Effective rescue treatment with vemurafenib of an infant with high-risk Langerhans cell histiocytosis.

INTRODUCTION: The recently identified role of a BRAF somatic mutation in the pathophysiology of Langerhans cell histiocytosis (LCH) offers new therapeutic options. Herein we describe the case of a 10-month-old infant with refractory high-risk LCH successfully treated with vemurafenib. OBSERVATION: The patient first presented with cutaneous LCH at the age of 2 months. The disease remained undiagnosed until she was 6 months old, when it rapidly evolved to a multisystemic high-risk and life-threatening disease, refractory to 2 lines of chemotherapy. BRAFV600E mutation was found at skin biopsy, and targeted therapy with vemurafenib was started when she was 10 months old. The treatment induced a fast and sustained response, but rapid relapse occurred after treatment discontinuation, leading to resumption of treatment, once more resulting in a sustained response. CONCLUSION: Our case highlights the first-line role of dermatologists in establishing the diagnosis of LCH, especially in children, in whom the eruption may be difficult to identify, leading to delayed diagnosis. Targeted therapy with vemurafenib has recently been described in children in this indication and our results support its efficacy, highlighting the need for prolonged treatment and raising the question of maintenance therapy, as well as the necessity for large-scale and long-term studies.

[Respiratory complications of sickle cell anemia in children: the acute chest syndrome]. / Les complications respiratoires de la drépanocytose chez les enfants: le syndrome thoracique aigu.

The acute chest syndrome (ACS) is one of the most frequent complications of sickle cell disease. It affects mostly young children and counts for one quarter of mortality in the young sickle cell disease (SCD) population. This retrospective study evaluates the impact of ACS among hospitalizations for other complications of SCD in patients at the University Childrens' Hospital Reine Fabiola (Brussels, Belgium) in order to isolate clinical conditions associated with a high risk of ACS development. The medical records of all SCD patients aged up to 18 years admitted for all SCD related acute complications over a period of 13 month have been reviewed. Two patient groups have been formed based on the presence of an ACS within the study period. Epidemiologic data, medical history, the clinical presentation at admission but also blood counts in steady state, at admission and along the hospital stay were compared for a total of 96 hospital stays. There is no difference for age or hemoglobin phenotype between the two major patient groups. Male sex and having had a previous ACS episode in the past were significantly more important in the group of patients hospitalized for ACS. Thoracic pain in an SCD patient who doesn't show typical ACS symptoms should be interpreted as a risk factor for ACS. In conclusion, male sex, medical history of at least one ACS and thoracic pain at hospital admission are associated with high risk of developing ACS.

Sickle cell disease from Africa to Belgium, from neonatal screening to clinical management.

AIM: To describe the severity of sickle cell disease (SCD) in newborns in Belgium and evaluate the impact of neonatal screening (NS) on clinical outcome. METHODS: Universal NS of umbilical cord blood for hemoglobinopathy was progressively deployed in Brussels and Liège starting in 1994. No particular population was targeted. Samples were analyzed initially using the isoelectric focusing technique and since 2008 the capillary electrophoresis technique. If a hemoglobin variant was suspected, further analysis was carried out using high performance liquid chromatography. Children presenting major hemoglobinopathy, especially SCD, were referred to a specialized centre for comprehensive management. Preventive measures included antipneumococcal prophylaxis immunization/antibiotic therapy, parental training to recognize severe anemia and splenic sequestration, and transcranial ultrasound recording for early detection of intracranial stenosis. A database was set up in Belgium to collect clinical and laboratory data including parental phenotype, diagnostic technique (neonatal screening or not), major clinical events (episodes of dactylitis, acute chest syndrome, severe anemia, infection, etc), number and duration of required hospitalizations, and treatment used. RESULTS: Screening of 222352 newborns in maternity units in Brussels led to diagnosis of SCD in 145 patients, Adequate data for analysis of clinical outcome was available for 96 of these children born before 2007. Median age in the study group was 4.2 years and the total duration of follow-up was 510 years. Most cases occurred in families from the Democratic Republic of Congo. (64/96 patients; 66.7%) and involved homozygous hemoglobin S disease (80/96 patients; 83.3%). Twenty-seven percent of patients (26/96) presented no severe clinical events during the study (17 SS, median age 2,1 years (0-13.1 years). Conversely 33% presented an episode of dactylitis and 47.9% (46/96) presented recurrent vasoocclusive crises. Severe anemia was observed in 39.6% (38/96) of cases. Six patients (6.3%) developed septicemia despite prophylactic antibiotic therapy and anti-pneumococcal immunization using heptavalent conjugate vaccine and polysaccharide vaccine, No penicillin-resistant strains were observed. The incidence of stroke was 2.1% (3/96). Two patients presenting homozygous hemoglobin S disease died due to septicemia due to non-compliance with antibiotic therapy in one case and severe anemia in one case. All episodes of septicemia and both deaths occurred at the beginning of the NS program. Hydroxyurea therapy was used in 30 patients (31.2%) including 7 in whom transcranial Doppler depicted blood flow abnormalities and 8 in whom allogeneic bone marrow transplantation was performed. CONCLUSIONS: Sickle cell disease is still associated with high morbidity and mortality but clinical care has improved and no death has occurred in the last 10 years. NS is an effective tool for early detection and management of SCD. Neonates with SCD diagnosed by NS in Belgium presented severe manifestations, but clinical outcomes were improved by comprehensive management.