Summary Sickle cell disease (SCD), the commonest single gene disorder worldwide, is an inherited disease that has different clinical and hematological manifestations in different populations. The objective of this study is to describe the characteristics of the Lebanese SCD population. This was a retrospective study that included information on 387 patients with either sickle cell anemia (SS) or sickle beta‐thalassemia (ST). The mean (±SD) age was 17.9 years (±12.5), and the mean (±SD) follow‐up was 9.3 ± 6.9 years. Fifty percent of the patients were males and SS/ST distribution was 3 : 1. The disease was clustered in two geographic areas in North and South Lebanon. Nearly, all patients were Muslims and 56% were the offspring of consanguineous parents. The prevalence of splenomegaly beyond 6 years of age among SS patients was 28.9%. The prevalence rates of stroke, leg ulcers and priapism were 4.1%, 1.4%, and 0.8%, respectively. Comparing the SS and the ST patients, there were no statistically significant differences in the prevalence of all clinical manifestations except for splenomegaly (SS: 28.9%, ST: 54.9%, P‐value < 0.001) and splenectomy (SS: 16.1%, ST: 35.7%, P‐value < 0.001). In contrast to Northern American populations and similar to some Mediterranean populations, Lebanese SCD patients have a higher prevalence of persistent splenomegaly. The relatively low incidence of thrombotic complications deserves further investigation. The study’s limitations include those of any other retrospective study and the fact that not all Lebanese centers caring for inherited hemoglobin disorders were included. However, the results of this first large scale national survey indicate that preventive efforts should target the Northern and Southern regions of Lebanon to decrease the number of new off springs afflicted with this disease similar to what has been successfully achieved with Thalassemia, another hemoglobinopathy that is highly prevalent in the country.

Background: Sickle cell disease (SCD) is one of the most prevalent hemoglobinopathies in Lebanon. Acute stroke, defined as an acute neurological syndrome secondary to arterial occlusion or hemorrhage with resultant neurological symptoms and signs lasting for more than 24 hours, is the most catastrophic brain injury seen in this disorder and has a prevalence of around 10% by 50 years of age. Silent cerebral infarcts (SCI), defined as an abnormal magnetic resonance image (MRI) of the brain and no history of neurologic deficit, are seen in 20–44% of children with sickle cell anemia (SCA) and represent a major risk factor for overt stroke. Identifying asymptomatic patients at high risk of developing sickle-related brain injury helps physicians implement preventive therapies. Aims: Determine prevalence of brain imaging abnormalities in a group of Lebanese patients with SCD and Identify predictive factors for these abnormalities. Methods: A review of brain MRI for 53 SCD patients followed in 2 centers specialized in inherited hemoglobin disorders was undergone. Of those, 42 asymptomatic patients had surveillance brain MRI and 20 had imaging at least twice. T1- and T2- weighted MR imaging at 1.0 T plus FLAIR at 5-mm section thickness were used. All images were read independently by two radiologists with a 10 years experience in neuroradiology. Brain images considered abnormal included atrophy, lacunar infarction, leukoencephalopathy and encephalomalacia. Fisher’s Exact test (Wilcoxon two sample rank-sum test) was employed to study the association of binary data (continuous data) with the 2 groups. The SAS v8.2 (Cary, N.C.) was used to analyze the data. A p-value less than 0.05 was considered significant. Results: Overall stroke prevalence in this group was 34% (18/53). 11 patients (21%), median age 14 years and 6 months, had overt strokes. Of those, 91% had SCA and 9% sickle beta thalassemia (ST). Of the remaining 42 patients, 6 (14%), median age 13 years and 5 months, all having SCA, had MRI findings compatible with SCI. 3 had brain atrophy and 3 encephalomalacia. None of the overt stroke patients had ever received hydroxyurea. As for SCI patients, 5 were on hydroxyurea at imaging time. No one of these 5 had undergone brain imaging prior to hydroxyurea treatment, and it is possible that these SCI are old ones. Bivariate analysis showed an association between the occurrence of overt stroke and premature death (p=0.006), regular blood transfusions (p=0.006), and osteomyelitis (p=0.009). Bivariate analysis showed an association between the occurrence of SCI and presentation of disease before 2 years of age (p=0.053, borderline) and acute chest syndrome (p=0.035). The small number of patients in this group did not allow for multivariate analysis. Conclusion: Stroke prevalence rate in Lebanese SCD patients is lower than reports from others. This may be attributed to the small sample size and to the imaging technology utilized being less sensitive than newer MRI technology. A multicenter Lebanese SCD trial is warranted to assess the true stroke prevalence, the importance of modifying genes and gene-gene interaction in predicting stroke risk, and the efficacy of hydroxyurea for primary stroke prevention.