Background: Despite an increase in the number of therapies available to treat patients with immune thrombocytopenia (ITP), there are minimal data from randomized trials to assist physicians with the management of patients. Objective: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the management of ITP. Methods: In 2015, ASH formed a multidisciplinary guideline panel that included 8 adult clinical experts, 5 pediatric clinical experts, 2 methodologists with expertise in ITP, and 2 patient representatives. The panel was balanced to minimize potential bias from conflicts of interest. The panel reviewed the ASH 2011 guideline recommendations and prioritized questions. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including evidence-to-decision frameworks, to appraise evidence (up to May 2017) and formulate recommendations. Results: The panel agreed on 21 recommendations covering management of ITP in adults and children with newly diagnosed, persistent, and chronic disease refractory to first-line therapy who have non–life-threatening bleeding. Management approaches included: observation, corticosteroids, IV immunoglobulin, anti-D immunoglobulin, rituximab, splenectomy, and thrombopoietin receptor agonists. Conclusions: There was a lack of evidence to support strong recommendations for various management approaches. In general, strategies that avoided medication side effects were favored. A large focus was placed on shared decision-making, especially with regard to second-line therapy. Future research should apply standard corticosteroid-dosing regimens, report patient-reported outcomes, and include cost-analysis evaluations.

An international, multicenter registry was established to collect retrospective and prospective clinical data on patients with pyruvate kinase (PK) deficiency, the most common glycolytic defect causing congenital nonspherocytic hemolytic anemia. Medical history and laboratory and radiologic data were retrospectively collected at enrollment for 254 patients with molecularly confirmed PK deficiency. Perinatal complications were common, including anemia that required transfusions, hyperbilirubinemia, hydrops, and prematurity. Nearly all newborns were treated with phototherapy (93%), and many were treated with exchange transfusions (46%). Children age 5 years and younger were often transfused until splenectomy. Splenectomy (150 [59%] of 254 patients) was associated with a median increase in hemoglobin of 1.6 g/dL and a decreased transfusion burden in 90% of patients. Predictors of a response to splenectomy included higher presplenectomy hemoglobin ( = .007), lower indirect bilirubin ( = .005), and missense mutations ( = .0017). Postsplenectomy thrombosis was reported in 11% of patients. The most frequent complications included iron overload (48%) and gallstones (45%), but other complications such as aplastic crises, osteopenia/bone fragility, extramedullary hematopoiesis, postsplenectomy sepsis, pulmonary hypertension, and leg ulcers were not uncommon. Overall, 87 (34%) of 254 patients had both a splenectomy and cholecystectomy. In those who had a splenectomy without simultaneous cholecystectomy, 48% later required a cholecystectomy. Although the risk of complications increases with severity of anemia and a genotype-phenotype relationship was observed, complications were common in all patients with PK deficiency. Diagnostic testing for PK deficiency should be considered in patients with apparent congenital hemolytic anemia and close monitoring for iron overload, gallstones, and other complications is needed regardless of baseline hemoglobin. This trial was registered at www.clinicaltrials.gov as #NCT02053480.

SUMMARY The optimal management of asparaginase-associated thrombotic complications is not well-defined. We report the features, management, and outcome of paediatric (ages 0–18 years) and adult (18–50 years) patients with acute lymphoblastic leukaemia (ALL) with asparaginase-related venous thromboembolic events (VTE) treated at Dana-Farber Cancer Institute on clinical trials for newly diagnosed ALL between 1991–2008. Of 548 patients, 43 (8%) had VTE, including 27/501 (5%) paediatric and 16/47 (34%) adult patients. Sinus venous thrombosis occurred in 1.6% of patients. Age was the only significant predictor of VTE, with those aged >30 years at very high risk (VTE rate 42%). 74% of patients received low molecular weight heparin after VTE. Complications of anticoagulation included epistaxis (9%), bruising (2%), and, in two adult patients, major bleeding. 30 patients (70%) ultimately received at least 85% of the intended doses of asparaginase. 33% of patients experienced recurrent VTE (paediatric 17% vs. adults 47%, p=0.07). The 48-month event-free survival for patients with VTE was 85 ± 6% compared with 88 ± 2% for those without VTE (p=0.36). This study confirms that, after VTE, asparaginase can be restarted with closely monitored anticoagulation after imaging demonstrates clot stabilization or improvement. With this management strategy, a history of VTE does not appear to adversely impact prognosis.

Over the last several decades, our understanding of the genetic variation, pathophysiology, and complications of the hemolytic anemia associated with red cell pyruvate kinase deficiency (PKD) has expanded. Nonetheless, there remain significant gaps in our knowledge with regard to clinical care and monitoring. Treatment remains supportive with phototherapy and/or exchange transfusion in the newborn period, regular or intermittent red cell transfusions in children and adults, and splenectomy to decrease transfusion requirements and/or anemia related symptoms. In this article, we review the clinical diversity of PKD, the current standard of treatment and for supportive care, the complications observed, and future treatment directions.Am. J. Hematol. 90:825–830, 2015. © 2015 Wiley Periodicals, Inc.

Vaccine administration is under way worldwide to combat the current COVID-19 pandemic. The newly developed vaccines are highly effective with minimal adverse effects. Recently, the AstraZeneca ChadOx1 nCov-19 vaccine has raised public alarm with concerns regarding the rare, but serious, development of thrombotic events, now known as vaccine-induced immune thrombotic thrombocytopenia (VITT). These thrombotic events appear similar to heparin-induced thrombocytopenia, both clinically and pathologically. In this manuscript, the ISTH SSC Subcommittee on Platelet Immunology outlines guidelines on how to recognize, diagnose and manage patients with VITT.

Key Points• ITP patients differ in their tendency to bleed despite similarly low platelet counts, thereby confounding treatment decisions.• Platelet function tests, independent of platelet count, are associated with bleeding severity in ITP patients.Immune thrombocytopenia (ITP) patients with similarly low platelet counts differ in their tendency to bleed. To determine if differences in platelet function in ITP patients account for this variation in bleeding tendency, we conducted a single-center, cross-sectional study of pediatric patients with ITP. Bleeding severity (assessed by standardized bleeding score) and platelet function (assessed by whole blood flow cytometry) with and without agonist stimulation was evaluated in 57 ITP patients (median age, 9.9 years). After adjustment for platelet count, higher levels of thrombin receptor activating peptide (TRAP)-stimulated percent P-selectin-and activated glycoprotein (GP)IIb-IIIa-positive platelets were significantly associated with a lower bleeding score, whereas higher levels of immature platelet fraction (IPF), TRAP-stimulated platelet surface CD42b, unstimulated platelet surface P-selectin, and platelet forward light scatter (FSC) were associated with a higher bleeding score. Thus, platelet function tests related to platelet age (IPF, FSC) and activation through the protease activated receptor 1 (PAR1) thrombin receptor (TRAPstimulated P-selectin, activated GPIIb-IIIa, and CD42b), independent of platelet count, are associated with concurrent bleeding severity in ITP. These tests may be useful markers of future bleeding risk in ITP. (Blood. 2015;126(7):873-879)

Summary Novel therapies in development have brought a new focus on pyruvate kinase deficiency (PKD), the most common congenital haemolytic anaemia due to a glycolytic enzyme deficiency. With an improved recognition of its clinical presentation and understanding of the diagnostic pathway, more patients are likely to be identified with this anaemia. Complications, including gallstones and non‐transfusion‐related iron overload, require monitoring for early diagnosis and management. Current management remains supportive with red cell transfusions, chelation and splenectomy. Decisions to transfuse and/or splenectomise must be individualised. Haematopoietic stem cell transplant has been pursued in a small number of patients with mixed outcomes. Novel treatment approaches, which range from a small molecule pyruvate kinase activator to gene therapy, may transform the way in which PKD is managed in the future. In this review, we discuss the pathophysiology of PKD and present our approaches to diagnosis, monitoring and management of patients with this anaemia.

Background: We studied 2 unrelated patients with immune thrombocytopenia and autoimmune hemolytic anemia in the setting of acute infections. One patient developed multisystem inflammatory syndrome in children in the setting of a severe acute respiratory syndrome coronavirus 2 infection. Objectives: We sought to identify the mechanisms underlying the development of infection-driven autoimmune cytopenias. Methods: Whole-exome sequencing was performed on both patients, and the impact of the identified variants was validated by functional assays using the patients' PBMCs. Results: Each patient was found to have a unique heterozygous truncation variant in suppressor of cytokine signaling 1 (SOCS1). SOCS1 is an essential negative regulator of type I and type II IFN signaling. The patients' PBMCs showed increased levels of signal transducer and activator of transcription 1 phosphorylation and a transcriptional signature characterized by increased expression of type I and type II IFN-stimulated genes and proapoptotic genes. The enhanced IFN signature exhibited by the patients' unstimulated PBMCs parallels the hyperinflammatory state associated with multisystem inflammatory syndrome in children, suggesting the contributions of SOCS1 in regulating the inflammatory response characteristic of multisystem inflammatory syndrome in children. Conclusions: Heterozygous loss-of-function SOCS1 mutations are associated with enhanced IFN signaling and increased immune cell activation, thereby predisposing to infectionassociated autoimmune cytopenias. (J Allergy Clin Immunol 2020;nnn:nnn-nnn.)