Evidence from in vitro and rodent studies suggests that leptin, a key signal of long-term energy reserves, promotes IGF1 synthesis and linear growth. This effect of leptin has not been fully investigated in humans. The aim of our study was to investigate the effect of leptin substitution on growth factors and linear growth in children with congenital leptin deficiency (CLD).

In this cohort study we included eight pediatric patients (six males), age 0.9-14.8 years, who were diagnosed with CLD and received leptin substitution at our University Medical Center. We calculated standard deviation scores (SDS) for serum levels of IGF1 and IGFBP3, IGF1/IGFBP3 molar ratio, and height at baseline (T0) and 12 months (T12) after the initiation of substitution with metreleptin.

All patients had severe obesity (BMI-SDS mean ± SD 4.14 ± 1.51) at T0 and significant BMI-SDS reduction to 2.47 ± 1.05 at T12. At T0, all patients were taller than the mid-parental median, yet had low IGF1 and IGF1/IGFBP3 molar ratios (IGF1-SDS[Formula see text]

-1.58 ± 0.92, IGF1/IGFBP3 molar ratio-SDS[Formula see text]

-1.58 ± 0.88). At T12, IGF1-SDS increased significantly (∆

1.63 ± 1.40, p = 0.01), and IGFBP3-SDS and IGF1/IGFBP3 molar ratio-SDS showed a trend toward an increase. In the three children within the childhood growth period (post-infancy, pre-puberty) height-SDS increased (∆height-SDS

0.57 ± 0.06, p = 0.003) despite substantial weight loss.

These results in CLD patients are contrary to observations in children with idiopathic obesity who typically have above-mean IGF1 levels that decrease with weight loss, and therefore suggest that leptin increases IGF1 levels and promotes linear growth.

These results in CLD patients are contrary to observations in children with idiopathic obesity who typically have above-mean IGF1 levels that decrease with weight loss, and therefore suggest that leptin increases IGF1 levels and promotes linear growth.The bone marrow microenvironment (BMME) plays a key role in the pathophysiology of myelodysplastic syndromes (MDS), clonal blood disorders affecting the differentiation, and maturation of hematopoietic stem and progenitor cells (HSPCs). In lower-risk MDS patients, ineffective late-stage erythropoiesis can be restored by luspatercept, an activin receptor type IIB ligand trap. Here, we investigated whether luspatercept can modulate the functional properties of mesenchymal stromal cells (MSCs) as key components of the BMME. Luspatercept treatment inhibited Smad2/3 phosphorylation in both healthy and MDS MSCs and reversed disease-associated alterations in SDF-1 secretion. Pre-treatment of MDS MSCs with luspatercept restored the subsequent clonogenic potential of co-cultured HSPCs and increased both their stromal-adherence and their expression of both CXCR4 and ß3 integrin. Luspatercept pre-treatment of MSCs also increased the subsequent homing of co-cultured HSPCs in zebrafish embryos. MSCs derived from patients who had received luspatercept treatment had an increased capacity to maintain the colony forming potential of normal but not MDS HSPCs. These data provide the first evidence that luspatercept impacts the BMME directly, leading to a selective restoration of the ineffective hematopoiesis that is a hallmark of MDS.Mutations in SET-binding protein 1 (SETBP1) are associated with poor outcomes in myeloid leukemias. In the Ras-driven leukemia, juvenile myelomonocytic leukemia, SETBP1 mutations are enriched in relapsed disease. While some mechanisms for SETBP1-driven oncogenesis have been established, it remains unclear how SETBP1 specifically modulates the biology of Ras-driven leukemias. In this study, we found that when co-expressed with Ras pathway mutations, SETBP1 promoted oncogenic transformation of murine bone marrow in vitro and aggressive myeloid leukemia in vivo. We demonstrate that SETBP1 enhances the NRAS gene expression signature, driving upregulation of mitogen-activated protein kinase (MAPK) signaling and downregulation of differentiation pathways. SETBP1 also enhances NRAS-driven phosphorylation of MAPK proteins. Cells expressing NRAS and SETBP1 are sensitive to inhibitors of the MAPK pathway, and treatment with the MEK inhibitor trametinib conferred a survival benefit in a mouse model of NRAS/SETBP1-mutant disease. Our data demonstrate that despite driving enhanced MAPK signaling, SETBP1-mutant cells remain susceptible to trametinib in vitro and in vivo, providing encouraging preclinical data for the use of trametinib in SETBP1-mutant disease.Tisagenlecleucel therapy has shown promising efficacy for relapsed/refractory (R/R) B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, relapses occur in 30-50% of patients. Determinants for CD19pos versus CD19neg relapses are poorly characterized. We report on 51 patients with R/R BCP-ALL (median age 17 years) infused with tisagenlecleucel after lymphodepletion. Complete remission rate at D28 was 96%. Prior blinatumomab increased the risk of early failure at D28. The 18-month cumulative incidence of relapse (CIR), event-free survival (EFS), and overall survival (OS) were 51%, 44%, and 74%, respectively, at a median follow-up of 15.5 months. Factors associated with a high tumor burden (occurrence of cytokine release syndrome) and prior blinatumomab were associated with an increased CIR, and a shorter EFS and OS. Pre-lymphodepletion high disease burden (MRD ≥ 10-2, SHR 10.4, p = 0.03) and detectable MRD at D28 (SHR 7.2, p = 0.006) correlated with an increased risk of CD19neg relapse. Low disease burden (SHR 5.3, p = 0.03) and loss of B-cell aplasia (BCA) (SHR 21.7, p = 0.004) predicted an increased risk of CD19pos relapses. These data highlight the impact of prior therapy on patient outcome. Finally, detectable MRD at D28 and loss of BCA both define patients at high risk of relapse for whom additional interventions are needed.We performed a meta-analysis to determine safety and efficacy of tocilizumab in persons with coronavirus disease-2019 (COVID-19). We searched PubMed, Web of Science and Medline using Boolean operators for studies with the terms coronavirus OR COVID-19 OR 2019-nCoV OR SARS-CoV-2 AND tocilizumab. Tanespimycin Review Manager 5.4 was used to analyze data and the modified Newcastle-Ottawa and Jadad scales for quality assessment. We identified 32 studies in 11,487 subjects including three randomized trials and 29 cohort studies with a comparator cohort, including historical controls (N = 5), a matched cohort (N = 12), or concurrent controls (N = 12). Overall, tocilizumab decreased risk of death (Relative Risk [RR] = 0.74; 95% confidence interval [CI], 0.59, 0.93; P = 0.008; I2 = 80%) but not of surrogate endpoints including ICU admission (RR = 1.40 [0.64,3.06]; P = 0.4; I2 = 88%), invasive mechanical ventilation (RR = 0.83 [0.57,1.22]; P = 0.34; I2 = 65%) or secondary infections (RR = 1.30 [0.97,1.74]; P = 0.08; I2 = 65%) and increased interval of hospitalization of subjects discharged alive(mean difference [MD] = 2 days [ less then 1, 4 days]; P = 0.