSION: Alpha-thalassemia -3.7 kb deletion and HbF-QTL are modulating factors of SCA clinical severity that interact with each other. They should be studied and interpreted together and not separately, at least in HU-free children.

Towards an Information System for Sickle Cell Neonatal Screening in Senegal.

Sickle cell disease is a major public health problem in Senegal. It is an inherited disease that affects about 300,000 births worldwide each year. There are 70 million people affected worldwide, 80% of whom live in sub-Saharan Africa. In Senegal, 1 in 10 people carries the sickle cell disease gene. This disease requires follow-up from birth and for life. The patient care requires the integration and the analysis of biological, clinical, social, economic data., etc. In this paper, we propose a health information system for data management of the blood sampling from the newborn at the maternity wards and the disease screening at the Center for Research and Ambulatory Care of the Sickle Cell Disease (CERPAD).

A Toll-like receptor 2 genetic variant modulates occurrence of bacterial infections in patients with sickle cell disease.

Despite adequate immunization and penicillin prophylaxis, bacterial infections remain a leading cause of morbidity and mortality in patients with sickle cell disease (SCD). Besides hyposplenism, inflammatory and genetic factors might modulate their susceptibility to bacterial infections. We performed a candidate gene association of single nucleotide polymorphisms (SNPs) located in Toll-like receptor (TLR) genes, encoding prominent molecules for innate immune responses, with the occurrence of bacterial infections in patients with SCD. A cohort followed in centres in Brazil, France and Senegal (n = 430) was divided in two groups: patients who presented at least one episode of bacterial infection (n = 235) and patients who never had bacterial infections (n = 195). There were no differences in gender or age distribution among the groups. The frequency of the TLR2 rs4696480 TA genotype was significantly lower in the infected group (50% vs. 67%, odds ratio [OR] = 0·50, 95% confidence interval [CI] 0·34-0·75, P < 0·001), and the TT genotype was significantly higher in the infected group (15% vs. 5%, OR = 3·18, 95% CI 1·53-6·61, P < 0·001). Previous reports demonstrated higher secretion of inflammatory factors in cells from AA individuals, lower occurrence and severity of immune diseases in T carriers. The rs4696480 TA genotype might stand between deleterious effects of over inflammatory response (AA genotype) and inefficient responses (TT genotype) to infectious agents in SCD settings.

Prevalence and correlates of growth failure in young African patients with sickle cell disease.

Growth failure (GF) in children with sickle cell disease (SCD) tends to decline in high-income countries, but data are lacking in sub-Saharan Africa. We performed a cross-sectional study nested in the CADRE (Cœur, Artères et DREpanocytose) cohort in Mali, Senegal, Cameroon, Gabon and the Ivory Coast. SCD patients and healthy controls aged 5-21 years old were recruited (n = 2583). Frequency of GF, defined as a height, weight or body mass index below the 5th percentile on World health Organization growth charts, was calculated. We assessed associations between GF and SCD phenotypic group, clinical and biological characteristics and history of SCD-related complications. GF was diagnosed in 51% of HbSS, 58% of HbSß0 , 44% of HbSC, 38% of HbSß+ patients and 32% of controls. GF in patients was positively associated with parents' lower education level, male sex, age 12-14 years, lower blood pressure, HbSS or HbSß0 phenotypes, icterus, lower haemoglobin level, higher leucocyte count and microalbuminuria. No association was found between GF and clinical SCD-related complications. In sub-Saharan Africa, GF is still frequent in children with SCD, especially in males and during adolescence. GF is associated with haemolysis and microalbuminuria, but not with the history of SCD-related clinical complications.

Subclinical Cardiac Dysfunction Is Associated With Extracardiac Organ Damages.

Background: Several studies conducted in America or Europe have described major cardiac remodeling and diastolic dysfunction in patients with sickle cell disease (SCD). We aimed at assessing cardiac involvement in SCD in sub-Saharan Africa where SCD is the most prevalent. Methods: In Cameroon, Mali and Senegal, SCD patients and healthy controls of the CADRE study underwent transthoracic echocardiography if aged ≥10 years. The comparison of clinical and echocardiographic features between patients and controls, and the associations between echocardiographic features and the vascular complications of SCD were assessed. Results: 612 SCD patients (483 SS or Sß0, 99 SC, and 19 Sß+) and 149 controls were included. The prevalence of dyspnea and congestive heart failure was low and did not differ significantly between patients and controls. While left ventricular ejection fraction did not differ between controls and patients, left and right cardiac chambers were homogeneously more dilated and hypertrophic in patients compared to controls and systemic vascular resistances were lower (p < 0.001 for all comparisons). Three hundred and forty nine SCD patients had extra-cardiac organ damages (stroke, leg ulcer, priapism, microalbuminuria or osteonecrosis). Increased left ventricular mass index, cardiac dilatation, cardiac output, and decreased systemic vascular resistances were associated with a history of at least one SCD-related organ damage after adjustment for confounders. Conclusions: Cardiac dilatation, cardiac output, left ventricular hypertrophy, and systemic vascular resistance are associated with extracardiac SCD complications in patients from sub-Saharan Africa despite a low prevalence of clinical heart failure. The prognostic value of cardiac subclinical involvement in SCD patients deserves further studies.

Degree of anemia, indirect markers of hemolysis, and vascular complications of sickle cell disease in Africa.

The hyperhemolysis paradigm that describes overlapping "hyperhemolytic-endothelial dysfunction" and "high hemoglobin-hyperviscous" subphenotypes of sickle cell disease (SCD) patients is based on North American studies. We performed a transversal study nested in the CADRE cohort to analyze the association between steady-state hemolysis and vascular complications of SCD among sub-Saharan African patients. In Mali, Cameroon, and Ivory Coast, 2407 SCD patients (1751 SS or sickle ß-zero-thalassemia [Sß0], 495 SC, and 161 sickle ß+-thalassemia [Sß+]), aged 3 years old and over, were included at steady state. Relative hemolytic intensity was estimated from a composite index derived from principal component analysis, which included bilirubin levels or clinical icterus, and lactate dehydrogenase levels. We assessed vascular complications (elevated tricuspid regurgitant jet velocity [TRV], microalbuminuria, leg ulcers, priapism, stroke, and osteonecrosis) by clinical examination, laboratory tests, and echocardiography. After adjustment for age, sex, country, and SCD phenotype, a low hemoglobin level was significantly associated with TRV and microalbuminuria in the whole population and with leg ulcers in SS-Sß0 adults. A high hemolysis index was associated with microalbuminuria in the whole population and with elevated TRV, microalbuminuria, and leg ulcers in SS-Sß0 adults, but these associations were no longer significant after adjustment for hemoglobin level. In conclusion, severe anemia at steady state in SCD patients living in West and Central Africa is associated with elevated TRV, microalbuminuria, and leg ulcers, but these vascular complications are not independently associated with indirect markers of increased hemolysis. Other mechanisms leading to anemia, including malnutrition and infectious diseases, may also play a role in the development of SCD vasculopathy.

Genetic Background of the Sickle Cell Disease Pediatric Population of Dakar, Senegal, and Characterization of a Novel Frameshift ß-Thalassemia Mutation [HBB: c.265_266del; p.Leu89Glufs*2].

Sickle cell disease is a genetic disorder with a large variability in the pattern and severity of clinical manifestations. Different genetic modulators have been identified but very few epidemiologic data are available on these modifier genes in Senegal. This study aimed to determine their prevalence in a Senegalese sickle cell disease pediatric population. The following genetic parameters were genotyped in 295 sickle cell disease children of the Dakar pediatric hospital: sickle cell disease genotype [ßS/ßS (HBB: c.20A>T), ßS/ßC (HBB: c.19G>A), ßS/ß0-thalassemia (ß0-thal)], XmnI polymorphism, the five most common α-thalassemia (α-thal) deletions and the A(-) and Betica glucose-6-phosphate-dehydrogenase (G6PD) deficient variants. Despite very few ßS/ßC and ßS/ß0-thal children (1.0% each), a novel frameshift ß0-thal mutation was characterized: HBB: c.265_266del; p.Leu89Glufs*2. The -α3.7 (rightward) deletion was the only α-thal deletion identified in this cohort (12.0% allelic frequency). Most of ßS/ßS patients (61.9%) were homozygous for the XmnI polymorphism and assumed to carry a Senegal/Senegal ßS haplotype. The remaining haplotypes were predominantly of the Benin type. While the Betica G6PD variant was quite frequent (13.0%), a low frequency of the A(-) variant was detected (1.0-2.0%). The systematic genotyping of the -α3.7 deletion and of the G6PD Betica variant in sickle cell disease patients from Senegal could be useful to identify patients at risk for several complications, such as cerebral vasculopathy, where it has been demonstrated that a normal α-globin genotype and G6PD deficiency are predisposing factors. These patients should be eligible for a transcranial Doppler examination that is not routinely offered in Senegal.

[Alobar holoprosencephaly associated with diabetes insipidus and hypothyroidism in a 10-month old infant]. / Holoprosencéphalie alobaire avec diabète insipide et hypothyroïdie chez un nourrisson de 10 mois.

Holoprosencephaly (HPE) is a serious brain malformation due to a failure of medial forebrain cleavage. This is an abnormality which is more often associated with craniofacial malformations, psychomotor development delay, diabetes insipidus and variable endocrine disorders. It is due to different causes including chromosomal abnormalities (trisomy 13, 18)and polymalformative syndromes (CHARGE Syndrome). Diagnosis is based on brain imaging. A few rare cases have been described in the literature. We here report the case of alobar HPE in a 10-month old infant. Diagnosis was based on cerebral CT scan performed due to delayed psychomotor development and in the absence of visible malformations. Endocrine assessment allowed to detect central diabetes insipidus and central hypothyroidism, probably of hypothalamic origin.

[Epidemiological, clinical and hematological profiles of homozygous sickle cell disease during the intercritical period among children in Ziguinchor, Senegal]. / Profils épidemiologiques, cliniques et hématologiques de la drépanocytose homozygote SS en phase inter critique chez l'enfant à Ziguinchor, Sénégal.

Sickle cell disease poses a public health problem in Senegal. It mainly affects children and adolescents. This study aimed to determine the epidemiological, clinical and hematological profiles of homozygous (SS) sickle cell disease in a cohort of children followed-up at the Peace Hospital in Ziguinchor. We conducted a retrospective study of the medical records from children with sickle cell disease. All patients aged between 2 months and 21 years with sickle cell disease SS during the intercritical period, hospitalized during the study period from 1st January 2015 to 31 August 2017 were included in our study. Compound heterozygous patients (SC, S Beta Thalassemia) were not included. We collected 46 medical records of patients with sickle cell disease SS (20 girls and 26 boys). The average age of children was 8,0 years [11 months-21 years]. Approximately 1/3 of children (39.1%) had an age less than or equal to 5 years. There was an ethnic diversity showing a predominance of the Diola (30.2%) followed by the Mandinga (27.9%) and the Poular (25.6%). The average age of children with first crisis was 35,5 months [7-192 months]. More than 1/3 of children (41.3%) had had first crisis before their second anniversary. In the child, first crisis was dominated by vaso-occlusive crisis (32.6%) followed by hand-foot syndrome (30.4%). Clinical signs during the intercritical period were pallor 95.6%), jaundice (36.9%) and splenomegaly (21.7%). Mean white blood cell count was 12465 leucocytes/mm3 [5340-26900]. Hyperleukocytosis greater than 10 000 leucocytes/mm3was found in 34 patients (73.9%). All patients had anemia with an average hemoglobin of 08,6 g/dl [05,7-11,8]. Hemoglobin S rate ranged between 54.6 and 98.4%. Diagnosis and medical management of sickle cell disease SS are delayed in Ziguinchor. Neonatal screening may lead to improve early management of patients in the region.

Arterial Stiffness Impairment in Sickle Cell Disease Associated With Chronic Vascular Complications: The Multinational African CADRE Study.

BACKGROUND: Although a blood genetic disease, sickle cell disease (SCD) leads to a chronic vasculopathy with multiple organ involvement. We assessed arterial stiffness in SCD patients and looked for associations between arterial stiffness and SCD-related vascular complications. METHODS: The CADRE (Coeur Artères et Drepanocytose, ie, Heart Arteries and Sickle Cell Disease) study prospectively recruited pediatric and adult SCD patients and healthy controls in Cameroon, Ivory Coast, Gabon, Mali, and Senegal. Patients underwent clinical examination, routine laboratory tests (complete blood count, serum creatinine level), urine albumin/creatinine ratio measure, and a measure of carotid-femoral pulse wave velocity (cf-PWV) and augmentation index (AI) at a steady state. The clinical and biological correlates of cf-PWV and AI were investigated by using a multivariable multilevel linear regression analysis with individuals nested in families further nested in countries. RESULTS: Included were 3627 patients with SCD and 943 controls. Mean cf-PWV was lower in SCD patients (7.5±2.0 m/s) than in controls (9.1±2.4 m/s, P<0.0001), and lower in SS-Sß(0) than in SC-Sß(+) phenotypes. AI, corrected for heart rate, increased more rapidly with age in SCD patients and was higher in SCD than in control adults. cf-PWV and AI were independently associated with age, sex, height, heart rate, mean blood pressure, hemoglobin level, country, and hemoglobin phenotype. After adjustment for these correlates, cf-PWV and AI were associated with the glomerular filtration rate and osteonecrosis. AI was also associated with stroke, pulmonary hypertension, and priapism, and cf-PWV was associated with microalbuminuria. CONCLUSIONS: PWV and AI are deeply modified in SCD patients in comparison with healthy controls. These changes are independently associated with a lower blood pressure and a higher heart rate but also with the hemoglobin phenotype. Moreover, PWV and AI are associated with several SCD clinical complications. Their prognostic value will be assessed at follow-up of the patients.

Early renal damage in patients with sickle cell disease in sub-Saharan Africa: a multinational, prospective, cross-sectional study.

BACKGROUND: Chronic kidney disease is one of the leading causes of mortality in patients with sickle cell disease. However, it has been almost exclusively studied in patients with the SS phenotype and in high-income countries, despite more than 80% of patients living in Africa. We looked for the determinants of glomerulopathy in a multinational cohort of patients with sickle cell disease of different phenotypes in sub-Saharan Africa. METHODS: In the CADRE cohort, we prospectively included patients 3 years and older with sickle cell disease of all haemoglobin phenotypes in Cameroon, Côte d'Ivoire, Mali, and Senegal. All individuals were assessed at steady state. The main outcome of interest was albuminuria defined as a urine albumin-to-creatinine ratio of greater than 30 mg/g. We investigated the clinical and biological determinants (including haemolysis markers) of albuminuria in two main phenotype groups (SS and Sß(0); SC and Sß(+)) with further stratification by age and country. FINDINGS: The study is ongoing because of follow-up. 2582 patients with sickle cell disease were included (1776 SS, 136 Sß(0), 511 SC, and 159 Sß(+)). 644 patients with the SS and Sß(0) phenotypes (33·7%, 95% CI 31·6-35·8) and 110 with the SC and Sß(+) phenotypes (16·4%, 13·6-19·2) had albuminuria. In the SS and Sß(0) group, albuminuria was detected in 144 (27%) of 527 children younger than 10 years and its frequency increased with age (29 [48%] of 60 patients aged >40 years). Multivariable analysis showed that albuminuria was associated with age (odds ratio 1·43, 95% CI 1·20-1·71; p<0·0001), female sex (1·35, 1·02-1·82; p=0·045), low haemoglobin (0·79, 0·66-0·93; p=0·006), high lactate dehydrogenase concentrations (1·33, 1·14-1·58; p=0·0009), and, using Côte d'Ivoire as the reference, Mali (2·49, 1·64-3·79; p=0·042) and Cameroon (1·59, 1·01-2·51; p=0·0007) in patients with the SS and Sß(0) phenotypes. The magnitude of the association of albuminuria with haemoglobin and lactate dehydrogenase concentrations increased with age. In the SC and Sß(+) patients, only low haemoglobin (0·69, 0·48-0·97; p=0·029), high blood pressure (1·63, 1·17-2·27; p=0·0017), and Mali (3·75, 1·75-8·04; p<0·0001) were associated with albuminuria. INTERPRETATION: Hyperhaemolysis is associated with albuminuria, with an age-dependent effect, in the SS and Sß(0) phenotypes only, suggesting a different pathological mechanism for glomerular disease in the patients with SC and Sß(+) phenotypes. However, both phenotypes are associated with a high prevalence of albuminuria in childhood. Therefore, screening for albuminuria is advised in African children with sickle cell disease to detect early renal damage. FUNDING: Paris Cité Sorbonne University (GrEX project) and Cardiology and Development.