The management of myelofibrosis: a British Society for Haematology guideline

This document represents an update of the British Society for Haematology guideline on Myelofibrosis first published in 2012 and updated in 2015 These guidelines aim to pro-vide healthcare professionals with clear guidance on stratified management for primary myelofibrosis (PMF), as well as post-polycythaemia myelofibrosis (post-PV MF) and postessential thrombocythaemia myelofibrosis (post-ET MF). A separate BSH guideline covers the diagnosis and prognostic evaluation of myelofibrosis and is published alongside this guideline

JAK-STAT signaling is activated in the kidney and peripheral blood cells of patients with focal segmental glomerulosclerosis.

Focal segmental glomerular sclerosis (FSGS) is a devastating disease with limited treatment options and poor prognosis. Activated JAK-STAT signaling has been implicated in other kidney diseases. Since new technologies allow us to better evaluate changes in systemic and renal JAK-STAT activity as it relates to kidney function, we examined this in 106 patients with biopsy-proven FSGS compared to 47 healthy control individuals. Peripheral immune function was assessed in peripheral blood mononuclear cells by phosphoflow studies before and after cytokine stimulation. Kidney JAK-STAT activity was measured by immunofluorescence and by transcriptomics. A STAT1 activity score was calculated by evaluating message status of downstream targets of pSTAT 1. Peripheral blood mononuclear cells were found to be upregulated in terms of pSTAT production at baseline in FSGS and to have limited reserve to respond to various cytokines. Increased staining for components of the JAK-STAT system in FSGS by microscopy was found. Furthermore, we found transcriptomic evidence for activation of JAK-STAT that increased pSTAT 1 and pSTAT 3 in glomerular and tubulointerstitial sections of the kidney. Some of these changes were associated with the likelihood of remission of proteinuria and progression of disease. JAK-STAT signaling is altered in patients with FSGS as compared to healthy controls with activated peripheral immune cells, increased message in the kidney and increased activated proteins in the kidney. Thus, our findings support immune activation in this disease and point to the JAK-STAT pathway as a potential target for treatment of FSGS.

Enhanced perforin expression associated with dasatinib therapy in natural killer cells.

We investigated the effects of dasatinib on natural killer (NK) cell-induced signaling protein and perforin expression as well as plasma cytokine levels by analyzing blood samples from patients with well-controlled chronic myeloid leukemia receiving tyrosine kinase inhibitor (TKI) therapy. Perforin expression and phosphorylation of signal transducer and activator of transcription (STAT) 1, STAT3, Janus kinase (JAK) 1, and JAK2 in NK cells were evaluated by flow cytometry, and the levels of plasma cytokines, including interferon (IFN)-γ and interleukin (IL)-2, were determined by enzyme-linked immunosorbent assays in 40 patients (dasatinib, n = 23; imatinib, n = 11; and nilotinib, n = 6). Perforin levels in NK cells were higher in dasatinib-treated patients before TKI treatment; phospho (p)-STAT1 levels were closely correlated with pJAK1 and perforin levels, and pSTAT3 levels were correlated with pJAK2 and perforin levels. The correlation between pJAK1 and pSTAT1 was apparent in dasatinib-treated patients but not in other TKI-treated patients, and the correlation between pJAK2 and pSTAT3 was apparent in patients treated with other TKIs. Constitutive expression of IFN-γ was higher in patients treated with dasatinib or with other TKIs than in those who were in treatment-free remission (TFR). In contrast, constitutive expression of IL-2 was lower in patients treated with other TKIs than in those treated with dasatinib or in those who were in TFR. These results provided insights into the effects of dasatinib on JAK/STAT signaling in NK cells in vivo and the mechanisms underlying NK cell activation induced by dasatinib therapy.

Upregulation of IL-9 and JAK-STAT signaling pathway in children with autism.

Autism spectrum disorder (ASD) gradually develops predominantly neurodevelopmental disorders, which are socially diagnosed in early childhood. Though the etiopathology of ASD is not clear, immune alteration has been suggested as autism's pathophysiological mechanism. Previous studies found that several cytokines and transcription factor activation pathways were significantly increased in ASD. IL-9 has been confirmed to play a significant role in the central nervous system (CNS). The aim of the present study was to investigate the understudied role of pro- and anti-inflammatory cytokines and the JAK-STAT signaling pathway in ASD. We examined the IL-1ß, IL-4, IFN-γ, and IL-9 positive immunostaining in all cells, and CD4+ T cells, in ASD and normally developing control children (TD), on peripheral blood mononuclear cells (PBMCs), using flow cytometry. We explored PBMC mRNA expression levels for IL-1ß, IL-4, IFN-γ, IL-9, JAK1, and STAT5, by using real-time PCR (RT-PCR). We also explored PBMC protein expression levels for IL-1ß, IL-4, IL-9, pJAK1, and pSTAT5 by using western blotting. We found that the children with ASD had increased IL-1ß, IL-4, IFN-γ, and IL-9 positive immunostaining in all cells, and in CD4+ cells, relative to the TD controls. The mRNA and protein expression for IL-1ß, IL-4, IFN-γ, IL-9, JAK1, pJAK1, STAT5, and pSTAT5 were also significantly elevated in ASD relative to TD controls. These results suggested that cytokines and JAK-STAT activation signaling have an essential role in immune dysfunction in ASD.

Plant miRNAs found in human circulating system provide evidences of cross kingdom RNAi.

BACKGROUND: Emerging evidence indicates that plant miRNAs can present within human circulating system through dietary intake and regulate human gene expression. Hence we deduced that comestible plants miRNAs can be identified in the public available small RNA sequencing data sets. RESULTS: In this study, we identified abundant plant miRNAs sequences from 410 human plasma small RNA sequencing data sets. One particular plant miRNA miR2910, conserved in fruits and vegetables, was found to present in high relative amount in the plasma samples. This miRNA, with same 6mer and 7mer-A1 target seed sequences as hsa-miR-4259 and hsa-miR-4715-5p, was predicted to target human JAK-STAT signaling pathway gene SPRY4 and transcription regulation genes. CONCLUSIONS: Through analysis of public available plasma small RNA sequencing data, we found the supporting evidence for the plant miRNAs cross kingdom RNAi within human circulating system.

Proinflammatory Cytokine IL-6 and JAK-STAT Signaling Pathway in Myeloproliferative Neoplasms.

The recent JAK1/2 inhibitor trial in myeloproliferative neoplasms (MPNs) showed that reducing inflammation can be more beneficial than targeting gene mutants. We evaluated the proinflammatory IL-6 cytokine and JAK-STAT signaling pathway related genes in circulating CD34(+) cells of MPNs. Regarding laboratory data, leukocytosis has been observed in polycythemia vera (PV) and JAK2V617F mutation positive versus negative primary myelofibrosis (PMF) patients. Moreover, thrombocytosis was reduced by JAK2V617F allele burden in essential thrombocythemia (ET) and PMF. 261 significantly changed genes have been detected in PV, 82 in ET, and 94 genes in PMF. The following JAK-STAT signaling pathway related genes had augmented expression in CD34(+) cells of MPNs: CCND3 and IL23A regardless of JAK2V617F allele burden; CSF3R, IL6ST, and STAT1/2 in ET and PV with JAK2V617F mutation; and AKT2, IFNGR2, PIM1, PTPN11, and STAT3 only in PV. STAT5A gene expression was generally reduced in MPNs. IL-6 cytokine levels were increased in plasma, as well as IL-6 protein levels in bone marrow stroma of MPNs, dependent on JAK2V617F mutation presence in ET and PMF patients. Therefore, the JAK2V617F mutant allele burden participated in inflammation biomarkers induction and related signaling pathways activation in MPNs.