Primary immune thrombocytopenia (ITP) is a bleeding disorder commonly encountered in clinical practice. The International Working Group (IWG) on ITP has published several landmark papers on terminology, definitions, outcome criteria, bleeding assessment, diagnosis, and management of ITP. The Chinese consensus reports for diagnosis and management of adult ITP have been updated to the 4th edition. Based on current consensus positions and new emerging clinical evidence, the thrombosis and hemostasis group of the Chinese Society of Hematology issued Chinese guidelines for management of adult ITP, which aim to provide evidence-based recommendations for clinical decision making.

Chronic immune thrombocytopenia (ITP) is characterized by autoimmune-mediated platelet destruction and impairment of thrombopoiesis. Mesenchymal stem cells (MSCs) are proposed to exhibit immune modulatory functions in self-tolerance maintenance. In this study, we aimed to characterize phenotypically and functionally bone marrow (BM)-derived MSCs from adult chronic ITP patients. Our results showed that BM-MSCs from patients with chronic ITP exhibited impaired proliferation, abnormal morphology and excessive apoptosis, and these defects could be ameliorated by modifying the culture environment. BM-MSCs from chronic ITP patients were shown to have similar immunophenotype and capacities to differentiate along adipogenic and osteogenic lineages as those from normal controls. However, the immune-inhibiting potential and the regulatory T cell-inducing ability of BM-MSCs from patients were defective compared to that of normal BM-MSCs. These findings suggest that the BM-MSCs were defective in chronic ITP patients. Whether the defective BM-MSCs are relevant to the pathogenesis of chronic ITP remains to be determined.

Myelofibrosis (MF) is associated with several constitutional symptoms. Currently, there are few therapeutic options for MF. Jaktinib, a novel, small-molecule inhibitor of JAK, is currently being studied for its potential to treat MF. This phase 2 trial investigated efficacy and safety of jaktinib in the treatment of MF patients. The primary end point was the proportion of patients with ≥35% reduction in spleen volume (SVR35, proportion of patients with ≥35% reduction in spleen volume) at week 24. The secondary end points included improvement of anemia, rates of symptom response, and safety profile. Between January 8, 2019 and August 29, 2020, 118 patients were recruited and treated with either jaktinib 100 mg BID or 200 mg QD. At week 24, 54.8% (34/62) of patients in the 100 mg BID group and 31.3% (15/48) in the 200 mg QD group achieved SVR35 (p = .0199). Jaktinib treatment increased hemoglobin level to ≥20 g/L in 35.6% (21/59) of patients with hemoglobin ≤100 g/L at baseline. The proportion of patients who achieved a ≥50% improvement in total symptom score at week 24 was 69.6% (39/56) in the BID group and 57.5% (23/40) in the QD group. The most common ≥ grade 3 hematological treatment-emergent adverse events (TEAEs; ≥ 10%) were anemia (100 mg BID: 24.2%, 200 mg QD: 28.8%), thrombocytopenia (16.7%, 11.5%), and neutropenia (3.0%, 11.5%). All non-hematological TEAEs were mild. These results indicate that jaktinib can shrink the spleen, improve anemia, and other clinical symptoms with good tolerability.