Ultrasonographic Splenic Indices Among Paediatric and Adults with Sickle Cell Disease in Nigeria

BackgroundUltrasonography is an established and reliable method for assessing the spleen. Because of variation due to genetic and other environmental factors including malaria endemicity, interpretation of splenic sizes requires a knowledge of the normal reference range for a given population. The aim of this study was to determine spleen size in different age groups among healthy people in North-Eastern Nigeria and use this as a reference to determine spleen size amongst sickle cell disease (SCD) patients. MethodsUsing a cross-sectional study design, spleen size was measured in healthy people of different age groups, and steady-state SCD patients (children and adults) using abdominal ultrasonography. Using the age-group specific reference values obtained from the controls, spleens were classified into small, normal size, or enlarged among the SCD patients. ResultsAbdominal ultrasonography was performed for 313 participants, comprising 109 (34.8%) healthy controls and 204 (65.2%) steady-state SCD patients. The spleen was visualized in all the controls. However, 97(47.6%) of the SCD patients had no visible spleen. Small, normal, and enlarged spleens were observed in 16.7% (n=18/107), 63.6% (n=68/107) and 19.6% (n=21/107) SCD patients, respectively. Compared to the control group, splenic length was three-fold higher in the first two years of life in SCD patients, followed by a progressive age-related decline in size. Enlarged spleens were detected among 5(2.4%) SCD patients by manual palpation method compared to 21 (19.6%) using ultrasonography. ConclusionModel-based age-specific reference ranges and percentile curves for splenic dimensions based on ultrasonography among normal controls in North-Eastern Nigeria were established and may be of value in assessing spleen sizes among SCD patients living in malaria-endemic regions of Africa. Regular spleen scans to assess changes in size can help identify SCD patients at risk of splenomegaly complications including subclinical acute sequestration and hypersplenism, and those who are developing splenic atrophy.