Efficacy and Safety of Manual Partial Red Cell Exchange in the Management of Severe Complications of Sickle Cell Disease in a Developing Country.

INTRODUCTION: The realization of red cell exchange (RCE) in Africa faces the lack of blood, transfusion safety, and equipment. We evaluated its efficacy and safety in severe complications of sickle cell disease. PATIENTS AND METHOD: Manual partial RCE was performed among sickle cell patients who had severe complications. Efficacy was evaluated by clinical evolution, blood count, and electrophoresis of hemoglobin. Safety was evaluated on adverse effects, infections, and alloimmunization. RESULTS: We performed 166 partial RCE among 44 patients including 41 homozygous (SS) and 2 heterozygous composites SC and 1 S/ß0-thalassemia. The mean age was 27.9 years. The sex ratio was 1.58. The regression of symptoms was complete in 100% of persistent vasoocclusive crisis and acute chest syndrome, 56.7% of intermittent priapism, and 30% of stroke. It was partial in 100% of leg ulcers and null in acute priapism. The mean variations of hemoglobin and hematocrit rate after one procedure were, respectively, +1.4 g/dL and +4.4%. That of hemoglobin S after 2 consecutive RCE was -60%. Neither alloimmunization nor viral seroconversion was observed. CONCLUSION: This work shows the feasibility of manual partial RCE in a low-resource setting and its efficacy and safety during complications of SCD outside of acute priapism.

Evaluation of transfusion practices in sickle cell disease in Senegal: cohort study of 1078 patients with sickle cell disease.

Blood transfusion is an essential therapeutic tool in the treatment of sickle cell disease. Its indications and modalities vary from one country to another as a function of the clinical severity of the disease and the availability of blood products. This study seeks to evaluate the frequency and modalities of blood transfusions as well as their indications in patients with sickle cell syndrome at the Dakar hematology department from 1995 through 2015. This retrospective study reviewed the records of a cohort of 1078 patients with SS, SC, Sß0 and Sß + thalassemia sickle cell syndromes and collected data about the type of blood products, indications, modalities, and acute transfusion complications. The frequency of transfusion was adjusted for age, sex, and sickle cell profile. The patients' mean age was 23 years (2-44 years) and the sex ratio 0.9. SS disease was predominant (87.4 %); 28.5% had transfusions during the study period. Patients older than 20 years received more transfusions (P = 0.047). The frequency of transfusions did not differ significantly by gender (P = 0.12), but did by profile: a higher percentage of patients with SS disease required transfusion (P = 0.043). Acute anemia was the most common indication for transfusion (50.03 %). Acute transfusion complications were rare (5.8 %). This study shows that less than one third of sickle cell anemia patients in Senegal have transfusions, a finding that confirms that our patients have fewer transfusions than patients in other countries in Africa or in the West. This limited use of transfusion therapy may be related to a less severe level of disease among patients in Senegal, but also to the availability of blood products.

[Profil course of SC sickle-cell patients in Dakar: a case-control study with SS sickle cell form]. / Profil evolutif de la drepanocytose SC A Dakar: étude cas-témoin avec la forme SS.

AIMS: The study aim to describe the epidemiological, clinico-biological and evolutionary aspects of SC sickle cell patients compared to SS sickle cell disease. PATIENTS AND METHODS: We realized a case-control study of 12 months duration including 98 major sickle cell patients (49 SC and 49 SS sickle cell patients). SS sickle cell patients were randomly selected according to age and sex. Socio-demographic, clinico-biological and evolutionary data were noted for each patient. RESULTS: Mean age was 24.7 years (5 - 53). Sex ratio was 0.8. Mean number of transfusions was 0.06 of SC patients and 0.34 for SS patients (p=0.0008). Mean number of vaso-occlusive crisis per year was 2.24 of SC patients and 2.37 of SS patients (p=0.3). Mean basic hemoglobin level was 10.8 of SC patients and 7.8 of SS patients (p=0.0000). Priapism was found in 2.04% of SC patients and 4.04% of SS patients (p=0.3) and acute anemia in 2.04% of SC and 24.48% of SS patients (p=0.003); 26.53% of SC patients had a chronic complication compared to 18.36% of SS patients (p=0.0001). CONCLUSION: This study shows that SC sickle cell patients are less symptomatology compared to SS patients, however they would develop more chronic complications from where the utility for regular follow-up.

BUTS: Le but de notre étude était de décrire les aspects épidémiologiques, clinico-biologiques et évolutifs des patients SC comparés aux patients SS. PATIENTS ET MÉTHODES: Il s'agissait d'une étude cas témoins d'une durée de 12 mois portant sur 98 patients (49 SC et 49 SS8). Les témoins SS étaient choisis de façon aléatoire après appariement selon l'âge et le sexe. Pour chaque patient nous avons noté les aspects sociodémographiques, clinicobiologiques et évolutifs. RÉSULTATS: L'âge moyen était de 24,7 ans (5 - 53). Le sex ratio était de 0,8. Le nombre moyen de transfusions était de 0,06 chez les SC et 0,34 chez les SS (p=0,0008). Le nombre moyen de CVO/an était de 2,24 chez les SC et 2,37 chez les SS (p=0,3). Le taux moyen d'hémoglobine de base était de 10,8 chez les SC et 7,8 chez les SS (p=0,0000). Le priapisme était trouvé chez 2,04% des SC et 4,04% des SS (p=0,3) et l'anémie aigue chez 2,04% des SC et 24,48% des SS (p=0,003); 26,53% des SC souffraient d'une complication chronique contre 18,36% des SS (p=0,0001). CONCLUSION: Cette étude montre que les drépanocytaires SC ont une symptomatologie moindre par rapport aux patients SS, cependant ils développeraient plus de complications chroniques d'où l'utilité d'un suivi régulier.

[Evaluation of the efficacy of medical screening of blood donors on preventing blood transfusion-transmitted infectious agents]. / Évaluation de l'efficacité de la sélection médicale des donneurs de sang dans la prévention des agents infectieux.

BACKGROUND: The aim of this study was to evaluate the efficacy of medical screening to retain blood donors in window period by comparing the seroprevalence of infectious agents (HIV, hepatitis B and C, syphilis) in deferred versus accepted blood donors. MATERIALS AND METHODS: This prospective and transversal study was performed during 4 months in the National Blood Transfusion Center in Dakar (Senegal). We conducted a convenience sampling comparing the seroprevalence of infectious agents (HIV, HBsAg, HCV and syphilis) in deferred versus accepted blood donors after medical selection. RESULTS: In total, 8219 blood donors were included. Medical selection had authorized 8048 donors (97.92%) and deferred donors were 171 (2.08%). The prevalence of HIV was higher in the deferred than in accepted blood donors (1.75% vs. 0.05%) (P=0.0003; OR=35.91), as well as for HBsAg (12.87% vs. 7.35%) (P=0.006; OR=1.86). HCV antibodies were present in 0.71% of accepted blood donors and 0.58% in deferred blood donors (P=0.65; OR=0.82). Only accepted donors had brought the infection of syphilis (0.34%) (P=0.56; OR=0). CONCLUSION: Medical selection is efficient to exclude blood donors at high risk of HIV transmission and to a lesser extent of HBV. However, current medical screening procedures do not allow us to exclude donors asymptomatic carriers of HCV and syphilis.

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 Dakar's 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 patient's 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.

Vitamin D3 improves respiratory adjustment to fatigue and H-reflex responses in paraplegic adult rats.

We previously demonstrated that vitamin D2 (ergocalciferol) triggers axon regeneration in a rat model of peripheral nerve transection. In order to confirm the regenerative potential of this neuroactive steroid, we performed a study in which vitamin D3 (cholecalciferol) was delivered at various doses to paralytic rats. After spinal cord compression at the T10 level, rats were given orally either vehicle or vitamin D3 at the dose of 50 IU/kg/day or 200 IU/kg/day. Three months later, M and H-waves were recorded from rat Tibialis anterior muscle in order to quantify the maximal H-reflex (H(max)) amplitude. We also monitored the ventilatory frequency during an electrically induced muscle fatigue known to elicit the muscle metaboreflex and an increase in respiratory rate. Spinal cords were then collected, fixed and immunostained with an anti-neurofilament antibody. We show here that vitamin D-treated animals display an increased number of axons within the lesion site. In addition, rats supplemented with vitamin D3 at the dose of 200 IU/kg/day exhibit (i) an improved breathing when hindlimb was electrically stimulated; (ii) an H-reflex depression similar to control animals and (iii) an increased number of axons within the lesion and in the distal area. Our data confirm that vitamin D is a potent molecule that can be used for improving neuromuscular adaptive mechanisms and H-reflex responses.

[Predictive factors of chronic complications in adult sickle cell anemia patients in Dakar, Senegal]. / Facteurs prédictifs des complications chroniques de la drépanocytose homozygote chez l'adulte à Dakar (Sénégal).

PURPOSE: Chronic complications of sickle cell disease (SS) usually involve irreversible organ damage. Several genetic factors have been shown to have predicative value for chronic complications but these data are not always available. The purpose of this study was to assess the value of sociodemographic and clinicobiological features in predicting chronic complications. METHODS: This study included a total of 229 adult SS patients who underwent quarterly follow-up examinations for at least 10 years (range, 10 - 16). All sociodemographic and clinicobiological data were recorded. Screening for complications was performed at least once every three years. The risk of developing chronic complications was analyzed in function of patient follow-up data. RESULTS: Mean patient age was 28.6 years (range, 20 - 57) and sex ratio was 1.3. Prevalence of chronic complications was 34.9% (80/229). The most common complication was bone necrosis in 27 cases (11.7%) followed by gallstones in 24 (10.4%). The only sociodemographic factor with predictive value was patient age (p=0.0008). Multivariate analysis identified two clinicobiological factors with predictive value. History of transfusion was associated with a 3-fold higher risk while hemoglobin F level was associated with decreased risk. CONCLUSION: In this study, age and low hemoglobin F level were the only predictive factors of chronic complications in SS patients.

[Cost of tetanus toxoid injection using a jet-injector (Imule) in collective immunization in Senegal: comparison with injection using a syringe and resterilizable needle]. / Coût de l'injection d'anatoxine tétanique par injecteur sans aiguille(Imule) lors dúne vaccination collective au Sénégal: comparaison avec l'injection par seringues et aiguilles restérilisables.

Needle-less jet injectors were developed by the US army after World War II. Their principal use, however, has been in the administration of lyophilized vaccines from multidose vials to at-risk populations in developing countries. In 1983, a hepatitis B epidemic occurred among customers of a beauty clinic in California (USA) following the use of jet-injectors, demonstrating a clear risk of cross-contamination associated with this technique. As a result, the WHO and Unicef stopped recommending jet-injectors for collective immunizations in developing countries. To eliminate the risk of contamination, Pasteur Mérieux Sérums et Vaccins (now Aventis Pasteur) developed, in 1990, jet-injectors for use with single-use vaccine cartridges. These injectors were tested for tetanus toxoid, DTP, influenza, hepatitis A and typhoid Vi vaccination. The immunogenic reaction was as strong and the injection as well tolerated as for injections using a standard needle and syringe. The additional cost of the Imule technique was evaluated in a district-wide (127,000 inhabitants) tetanus toxoid immunization program at Velingara, Senegal in 1993. The total cost was estimated to be 1.51 FF (76 F CSA, 0.32 US dollars) for one dose of tetanus vaccine given by needle and syringe and 2.41 FF (121 F CSA, 0.56 US dollars) for one dose given by Imule. Thus, the additional cost of injection by ImuleTM was 0.90 FF (45 F CSA, 0.21 US dollars). The cost of cross infection in sub-Saharan Africa has been estimated to be 2.37 FF (118 F CSA, 0.55 US dollars) per injection if injection practices are not supervised. Therefore, the Imule technique may be considered to be cost-effective. However, the technique is still not completely reliable, as shown by the total breakdown of four jet injectors during this vaccination session. Lyophilized vaccines have also not been tested in the field. Vaccinators prefer Imule, training is easy and immunization can be carried out on a day-to-day basis with no vaccine wastage. Imule is not yet in mass production, which would reduce costs. In the face of the ever-increasing risk of cross-contamination during vaccination sessions in sub-Saharan Africa, the Imule technique deserves considerable attention.