Sickle cell disease (SCD) predominates in sub-Saharan Africa, East Mediterranean areas, Middle East, and India. Nigeria, being the most populous black nation in the world, bears its greatest burden in sub-Saharan Africa. The last few decades have witnessed remarkable scientific progress in the understanding of the complex pathophysiology of the disease. Improved clinical insights have heralded development and establishment of disease modifying interventions such as chronic blood transfusions, hydroxyurea therapy, and haemopoietic stem cell transplantation. Coupled with parallel improvements in general supportive, symptomatic, and preventive measures, current evidence reveals remarkable appreciation in quality of life among affected individuals in developed nations. Currently, in Nigeria and other West African states, treatment and control of SCD are largely suboptimal. Improved knowledge regarding SCD phenotypes and its comprehensive care among Nigerian physicians will enhance quality of care for affected persons. This paper therefore provides a review on the aetiopathogenesis, clinical manifestations, and management of SCD in Nigeria, with a focus on its local patterns and peculiarities. Established treatment guidelines as appropriate in the Nigerian setting are proffered, as well as recommendations for improving care of affected persons.

Background: The clinical prospects of hydroxyurea therapy in the management of sickle cell disease (SCD) require evaluation in the Nigerian setting to develop indigenous guidelines. This survey examines the pattern of hydroxyurea therapy, its clinico-haematologic benefits and safety profile in Nigerian SCD subjects. Methods: A cross sectional pilot survey was carried out among 60 adult SCD subjects over 3 months. Data on clinical phenotypes, relevant haematological parameters and details of hydroxyurea therapy were obtained using a structured questionnaire through an interview process and case file review. Results: The median age was 30 years. Thirty-four (56.7%) of the subjects are aware of hydroxyurea therapy in SCD. Twenty-four (40%) SCD patients had previously used hydroxyurea. Only 4 subjects were fully compliant. Reasons for non-compliance included poor knowledge and lack of funds. In particular, hydroxyurea reduced leucocyte count and increased mean red cell volume (MCV) in compliant subjects. Conclusion: Hydroxyurea use is low among Nigerian SCD subjects despite its proven efficacy/clinical prospects in the developed nations. Large scale multicenter studies and clinical trials are needed to form a basis for developing standard local treatment protocol for its use.

Introduction. Hypertransfusion refers to chronic blood transfusion therapy aimed at ameliorating disease complications in various haemopathies particularly the haemoglobinopathies. In sickle cell disease, hypertransfusion is aimed at maintaining patient's haemoglobin level at 10 to 11 g/dL using haemoglobin AA blood and its resultant dilutional effect on sickle haemoglobin is sustained by intermittent long-term transfusions. Aim and Objective. This paper highlights hypertransfusion and its privileged position as a secondary measure in prevention and treatment of sickle cell disease, especially in the Nigerian context. Materials and Methods. Relevant literatures were searched on PubMed, Google Scholar and standard texts in haematology and transfusion medicine. Keywords used in the search are hypertransfusion, sickle cell disease, chronic transfusion, and Nigeria. Literatures gathered were reviewed, summarized, and presented in this paper. Result. Immense clinical benefit is associated with hypertransfusion therapy including prevention of stroke and amelioration of severe sickle cell disease especially in transplant ineligible patients. Careful patient selections, appropriate blood component, and prevention of transfusion hazards as well as oversight function of an experienced haematologist are pertinent to a successful hypertransfusion therapy. Conclusion. Improved knowledge of the benefits and practice of hypertransfusion will effectively translate into improved health status even among Nigerian sickle cell disease patients.

No abstract

Sickle cell disease (SCD) poses a major public health challenge in sub-Saharan Africa, including Nigeria. Blood transfusion is a mainstay in SCD treatment. Erythrocyte alloimmunization is known to complicate the transfusional care of patients with SCD. Immune alloantibodies are associated with hemolytic transfusion reactions and transfusion refractoriness. We aimed to determine the prevalence, specificities, and clinical associations/ risk factors of immune erythrocyte alloantibodies among adult patients with SCD compared with healthy blood donors in Lagos, Nigeria, through a cross-sectional study. All participants were interviewed using a structured questionnaire to obtain details on bio-data, hemoglobin phenotype, blood transfusion history, and SCD history where relevant. Blood specimens obtained from each participant were subjected to antibody screening/identification using tube agglutination method. The mean age of the SCD participants and healthy blood donors was 27.92 and 29.04 years, respectively. The majority (72.5%) of the SCD participants had received at least 1 unit of red blood cell (RBC) transfusion in their lifetime, compared with only 7.5 percent of blood donors. Six SCD participants (7.5%) tested positive for atypical erythrocyte alloantibodies, with none among blood donors. Most of the antibodies (75%) belonged to the Rh blood group system. The most frequent antibody was anti-E, followed by anti-C and anti-D. Advancing age (30 years or more), recent transfusions (last 4 weeks), higher transfusion rates, and established renal disease were significantly associated with alloimmunization (p values of 0.026, 0.043, 0.002, and 0.043, respectively). This study suggests blood transfusion as a strong risk factor for RBC alloimmunization in SCD patients. Extended RBC phenotyping is recommended for all patients with SCD, especially those receiving regular transfusions.

No abstract

Antigens belonging to the Rh and Kell blood group systems are of major clinical significance because of their immunogenicity and the potential of their consequent antibodies to cause in vivo destruction of exogenous red blood cells (RBCs). Despite the widespread use of transfusion, there are sparse data on the prevalence of Rh and Kell system antigens and their ethnic variability in Nigeria. The objective of this study was to determine the prevalence of the five major Rh (D, C, c, E, e) and Kell (K) system antigens in Nigeria with the goal of understanding alloimmunization risk in transfusion recipients and improving transfusion safety through the availability of resources, such as antisera for extended RBC typing and antigen panels for alloantibody detection. A multi-ethnic cohort of 302 healthy Nigerian individuals was created to study RBC antigen prevalence. The antigen status of these individuals for Rh and K antigens was determined using commercially prepared antisera and conventional tube agglutination methods. The prevalence of the Rh antigens in the study cohort was found to be: D (92.7%), C (20.5%), c (97.7%), E (19.5%), and e (97.4%). Dce was the most common Rh phenotype (53.3%). The prevalence of K was 0 percent. For all antigens, there was no association between ethnicity and antigen prevalence. This study is the first to document the prevalence of the major Rh and K antigens in the Nigerian population, using a multi-ethnic cohort. Serologic testing demonstrates a zero prevalence of K antigen, which has never been described. C and E pose the higher risks of alloimmunization, hence showing a need for extended RBC typing and matching in at-risk blood recipients. This study demonstrates that phenotyping for major Rh and K antigens within the Nigerian population can potentially improve transfusion safety and prevent alloimmunization.

On a global scale, 5% to 7% of the population carries an abnormal hemoglobin. With a sickle hemoglobin (HbS) carrier prevalence of 25% to 40%, Nigeria bears the greatest burden of sickle cell disorder worldwide. Until recent times, detection of other clinically significant hemoglobin variants associated with HbS has been unavailable, resulting in missed/wrong diagnosis, weak national data, and suboptimal control of hemoglobin disorders. This study aimed to review hemoglobin assays over a 2-year period at a national reference laboratory in Nigeria, in order to describe the prevalent hemoglobin phenotypes for health planning. The study was a retrospective, laboratory data-based survey. Sociodemographics and hemoglobin assay results of 6,851 specimens between January 2016 and December 2017 were analyzed. Study protocol was approved by the Institutional Review Board. Participants aged less than 1 year and who had recent transfusions and a history of hydroxyurea therapy were excluded. At the hemoglobin laboratory, specimens were analyzed using cation exchange high-performance liquid chromatography (CE-HPLC) (Bio Rad D10, California). When indicated, further analysis of suspected abnormal hemoglobins was confirmed using a second method, capillary electrophoresis (SEBIA Capiflex II, France). The distribution of the identified hemoglobin phenotypes was determined as a proportion of the total number of participants. The mean (SD) age of the participants was 31.8 (14.9) years. The most frequent hemoglobin phenotypes were AA (59.4%), AS (23.3%), and SS (13.3%). Hemoglobin phenotypes AC (2.1%), SC (0.9%), AGPhiladelphia (0.2%), and CC (0.2%) were less frequent. Least occurring phenotypes were ADIbadan, AE, AGPhiladelphia, AOArab, DD, and hereditary persistence of fetal hemoglobin (HPFH). In the Nigerian context, accurate diagnosis of hemoglobin variants using quantitative, high-resolution hemoglobin assays, compared to zone (cellulose acetate) electrophoresis at alkaline pH will provide data for health planning, better access to genetic counseling, informed reproductive health choices, and secondary prevention of hemoglobinopathies.