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.

Strengthening human genetics research in Africa: report of the 9th meeting of the African Society of Human Genetics in Dakar in May 2016.

The 9th meeting of the African Society of Human Genetics, in partnership with the Senegalese Cancer Research and Study Group and the Human Heredity and Health in Africa (H3Africa) Consortium, was held in Dakar, Senegal. The theme was Strengthening Human Genetics Research in Africa. The 210 delegates came from 21 African countries and from France, Switzerland, UK, UAE, Canada and the USA. The goal was to highlight genetic and genomic science across the African continent with the ultimate goal of improving the health of Africans and those across the globe, and to promote the careers of young African scientists in the field. A session on the sustainability of genomic research in Africa brought to light innovative and practical approaches to supporting research in resource-limited settings and the importance of promoting genetics in academic, research funding, governmental and private sectors. This meeting led to the formation of the Senegalese Society for Human Genetics.

Le 9ème congrès de la Société Africaine de Génétique Humaine, en partenariat avec le Groupe d'Etude et de Recherche sur le Cancer (GERC) et le Consortium H3Africa, s'est tenu à Dakar, au Sénégal. Le thème était «Renforcer la recherche en Génétique Humaine en Afrique¼. Les 210 participants sont venus de 21 pays africains et de six non africains. L'objectif était de valoriser la génétique et la génomique à travers l'Afrique avec comme but ultime d'améliorer la santé des populations, et de promouvoir les carrières des jeunes chercheurs Africains. Une session sur la pérennité de la recherche génomique a révélé des approches innovantes et pratiques supportant la recherche dans des contextes de ressources limitées et l'importance de promouvoir la formation universitaire en génétique, le financement de la recherche par les gouvernements et le privé. Ce congrès conduisit à la création de la Société Sénégalaise de Génétique Humaine.

[Seroprevalence of hepatitis C virus (HCV) in Senegalease blood donors]. / Seroprevalence du virus de l'hepatite C (VHC) chez les donneurs de sang au Senegal.

INTRODUCTION: Hepatitis C virus (HCV) is an important problem of public health in the world according to its transmission mode and its pathogenesis. The risk of blood transmission has led to be the systematic screening of blood donors in the world. In Senegal no study about HCV prevalence on the general population and also has been done. The aim of our study was to determine HCV prevalence in blood donors and the rate of co-infection with hepatitis B (HCV/HBV) or with HIV infection (HCV/HIV). MATERIALS AND METHODS: This study had been done in the National Blood Transfusion Centre (CNTS) in Dakar. Two different techniques has been used for the assessment HCV: 1/ ELISA technique and 2/ Immunoblot RIBA as confirmation test. RESULTS: Our study relates to 1565 blood donors recruited in CNTS during 2002. 369 of them were new blood donors with 365 females and 1200 males. The mean average was 30.5 +/- 9.5 years, ranged from 18 to 59 years. HCV ELISA test were positive in 22 plasma samples and one of them were co-infected with hepatitis B (HCV/HBV). Four out of these 22 samples have been confirmed positive to RIBA test and three of them were not determined. HCV seroprevalence were 1.4% after ELISA and 0.25% after RIBA testing. This seroprevalence were similar in male and in female and higher in new blood donors than in regular blood donors. CONCLUSION: Our results reinforce the necessity to screen hepatitis C virus in all Senegalese blood transfusion centres.

Quantification of all fetal nucleated cells in maternal blood in different cases of aneuploidies.

We quantified all fetal nucleated cells (FNCs) per unit volume of maternal blood in different aneuploid pregnancies using molecular cytogenetic techniques. Seven cases of male trisomy 18, two triploidies (69,XXX), two 47,XXX, one 47,XXY, one 47,XYY, one male trisomy 13, and one case of 47,XY,r(22),+r(22) were analyzed. Whole blood samples were obtained from 15 women between 17 and 29 gestational weeks and harvested without using fetal cell enrichment procedures. Fluorescence in situ hybridization and primed in situ labeling were performed to identify the FNCs. All slides were manually scanned to quantify those cells. We have identified 4-20 FNCs/ml of maternal blood in the cases of trisomy 18; 10 and 25 FNCs/ml in the two cases of triploidy; 16 and 14 FNCs/ml, respectively, in the two X trisomies; 19 FNCs/ml in the 47,XXY; 26 FNCs/ml in the 47,XYY; nine FNCs/ml in the trisomy 13; and 10 FNCs/ml in the case of r(22). To detect all FNCs in all aneuploid pregnancies, we have used a very simple method that minimizes the manipulation steps to avoid losing fetal cells. The number of FNCs identified in aneuploid pregnancies was 2-5 times higher than in normal pregnancies. This higher number of FNCs will favor the design of a non-invasive pre-natal test.

[Physical performance and thermoregulatory study of subjects with sickle cell trait during a sub-maximal exercise]. / Etude de la performance physique et de la thermoregulation des sujets porteurs du trait drepanocytaire au cours d'un exercice sous maximal.

The sickle cell trait is a genetic abnormality of red blood cells. It is due to the mutation of a parental gene, which rest Its to the substitution of glutamic acid by valin on beta globin chain of haemoglobin. The possibility for sickle cell trait carriers (SCT) to present any disturbance during predominantly anaerobic and aerobic exercises is unclear. Ten (10) subjects with sickle cell trait and 10 subjects control were studied during exercise test on cycloergometer. They were all students of the National Institute of Popular Education and Sport of Dakar. The mean of environmental temperature was 26 degrees C and humidity was 60 to 80%. After haematological analysis, a submaximal muscular exercise for one hour with 75% of maximal heart rate was done. We have determined heart rate, blood pressure, rectal and skin temperature during exercise. Haematological parameters shown any significant difference between the two groups. No significant difference was found in cardiocirculatory variables during maximal exercise in cycloergometer between control group and sickle cell trait group. The two groups have done submaximal exercise during 1 hour without particular difficulty. We have not observed a significant difference between the two groups in cardiovascular variables, rectal and skin temperature during exercise, and after 3 minutes of rest. These results show that subjects with SCT have physical capacity comparable with control subjects during a sub maximal exercise for 1 hour. We can assure that subjects with SCT in our country may participate in sports competition, as well as normal subjects (HbAA).

Simultaneous identification of chromosomes 18, X and Y in uncultured amniocytes by using multi-primed in situ labelling technique.

The aim of this study is to validate the multi-PRINS (primed in situ labelling) technique for simultaneous detection of chromosomes 18, X and Y in uncultured amniocytes for prenatal diagnosis of aneuploidy. The sites of the newly synthesized DNA sequences were showed as fluorescent signals by using immunochemistry. A multi-PRINS technique was specifically performed for simultaneous detection in the same cells of three chromosome targets, e.g. chromosomes 18, X and Y. Fluorescent signals corresponding to chromosomes 18, X and Y were showed as yellow, red and green colour spots, respectively. A multi-FISH technique using chromosome 18, X and Y probes was performed for comparison. Sixty cases were analysed using both multi-PRINS and multi-FISH. Fifty to two hundred nuclei were scored for each case for each technique. In all cases, there was no significant difference in the detection of chromosomes 18, X and Y regarding the sensitivity, the specificity and the efficiency; multi-PRINS and multi-FISH yield a similar distribution of the number of spots per nucleus. Both techniques were able to identify aneuploid cases without any ambiguity. Both multi-PRINS and multi-FISH can accurately and reliably detect aneuploidies involving chromosomes 18, X and Y in uncultured amniocytes. Finally, multi-PRINS represents a faster and more cost-effective alternative to FISH for prenatal testing of aneuploidy in uncultured amniocytes.

[Maternal anaemia: effect on the newborn]. / Anémie par carence en fer maternelle: retentissement sur le nouveau-né.

Pregnancy increases considerably iron needs in mother and her foetus. The purpose of our study is to measure the effect of maternal anaemia on the foetus and the effect of iron supplementation on the maternal and foetal reserves. Therefore, we conducted a three-month cross sectional study at the gynaecological and obstetrics clinics of Aristide Le Dantec Hospital. Ninety-five women aged 16 to 43 years old and having an haemoglobin rate < 11 g/dl were recruited. Most of them were primipares. Among them 69 had a low ferritinemia (< 50 ng/ml), 36, a ferritinemia collapsed (< 30 ng/ml) and 13 virtually non-existent reserves (< 12 ng/ml). All newborns were born in terms with an apgar score >/= in 93 of them. Among them 24 had anemia (rate of haemoglobin < 14 g/dl) and 54.7% a low ferritinemia. There is no relationship between the maternal and foetal rates of haemoglobin; 74% of newborn had a normal rate of haemoglobin. Among 36 women with low ferritinemia only two gave birth to a newborn without iron reserves. In our study, among 68 women who received iron regularly, 41 had normal reserves and 43 gave birth to a newborn with high ferritinemia. There is significant difference between the women having received iron during their pregnancy and those not supplemented as regards the effect on newborn (p = 0.00001). The prevention of iron deficiency and anaemia can be done by the iron systematic and premat supplementation.

[Homozygous drepanocytosis in Dakar: effect of the hemoglobin F level, and sociocultural and economic factors]. / La drépanocytose homozygote a Dakar: influence du taux d'hemoglobine F, des facteurs socio-culturels et économiques.

Sickle cell anemia exhibits significant variations in clinical presentation in different populations despite the homogeneity of the genetic defect which is involved. Genetic modulation of this disease is known but cannot explain alone such observations. Our objectives were to determine the effects of Hb F level, sociocultural and economic factors on disease severity in Dakar. Sixty homozygous sickle cell patients were followed up between october 1996 and April 1998 during which period the severity of the disease was assessed and a "severity index" was calculated for each patient. The factors which were identified with proved benefit were: Hb F > 15%, a high socioeconomic level, a good understanding of the disease, at least 4 medical visits per year. These results allow us to identify some potential targets to improve preventive and curative care of this disease.