Erythrocyte Transfusion and Alloimmunisation Patterns among Sickle Cell Disease Patients, Benin City, Nigeria

Introduction: Blood transfusion remains a mainstay therapy in sickle cell disease (SCD).Transfusional therapy may be complicated by allo-immunisation due to exposure to foreign red cell antigens. However, the prevalence and patterns of atypical antibodies in Nigerian SCD has been sparsely reported majorly due to underdeveloped blood banking systems. A prospective study was therefore undertaken to assess patterns of blood transfusion and allo-immunisation among SCD patients in Benin City, Nigeria.

Methodology: The study was conducted among adult and paediatric SCD subjects seen at a sickle cell centre in Benin City, Nigeria. All subjects (parents in case of children) who gave consent/assent to the study were interviewed using a structured questionnaire to obtain details on bio-data, SCD history and blood transfusion history. Blood specimen obtained from each participant was subjected to antibody screening/identification test using tube agglutination technique. Association of categorical variables was tested using chi-square or fisher exact test as appropriate.

Results: Fifty five SCD patients were studied with a mean (SEM) age of 22.95 (1.66) years. More of the subjects (67.3%) were aged 15 years and above. 74.5% of the subjects have a past history of blood transfusion. Four (7.3%) of the subjects had unexpected erythrocyte allo-antibodies. Antibodies belonging to the Rh and Kell blood group systems were implicated. The risk of alloimmunisation increased with total lifetime transfusions (p = 0.002)

Conclusion: Erythrocyte alloimmunisation is a significant therapy related complication in Nigerian SCD. Hydroxyurea use reduces transfusion requirements and should be maximized. There is need to upgrade local/regional transfusion services to include routine allo-antibody screening/identification as part of precompatibility testing particularly SCD patients who have received more than 10 units of red cell transfusion.