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Background Blood transfusion is the cornerstone treatment to reduce the clinical severity of sickle cell disease (SCD), but we need to maintain the haematocrit (Hct) within an acceptable range to avoid a deleterious increase in blood viscosity. The aim of this study was to compare the effects of manual versus automated red blood cell (RBC) Exchange on haematological parameters and blood viscosity. Study design and methods This prospective, single-centre, open nonrandomized observational study included forty-three sickle cell patients: 12 had automated RBC Exchange and 31 manual RBC Exchange. Samples were collected in EDTA tubes just before and within one hour after the end of the RBC Exchange to measure the haematological parameters and blood viscosity. Results Both automated and manual RBC Exchange decreased haemoglobin S levels and leucocyte and platelet counts, but the decrease was greater for automated RBC Exchange. Manual RBC Exchange caused a significant rise in haematocrit and haemoglobin levels and did not change blood viscosity. In contrast, automated RBC Exchange decreased blood viscosity without any significant change in haematocrit and only a very slight increase in haemoglobin levels. The change in blood viscosity correlated with the modifications of haematocrit and haemoglobin levels, irrespective of the RBC Exchange procedure. When adjusted for the volume of RBC Exchange, the magnitude of change in each biological parameter was not different between the two procedures. Conclusion Our study demonstrates that the automated RBC Exchange provided greater haematological and haemorheological benefits than manual RBC Exchange, mainly because of the higher volume exchanged, suggesting that automated RBC Exchange should be favoured over manual RBC Exchange when possible and indicated.

Objective: Impaired baroreflex function is an early indicator of cardiovascular autonomic imbalance. Patients with type 2 diabetes mellitus (T2D) have decreased baroreflex sensitivity (BRS), however, whether the neural and/or mechanical component of the BRS (nBRS and mBRS, respectively) is altered in those with high metabolic risk (HMR, impaired fasting glucose and/or metabolic syndrome) or with overt T2D, is unknown. We examined this in a community-based observational study, the Paris Prospective Study III (PPS3). Approach and Results: In 7626 adults aged 50 to 75 years, resting nBRS (estimated by low-frequency gain, from carotid distension rate and RR intervals [time intervals between successive R waves]) and mBRS were measured by high-precision carotid echotracking. The associations between overt T2D or HMR as compared with subjects with normal glucose metabolism (NGM) and nBRS or mBRS were quantified using multivariable linear regression analysis. There were 319 subjects with T2D (61±6 years, 77% male), 1450 subjects with HMR (60±6 years, 72% male), and 5857 subjects with NGM (59±6 years, 57% male). Compared with NGM subjects, nBRS was significantly lower in HMR subjects (β=−0.07 [95% CI, −0.12 to −0.01]; P =0.029) and in subjects with T2D (β=−0.18 [95% CI, −0.29 to −0.07]; P =0.002) after adjustment for confounding and mediating factors. Subgroup analysis suggests significant and independent alteration in mBRS only among HMR patients who had both impaired fasting glucose and metabolic syndrome. Conclusions: In this community-based study of individuals aged 50 to 75, a graded decrease in nBRS was observed in HMR subjects and patients with overt T2D as compared with NGM subjects.

Background: Paediatric outpatient prescription (POP) monitoring is pivotal to identify inadequate prescriptions and optimize drug use. We aimed at describing recent trends in POPs in France. Methods: All reimbursed dispensations of outpatient prescribed drugs (excluding vaccines) were prospectively collected for the paediatric population (

To study the association between chewing capacity-a prerequisite for eating- and the level of cardiovascular health (CVH).This is a cross-sectional analysis conducted on 5430 study participants from the Paris Prospective Study 3 that were subjected to an oral examination by trained dentists at study recruitment between 2008 and 2012. Chewing capacity was determined by the number of functional tooth units (FTUs), and ≥ 5FTUs defined adequate chewing capacity. Subjects were categorized into poor, intermediate, or ideal CVH for the 4 behavioural (smoking status, body mass index, physical activity, diet) and the 3 biological (total cholesterol, fasting glycemia, and blood pressure) factors according to the American Heart Association Life's Simple 7. Multinomial logistic regression was used to explore the association between the number of FTUs (exposure) and ideal or intermediate vs. poor CVH (main outcome).10.31% of the study participants had an ideal CVH and 7% presented an impaired chewing capacity (5 FTUs). Subjects with at least 5 FTUs (OR = 2.37; 95% CI: 1.37-4.12) were more likely to have an ideal global CVH, after adjustment for age, sex, marital status, education, deprivation, depressive status, and dental plaque. This association existed for the behavioural but not the biological CVH, with the strongest association being observed with the diet metric.This is the first study suggesting that adults with a preserved chewing capacity have an increased likelihood to be at an ideal behavioural CVH.

Resume Introduction La retinopathie est une complication chronique a risque fonctionnel important chez le drepanocytaire, dont l’incidence est mal connue en Afrique subsaharienne, faute de depistage. Ce travail decrit les resultats d’un depistage systematique de la retinopathie drepanocytaire dans un centre de suivi des drepanocytaires au Mali. Methodes Tous les drepanocytaires âges de 10 ans et plus, suivis au centre, ont ete depistes entre 2010 et 2012 par un examen du fond d’œil complete si besoin par une angiographie. Les caracteristiques des patients porteurs d’une retinopathie ont ete comparees a celles de drepanocytaires sans retinopathie recrutes durant la meme periode et selectionnes au hasard. Resultats La retinopathie avait une prevalence globale de 8,8 % chez les 1604 drepanocytaires âges de 10 ans et plus et concernait 91/731 (12,4 %) drepanocytaires SC, 38/734 (5,2 %) SS, 5/53 (9,4 %) Sβ 0 thalassemiques et 8/86 (9,3 %) Sβ + thalassemiques. La forme proliferante de la retinopathie etait plus frequente chez les SC ( p 0 thalassemiques. Conclusion La retinopathie touche pres d’un patient drepanocytaire sur dix et sa prevalence est negativement associee au taux d’hemoglobine fœtale. L’efficience d’un depistage systematique de la retinopathie drepanocytaire doit etre etudiee en Afrique, ainsi que l’interet de la phlebotomie et de l’hydroxycarbamide en traitement preventif.

Physical activity (PA) is a preventative behavior for noncommunicable disease. However, little consideration is given as to whether different domains of PA have differing associations with health outcomes. We sought to determine the association between occupational, sport, leisure, and total PA with baroreflex sensitivity (BRS), distinguishing between neural (nBRS) and mechanical (mBRS) BRS. In a cross-sectional analysis of 8649 adults aged 50 to 75 years, resting nBRS (estimated by low-frequency gain, from carotid distension rate and heart rate) and mBRS (carotid stiffness) were measured by high-precision carotid echo-tracking. PA was self-reported using the validated Baecke questionnaire. The associations between PA and nBRS and mBRS were quantified using multivariate linear regression analysis, separately in the working and nonworking population. In working adults (n=5039), occupational PA was associated with worse nBRS (unstandardized β=−0.02; [95% CI, −0.04 to −0.003]; P =0.022) whereas sport PA was associated with better nBRS (β=0.04; [95% CI, 0.02–0.07]; P =0.003) and mBRS (β=−0.05; [95% CI, −0.09 to −0.00001]; P =0.049). Neither leisure PA nor total PA was associated with nBRS or mBRS. In nonworking adults (n=3610), sport PA and total PA were associated with better mBRS (β=−0.08; [95% CI, −0.15 to 0.02]; P =0.012 and β=−0.05; [95% CI, −0.10 to 0.009]; P =0.018) but not nBRS. These findings suggest differential associations between domains of PA and BRS and may provide insights into the mechanisms underlying the association between occupational PA and cardiovascular disease.

International audience; OC5.1Positive impact of genetic test on the management and outcome of patients with paraganglioma and/or pheochromocytomaContextParagangliomas and pheochromocytomas (PPGL) are rare neuroendocrine tumors, characterized by a strong genetic component. Indeed, up to 40% of patients carry a germline mutation in a PPGL susceptibility gene. In accordance with the international recommendations, genotyping of PPGL susceptibility genes is therefore proposed to all patients with PPGL, but it has actually never beenshown whether the identification of a germline mutation in one PPGL susceptibility gene changes the outcome of mutation-carriers.ObjectiveOur objective was to evaluate how a positive genetic test impacts the management and outcome of propositus patients with PPGL carrying a germline mutation in one of the four major PPGL susceptibility genes (SDHB, SDHD, SDHC and VHL).DesignWe performed a multicentric retrospective study on 221 propositus carrying a SDHB, SDHD, SDHC or VHL germline mutation and followed in 24 French clinical centers of the Group of Endocrine Tumors and/or the COMETE network. Patients were divided into two groups: Genetic patients, who were informed of their genetic status within the year following the first PPGL diagnosis, and Historic patients who only benefited from the genetic test several years after initial PPGL diagnosis.ResultsCompared to Historic patients, Genetic patients had a better follow-up, with a higher number of examinations and a reduced number of patients lost to follow-up (9.6% versus 72%). During follow-up, smaller (18.7 mm versus 27.6, PZ0.0128) new PPGL and metastases as well as lower metastatic spread were observed in Genetic patients. Importantly, these differences were reversed in the Historic cohort after genetic testing. Genetic patients who developed metachronous metastases had a better 5-year survival than Historic ones (PZ0.0127).ConclusionAltogether our study clearly shows the positive impact of the identification of an SDHx or VHL mutation in the management, clinical outcome and survival of patients with PPGL. It reveals, for the first time, the clinical benefits of the practice of oncogenetics for patients with a rare cancer and strongly strengthens the recommendations of the Endocrine Society to consider PPGL genetic testingin all patients affected by PPGL.DOI: 10.1530/endoabs.63.OC5.1

BACKGROUND: Arterial stiffness may contribute to late-life depression via cerebral microvascular damage, but evidence is scarce. No longitudinal study has evaluated the association between arterial stiffness and risk of depressive symptoms. Therefore, we investigated the association between carotid artery stiffness and incident depressive symptoms in a large community-based cohort study.METHODS: This longitudinal study included 7013 participants (mean age 59.7 +/- 6.3 years; 35.8% women) free of depressive symptoms at baseline. Carotid artery stiffness (high-resolution echo tracking) was determined at baseline. Presence of depressive symptoms was determined at baseline and at 4 and 6 years of follow-up, and was defined as a score >= 7 on the validated Questionnaire of Depression, Second Version, Abridged and/or new use of antidepressant medication. Logistic regression and generalized estimating equations were used.RESULTS: In total, 6.9% (n = 484) of the participants had incident depressive symptoms. Individuals in the lowest tertile of carotid distensibility coefficient (indicating greater carotid artery stiffness) compared with those in the highest tertile had a higher risk of incident depressive symptoms (odds ratio: 1.43; 95% confidence interval: 1.10-1.87), after adjustment for age, sex, living alone, education, lifestyle, cardiovascular risk factors, and baseline Questionnaire of Depression, Second Version, Abridged scores. Results were qualitatively similar when we used carotid Young's elastic modulus as a measure of carotid stiffness instead of carotid distensibility coefficient, and when we used generalized estimating equations instead of logistic regression.CONCLUSIONS: Greater carotid stiffness is associated with a higher incidence of depressive symptoms. This supports the hypothesis that carotid stiffness may contribute to the development of late-life depression.

International audience; Background - Our knowledge of hypertrophic cardiomyopathy (HCM) mainly originates from quarternary centres. The objective is to assess the current management of HCM patients in a large multicentre French register according to the level of expertise. Methods and results - A total of 1431 HCM patients were recruited across 26 (11 expert and 15 non-expert) centres in REMY, a prospective hospital-based register of adult HCM patients. A sarcomeric origin was suspected in 1284 (89.7%) patients [261 (20.3%) with a reported gene mutation, 242 (18.8%) genotype-negative], while 107 (7.5%) had a diagnosis of non-sarcomeric HCM. Patients managed in non-expert centres were older (P

Background: Late-life depression is related to poor quality of life and increased risk of mortality and cardiovascular disease. Effective interventions for prevention and treatment of late-life depression need to be developed, which requires a better understanding of late-life depression risk factors. Arterial stiffness may contribute to late-life depression via cerebrovascular damage, but evidence is scarce. Aim: To investigate the association between carotid artery stiffness and incident depressive symptoms in a large community-based cohort study. Methods: This longitudinal study included 7,013 participants (60 (SD 6) years; 36% women) free of depressive symptoms at baseline. Carotid stiffness (high-resolution echotracking) was determined at baseline. Presence of depressive symptoms was determined at baseline and at 4 and 6 years of follow-up and was defined as a score ≥7 on a validated 13-item questionnaire (Q2DA) and/or new use of antidepressants. Logistic regression and generalized estimating equations (GEE) were used. Results: In total, 6.9% (n = 484) of the participants had incident depressive symptoms at 4 or 6 years of follow-up. Greater carotid stiffness was associated with a higher incidence of depressive symptoms (Figure). Results were qualitatively similar when GEE was used instead of logistic regression. Conclusions: Greater carotid artery stiffness is associated with a higher incidence of depressive symptoms. This study supports the hypothesis that carotid artery stiffness contributes to the development of late-life depression.

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 Sβ0, 99 SC, and 19 Sβ+) 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.

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, Arteres 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 HbSβ0 , 44% of HbSC, 38% of HbSβ+ 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 HbSβ0 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.

Introduction La prevalence de la drepanocytose augmente rapidement en Europe, du fait d’une augmentation de l’esperance de vie des patients drepanocytaires et de l’arrivee de migrants originaires d’Afrique sub-Saharienne (ASS). Le but de l’etude etait de comparer le phenotype de patients adultes nes en ASS, ayant migre en France a celui de patients originaires d’ASS nes en France. Patients et methodes Etude retrospective monocentrique comparant les caracteristiques demographiques, cliniques et biologiques de patients adultes drepanocytaires (tous genotypes) originaires d’ASS, nes en France ou en ASS. Tous les patients de notre cohorte dont les parents etaient originaires d’ASS etaient inclus. Les donnees etaient colligees a partir d’un dossier medical informatise specifique pour les patients drepanocytaires comprenant aussi des donnees sociologiques. Ces 2 groupes etaient compares par regression logistique multivariee, avec ajustement sur l’âge et le sexe. Un avis positif du CERES et de la CNIL etait obtenu. Resultats Parmi 323 patients suivis dans notre centre au 28 fevrier 2018, 235 ont ete inclus : 111 nes en France, 124 nes en ASS. Les genotypes drepanocytaires etaient repartis de facon identique. Les patients nes en ASS etaient plus âges (âge median 32,1 [24,4–39] vs 25,6 [22,1–30,5] ans, p Conclusion Les patients drepanocytaires migrants, nes en ASS, compares aux patients de meme origine geographique parentale nes en France, presentent une maladie moins severe, quel que soit l’âge. Cette observation peut sembler paradoxale etant donne les difficultes d’acces aux soins medicaux en Afrique (notamment a l’hydroxyuree et aux transfusions) mais pourrait resulter d’un biais de mortalite survenant durant l’enfance en Afrique et au cours de l’emigration vers l’Europe, selectionnant les phenotypes les plus favorables.

Summary Objective Sickle retinopathy is a severe complication of sickle cell disease than can lead to blindness. We aim to describe the epidemiology of sickle retinopathy in homozygous sickle cell (SS) African patients and to analyze its association with non-ophthalmologic disease complications of sickle cell anemia. Methods We conducted a nested study within the CADRE cohort in Cameroon. Eighty-four consecutive SS outpatients, aged 10 years and older, with no visual symptoms, underwent an ophthalmologic examination. Mean age was 23 ± 10 years. Clinical and biological features were compared between patients with and without sickle retinopathy. We compared the prevalence of the clinical complications and main biological characteristics in patients with and without sickle retinopathy using a univariate logistic regression . The same analysis was used to compare the patients with non-proliferative sickle retinopathy to those with proliferative sickle retinopathy. Statistical analyses were done using the R software (version 3.1.2). Results Fifty-two patients (62%) displayed sickle retinopathy, among them 23 (27%) had a non-proliferative sickle retinopathy, and 29 (35%) had proliferative sickle retinopathy. Patients with proliferative sickle cell retinopathy had a mean age of 28 ± 11 years. Sickle retinopathy was associated with higher hemoglobin level (P = 0.047) and fewer leg ulcers ( P = 0.018). Proliferative SR was associated with increasing age (P = 0.008) and male sex (P = 0.025) independently of the hemoglobin level. Conclusions Sickle retinopathy is particularly frequent in sub-Saharan sickle cell SS patients, which advocates for early systematic screening.

Background Osteosclerosis (OSC) is a rarely studied complication of sickle cell disease (SCD). The objective of our study was to determine the prevalence and characteristics of high bone mineral density (BMD) and its radiological features in adult SCD patients. Methods This prospective observational study was conducted from May 2007 to May 2016 in consecutive patients with steady-state SCD at two university hospitals. The BMD of the lumbar spine (L1-L4) and right femoral neck was determined by dual energy X-ray absorptiometry. Clinical, laboratory and radiographic data were recorded. High BMD was defined as a BMD Z-score of at least +2.5 standard deviations at the lumbar spine or hip. The characteristics of the patients with high BMD were compared to those of individuals with low or middle BMD, using multivariate ordinal logistic regression. Results 135 patients (86 women and 49 men) with a median age of 27 (IQR 23-33) years were included. High BMD was diagnosed in 20 (15%) patients with a median age of 33.5 (IQR 28-45) years. The SCD genotypes of these patients were SS in 11, SC in 5, S/beta+ in 3, and S/beta0 in 1. High BMD patients more frequently harbored the S/beta SCD genotype (21% vs 5% in non-high BMD patients; p = 0.047) and were older (p = 0.0007). Compared to patients with low or middle BMD, after adjustment for age and SCD genotype, high BMD patients had a higher prevalence of avascular necrosis history (p = 0.009), higher BMI (p = 0.007), and lower serum resorption marker CTX (p = 0.04), bilirubin (p = 0.02) and parathyroid hormone levels (p = 0.02). There were no differences between groups regarding fracture history, H-shaped vertebrae or other biological variables. Conclusion High-BMD values is a common manifestation in SCD patients, especially in those with the S/beta-thalassemia genotypes. The prevalence of high-BMD in SCD is associated with older age, suggesting that it will be more common in the future because the life span of patients with SCD is increasing thanks to significant progress in SCD treatment.

Although most individuals with sickle cell disease (SCD) live in sub-Saharan Africa, the history of the disease in this continent remains largely unknown. SCD is characterized by chronic hemolytic anemia, acute-vaso occlusive events and progressive vascular organ damage. The CADRE study is a large cohort of SCD patients in five countries of West and Central Africa aiming at studying SCD-related vascular complications. The inclusion data of this study did not match the hyper-hemolysis paradigm (Dubert et al. Blood 2018), but several methodological limitations were raised, including probable mortality bias and questionable reliability of classical hemolysis markers in Africa. For the 5-year follow-up of the CADRE study, we designed a case-control study nested in the cohort, based on extreme phenotypes, to look for new markers of vasculopathy, including new markers of hemolysis. Patients and Methods SS adult patients of the CADRE cohort were selected in the centres of Dakar (Senegal) and Bamako (Mali), depending on the presence of none or at least one of the following complications at inclusion: tricuspid regurgitant jet velocity (TRJV)>2,5 m/s (which may indicate pulmonary hypertension), albuminuria/creatininuria>100 mg/g, leg ulcer, priapism, aseptic osteonecrosis and retinopathy. We chose the youngest patients with a vascular complication and the oldest without any complication. Overall, 6 groups of 40 SS patients with extreme phenotypes were constituted (20 in each centre). Patients were called for a specific visit and investigated at steady state. Besides clinical examination, usual laboratory blood tests and albuminuria measure, additional plasma and saliva samples were collected. A trained investigator isolated microparticles immediately after blood sampling by successive centrifugations, measured blood and plasma viscosities and assessed microcirculation function using peripheral arterial tonometry. A cardio-echography was performed by a trained cardiologist. Plasma samples were stored at -80 °C and shipped to Paris. High technology tests were performed in Paris, including blood cell derived microparticles, free hemoglobin, inflammatory cytokines, neutrophile extracellular trap (NETs). Using saliva DNA, we also genotyped the known SCD genetic modifiers and new candidate genes implicated in the catabolism of hemoglobin. Potential associations between those markers, usual hematological parameters, and the vascular complications were assessed statistically . Results We recalled 240 selected patients 5 years after their first visit: 38 could not be retrieved, 21 had deceased, 62 had at least one new complication, and only 15 still had no complication. Therefore, we selected 56 more patients to obtain at least 30 patients in each group. 237 SS adults were eventually investigated and the plasma samples of 232 SS patients were analyzable in Paris (106 from Bamako and 126 from Dakar). In these patients, at a mean age of 29 years (+/- 11), high TRJV was present in 58, macroalbuminuria in 33, leg ulcers in 36, priapism in 43, aseptic osteonecrosis in 45 and retinopathy in 31 whereas 28 had no vascular complication. A principal component analysis found no cluster of complications. Among patients with one "hyper-viscous" complication (retinopathy or osteonecrosis) or more, 78% also had at least one "hyper-haemolytic" complication (high TRJV, albuminuria, leg ulcer or priapism) and 49% of patients with a "hyper-haemolytic" complication also had a "hyper-viscous" complication. The microvascular function was not associated with any of the complications, whereas higher blood viscosity was associated with retinopathy. The results of the associations between the vascular complications and specific biological tests are presented in other publications. Conclusion This study illustrates the feasibility of high-technology experiments in SCD patients living in sub-Saharan Africa, but was particularly challenging because of the difficulty to prepare, store and transport frozen plasma samples. Moreover, in agreement with previously published data from the CADRE study, we found that the dichotomization of vascular complications into hyperhemolytic and hyperviscous subgroups is not clinically relevant in Africa. Other simple predictive markers of vascular complication are needed to optimize the follow-up of African patients with SCD. Disclosures No relevant conflicts of interest to declare.

Introduction Although most individuals with sickle cell disease (SCD) live in sub-Saharan Africa, the history of the disease on this continent remains largely unknown. SCD is characterized by the association of chronic hemolytic anemia with episodes of acute vaso-occlusive events and progressive vascular organ damage. Several pathophysiological pathways in SCD result in the activation of circulating blood cells and the release of microparticles (MPs). In the present study, we investigated cell-derived MPs in patients with SCD living in Africa and analyzed their relationship with clinical complications. Patients and Methods This cross-sectional case-control study is nested in the CADRE cohort (clinical trials.gov identifier NCTO3114137). We included 232 SS adults in two African centers: Bamako (Mali) and Dakar (Senegal). Patients were chosen depending on the absence or the presence of at least one of the following complications: tricuspid regurgitant jet velocity (TRJV) >3 m/s (which may indicate pulmonary hypertension), macroalbuminuria, leg ulcer, priapism, aseptic osteonecrosis, and retinopathy. Overall, 7 groups of 40 SS patients were constituted (20 in each center). Patients were investigated at steady state (i.e.,at least 15 days after a vaso-occlusive crisis, 8 days after fever or infectious disease, and 3 months after a transfusion). MPs were isolated in the African centers immediately after blood sampling by successive centrifugations at increasing speed: 2,500g x2 and 21,000g x2. MPs pellets were stored at -80 °C. The cellular origin of the MPs, erythrocyte, reticulocyte, endothelial, platelet, and leucocyte, was determined using antibodies directed against CD235a, CD71, CD106, CD41, and CD45, respectively, at the National Institute of Blood TransfusioninParis. To maintain the background at an acceptable level, events of 0.16 µm size were excluded (Fig 1A). Only MPs positive for Annexin V and the cell-type-specific labelling were retained. Potential associations between cell-derived MPs, hematological parameters, and vascular complications were assessed using logistic regression with adjustment for age, sex and country. Results The MP pellets of 106 SS patients from Bamako and 126 from Dakar were analyzed in Paris. In these patients, at a mean age of 29 years (+/- 11), high TRJV was present in 64, microalbuminuria in 84, leg ulcers in 33, priapism in 43, aseptic osteonecrosis in 45, and retinopathy in 31 patients whereas 28 patients had no complication at the time of sampling. As a typical result, Fig 1B shows erythrocyte-derived MPs labelled by Annexin V and CD235a (quarter Q2). The MPs distribution was as follows: erythroid 52% [reticulocytes (CD235a+CD71+) 14%, erythrocytes (CD235a+ CD71-) 38%], leukocyte 18%, platelet 21%, and endothelial 9%. Neither erythrocyte- nor reticulocyte-derived MPs significantly correlated with hemolysis markers (LDH, unconjugated bilirubin or reticulocytes) or hemoglobin levels. Erythrocyte- and reticulocyte-derived MPs were significantly lower in patients with retinopathy (OR=0.48, p=0.003 and OR=0.68, p=0.005, respectively). Reticulocyte-derived MPs were negatively associated with a history of priapism (OR=0.76, p=0.020) and positively associated with a history of leg ulcers (OR=1.23, p=0.040). No correlation was found between MPs of other cellular origin and chronic complications, except for a negative association between endothelial-derived MPs and priapism (OR=0.76, p=0.036). Conclusion In our African patients with SCD, erythroid-derived MPs, although recognized cellular products of hemolysis, were not associated with other markers of hemolysis. We hypothesize that erythroid MPs are not only derived from hemolysis but also probably from the sickling process in this population. They were negatively associated with retinopathy and priapism and positively associated with leg ulcers, but not with the other complications classically associated with the hyperhemolytic sub-phenotype. The search for pertinent biomarkers of SCD complications in Africa is an essential challenge. To our best knowledge, this report is the first illustrating the feasibility of high-technology experiments in an African context. Disclosures No relevant conflicts of interest to declare.

Introduction About 80 % of sickle cell disease (SCD) patients live in sub-Saharan Africa whereas most studies on SCD are performed in Europe and America. Hyperhemolysis is thought to play a major role in the pathological process of SCD vasculopathy. Nevertheless, the paradigm of hyperhemolysis is controversial and has never been studied in the African context. We aim to analyze the association between hemolysis and clinical vascular complications among SCD African patients. Methods CADRE is a multinational cohort of SCD African patients aged 3 years and older, included prospectively and explored in a steady state. All patients from the CADRE cohort in Ivory Coast, Cameroun and Mali were included in the present study. Patients were classified in SS-Sβ0 phenotype or SC-Sβ+ phenotype. SCD vascular complications (pulmonary arterial hypertension (PAH), microalbuminuria, leg ulcers, priapism, stroke and osteonecrosis) were assessed using clinical examination, laboratory exams and echocardiography. Hemolysis was measured by a composite score, created with a principal component analysis, that included LDH, hemoglobin and bilirubin rates and clinical icterus. The association between hyperhemolysis (upper quartile of the hemolysis score) and the vascular complications was assessed using multivariate regression analysis in the whole population with further stratification by hemoglobin phenotype. Results We included 2409 patients among which 1751 SS-Sβ0 patients and 658 SC-Sβ+ patients. Compared to SC-Sβ+ patients, SS-Sβ0 patients were younger (15 years old versus 21 years old) and exhibited more leg ulcers (166 (9.5%) versus 24 (3.7%)) and microalbuminuria (573 (42.4%) versus 119 (20.0%)). The hemolysis score was higher in SS-Sβ0 patients as compared to SC-Sβ+ patients (median 1.18 versus 0.43, Figure). After adjustment for age, sex and country, hyperhemolysis was associated with microalbuminuria (OR = 1.59 [1.17-2.16]) and priapism (OR=1.58 [1.01-2.49]) (Table). In SS-Sβ0 patients, hyperhemolysis was associated with microalbuminuria (OR=1.54 [1.10-2.15]) and there was a trend to an association with PAH (OR=1.65 [0.91-2.98]) and priapism (OR=1.50 [0.95-2.39]). In SC-Sβ+ patients, only the association between hyperhemolysis and microalbuminuria remained significant. Sensibility analysis in the adult population showed that hyperhemolysis was significantly associated with all the SCD vascular complications, except for osteonecrosis. Conclusion In African SCD patients, associations between hyperhemolysis and SCD vascular complications were statistically significant but of modest magnitude, and depended on the hemoglobin phenotype. These results suggest that in the African context, hemolysis is not a major determinant of the development of SCD vasculopathy. Table. Associations between SCD complications and hemolysis score (quartiles 1 to 3 versus quartile 4) in the whole population: multivariate analysis with adjustment for age, sex, country and hemoglobin phenotype % of patients with the complication Multivariate analysis N event/N total Quartiles 1 to 3 Quartile 4 OR IC 95% P value PAH* 115/431 6.14 7.08 1.58 0.89-2.83 0.123 Urine albumin/creatinine > 30mg/g 724/1991 24.88 45.36 1.59 1.17-2.16 0.004 Leg ulcer, lifetime 190/2409 6.80 11.01 1.20 0.81-1.78 0.355 Priapism, lifetime ** 160/1095 13.27 17.90 1.58 1.01-2.49 0.046 Stroke, lifetime 25/2409 0.79 1.77 1.32 0.49-3.54 0.578 Osteonecrosis, lifetime 277/2409 11.22 12.28 1.00 0.70-1.43 1.000 PAH: Pulmonary Arterial Hypertension. * Patients from Mali and Cameroun only ** Males only Figure 1. Distribution of the hemolysis score: global population, SS-Sβ0 patients and SC-Sβ+ patients Figure 1. Distribution of the hemolysis score: global population, SS-Sβ0 patients and SC-Sβ+ patients Disclosures No relevant conflicts of interest to declare.