Unite Transversale de la Drepanocytose

Guadeloupe, France

Unite Transversale de la Drepanocytose

Guadeloupe, France
SEARCH FILTERS
Time filter
Source Type

Garnier Y.,French Institute of Health and Medical Research | Ferdinand S.,French Institute of Health and Medical Research | Etienne-Julan M.,French Institute of Health and Medical Research | Elana G.,Pole mere enfant | And 9 more authors.
PLoS ONE | Year: 2017

Sickle cell anemia (SCA) and hemoglobin SC (HbSC) disease are the two most common forms of sickle cell disease (SCD), a frequent hemoglobinopathy which exhibits a highly variable clinical course. Although high levels of microparticles (MPs) have been consistently reported in SCA and evidence of their harmful impact on the SCA complication occurrences have been provided, no data on MP pattern in HbSC patients has been reported so far. In this study, we determined and compared the MP patterns of 84 HbSC and 96 SCA children, all at steady-state, using flow cytometry. Most of circulating MPs were derived from platelets (PLTs) and red blood cells (RBCs) in the two SCD syndromes. Moreover, we showed that HbSC patients exhibited lower blood concentration of total MPs compared to SCA patients, resulting mainly from a decrease of MP levels originated from RBCs and to a lesser extent from PLTs. We did not detect any association between blood MP concentrations and the occurrence of painful vaso-occlusive crises, acute chest syndrome and pulmonary hypertension in both patient groups. We also demonstrated for the first time, that whatever the considered genotype, RBC-derived MPs exhibited higher externalized phosphatidylserine level and were larger than PLT-derived MPs. © 2017 Garnier et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Lemonne N.,Unite Transversale de la Drepanocytose | Billaud M.,Unite Transversale de la Drepanocytose | Waltz X.,University of the French West Indies and Guiana | Waltz X.,Laboratory of Excellence GR Ex | And 9 more authors.
Clinical Hemorheology and Microcirculation | Year: 2016

Patients with hemoglobin C disease (CC) usually do not develop severe complications in comparison with individuals with sickle cell anemia (SS) or with sickle cell hemoglobin C disease (SC). The present study compared the hematological, biochemical, hemorheological and clinical characteristics of CC patients to those of SS, SC and healthy individuals (AA). Blood viscosity was measured at 225 s-1 with a cone plate viscometer. The hematocrit-to-blood viscosity ratio (HVR), i.e. an index of red blood cell (RBC) oxygen transport effectiveness, was calculated. RBC deformability was determined at 30 Pa by ektacytometry, and RBC aggregation properties by syllectometry. CC and SC had higher blood viscosity and lower HVR than AA. Nevertheless, HVR was higher in CC compared to SS and tended to be higher than in SC. The CC group exhibited very rigid hyperchromic RBC compared to the three other groups. RBC aggregation abnormalities were observed in CC: low RBC aggregation index and high RBC aggregates strength. Despite these hemorheological abnormalities, CC never had hospitalized painful vaso-occlusive crisis or acute chest syndrome. In contrast, all of them had splenomegaly. Of note, 2 out of 7 CC developed retinopathy or otologic disorders. Whether the blood hyperviscosity and decreased RBC deformability are responsible for these complications is unknown. The higher oxygen transport effectiveness (i.e., HVR) of CC compared to SS is probably at the origin of the very low risk of medical complication in this population. © 2015 - IOS Press and the authors.


Hierso R.,French Institute of Health and Medical Research | Hierso R.,CEA DAM Ile-de-France | Hierso R.,University of the French West Indies and Guiana | Hierso R.,Laboratory of Excellence GR Ex | And 22 more authors.
British Journal of Haematology | Year: 2014

Sickle cell anaemia (SS) and sickle cell-haemoglobin C disease (SC) patients exhibit severe red blood cell (RBC) rheological alterations involved in the development of several complications. The contribution of oxidative stress in these haemorheological abnormalities is still unknown. We compared RBC reactive oxygen species (ROS) and glutathione (GSH) content, and the haemorheological profile of SS (n = 11), SC (n = 11) and healthy subjects (n = 12) at baseline and after in-vitro treatment with t-butyl hydroperoxide (TBHP). We showed: (i) higher RBC ROS content in SS and SC patients, with the highest level observed in SS patients; (ii) lower RBC GSH content in sickle syndrome patients, especially in SS patients; (iii) TBHP increased RBC ROS production and decreased RBC GSH content in all groups; (iv) TBHP decreased RBC aggregation and increased the strength of RBC aggregates in all groups but the increase in RBC aggregates strength was greater in sickle cell patients; (v) TBHP decreased RBC deformability in the three groups but with a higher magnitude in sickle cell patients. These data suggest that RBCs from sickle cell patients have an exaggerated response to oxidative stress, which is accompanied by a profound abnormal haemorheological profile, with greater alterations in SS than in SC patients. © 2014 John Wiley & Sons Ltd.


Lamarre Y.,French Institute of Health and Medical Research | Lamarre Y.,University of the French West Indies and Guiana | Lamarre Y.,University of Paris Pantheon Sorbonne | Romana M.,French Institute of Health and Medical Research | And 19 more authors.
Clinical Hemorheology and Microcirculation | Year: 2014

While chronic hemolysis has been suspected to be involved in the development of glomerulopathy in patients with sickle cell anemia (SCA), no study focused on the implications of blood rheology. Ninety-six adults with SCA at steady state were included in the present cross-sectional study. Three categories were defined: normo-albuminuria (NORMO, n = 41), micro-albuminuria (MICRO, n = 23) and macro-albuminuria (MACRO, n = 32). Blood was sampled to measure hematological and hemorheological parameters, and genomic DNA extraction was performed to detect the presence of α-thalassemia. The prevalence of α-thalassemia was lower in the MACRO group compared with the two other groups. Anemia was more severe in the MACRO compared with the NORMO group leading the former group to exhibit decreased blood viscosity. Red blood cell deformability was lower and red blood cell aggregates strength was greater in the MACRO compared to the two other groups, and this was directly attributed to the lower frequency of α-thalassemia in the former group. Our results show the protective role of α-thalassemia against the development of sickle cell glomerulopathy, and strongly suggest that this protection is mediated through the decrease of anemia, the increase of RBC deformability and the lowering of the RBC aggregates strength. © 2014 ? IOS Press and the authors.


PubMed | University Claude Bernard Lyon 1, French Institute of Health and Medical Research, Unite Transversale de la Drepanocytose and University of Paris Pantheon Sorbonne
Type: Journal Article | Journal: PloS one | Year: 2014

We compared the blood thixotropic/shear-thinning properties and the red blood cells (RBC) rheological properties between a group of patients with sickle cell anaemia (SS) and healthy individuals (AA). Blood thixotropy was determined by measuring blood viscosity with a capillary viscometer using a loop protocol: the shear rate started at 1 s-1 and increased progressively to 922 s-1 and then re-decreased to the initial shear rate. Measurements were performed at native haematocrit for the two groups and at 25% and 40% haematocrit for the AA and SS individuals, respectively. RBC deformability was determined by ektacytometry and RBC aggregation properties by laser backscatter versus time. AA at native haematocrit had higher blood thixotropic index than SS at native haematocrit and AA at 25% haematocrit. At 40% haematocrit, SS had higher blood thixotropic index than AA. While RBC deformability and aggregation were lower in SS than in AA, the strength of RBC aggregates was higher in the former population. Our results showed that 1) anaemia is the main modulator of blood thixtropy and 2) the low RBC deformability and high RBC aggregates strength cause higher blood thixotropy in SS patients than in AA individuals at 40% haematocrit, which could impact blood flow in certain vascular compartments.


PubMed | University of the French West Indies and Guiana, University Claude Bernard Lyon 1, French Institute of Health and Medical Research and Unite Transversale de la Drepanocytose
Type: Journal Article | Journal: Blood cells, molecules & diseases | Year: 2015

Vascular resistance and tissue perfusion may be both affected by impaired vascular function and increased blood viscosity. Little is known about the effects of vascular function on the occurrence of painful vaso-occlusive crises (VOC) in children with sickle cell anemia (SCA). The aim of the present study was to determine which side of the balance (blood viscosity or vascular function) is the most deleterious in SCA and increases the risk for frequent hospitalized VOC. Microvascular function, microcirculatory oxygenation and blood viscosity were determined in a group of 22 SCA children/adolescents at steady state and a group of 13 healthy children/adolescents. Univariate analyses demonstrated blunted microvascular reactivity during local thermal heating test and decreased microcirculatory oxygenation in SCA children compared to controls. Multivariate analysis revealed that increased blood viscosity and decreased microcirculatory oxygenation were independent risk factors of frequent VOC in SCA. In contrast, the level of microvascular dysfunction does not predict VOC rate. In conclusion, increased blood viscosity is usually well supported in healthy individuals where vascular function is not impaired. However, in the context of SCA, microvascular function is impaired and any increase of blood viscosity or decrease in microcirculatory oxygenation would increase the risks for frequent VOC.


PubMed | Service dImmunologie Hematologie, Thomas Jefferson University, Unite Transversale de la Drepanocytose, University of the French West Indies and Guiana and 2 more.
Type: Journal Article | Journal: Clinical hemorheology and microcirculation | Year: 2016

The aim of the present study was to test the effects of Pfaffia paniculata (PP) extract on the red blood cell (RBC) rheological properties of patients with sickle cell disease (SCD) and healthy (AA) individuals. Blood from 7 SCD and 4 AA individuals were collected in EDTA tubes. Washed RBCs were incubated with various concentration of PP extract: 0.0, 0.2 or 0.5mg/ml of PP solution for 5hrs at 37C. RBC deformability was measured by ektacytometry at 9 shear stresses ranging from 0.3 to 30Pa, and RBC aggregation properties were determined by laser-backscattered techniques. Because RBCs from SCD patients are fragile, a stability test was also performed to test for the fragility of RBC exposed to a constant shear stress (70Pa) for 10min. While RBC deformability was not improved by the use of PP extract in AA, we noted an improvement of this parameter in patients with SCD between the 0.0 and 0.5mg/ml conditions. In contrast to AA RBCs, the fragility of SCD RBCs was not affected by PP extract. In conclusion, this study demonstrates the beneficial effects, in-vitro, of PP extract on the RBC deformability of SCD patients, notably at high shear stress (a shear stress condition usually found in capillaries).


Nebor D.,University of the French West Indies and Guiana | Durpes M.C.,University of the French West Indies and Guiana | Mougenel D.,Unite Transversale de la Drepanocytose | Mukisi-Mukaza M.,University of the French West Indies and Guiana | And 3 more authors.
Clinical Immunology | Year: 2010

Since inflammation plays a prominent role in the pathogenesis of sickle cell anemia (SCA) and Duffy antigen receptor for chemokines (DARC) modulates the function of inflammatory processes, we analyzed the relationship between the erythrocyte DARC phenotype and clinical expression of SCA. DARC locus was genotyped in 212 SS adult patients followed by the sickle cell center of Guadeloupe (French West Indies). After patients' stratification according to RBC DARC expression, the prevalence of renal disease, leg ulcers, priapism and osteonecrosis was compared between patient groups as well as hematological variables and plasma levels of chemokines. Duffy-positive patients exhibited higher counts of white blood cells (9.95 ± 2.36 vs 8.88 ± 2.32 109/L, p = 0.0066), polynuclear neutrophils (5.1 ± 1.73 vs 4.51 ± 1.71 109/L, p = 0.0227), higher plasma levels of IL-8 (4.46 ± 1.22 vs 1.47 ± 0.5 pg/mL, p = 0.0202) and RANTES (27.8 ± 4.3 vs 18.1 ± 2.3 ng/mL, p = 0.04) than Duffy-negative patients. No association was detected between RBC expression of DARC and the studied complications. © 2010 Elsevier Inc. All rights reserved.


Lemaire C.,Service Route | Lamarre Y.,French Institute of Health and Medical Research | Lemonne N.,Unite Transversale de la Drepanocytose | Waltz X.,French Institute of Health and Medical Research | And 8 more authors.
Clinical Hemorheology and Microcirculation | Year: 2013

Little is known about the impact of blood rheology on the occurrence of retinopathy in sickle cell disease (SCD). Fifty-nine adult SCD patients in steady-state condition participated to the study: 32 with homozygous SCD (sickle cell anemia; SCA) and 27 with sickle cell hemoglobin-C disease (SCC). The patients underwent retinal examination and were categorized according to the classification of Goldberg: 1) no retinopathy (group 1), 2) non-proliferative or proliferative stage I-II retinopathy (group 2) and 3) proliferative stage III-IV-V retinopathy (group 3). Hematological and hemorheological (whole blood viscosity, RBC deformability and aggregation properties) measurements were performed for each patient. In the whole SCD group (SCA + SCC patients) and in SCC patients, the group 3 had higher platelets count than group 2 but the difference between group 3 and group 1 did not reach statistical significance. No difference was observed for the other parameters between the three groups. SCC patients from the group 3 exhibited higher whole blood viscosity than SCC patients from the group 1. No significant difference was observed between the three groups in SCA patients. This study revealed that severe sickle proliferative retinopathy is associated with blood hyperviscosity in SCC patients but not in SCA patients. © 2013 - IOS Press and the authors.


PubMed | University of the French West Indies and Guiana and Unite Transversale de la Drepanocytose
Type: Journal Article | Journal: Clinical hemorheology and microcirculation | Year: 2016

Patients with hemoglobin C disease (CC) usually do not develop severe complications in comparison with individuals with sickle cell anemia (SS) or with sickle cell hemoglobin C disease (SC). The present study compared the hematological, biochemical, hemorheological and clinical characteristics of CC patients to those of SS, SC and healthy individuals (AA). Blood viscosity was measured at 225 s(-1) with a cone plate viscometer. The hematocrit-to-blood viscosity ratio (HVR), i.e. an index of red blood cell (RBC) oxygen transport effectiveness, was calculated. RBC deformability was determined at 30 Pa by ektacytometry, and RBC aggregation properties by syllectometry. CC and SC had higher blood viscosity and lower HVR than AA. Nevertheless, HVR was higher in CC compared to SS and tended to be higher than in SC. The CC group exhibited very rigid hyperchromic RBC compared to the three other groups. RBC aggregation abnormalities were observed in CC: low RBC aggregation index and high RBC aggregates strength. Despite these hemorheological abnormalities, CC never had hospitalized painful vaso-occlusive crisis or acute chest syndrome. In contrast, all of them had splenomegaly. Of note, 2 out of 7 CC developed retinopathy or otologic disorders. Whether the blood hyperviscosity and decreased RBC deformability are responsible for these complications is unknown. The higher oxygen transport effectiveness (i.e., HVR) of CC compared to SS is probably at the origin of the very low risk of medical complication in this population.

Loading Unite Transversale de la Drepanocytose collaborators
Loading Unite Transversale de la Drepanocytose collaborators