National Clinical Data Base for Sickle Cell Disease In Belgium
Authors: Lê Phu-Quoc , Ferster Alina , Vertongen Françoise , Vermylen Christiane , Vanderfaeillie Anna , Heijmans Catherine , Efira André , Nguyen Ba-Cuong , Mujinga Malou Ngalula , Gulbis Beatrice 
Published: October 2019

Abstract 2659

Sickle cell disease (SCD) has polymorphic manifestations, it is not well known by many physicians, and patients have often a precarious status. So despite enormous improvements in the understanding of the pathogenesis of SCD, patient care remains difficult.The objectives of this work were to create a clinical data base in order to learn the characteristics of this population, to create a network between practitioners (general, emergency and specialist practitioners), to provide state-of-the art and guidelines, it could be a tool to disseminate information, for education projects and for research; it could also represent a pilot project for other chronic diseases. A practical aspect of this data base is to improve follow-up and treatment of SCD patients by “online access from everywhere”. The SCD clinical data base was a national project and was approved by each local ethic committee; informed consent of each patient was obtained. The first step was to create the electronic database with several security measures (i.e. login, password, and separate administrators). The second step was to introduce patient's data. Patients were followed in different Academic and Secondary Care Centers. Data were collected from the initial contact until December 31, 2007. The data collection included parents' origin, hemoglobin phenotype, origin of diagnosis, clinical events, biological and radiological data, hospitalizations, and types of treatment.

Up to date, we introduced 280 medical records (146 diagnosed by neonatal screening). The median age and follow-up of the cohort was 9.3 year (range, 0–44) and 6.5 year (range, 0–32), respectively. The first information provided was the predominance of patients from DR Congo (67.5 %), the occurence of severe events in 84 % of patients (Table 1), the predominance of Hb SS phenotype (90 %) and its severity, the report of septicemia which remain still very worrying (8.2 %), but also that clinical and radiological neurological events are sizeable, and that there is a good response to treatment intensification, particularly to bone marrow transplantation (BMT) and hydroxyurea.

Table 1: SCD related events reported in the Belgian data base SCD related events Patients,%(n) Dactilytis 24.3 (68/280) Acute Chest Syndrome 18.9 (53/280) Recurrent Vaso-occlusive Crisis 61.8 (173/280) Anemia ≤ 6 g/dl 51.8 (145/280) Septicemia 8.2 (23/280) Splenic sequestration 7.9 (22/280) Stroke/TIA 3.9 (11/280) Osteonecrosis 5.0 (14/280) Osteomyelitis 2.5 (7/280)

The main pathogen remained Streptococcus pneumoniae with no resistant strain despite regular prophylaxis. The second most common germ was Salmonella. Haemophilus influenza concerned older patients and disappeared since the introduction of the vaccination. The incidence of death was 2.86% (8/280). All of them were homozygous for Hb S. Two deaths occurred in the very early childhood due to the no compliance to antibio-prophylaxis in the first patient and poor follow-up in the second one. One death was very sudden after meningeal hemorrhage. Two other deaths happened in the adulthood, one after cerebral hemorrhage and the other one of unknown cause after going back to native country. The last three deaths were due to BMT complications (Table 2).

Table 2: Causes of death reported in the national data base Patient Sex Phenotype Age at event Origin 1 F SS 18 m Cardiopulmonary arrest - Severe anemia 2 M SS 26 m Septic shock on St pmeumococcus septicaemia 3 M SS 7 y Secondary Leukemia after BMT 4 F SS 11 y 9 m Obliterans bronchiolitis/MOF* post BMT 5 M SS 14 y 3 m Meningeal hemorrhage 6 F SS 14 y 9 m Hemorrhage diathesis/MOF post BMT 7 F SS 18 y 9 m Cerebral aneurysm rupture 8 M SS 24 y 3 m Return to native country * Multiple Organ Failure

In conclusion, the preliminary results confirmed the still high morbidity and mortality of SCD. It is not only a precious practical tool, but it also helps to improve clinical management of patients with SCD, it is a tool to identify risk factors and to tailor treatments. In this perspective, it constitutes a basis for prospective studies in view to validate criteria of disease severity and to adopt guidelines for adequate treatment.

Disclosures:

No relevant conflicts of interest to declare.