Moussa Seck

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-S&bgr;0 than in SC-S&bgr;+ 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.

Implementing haemophilia care in Senegal, West Africa

Despite significant progres on haemophilia care in developed world, this disease remains unknown in many sub‐Saharan African countries. The objectives of this article were to report Senegalese experience on the management of haemophilia care through 18 years of follow‐up. This cohort study included 140 patients (127 haemophilia A, 13 haemophilia B), followed in Dakars haemophilia treatment centre from 1995 to 2012. Our study reported a prevalence of 2.3/100 000 male births, accounting for 11.6% of what is expected in Senegal. From the period 1995–2003 to 2004–2012, significant progress was seen including 67.9% increase in new patients identification, 11.3 years reduction in mean age at diagnosis (from 15.5 to 4.2 years), lower mortality rate (from 15.3% to 6.8%) and age at death evolved from 6.5 to 23.3 years. Of the 50 haemophilia A patients who were tested for inhibitor presence, 10 were positive (eight severe and two moderate) that is prevalence of 20%. All patients were low responders since inhibitor titre was between 1.5 and 3.8 BU. Disabilities were seen in 36.5% of patients above 20 years old who had musculoskeletal sequels and 39% had no scholar or professional activities in our setting. Implementing haemophilia care in sub‐Saharan Africa is a great challenge as this disease is not yet counted in national health problems in many countries. Lessons learned from this study show a significant improvement in diagnosis and prognosis parameters. This emphasizes the needs to set up such follow‐up initiatives and to enhance medical and lay cooperation for better results.

Antiphospholipid antibodies and systemic scleroderma.

Objective: Antiphospholipid antibodies (APLs) could be associated with an increased risk of vascular pathologies in systemic scleroderma. The aim of our study was to search for APLs in patients affected by systemic scleroderma and to evaluate their involvement in the clinical manifestations of this disease. Materials and Methods: We conducted a cross-sectional descriptive study, from January 2009 until August 2010, with patients received at the Department of Dermatology (Dakar, Senegal). Blood samples were taken at the hematology laboratory and were analyzed for the presence of APLs. Results: Forty patients were recruited. Various types of either isolated or associated APLs were found in 23 patients, i.e. 57.5% of the study population. The most frequently encountered antibody was IgG anti-β2 GPI (37.5% of the patients), followed by anticardiolipins (17.5%) and lupus anticoagulants (5%). No statistically significant association of positive antiphospholipid-related tests to any of the scleroderma complications could be demonstrated. Conclusion: A high proportion of patients showing association of systemic scleroderma and APLs suggests the presence of a morbid correlation between these 2 pathologies. It would be useful to follow a cohort of patients affected by systemic scleroderma in order to monitor vascular complications following confirmation of the presence of antiphospholipid syndrome. Conflict of interest:None declared.

Blood viscosity is lower in trained than in sedentary sickle cell trait carriers

The aim of this study was to compare blood and plasma viscosities, as well as the hematocrit/blood viscosity ratio (HVR), between trained and sedentary SCT carriers. Thirty African male SCT carriers from the city of Dakar (Senegal) participated in the study: one group composed of 15 trained SCT carriers (TSCTc) and one group composed of 15 sedentary individuals (SSCTc). Blood was sampled in resting condition and blood and plasma viscosities were measured using a cone-plate viscometer. After the determination of hematocrit by microcentrifugation, HVR was determined for each subject. Blood and plasma viscosities, as well as hematocrit, were significantly reduced in TSCTc compared to SSCTc. As a consequence, HRV was greater in TSCTc. These findings provide evidence that SCT carriers should be encouraged to practice regular physical activity to limit the cardiovascular strain usually caused by their blood hyperviscosity.

Rosai Dorfman disease diagnosed by fine‐needle aspiration cytology in a young man with HIV infection

RDD (Rosai Dorfman disease) is a rare and benign histiocytic proliferative disorder of unknown etiology. FNAC (Fine‐needle aspiration cytology) is a useful and reliable tool for the diagnosis of RDD, and as such, biopsy is avoidable.

Risk factors for thrombosis in an african population.

Little is known about the biological, epidemiological, and clinical risk factors for thrombosis and venous thromboembolism (VTE) among Black Africans. We undertook a study of the prevalence of VTE risk factors for thrombosis in a Senegalese population. A three-year cross-sectional and case-control study involving 105 cases and 200 controls was conducted in various hospitals in Dakar (Senegal). Our results demonstrate that oral contraception, immobilization by casts, surgery, and blood group were significantly associated with VTE occurrence. Additionally, 16 cases and 2 controls had protein S (PS) values of less than 48.4% (M-2SD), exhibiting a highly significant difference (P < 1 x 10−4). The number of cases with a low protein C (PC) level was significantly higher than the respective number of controls. Using logistic regression methods, we established a correlation between significantly associated variables and deep venous thrombosis (DVT) occurrence. Age, obesity, sickle cell disease, and PC deficiency were not significantly associated with thrombosis. In contrast, gender, PS deficiency, varicose veins, surgery, non-O blood type, and the presence of anti-phospholipid antibodies were significantly and independently associated with DVT. These findings are extremely useful for clinical management of patients suffering from DVT and can help to reduce the high recurrence rate observed in our study.

Molecular diagnosis of haemophilia A in patients from Senegal

M. SECK,* C. COSTA,† B. F. FAYE,* D. SY BAH,* S. A. TOUR E,* N. DIENG,* A. SALL,* M. GADJI ,* A. O. TOUR E,* D. LASNE,‡ C. ROTHSCHILD§ and S. DIOP* *Hematology Cheikh Anta Diop University, Dakar, Senegal; †Laboratory of Genetic and Molecular Biology Cochin Hospital, APHP; ‡Laboratory of Hemostasis, Hôpital Universitaire Necker-Enfants Malades, AP-HP; and §Haemophilia Treatment Centre, Department of Haematology, Hôpital Universitaire Necker-Enfants Malades, AP-HP, Paris, France

Challenges in the management of sickle cell disease during pregnancy in Senegal, West Africa

ABSTRACT Objectives: The aim of this study was to evaluate the maternal and fetal complications in pregnant patients with sickle cell disease (SCD) and find risk factors of stillbirth. Method: We conducted a prospective study in pregnant women with SCD. Demographic characteristics, maternal and fetal morbi-mortality, and outcome of pregnancies were described. Risk factors of fetal loss were evaluated by comparing the parameters of the pregnancies that led to a live birth with those interrupted. Results: We included 70 pregnancies in 58 women with SCD. The average age was 29.3 years. The average gestational age at the start of follow-up was 13 weeks. The occurrence of acute complications was significantly higher during pregnancy compared to the year before (p < 0.05). Maternal mortality was 0%. Live birth rate was 80%. Fetal loss rate was 3.9 times higher in previous pregnancies that had not been monitored in hematology (71.8 versus 18.6%). Stillbirth was associated with nulliparity, high leukocytes or platelet counts (p < 0.05). Conclusion: Pregnancy in SCD was associated with a high maternal morbidity and stillbirth. Nulliparity, high leucokocytes or platelet count were identified as risk factors of fetal loss.

Profil biochimique et hématologique des patients drépanocytaires homozygotes en phase stationnaire au centre National de Transfusion Sanguine de Dakar

La drepanocytose est caracterisee par une grande variabilite d’expression clinique et biologique qui depend de plusieurs facteurs. L’objectif de ce travail etait d’etudier les perturbations biologiques des patients drepanocytaires homozygotes en phase stationnaire. Il s’agit d’une etude prospective transversale ayant inclus 100 drepanocytaires homozygotes en phase stationnaire d’âge superieur a 15 ans. Chaque patient a beneficie de deux tubes de prelevements pour l’etude des parametres hematologiques et pour les dosages biochimiques. Un questionnaire a ete utilise pour recueillir les variables epidemiologiques, cliniques et biologiques. Ces donnees ont ete saisies et analysees par le logiciel Epi-info 7.2. Une valeur p ≤ 0,05 a ete consideree comme significative. L’âge moyen des patients etait de (28 ± 8,94) ans, les extremes (15-57 ans) et le sex-ratio (H/F) de 0,75. Le taux d’hemoglobine de base etait en moyenne de (8,2 ± 1,4g/dl), les globules blancs de (12352 ± 6.906/ mm 3 ), les plaquettes (439.920 ± 139.000/mm 3 ), la TCMH (31,18pg ± 4,12 pg). Le taux d’hemoglobine S etait en moyenne de (87,79 ± 8,19 %) et l’hemoglobine F (HbF) (9,5 ± 8,3%). Le taux HbF etait associee de facon significative avec le syndrome thoracique aigu et la lithiase biliaire (r=0,56 ; p=0,003). Cette etude a montre que les perturbations biologiques sont frequentes chez les dans la drepanocytaires homozygotes. Leur connaissance servira de base de comparaison lors des crises et pour evaluer l’efficacite du traitement.

Bleeding risk assessment in hemophilia A carriers from Dakar, Senegal

&NA; Hemophilia A carriers have an abnormal X chromosome with a molecular abnormality of FVIII gene. These carriers, long considered to be free of bleeding risk, could have the same symptoms as mild hemophiliacs. This study aim to assess bleeding risk of hemophilia A carriers monitored at the Clinical Hematology Department of Dakar. This is a prospective study of a period of 6 months including 22 hemophilia A carriers aged between 8 and 48 years. Hemophilia carriers were recruited using the genealogical tree of hemophiliacs followed in the service. Their diagnosis was carried out by long range PCR and Sanger sequencing method searching the molecular abnormality responsible for hemophilia in their family. Bleeding risk was determined using a questionnaire consisting of different bleeding symptoms quoted from −1 to 4 according to the severity. Total of different values allow to determine the bleeding score which was pathological if it was greater than or equal to 1. Medium age was 22.5 years (8–48) (SD = 9.28). Four hemophilia A carriers (18.1%) presented bleeding symptoms and had a bleeding score at least 1 (P = 0.02). Menorrhagia was predominant (13.6%) followed by epistaxis (9%), gingivorrhagia (9%), and prolonged bleeding after tooth extraction (9%). Factor VIII level was lower in hemophilia carriers who presented bleeding (42 ± 8.61 UI/l) versus hemophilia carriers without bleeding (100 ± 50.95 UI/l) (P = 0.001). There was no significant correlation between bleeding occurrence and age (P = 0.81), activated patial thromboplastin time value (P = 0.97) and FVIII/Von Willebrand Factor ratio (P = 0.12). One in five hemophilia carriers presented bleeding and the questionnaire was effective to identify hemophilia carriers who had a risk of bleeding.