Tapering of the thrombopoietin receptor agonist in paediatric patients with chronic immune thrombocytopenia: Is it possible?

It is not clear if platelet responses are sustained after thrombopoietin receptor agonist (ar-TPO) withdrawal in paediatric patients. A multicentre retrospective observational study was performed in children with chronic immune thrombopenia (cITP) to describe ar-TPO tapering and withdrawal in patients who had achieved a sustained complete response to ar-TPOs. Ten patients (eltrombopag n = 6, romiplostim n = 4) were included. Treatment withdrawal was performed after a mean tapering time of 7.6 months. Two patients relapsed (median follow-up time of 24 months). Slow tapering and withdrawal of ar-TPOs can be safely performed in cITP paediatric patients after achieving a sustained complete response.

[Protocol for the study and treatment of primary immune thrombocytopenia: PTI-2018]. / Protocolo de estudio y tratamiento de la trombocitopenia inmune primaria: PTI-2018.

Primary immune thrombocytopenia, formerly known as immune thrombocytopenic purpura, is a disease for which the clinical and therapeutic management has always been controversial. The ITP working group of the Spanish Society of Paediatric Haematology and Oncology has updated its guidelines for diagnosis and treatment of primary immune thrombocytopenia in children, based on current guidelines, bibliographic review, clinical assays, and member consensus. The main objective is to reduce clinical variability in diagnostic and therapeutic procedures, in order to obtain best clinical results with minimal adverse events and good quality of life.

Severe and moderate hemophilia A: identification of 38 new genetic alterations.

Hemophilia A is an X-linked recessive disorder caused by a lack or decrease of factor VIII activity. Its socio-economic impact is high given its high bleeding expression and treatment cost. Our aim was to establish the mutation of each patient to improve family management. A total of 116 unrelated families with severe and moderate hemophilia A were involved. Non-carriers of intron 22 and intron 1 rearrangements were included in F8 gene screening. Intron 1 and 22 inversion frequencies were 3% and 52.5% respectively. Putative mutations were identified in all the families; 38 were new. The cumulative inhibitor incidence was 22%. Approximately half the families carry non-recurrent mutations, which were unique in around one third. Harmful effects for mutations predicting null alleles are expected. Missense mutation consequences are not easily predictable, despite the help of some bio-informatics tools.

Detectable clonal mosaicism in blood as a biomarker of cancer risk in Fanconi anemia.

Detectable clonal mosaicism for large chromosomal events has been associated with aging and an increased risk of hematological and some solid cancers. We hypothesized that genetic cancer predisposition disorders, such as Fanconi anemia (FA), could manifest a high rate of chromosomal mosaic events (CMEs) in peripheral blood, which could be used as early biomarkers of cancer risk. We studied the prevalence of CMEs by single-nucleotide polymorphism (SNP) array in 130 FA patients' blood DNA and their impact on cancer risk. We detected 51 CMEs (4.4-159 Mb in size) in 16 out of 130 patients (12.3%), of which 9 had multiple CMEs. The most frequent events were gains at 3q (n = 6) and 1q (n = 5), both previously associated with leukemia, as well as rearrangements with breakpoint clustering within the major histocompatibility complex locus (P = 7.3 × 10-9). Compared with 15 743 age-matched population controls, FA patients had a 126 to 140 times higher risk of detectable CMEs in blood (P < 2.2 × 10-16). Prevalent and incident hematologic and solid cancers were more common in CME carriers (odds ratio [OR] = 11.6, 95% confidence interval [CI] = 3.4-39.3, P = 2.8 × 10-5), leading to poorer prognosis. The age-adjusted hazard risk (HR) of having cancer was almost 5 times higher in FA individuals with CMEs than in those without CMEs. Regarding survival, the HR of dying was 4 times higher in FA individuals having CMEs (HR = 4.0, 95% CI = 2.0-7.9, P = 5.7 × 10-5). Therefore, our data suggest that molecular karyotyping with SNP arrays in easy-to-obtain blood samples could be used for better monitoring of bone marrow clonal events, cancer risk, and overall survival of FA patients.

Erythrocyte deformability and aggregation in homozygous sickle cell disease.

Rheological properties of homozygous sickle cell anaemia (SCA) show marked heterogeneity, which may be explained in part by the concomitance of alpha genotypes or beta haplotypes, along with hydroxurea (HU) treatment. To further clarify this issue, in 11 homozygous patients with SCA in the steady state and in 16 healthy controls, we analysed erythrocyte deformability (ED) in a Rheodyn SSD by means of the Elongation Index (EI) at 12, 30 and 60 Pa, and erythrocyte aggregation at stasis (EA0) and at 3 sec-1 (EA1) in a Myrenne aggregometer along with fibrinogen, biochemical and haematological parameters. When compared with controls, homozygous (SS) patients showed a lower EI at all the shear stresses tested (p < 0.01) and higher EA0 (p < 0.014), but not higher EA1 (p = 0.076). Fibrinogen did not show statistical differences (p = 0.642). In the Spearman's correlation IE60 correlated inversely with Hb S (p < 0.05) and directly with MCV, MCH and Hb F levels (p < 0.01). EA0 correlated inversely with MCV, MCH, Hb F (p < 0.01) and directly with Hb S (p < 0.05). HU treatment improved EI and EA0, but not EA1. This paradoxical behaviour of HU on erythrocyte aggregation merits further research to be clarified.