Preliminary Evaluation of a Point-of-Care Testing Device (SickleSCAN™) in Screening for Sickle Cell Disease.

Sickle cell disease affects about 150,000 births annually in Nigeria. Early diagnosis is hampered by factors such as centralized and urban localization of laboratories, high cost of diagnostic equipment and inadequate skilled manpower to operate them. The need for a low-cost, portable, easy-to-use diagnostic test for sickle cell disease is critical, especially in resource-poor countries. In this study, we evaluated the performance characteristics of a novel point-of-care testing device (SickleSCAN™), and its acceptability and feasibility, as a possible screening tool for sickle cell disease. In the first phase, we assessed the performance characteristics of SickleSCAN™ by evaluating 57 subjects comprising both children and adults attending a primary health center, for Hb SS (ßS/ßS; HBB: c.20A>T), Hb SC (ßS/ßC; HBB: c.19G>A) and Hb AS (ßA/ßS) using SickleSCAN™, cellulose acetate electrophoresis (CAE) and high performance liquid chromatography (HPLC). Performance characteristics such as diagnostic sensitivity and specificity were compared to HPLC as a standard method. We subsequently undertook a second phase wherein the acceptability and feasibility of the device for sickle cell disease screening, was evaluated using semi-structured and structured questionnaires among 197 healthcare personnel and 221 subjects, respectively. Sickle cell disease was carried by 3.4% of the subjects. The diagnostic sensitivity, specificity and test efficiency of SickleSCAN™ for sickle cell disease (Hb SS and Hb SC), were 100.0, 98.2 and 98.2%, respectively. Findings from this study showed SickleSCAN™ to be a viable screening tool that can easily be applied in community-based screening for early diagnosis of sickle cell disease with little expertise and low cost.

Prevalence of pulmonary hypertension in sickle cell anaemia patients of a tertiary hospital in Nigeria.

BACKGROUND: Sickle cell disease (SCD) is an inherited haemoglobinopathy characterised by recurrent organ hypoxia-reperfusion cycles which may result in repeated organ damage including the lungs and heart. In SCD, pulmonary hypertension is a known complication that may precede or complicate acute chest syndrome which is often fatal. This study seeks to know the prevalence of pulmonary hypertension and its relationship with clinical and laboratory parameters in sickle cell disease patients attending a tertiary hospital in Lagos. MATERIALS AND METHODS: This was a case - control study involving patients with sickle cell disease recruited from adult sickle cell clinic of Lagos State University Teaching Hospital, Ikeja and HbAA controls matched for age and sex from a tertiary educational institution in Lagos. Both the patients and controls were subjected to echocardiography and pulmonary hypertension was deduced from their cardiac tricuspid regurgitant jet velocity. Other parameters measured were age, body mass index, full blood count, red cell indices, foetal haemoglobin, chest X-ray, liver function tests, lactate dehydrogenase and pulmonary function tests. Consenting patients were 56 HbSS in steady state and 28 HbAA controls matched for age and sex. Data was analysed using SPSS version 16.0. RESULTS: The mean age of patients was 22 ± 6 years. In two 2 of 56 (3.6%) of the participants with sickle cell disease, the pulmonary artery pressure was > 25mmHg and there was significant difference in the mean of the pulmonary artery pressure of the control and that of the patients (P-value 0.013). Also, using the appropriate correlation tests, there was significant relationship between the pulmonary artery pressure and lactate dehydrogenase, aspartate transferase and haematocrit in patients with sickle cell disease. CONCLUSION: Sickle cell disease is an independent cause of pulmonary artery hypertension. Variation in cardiovascular reactions to recurrent hyperhaemolysis and hyperdynamic state in sickle cell disease may explain differences in the development of cardiac complications. Exploration of these reactions may reveal other therapeutic measures to prevent complications in sickle cell disease. Clinical assessment of adult patients with sickle cell disease should include echocardiography.