Contents lists available at ScienceDirect Blood Cells, Molecules and Diseases journal homepage: www.elsevier.com/locate/bcmd Prevalence and predictive factors of splenic sequestration crisis among 423 pediatric patients with sickle cell disease in Tunisia Monia Ben Khaled a,b, ⁎ , Monia Ouederni a,b , Yosra Mankai b , Samia Rekaya a,b , Ilhem Ben Fraj b , Nawel Dhouib b , Ridha Kouki b , Fethi Mellouli a,b , Mohamed Bejaoui a,b a Faculty of Medicine, University of Tunis El Manar, Tunis, Tunisia b Pediatric Immuno-Hematology Unit, Bone Marrow Transplantation Center Tunis, Tunis, Tunisia ARTICLE INFO Editor: Mohandas Narla Keywords: Spleen Sickle cell disease Children Acute splenic sequestration ABSTRACT This study was aimed to identify the predictors of splenic sequestration crisis (SSC) among pediatric patients with sickle cell disease (SCD). This prognosis study was carried out in the pediatric immuno-hematology unit, over 20 years (1998 to 2017), enrolling patients with SCD. The cox model was used in multivariate analysis. Among 423 patients with SCD (240 S/S phenotype, 128 S/B0, 30 S/B+, 14 S/O arab and 11 S/C), 150(35.4%) had at least one episode of SSC. The average age of patients at the first episode was 48.3 months ± 32.4(2–168). Recurrence of SSC was observed in 117 patients (78%). Spleen size ≥3 cm at baseline was the strongest predictor of SSC occurrence (HR = 7.27, CI: 4.01–13.20, p = 0.05) and recurrence (HR = 6.37, CI: 1,46–27.83, p = 0.01). Pallor revealing the disease, age at onset of symptoms < 24 months and reticulocytosis ≥300,000/mm 3 increased the risk of SSC. Pain crisis revealing the disease as well as neutrophilia was associated with a lower risk of SSC. In conclusion, this study confirmed the high prevalence of SSC in SCD and the high frequency of recurrence after a first episode. The SSC occurrence and recurrence were intimately linked to the presence of splenomegaly, chronic pallor revealing the disease as well as reticulocytosis. 1. Introduction Sickle cell disease (SCD) is a group of inherited red blood cell (RBC) diseases caused by the presence of hemoglobin S (HbS). It includes homozygous forms for the sickle mutation in the beta globin chain of hemoglobin (S/S) and compound heterozygosity of a sickle beta globin mutation with another beta globin mutation [1]. It is the most common hereditary hemoglobinopathy in the African region. The prevalence rate of SCD in these countries is 2% according to WHO [2]. The main clinical features include acute vaso-occlusive crisis (VOC), chronic he- molytic anemia with episodes of aggravations and infectious compli- cations. Splenic sequestration crisis (SSC) results from massive trapping of RBCs in the spleen causing a sudden enlargement of the spleen and acute trapping of a large proportion of the circulatory volume. It is one of the earliest acute life-threatening complications [3]. It was con- sidered the second cause of death in patients with SCD, during the first decade of life, after infections [1]. Diagnosis and management must be urgent in view of the impact on survival and quality of life. Despite the gravity of this complication, predictive factors are unknown [3]. Few studies have addressed this topic and no study has investigated the factors predicting the SSC occurrence based on baseline clinical and hematological characteristics of the disease. Early identification of pa- tients at risk, based on baseline parameters, will allow the practitioner to establish a preventive strategy and a close monitoring of SSC in order to decrease SSC-related morbidity and mortality rate. This study, conducted in a pediatric population with SCD in a re- ference center for hemoglobinopathies, was aimed to evaluate the fre- quency of SSC and to identify the predictive factors of SSC occurrence and recurrence among patients with SCD. https://doi.org/10.1016/j.bcmd.2019.102374 Received 26 August 2019; Received in revised form 28 September 2019; Accepted 29 September 2019 ⁎ Corresponding author at: Pediatric Immuno-Hematology Unit, Bone Marrow Transplantation Center Tunis, Tunis, Tunisia. E-mail address: moniabkhaled@yahoo.fr (M. Ben Khaled). Blood Cells, Molecules and Diseases 80 (2020) 102374 Available online 18 October 2019 1079-9796/ © 2019 Elsevier Inc. All rights reserved. T