Aspects épidémiologiques et évolutifs de la splénomégalie chez les enfants et adolescents porteurs de syndromes drépanocytaires majeurs au Sénégal

The German sickle cell disease registry reveals a surprising risk of acute splenic sequestration and an increased transfusion requirement in patients with compound heterozygous sickle cell disease HbS/β-thalassaemia and no or low HbA expression

Patients with sickle cell disease (SCD) in Germany exhibit a substantial genetic diversity in the β-globin genotype. Data collected by the national German SCD registry reflect this diversity and allowed us to analyze the phenotypes associated with different SCD genotypes. Our study focused on 90 patients with HbS/β-thalassaemia (HbS/β-thal) and compared these to patients with HbSS and HbSC. Patients with HbS/β-thal were classified into three groups: HbS/β0-thal (no HbA), HbS/β+-thal (HbA < 14%), and HbS/β++-thal (HbA≥14%). In comparison to HbSS, patients with HbS/β++-thal had higher Hb-levels, lower hemolytic activity and rarely required red blood cell transfusions. HbS/β0-thal and HbS/β+-thal closely resembled each other and are jointly referred to as HbS/β0/+-thal. Compared to HbSS, patients with HbS/β0/+-thal experienced a similar frequency of vasoocclusive crises and degree of hemolysis. However, the frequency of red blood cell transfusions (0.6 vs. 0.39/year, p = .0049) and splenic sequestration crises (42.4 vs. 15.5% of patients, p = 3.799e-05) was higher in HbS/β0/+-thal than in HbSS, but close to zero in HbS/β++-thal. In conclusion, the level of HbA expression determines the phenotype of HbS/β+-thal. HbS/β-thal expressing no or little HbA is hematologically similar to HbSS, but causes a previously unknown high risk of splenic sequestration.

The spectrum of splenic complications in patients with sickle cell disease in Africa: a systematic review

The majority of the global population of sickle cell disease (SCD) patients resides in Africa. Individuals with this condition are at great risk of serious infections and early mortality secondary to splenic dysfunction without preventative measures. This review investigated the spectrum of splenic complications encountered in SCD among populations in Africa. We systematically searched several databases for all articles published through March 3, 2020. We included 55 studies from 14 African countries. This review reveals the difference in frequency of splenic complications in SCD in Africa when compared with their counterparts in the United State and Europe. While several studies (n = 45) described splenomegaly with a prevalence of 12% to 73% among children, and 4% to 50% among adults with HbSS, the reported prevalence for acute splenic sequestration crisis (n = 6 studies) and hypersplenism (n = 4 studies) was <10% and <5% respectively. A total of 30 surgical splenectomy was reported across eight studies. Only two (3.7%) studies provided data on spleen function. A conflicting pattern was observed amongst studies that evaluated the relationship between splenomegaly and the presence of bacterial and malaria infections. This review reveals the paucity of studies describing the role of SCD-induced splenic dysfunction in morbidity and infection related mortality in Africa.

The clinical characteristics of Congolese children and adolescents suffering from sickle-cell anemia are marked by the high frequencies of epistaxis compared to Western series

Background: Sickle cell anaemia (SCA) is the most common genetic diseases in the Democratic Republic of Congo (DRC). It is estimated 30,000 to 40,000 neonates with SCA are born annually. Despite this high incidence rate, and the severity of the Bantu haplotype found in Congolese patients, major clinical characteristics remain poorly defined. The objective of this study was to assess the clinical and haematological profile of the SCA in patients less than 24 years of age. Methods: A cross-sectional study was conducted in Kinshasa, the large city of the DRC. Patients were consecutively selected in three health institutions. Results: The study includes 256 sickle cell patients. The mean age of 8.4 (SD = 4.9) years. The Hand-foot syndrome was most common (52.7%) first presentation revealing the disease in our series. The most prevalent crises found in our series were vaso-occlusive crises (VOC) in 170 cases (66.4%) and severe hemolysis in 136 cases (53.1%). Splenic sequestration was noted in 19 cases (7.4%). The age at the first pain crisis was 18.2±15.2 months-of-age and the age at the first transfusions was 29.2±27.6 months-of -age. The most common signs associated with sickle cell disease in our series were hepatomegaly (53.9%), splenomegaly (41.7%), and adenotonsillar hypertrophy (34.8%). Epistaxis was reported in 9.4%. Conclusion: The clinical course of patients in DRC was comparable to reports from Western countries, with the notable exception of epistaxis which was significantly higher in patients in the DRC.