Search

Agathe Bridoux,1,2 Stephane Moutereau,3 Ala Covali-Noroc,1 Laurent Margarit,1 Stephane Palfi,4 Jean-Paul Nguyen,5 Jean-Pascal Lefaucheur,1,2 Pierre Césaro,6 Marie-Pia d'Ortho,7 Xavier Drouot1,21Service de Physiologie, Groupe Henri Mondor, 2Faculté de Médecine, Université Paris Est Créteil, 3Service de Biochimie, Groupe Henri Mondor, 4UF Neurochirurgie Fonctionnelle, Groupe Henri Mondor, Créteil, France; 5Service de Neurochirurgie, Hôpital Nord Laënnec, Nantes, France; 6Service de Neurologie, Groupe Henri Mondor, Créteil, France; 7Service de Physiologie, Groupe Bichat – Claude Bernard, Paris, FranceObjective: Patients with Parkinson's disease frequently complain of sleep disturbances and loss of muscle atonia during rapid-eye-movement (REM) sleep is not rare. The orexin-A (hypocretin-1) hypothalamic system plays a central role in controlling REM sleep. Loss of orexin neurons results in narcolepsy-cataplexy, a condition characterized by diurnal sleepiness and REM sleep without atonia. Alterations in the orexin-A system have been also documented in Parkinson's disease, but whether these alterations have clinical consequences remains unknown.Methods: Here, we measured orexin-A levels in ventricular cerebrospinal fluid from eight patients with Parkinson's disease (four males and four females) who underwent ventriculography during deep brain-stimulation surgery and performed full-night polysomnography before surgery.Results: Our results showed a positive correlation between orexin-A levels and REM sleep without muscle atonia.Conclusion: Our results suggest that high levels of orexin-A in Parkinson's disease may be associated with loss of REM muscle atonia.Keywords: Parkinson, orexin-A, ventricular CSF, REM atonia

Rationale: Chronic mountain sickness or Monge's disease is characterized by an excessive polycythemia in high-altitude dwellers, with a prevalence of 5 to 18% above 3,200 m. To date, no pharmacologic treatment is available.Objectives: We evaluated the efficacy of acetazolamide in the treatment of chronic mountain sickness and the importance of nocturnal hypoxemia in its pathophysiology.Methods: A double-blind placebo-controlled study was performed in three groups of patients from Cerro de Pasco, Peru (4,300 m), treated orally for 3 weeks with placebo (n = 10), 250 mg of acetazolamide (n = 10), or 500 mg of acetazolamide (n = 10), daily.Results: Acetazolamide decreased hematocrit by 7.1% (p < 0.001) and 6.7% (p < 0.001), serum erythropoietin by 67% (p < 0.01) and 50% (p < 0.001), and serum soluble transferrin receptors by 11.1% (p < 0.05) and 3.4% (p < 0.001), and increased serum ferritin by 540% (p < 0.001) and 134% (p < 0.001), for groups treated with 250 and 500 mg of acetazolamide, respectively. Acetazolamide (250 mg) increased nocturnal arterial O[2] saturation by 5% (p < 0.01) and decreased mean nocturnal heart rate by 11% (p < 0.05) and the number of apnea-hypopnea episodes during sleep by 74% (p < 0.05). The decrease in erythropoietin was attributed mainly to the acetazolamide-induced increase in ventilation and arterial O[2] saturation.Conclusions: Acetazolamide, the first efficient pharmacologic treatment of chronic mountain sickness without adverse effects, reduces hypoventilation, which may be accentuated during sleep, and blunts erythropoiesis. Its low cost may allow wide development with a considerable positive impact on public health in high-altitude regions. [ABSTRACT FROM AUTHOR]

Voxelotor modifies hemoglobin-oxygen affinity improving anemia and reducing hemolysis in sickle cell patients. However, the impact of Voxelotor on fetal hemoglobin (HbF) levels is unknown. We describe here variations of percentage of HbF measured by high performance liquid chromatography and mean corpuscular fetal Hb in a cohort of sickle cell patients treated with Voxelotor at Henri Mondor Sickle Cell Referral Center. Our data show a decrease in HbF levels in sickle cell patients after 6 months of treatment with Voxelotor, which is likely to be associated with an increase in the lifespan of red blood cells that are no longer prematurely removed from the circulation, particularly those with low HbF. This work raises the question of the risk of a rebound effect when stopping Voxelotor, which has a short half-life, during the time it takes to increase HbF., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: Transfusion has a central place in the treatment of patients with sickle cell disease (SCD). Matching blood groups of red blood cell (RBC) units with the blood groups of the patient is essential to prevent alloimmunization and delayed hemolytic transfusion reaction. African ancestry donors have the best phenocompatibility with patients of the same origin, however their RBCs may present characteristic that can alter quality of the unit such as glucose-6-phosphate dehydrogenase (G6PD) deficiency. The objective is to analyze transfusion protocol, immunization rate and mismatch situations of SCD recipients and to evaluate the frequency of G6PD deficiency in RBCs units from African ancestry donors., Methods: Samples of units transfused to SCD patients were analyzed. Transfusion data were collected from institutional databases. The activity of G6PD was measured in the segment of the RBC units., Results: A total of 98 segments of units transfused to 37 SCD recipients in 41 transfusions episodes was collected. Among patients, 35.1% (n = 13) had no antibodies; 10.8% (n = 4) had antibodies against Fy a /Fy b , Jk a /Jk b , M/N, S/s; 21.6% (n = 8) against RH/K antigens. In all cases, the protocols were in line with the recommendations. G6PD deficiency was observed in 9 units, that were all collected from Afro-Caribbean donors., Conclusion: The transfusion protocol is established to prevent immunological reactions due to disparities in blood group antigens between donors and SCD recipients. However, the units of African ancestry donors, which allowed the best compatibility, displayed a high rate of G6PD deficiency. The storage and recovery impact of this deficiency must be evaluated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Société française de transfusion sanguine (SFTS). Published by Elsevier Masson SAS. All rights reserved.)

Voxelotor (GBT440, OXBRYTA®) appeared recently as one of the possible treatments for sickle cell disease. This molecule, by binding the alpha globin of hemoglobin, causes hyperaffinity of the latter for oxygen and reduces its polymerization properties. Several therapeutic trials have been able to show its effectiveness on certain aspects of sickle cell disease; thus, the french HAS (High Authority of Health) college issued an early access authorization and, since 2021, this treatment can be offered to patients under a temporary authorization for use. Consequently, the laboratories that carry out the biological monitoring of sickle cell patients will be confronted with new profiles characteristic of the presence of hemoglobin combined with GBT440. This work presents a collection of images obtained by different techniques: HPLC, capillary electrophoresis, isoelectrofocusing, alkaline gel and acid agar gel electrophoresis in transfused or non-transfused sickle cell disease patients. The ability to observe the presence of GBT440 by these analyzes could be useful in order to characterize the therapeutic follow-up of patients.

Aims: Iron deficiency (ID) is common in patient with chronic heart failure (HF) and has been widely studied. In contrast, data concerning ID in cardiac amyloidosis (CA) are limited. Amyloidosis is a severe and fatal systemic disease, characterized by an accumulation of amyloid fibrils in various tissues/organs, including nerves, kidneys, gastrointestinal tract, and heart. Amyloid deposits in the heart eventually cause HF. The main subtypes of CA are light chain (AL), hereditary transthyretin (ATTRv), and wild-type transthyretin (ATTRwt). We performed this study to determine the prevalence, clinical outcome (all-cause mortality), and determinants of ID among the three main subtypes of CA., Methods and Results: Iron deficiency status were analysed in 816 CA patients enrolled at the French Referral Centre for Cardiac Amyloidosis: 271 (33%) had AL, 164 (20%) ATTRv, and 381 (47%) ATTRwt. ID affected 49% of CA patients, 45% with AL, 58% with ATTRv, and 48% with ATTRwt. We identified ATTR status (ATTRv P = 0.003, ATTRwt P = 0.037), diabetes (P = 0.003), aspirin treatment (P = 0.009), haemoglobin levels (P = 0.006), and altered global longitudinal strain (P = 0.02) as independent ID determinants. There is no difference in all-cause mortality considering ID status., Conclusions: Iron deficiency is common in patients with CA, irrespective of the subtype. Patients seem more likely to have ID if diagnosed with ATTR, if diabetic, and/or treated with aspirin. In CA, the benefit of intravenous iron therapy, for ID, on morbidity and mortality needs further study., (© 2022 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Background: Erythrocytosis is a hematological disorder usually related to hematopoietic stem cell somatic mutations. However, unexplained erythrocytosis remains frequent. In this study, we evaluated the involvement of IgA1, a regulator of erythropoiesis also implicated in IgA nephropathy (IgAN) pathophysiology, in unexplained polycythemia/erythrocytosis (PE) of IgAN patients., Methods: IgAN-PE patients' serum was collected, analyzed and used to study IgA1 effect on proliferation and differentiation of erythroid progenitors. Hematological parameters of transgenic mice for human alpha1 heavy chain were studied. Multicentric observational cohorts of chronic kidney disease (CKD) patients, including both native kidney diseases and renal transplants, were studied to analyze patient hemoglobin levels., Findings: We retrospectively identified 6 patients with IgAN and unexplained PE. In large CKD cohorts, IgAN was associated with PE in 3.5% of patients (p<0.001 compared to other nephropathies). IgAN was an independent factor associated with higher hemoglobin levels (13.1g/dL vs 12.2 g/dL, p=0.01). During post-transplant anemia, anemia recovery was faster in IgAN patients. Elevated polymeric/monomeric IgA1 ratio as well as high Gd-IgA1 rate were observed in circulating IgA1 of the 6 IgAN-PE patients as compared with control or IgAN patients without PE. IgA1 from these patients increased the sensitivity of erythroid progenitors to Epo. In mice, we also observed an elevation of hematocrit in alpha1 knock-in mice compared to wild type controls., Interpretation: These data identify a new etiology of erythrocytosis and demonstrate the role of pIgA1 in human erythropoiesis. This syndrome of IgA-related erythrocytosis should be investigated in case of unexplained erythrocytosis and renal disease., Funding: This work was supported by INSERM (French national institute for health and medical research), Labex GRex and Imagine Institute (Paris, France)., Competing Interests: Declaration of interests No conflict of interest to disclose, (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Acute chest syndrome (ACS) is a major complication of sickle-cell disease. Bacterial infection is one cause of ACS, so current guidelines recommend the routine use of antibiotics. We performed a prospective before-after study in medical wards and an intensive-care unit (ICU). During the control phase, clinicians were blinded to procalcitonin concentration results. We built an algorithm using the obtained measurements to hasten antibiotic cessation after three days of treatment if bacterial infection was not documented, and procalcitonin concentrations were all <0.5 μg/L. During the intervention period, the procalcitonin algorithm was suggested to physicians as a guide for antibiotic therapy. The primary endpoint was the number of days alive without antibiotics at Day 21. One-hundred patients were analyzed (103 ACS episodes, 60 in intervention phase). Possible or proven lung infection was diagnosed during 13% of all ACS episodes. The number of days alive without antibiotics at Day 21 was higher during the intervention phase: 15 [14-18] vs. 13 [13,14] days ( p = 0.001). More patients had a short (≤3 days) antibiotic course during intervention phase: 31% vs 9% ( p = 0.01). There was neither infection relapse nor pulmonary superinfection in the entire cohort. A procalcitonin-guided strategy to prescribe antibiotics in patients with ACS may reduce antibiotic exposure with no apparent adverse outcomes.

Background: Congenital hemolytic anemia constitutes a heterogeneous group of rare genetic disorders of red blood cells. Diagnosis is based on clinical data, family history and phenotypic testing, genetic analyses being usually performed as a late step. In this study, we explored 40 patients with congenital hemolytic anemia by whole exome sequencing: 20 patients with hereditary spherocytosis and 20 patients with unexplained hemolysis., Results: A probable genetic cause of disease was identified in 82.5% of the patients (33/40): 100% of those with suspected hereditary spherocytosis (20/20) and 65% of those with unexplained hemolysis (13/20). We found that several patients carried genetic variations in more than one gene (3/20 in the hereditary spherocytosis group, 6/13 fully elucidated patients in the unexplained hemolysis group), giving a more accurate picture of the genetic complexity of congenital hemolytic anemia. In addition, whole exome sequencing allowed us to identify genetic variants in non-congenital hemolytic anemia genes that explained part of the phenotype in 3 patients., Conclusion: The rapid development of next generation sequencing has rendered the genetic study of these diseases much easier and cheaper. Whole exome sequencing in congenital hemolytic anemia could provide a more precise and quicker diagnosis, improve patients' healthcare and probably has to be democratized notably for complex cases.

The pathology of sickle cell disease is caused by polymerization of the abnormal hemoglobin S upon deoxygenation in the tissues to form fibers in red cells, causing them to deform and occlude the circulation. Drugs that allosterically shift the quaternary equilibrium from the polymerizing T quaternary structure to the nonpolymerizing R quaternary structure are now being developed. Here we update our understanding on the allosteric control of fiber formation at equilibrium by showing how the simplest extension of the classic quaternary two-state allosteric model of Monod, Wyman, and Changeux to include tertiary conformational changes provides a better quantitative description. We also show that if fiber formation is at equilibrium in vivo, the vast majority of cells in most tissues would contain fibers, indicating that it is unlikely that the disease would be survivable once the nonpolymerizing fetal hemoglobin has been replaced by adult hemoglobin S at about 1 y after birth. Calculations of sickling times, based on a recently discovered universal relation between the delay time prior to fiber formation and supersaturation, show that in vivo fiber formation is very far from equilibrium. Our analysis indicates that patients survive because the delay period allows the majority of cells to escape the small vessels of the tissues before fibers form. The enormous sensitivity of the duration of the delay period to intracellular hemoglobin composition also explains why sickle trait, the heterozygous condition, and the compound heterozygous condition of hemoglobin S with pancellular hereditary persistence of fetal hemoglobin are both relatively benign conditions., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

Aims: Cardiac fibrosis is associated with left ventricular (LV) remodelling and contractile dysfunction in aortic stenosis (AS). The fibrotic process in this condition is still unclear. The aim of this study was to determine the role of both local and systemic inflammation as underlying mechanisms of LV fibrosis and contractile dysfunction. The diagnostic values of 2D-strain echocardiography and serum biomarkers in the evaluation of cardiac fibrosis in this condition were assessed through correlation analyses., Methods and Results: Patients with AS referred for surgical valve replacement were prospectively and consecutively included. They all had a comprehensive echocardiography including 2D strain. Blood samples were collected to measure cytokines and inflammatory biomarkers using Luminex bead-based assays. A per-surgical myocardial biopsy of the basal antero-septal segment (S1) was performed. Serial sections of each biopsy were stained with Sirius red. Digital image analysis was used to quantify fibrosis. Immunostainings using specific antibodies against macrophage, glycoprotein (gp) 130, and interleukin 6 (IL-6) were also performed. Patients were divided into tertiles reflecting the severity of fibrosis: mild, moderate, and severe load (TF1 to TF3). The mean age of the 58 included patients was 73 ± 11 years. Twenty-four (43%) were in New York Heart Association III-IV. Mean aortic valve area was 0.8 ± 0.2 cm 2 . Mean aortic stenosis peak velocity and mean gradient were respectively 4.5 ± 0.8 m/s and 54 ± 15 mmHg. The mean LV ejection fraction was 54 ± 12%, and the global LV longitudinal strain was -15 ± 4%. The mean S1 strain, corresponding to the biopsied region, was -10 ± 6% and was strongly correlated to fibrosis load (R = 0.83, P < 0.0001). TF3 was associated with higher mortality (P = 0.009), higher serum C-reactive protein and IL-6, and lower gp130 compared with the other tertiles (P < 0.05). IL-6 and gp130 were expressed in the heart and respectively in the plasma membrane of macrophages and in the cytoplasm of both macrophages and cardiomyocytes. During follow-up, three patients died and were all in the third fibrosis tertile., Conclusions: We found a positive correlation between elevated inflammatory markers and degree of fibrosis load. These two parameters were associated with worse outcomes in patients with severe AS. Our results may be of interest especially in patients for whom a transcatheter aortic valve implantation is indicated and myocardial biopsy is not possible. Strategies aiming at preventing inflammation might be considered to decrease or limit the progression of cardiac fibrosis in patients followed for AS., (© 2019 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.)

Sickle cell disease (SCD) is the most common monogenic disorder in the world. Notably, there is extensive clinical heterogeneity in SCD that cannot be fully accounted for by known factors, and in particular, the extent to which the phenotypic diversity of SCD can be explained by genetic variation has not been reliably quantified. Here, in a family-based cohort of 449 patients with SCD and 755 relatives, we first show that 5 known modifiers affect 11 adverse outcomes in SCD to varying degrees. We then utilize a restricted maximum likelihood procedure to estimate the heritability of 20 hematologic traits, including fetal hemoglobin (HbF) and white blood cell count (WBC), in the clinically relevant context of inheritance from healthy carriers to SCD patients. We report novel estimations of heritability for HbF at 31.6% (±5.4%) and WBC at 41.2% (±6.8%) in our cohort. Finally, we demonstrate shared genetic bases between HbF, WBC, and other hematologic traits, but surprisingly little overlap between HbF and WBC themselves. In total, our analyses show that HbF and WBC have significant heritable components among individuals with SCD and their relatives, demonstrating the value of using family-based studies to better understand modifiers of SCD., (© 2019 Wiley Periodicals, Inc.)

The presence of hemoglobin variants can adversely affect the accuracy of some HbA1c methods depending on the variant. We examine the analytical interference from a rare Hb variant (Hb N Baltimore) with six different HbA1c methods using various method principles: two immunoassays methods (Tina-quant ® HbA1c Gen et DCA Vantage), three high-performance liquid chromatography methods (G8 HPLC, Variant II Turbo A1c 2.0 et Variant II Dual kit), and one capillary-electrophoresis method (Capillarys Hb A1c kit). Hb N Baltimore can adversely affect determination of HbA1c levels. An underestimation of HbA1c level is observed with the chromatographic methods included in this study and no HbA1c result can be obtained with the capillary-electrophoresis method. Inversely, limited impact is observed with the immunoassays methods. The presence of an hemoglobin variant should be suspected when inconsistencies are observed between a patient's home blood glucose monitoring and laboratory-measured HbA1c. In these situations additional testing should be carried out using a test based on a different analytical method.

Aim: To test whether a delayed and short course of rapamycin would induce immunosuppressive effects following allogeneic orthotopic liver transplantation (OLT) in rats., Methods: Allogeneic OLTs were performed using Dark Agouti livers transplanted into Lewis recipients, and syngeneic OLTs were performed using the Lewis rat strain. Rapamycin (1 mg/kg per day) was administered by gavage from day 4 to day 11 post-transplantation. Lymphocyte cellular compartments were analyzed by flow cytometry in draining lymph nodes, non-draining lymph nodes and the spleen at days 11 and 42 in rapamycin-treated rats, untreated control rats and syngeneic grafted rats. Skin grafts from Dark agouti or from F344 RT were performed at day 30 on liver grafted rats treated with rapamycin., Results: An 8-d course of rapamycin treatment initiated 4 d following transplantation resulted in the survival of grafted rats for more than 100 d. In contrast, untreated rats died of liver failure within 13 to 21 d. The analysis of the cellular compartment revealed an increase in two cellular subpopulations, specifically myeloid-derived suppressor cells (MDSCs) and CD8 + CD45RC low T cells, without major modifications in the regulatory T cell (Treg) compartment in treated rats in the early stages after grafting. We evaluated the ability of treated rats to reject third-party allogeneic skin grafts to confirm their immune competence. In contrast, when skin was collected from rats syngeneic to the grafted liver, it was not rejected., Conclusion: Our results demonstrate that short and delayed rapamycin treatment allows for tolerance in allogeneic OLT. The results also allowed for the identification of the mechanisms of tolerance induced by rapamycin by identifying MDSCs and CD8 + CD45RC low T cells as associated with the state of tolerance., Competing Interests: Conflict-of-interest statement: The authors have no conflicts of interest to declare.

Background: Relative adrenal insufficiency (RAI) is common in intensive care unit patients, particularly during septic shock (SS). Cardiogenic shock (CS) may share some pathophysiological features with SS. The aim of this study was to evaluate the prevalence and long-term prognosis of RAI during CS., Patients and Methods: Prospective observational study conducted in the intensive care and cardiology units in one university hospital in France. Patients meeting the criteria for CS without prior corticosteroid therapy were included. Total blood cortisol levels were assessed immediately before (T0) a short corticotropin stimulation test (0.25 mg i.v. of tetracosactrin) and 30 and 60 min afterward. Δmax was defined as the difference between the maximal value after the test and T0., Results: Of the 92 patients enrolled, 42 (46%) (95% confidence interval [CI] [36%-56%]) died in hospital and 7 more died during a median follow-up of 616 [57-2,498] days, for an overall mortality rate of 53% (95% CI [43%-63%]). Three groups were identified based on the corticotropin test: group 1 (T0 ≤798 nmol/L and Δmax >473 nmol/L), group 2 ([T0 >798 nmol/L and Δmax >473 nmol/L] or [T0 ≤798 nmol/L and Δmax ≤473 nmol/L]), and group 3 (T0 >798 nmol/L and Δmax ≤473 nmol/L) with an overall survival of 76%, 43%, and 15%, respectively (log rank P = 0.003). In the multivariable analysis, adrenal nonresponse (group 3) was an independent predictor of mortality (P = 0.04), along with left ventricular ejection fraction, Simplified Acute Physiology Score II, and cardiac arrest., Conclusions: These data suggest that a short corticotropin test has a good prognostic value in CS and allows identifying patients at higher risk of death.

Diagnosis of delayed hemolytic transfusion reactions (DHTR), one of the most dreaded complications of transfusion in patients with sickle cell disease (SCD), is challenging and not straightforward. Current diagnostic approaches are complex and not consensual; they are based on assessment of hemoglobin (Hb) drop and enhanced hemolysis, features also seen during classical vaso-occlusive events. In this observational study, we tested the hypothesis that the rate of decline in HbA after an index transfusion is a surrogate marker for the destruction of transfused RBC, which could be used diagnostically. We examined 421 transfusion episodes (in 128 patients of a French referral center for SCD) for which an Hb electrophoresis was obtained within 1 week following an index transfusion and repeated within 2 months (before a subsequent scheduled transfusion or during an acute complication). Chart review found DHTR to be present in 26 cases (6.2%), absent in 389 cases (92.4%), and possible in six cases (1.4%). As expected, DHTR was associated with accelerated hemolysis (increased serum bilirubin and lactic dehydrogenase concentrations) and a decline in total Hb as compared to the early post-transfusion value. However, the decline in HbA concentration appeared more effective in segregating between patients without DHTR and others. We propose a diagnostic nomogram for DHTR based on Hb A as a biologic marker of the survival of transfused RBCs. Am. J. Hematol. 91:1181-1184, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Background: Huntington's disease (HD) is one of several neurodegenerative disorders that have been associated with metabolic alterations. Changes in Insulin Growth Factor 1 (IGF-1) and/or insulin input to the brain may underlie or contribute to the progress of neurodegenerative processes. Here, we investigated the association over time between changes in plasma levels of IGF-1 and insulin and the cognitive decline in HD patients., Methods: We conducted a multicentric cohort study in 156 patients with genetically documented HD aged from 22 to 80 years. Among them, 146 patients were assessed at least twice with a follow-up of 3.5 ± 1.8 years. We assessed their cognitive decline using the Unified Huntington's Disease Rating Scale, and their IGF-1 and insulin plasmatic levels, at baseline and once a year during the follow-up. Associations were evaluated using a mixed-effect linear model., Results: In the cross-sectional analysis at baseline, higher levels of IGF-1 and insulin were associated with lower cognitive scores and thus with a higher degree of cognitive impairment. In the longitudinal analysis, the decrease of all cognitive scores, except the Stroop interference, was associated with the IGF-1 level over time but not of insulin., Conclusions: IGF-1 levels, unlike insulin, predict the decline of cognitive function in HD., Competing Interests: The authors have declared that no competing interests exist.

Background: Vaso-occlusive crisis (VOC), hallmark of sickle-cell disease (SCD), is the first cause of patients' Emergency-Room admissions and hospitalizations. Acute chest syndrome (ACS), a life-threatening complication, can occur during VOC, be fatal and prolong hospitalization. No predictive factor identifies VOC patients who will develop secondary ACS., Methods: This prospective, monocenter, observational study on SS/S-β0thalassemia SCD adults aimed to identify parameters predicting ACS at Emergency-Department arrival. The primary endpoint was ACS onset within 15days of admission. Secondary endpoints were hospitalization duration, morphine consumption, pain evaluation, blood transfusion(s) (BT(s)), requiring intensive care and mortality., Findings: Among 250 VOCs included, 247 were analyzed. Forty-four (17.8%) ACSs occurred within 15 (median [IQR] 3 [2, 3]) days post-admission based on auscultation abnormalities; missing chest radiographs excluded three patients. Comparing ACS to VOC, respectively, median hospital stay was longer 9 [7-11] vs 4 [3-7] days (p<0.0001), 7/41 (17%) vs 1/203 (0.5%) required intensive care (p<0.0001), and 20/41 (48.7%) vs 6/203 (3%) required BTs (p<0.0001). No patient died. The multivariate model retained reticulocyte and leukocyte counts, and spine and/or pelvis pain as being independently associated with ACS; the resulting ACS-predictive score's area under the ROC was 0.840 [95% CI 0.780-0.900], 98.8% negative-predictive value and 39.5% positive-predictive value for the real ACS incidence., Interpretation: The ACS-predictive score is simple, easily applied and could change VOC management and therapeutic perspectives. Assessed ACS risk could lead to earlier discharges or close monitoring and rapid medical intensification to prevent ACS., (Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.)