A. Ferster MD, PhD

Retrospective analysis of the incidence and characteristics of paediatric myelodysplastic syndrome and juvenile myelomonocytic leukaemia in Belgium

SUMMARY

Childhood myelodysplastic syndrome (MDS) and juvenile myelomonocytic leukaemia (JMML) are very rare clonal stem cell disorders of early childhood. Paediatric MDS can be further subdivided in refractory cytopenia of childhood (RCC) and high grade MDS, in case of excess blasts. Given their rarity, little is known about the epidemiology of these diseases in Belgium. The aim of this study is to investigate the incidence, characteristics, treatment and prognosis of paediatric MDS and JMML in Belgium. Prospectively collected data of 56 Belgian patients with MDS and JMML were enrolled in the study, of which 41 (73%) with MDS, eleven with JMML (20%) and four (7%) with Noonan syndrome associated myeloproliferative disorder. The incidence rates of MDS and JMML in Belgium were 1.5 and 0.4 per million children per year respectively, with a median age of diagnosis of 9.3 years for RCC, 9.5 years for high grade MDS and 2.6 years for JMML. Monosomy 7 was the most common cytogenetic abnormality and could particularly be found in high grade MDS (33%) and JMML (45%). RCC treatment consisted of immunosuppressive therapy (IST) and haematopoietic stem cell transplantation (HSCT), but in high grade MDS and JMML only HSCT was a valid treatment option. Overall survival was significantly lower in high grade MDS (45.0%) compared to JMML (79.5%) and RCC (80.6%) (log-rank p-value = 0.038), whereas event-free survival (EFS) was comparably low in high grade MDS and JMML (46.7% and 58.4% respectively) due to a high cumulative incidence of relapse (CIR) of 33% and 29.9%, respectively. Outcome was best for RCC patients with highest EFS (76.3%; 57.1% if IST failure was considered as event) and lowest CIR (9.3%). This study highlights that paediatric MDS and JMML are very rare disorders with associated morbidity and mortality, especially in high grade MDS and JMML. Considering the high relapse risk in high grade MDS and JMML, new therapeutic options are required.

(BELG J HEMATOL 2020;11(6):233-9)

BHS clinical guidelines on the management of acute complications in sickle cell disease

With the increasing prevalence of sickle cell disease patients in Western countries, it is of importance to improve awareness among medical doctors of its complications. To reduce long-term morbidity and mortality, the prompt recognition and treatment of acute complications is important. The existing clinical guideline ‘Follow-up and treatment of patients with sickle cell disease hospitalised for Vaso Occlusive Crisis or infection’, published in 2012 by the Belgian Haematological Society, was revisited to better suit the practical needs of first-line practitioners.

(BELG J HEMATOL 2019;10(4):165–8)

P37 CD123 expression on acute leukemia blasts, hematogones, and monocytes; used as Minimal Residual Disease Marker

A-103 VALIDATION OF A CHROMOGENIC ASSAY FOR FVIII: C AND FIX: C (CSA) MEASURING AND COMPARISON WITH A CHRONOMETRIC ASSAY (OSA)

Endogenous thrombin generation potential: an added value parameter to individualize prophylaxis treatment in pediatric haemophiliac patients?

Minimal residual disease quantification by PCR in childhood acute lymphoblastic leukaemia

Summary

In Belgium approximately 70 children are diagnosed with acute lymphoblastic leukaemia annually. For these children, the monitoring of minimal residual disease has an important prognostic value. The level of minimal residual disease during the first three months of therapy is used to recognise subgroups that differ substantially in outcome. Two techniques are used for minimal residual disease monitoring: the Genescan method and the allele specific oligonucleotide polymerase chain reaction. The Genescan method is a less sensitive method (10⁻³) but is fast and less expensive. The allele specific oligonucleotide polymerase chain reaction requires more time and budget but has a sensitivity of 10⁻⁴–10⁻⁵. Both techniques have proven their value in minimal residual disease monitoring in childhood acute lymphoblastic leukaemia.

(BELG J HEMATOL 2014;5(3):81–8)

Management of Sickle Cell Disease