Structure and antigenicity of the divergent human astrovirus VA1 capsid spike.

Human astrovirus (HAstV) is a known cause of viral gastroenteritis in children worldwide, but HAstV can cause also severe and systemic infections in immunocompromised patients. There are three clades of HAstV: classical, MLB, and VA/HMO. While all three clades are found in gastrointestinal samples, HAstV-VA/HMO is the main clade associated with meningitis and encephalitis in immunocompromised patients. To understand how the HAstV-VA/HMO can infect the central nervous system, we investigated its sequence-divergent capsid spike, which functions in cell attachment and may influence viral tropism. Here we report the high-resolution crystal structures of the HAstV-VA1 capsid spike from strains isolated from patients with gastrointestinal and neuronal disease. The HAstV-VA1 spike forms a dimer and shares a core beta-barrel structure with other astrovirus capsid spikes but is otherwise strikingly different, suggesting that HAstV-VA1 may utilize a different cell receptor, and an infection competition assay supports this hypothesis. Furthermore, by mapping the capsid protease cleavage site onto the structure, the maturation and assembly of the HAstV-VA1 capsid is revealed. Finally, comparison of gastrointestinal and neuronal HAstV-VA1 sequences, structures, and antigenicity suggests that neuronal HAstV-VA1 strains may have acquired immune escape mutations. Overall, our studies on the HAstV-VA1 capsid spike lay a foundation to further investigate the biology of HAstV-VA/HMO and to develop vaccines and therapeutics targeting it.

Fostamatinib effectiveness and safety for immune thrombocytopenia in clinical practice.

ABSTRACT: Fostamatinib, a recently approved Syk inhibitor used in adult primary immune thrombocytopenia (ITP), has been shown to be safe and effective in this disorder. However, clinical trial results may not be similarly reproduced in clinical practice. Here, 138 patients with ITP (both primary and secondary) from 42 Spanish centers who had been treated with fostamatinib were evaluated prospectively and retrospectively. The median age of our cohort (55.8% women) was 66 years (interquartile range [IQR], 56-80). The median time since ITP diagnosis at fostamatinib initiation was 51 months (IQR, 10-166). The median number of therapies before fostamatinib initiation was 4 (IQR, 2-5), including eltrombopag (76.1%), romiplostim (57.2%), and IV immunoglobulins (44.2%). Fifty-eight patients (42.0%) had signs/symptoms of bleeding in the month before treatment initiation. Seventy-nine percent of patients responded to fostamatinib with 53.6% complete responses (platelet count > 100 × 109/L). Eighty-three patients (60.1%) received fostamatinib monotherapy, achieving a high response rate (85.4%). The proportion of time in response during the 27-month period examined was 83.3%. The median time to platelet response was 11 days (IQR, 7-21). Sixty-seven patients (48.5%) experienced adverse events, mainly grade 1 to 2; the commonest of which were diarrhea (n = 28) and hypertension (n = 21). One patient had deep venous thrombosis, and one patient developed acute myocardial infarction. Fostamatinib was shown to be effective with good safety profile in patients with primary and secondary ITP across a wide age spectrum in this real-world study.

Mouse and human immune responses share neutralization epitopes of HAstV-VA1.

Astroviruses are highly divergent and infect a wide variety of animal hosts. In 2009, a genetically divergent human astrovirus (HAstV) strain VA1 was first identified in an outbreak of acute gastroenteritis. This strain has also been associated with fatal central nervous system disease. In this work, we report the isolation of three high-affinity neutralizing monoclonal antibodies (Nt-MAbs) targeting the capsid spike domain of HAstV-VA1. These antibodies (7C8, 2A2, 3D8) were used to select individual HAstV-VA1 mutants resistant to their neutralizing activity and a HAstV-VA1 triple mutant that escapes neutralization from all three Nt-MAbs. Sequencing of the virus genome capsid region revealed escape mutations that map to the surface of the capsid spike domain, define three potentially independent neutralization epitopes, and help delineate four antigenic sites in human astroviruses. Notably, two of the escape mutations were found to be present in the spike sequence of the HAstV-VA1-PS strain isolated from an immunodeficient patient with encephalitis, suggesting that those mutations arose as a result of the immune pressure generated by the patient's immunotherapy. In agreement with this observation, human serum samples exhibiting strong neutralization activity against wild-type HAstV-VA1 had a 2.6-fold reduction in neutralization titer when evaluated against the triple-escape HAstV-VA1 mutant, suggesting that both mouse and human antibody responses target shared neutralization epitopes. The isolated Nt-MAbs reported in this work will help to characterize the functional domains of the virus during cell entry and have the potential for developing a specific antibody therapy for the neurological disease associated with HAstV-VA1. IMPORTANCE: Human astroviruses (HAstVs) have been historically associated with acute gastroenteritis. However, the genetically divergent HAstV-VA1 strain has been associated with central nervous system disease. In this work high-affinity neutralizing monoclonal antibodies directed to HAstV-VA1 were isolated and characterized. The proposed binding sites for these antibodies and for neutralizing antibodies against classical HAstVs suggest that there are at least four neutralization sites on the capsid spike of astroviruses. Our data show that natural infection with human astrovirus VA1 elicits a robust humoral immune response that targets the same antigenic sites recognized by the mouse monoclonal antibodies and strongly suggests the emergence of a variant HAstV-VA1 virus in an immunodeficient patient with prolonged astrovirus infection. The isolated Nt-MAb reported in this work will help to define the functional sites of the virus involved in cell entry and hold promise for developing a specific antibody therapy for the neurological disease associated with HAstV-VA1.

Autoimmune hemolytic anemia during pregnancy and puerperium: an international multicenter experience.

Relapsing or occurring de novo autoimmune hemolytic anemia (AIHA) during pregnancy or puerperium is a poorly described condition. Here, we report 45 pregnancies in 33 women evaluated at 12 centers from 1997 to 2022. Among the 20 women diagnosed with AIHA before pregnancy, 10 had a relapse. An additional 13 patients developed de novo AIHA during gestation/puerperium (2 patients had AIHA relapse during a second pregnancy). Among 24 hemolytic events, anemia was uniformly severe (median Hb, 6.4 g/dL; range, 3.1-8.7) and required treatment in all cases (96% steroids ± intravenous immunoglobulin, IVIG, 58% transfusions). Response was achieved in all patients and was complete in 65% of the cases. Antithrombotic prophylaxis was administered to 8 patients (33%). After delivery, rituximab was administered to 4 patients, and cyclosporine was added to 1 patient. The rate of maternal complications, including premature rupture of membranes, placental detachment, and preeclampsia, was 15%. Early miscarriages occurred in 13% of the pregnancies. Fetal adverse events (22% of cases) included respiratory distress, fetal growth restriction, preterm birth, AIHA of the newborn, and 2 perinatal deaths. In conclusion, the occurrence of AIHA does not preclude the ability to carry out a healthy pregnancy, provided close monitoring, prompt therapy, and awareness of potential maternal and fetal complications.

The problem of immune thrombocytopenia refractory to both eltrombopag and romiplostim.

Immune thrombocytopenia refractory to multiple thrombopoietin receptor agonists remains a challenging clinical problem. This commentary discusses and contextualizes the recent report on this entity from Moulis and colleagues, and how to move forward with these patients. Commentary on: Moulis et al. Difficult-to-treat primary immune thrombocytopenia in adults: Prevalence and burden. Results from the CARMEN-France Registry. Br J Haematol 2024;204:1476-1482.

Real-life clinical practice in Spain in the setting of new drug availability for ITP treatment. A Delphi-based Spanish expert panel consensus.

Immune thrombocytopenia (ITP) is a common autoimmune hematological disorder. Despite this, diagnosis is still challenging due to clinical heterogeneity and the lack of a specific diagnostic test. New findings in the pathology and the availability of new drugs have led to the development of different guidelines worldwide. In the present study, the Delphi methodology has been used to get a consensus on the management of adult patients with ITP in Spain and to help in decision-making. The Delphi questionnaire has been designed by a scientific ad hoc committee and has been divided into 13 topics, with a total of 127 items, covering the maximum possible scenarios for the management of ITP. As a result of the study, a total consensus of 81% has been reached. It is concluded that this Delphi consensus provides practical recommendations on topics related to diagnosis and management of ITP patients to help doctors to improve outcomes. Some aspects remain unclear, without consensus among the experts. Thus, more advances are needed to optimize ITP management.

What is the context? Immune thrombocytopenia (ITP) is a hematologic autoimmune disease characterized by accelerated destruction and inadequate production of platelets mediated by autoantibodies (platelet count <100 × 10⁹ /L).Despite being a common condition, its heterogeneous clinical course makes its diagnosis and management still a challenge.In recent years, new molecules with different mechanisms of action have emerged for the treatment of ITP.Due to the increasing information about the pathology and its therapies, several international guidelines have recently been established to provide recommendations for the management and treatment of ITP.There are still many patient scenarios and disease aspects which are not addressed in the guidelines.What is new? Our Spanish ITP Expert Group has developed a Delphi consensus study to provide recommendations and promote standardization of the management of adult patients with ITP in Spain.The scientific committee defined 127 statements for consensus, corresponding to 13 chapters: (i) Diagnosis of ITP, (ii) First-line treatment, (iii) Second-line treatment, (iv) Treatment of refractory patients, (v) Follow-up, (vi) Emergency and surgery, (vii) ITP in the elderly, (viii) ITP in pregnancy, (ix) Anticoagulation and antiplatelet, (x) Secondary ITP, (xi) Quality of life, (xii) Discontinuation of TPO-RA, and (xiii) ITP and Covid.The total number of agreed statements achieved was 103, giving a final percentage of consensus in the Delphi questionnaire of 81%.What is the impact? This Delphi consensus provides recommendations based on real clinical practice data, regarding the diagnosis, treatment, and management of patients and scenarios in ITP to assist clinicians in addressing this disease and achieving optimal outcomes for the patient.

The relationship between serum vitamin D, bone mineral density, and injury in collegiate acrobatics and tumbling athletes.

Background: Medical staff for indoor aesthetic sports such as acrobatics and tumbling (A&T) is often concerned with athletes' bone mineral density (BMD), serum vitamin D (SvD), and associated injury risks. Aim: To evaluate the relationship between BMD, SvD, and injury among A&T athletes. Methods: 42 (19 tops, 23 bases) female A&T athletes aged 19.6 (±1.17) years participated. Two samples of SvD were taken. Injury and BMD data were provided by support staff. Bivariate and multivariate analysis assessed relationships between and among variables. Results: Participants experienced a decrease in SvD (6.093 ± 10.973). Spine BMD was significantly higher in bases compared to tops (p = 0.039). BMD and SvD did not differ based on injuries sustained. Conclusion: Relationships between SvD, BMD, and injury were not identified. Positional differences in BMD may be related to the demands of each role. Participants possessed low SvD and high BMDs, which may provide useful information for medical staff.

Effects of L-Leucine Supplementation and Resistance Training on Adipokine Markers in Untrained Perimenopausal and Postmenopausal Women.

ABSTRACT: Chapman-Lopez, TJ, Funderburk, LK, Heileson, JL, Wilburn, DT, Koutakis, P, Gallucci, AR, and Forsse, JS. Effects of L-leucine supplementation and resistance training on adipokine markers in untrained perimenopausal and postmenopausal women. J Strength Cond Res 38(3): 526-532, 2024-This study examined the effects of supplementing 5 g of leucine compared with a placebo during a 10-week resistance training program on body composition parameters and adipokine concentrations in untrained, perimenopausal and postmenopausal women. Thirty-five women were randomly assigned to 2 groups-leucine (LEU, n = 17) and placebo (PLC, n = 18)-in a double-blind, placebo-controlled trial. Each group consumed the supplement or placebo every day and completed a resistance training program for 10 weeks. Using 3-day food records, a diet was assessed before the intervention and after its cessation. Body composition was assessed preintervention and postintervention using dual-energy x-ray absorptiometry. Moreover, the concentrations of adipokines, such as adiponectin, visfatin, leptin, and monocyte chemoattractant protein-1 (MCP-1), were assessed preintervention and postintervention. Both groups showed an increase in visceral adipose tissue (VAT) area ( p = 0.030) and fat-free mass (FFM; p = 0.023). There were significant group differences in concentrations of visfatin ( p = 0.020) and leptin ( p = 0.038) between the PLC and LEU groups. Visfatin displayed higher concentrations in the PLC group and leptin displayed higher concentrations in the LEU group. In addition, there were significant decreases in adiponectin concentrations for both groups (LEU: 652 ± 513 to 292 ± 447 pg·ml -1 ; PLC: 584 ± 572 to 245 ± 356 pg·ml -1 , p = 0.002) and MCP-1 only decreased in the PLC group (253 ± 119 to 206 ± 106 pg·ml -1 , p = 0.004). There were significant decreases in adiponectin concentrations in both groups and a decrease in MCP-1 concentrations in the PLC group. These decreases may be due to both adipokines possible relationship with VAT area. However, it is not known whether leucine has underlying properties that hinder changes in MCP-1 concentrations.

Early immunomodulation in immune thrombocytopenia-A report of the ICIS meeting in Lenzerheide, Switzerland 2022.

The only way to prevent immune thrombocytopenia (ITP) from becoming refractory would be to restore tolerance to platelets at an early phase of the disease. Numerous immune alterations probably accumulate in chronic ITP; thus, the chances of cure decrease significantly with time. Currently, sustained remission off treatment (SROT) is a clinical definition describing patients who can discontinue their ITP treatment without risk and maintain a state of remission. Different treatment strategies are presently being evaluated with the goal of attaining SROT, mostly combining drugs targeting the innate and/or the adaptive immune system, the inflammation state, so as increasing the platelet load. In this sense, thrombopoietin receptor agonists (TPO-RAs) have shown promising results if used as upfront treatment. TPO-RAs seem to exhibit immunomodulation and immune tolerance properties, increasing not only the platelet antigen mass but also increasing the transforming growth factor-ß concentration, and stimulating regulatory T and B lymphocytes. However, more immunological studies are needed to establish accurate molecular alterations in ITP that are potentially reversed with treatments.

The Capsid Precursor Protein of Astrovirus VA1 Is Proteolytically Processed Intracellularly.

Human astrovirus VA1 has been associated with neurological disease in immunocompromised patients, and its recent propagation in cell culture has opened the possibility to study its biology. Unlike classical human astroviruses, VA1 growth was found to be independent of trypsin during virus replication in vitro. In this work, we show that despite its independence on trypsin activation for cell infection, the VA1 capsid precursor protein, of 86 kDa (VP86), is processed intracellularly, and this proteolytic processing is important for astrovirus VA1 infectivity. Antibodies raised against different regions of the capsid precursor showed that the polyprotein can be processed starting at either its amino- or carboxy-terminal end, and they allowed us to identify those proteins of about 33 (VP33) and 38 (VP38) kDa constitute the core and the spike proteins of the mature infectious virus particles, respectively. The amino-terminal end of the spike protein was found to be Thr-348. Whether the protease involved in intracellular cleavage of the capsid precursor is of viral or cellular origin remains to be determined, but the cleavage is independent of caspases. Also, trypsin is able to degrade the capsid precursor but has no effect on VP33 and VP38 proteins when assembled into virus particles. These studies provide the basis for advancement of the knowledge of astrovirus VA1 cell entry and replication. IMPORTANCE Human astrovirus VA1 has been associated with neurological disease in immunocompromised patients. Its recent propagation in cell culture has facilitated the study of its biology. In this work, we show that despite the ability of this virus to grow in the absence of trypsin, a marked feature of human classical astroviruses, the capsid precursor protein of astrovirus VA1 is cleaved intracellularly to yield the mature infectious particles, formed by two polypeptides, VP33 that constitutes the core domain of the virus particle, and VP38 that forms the spike of the virus. These studies provide a platform to advance our knowledge on astrovirus VA1 cell entry and replication.

Structures of Two Human Astrovirus Capsid/Neutralizing Antibody Complexes Reveal Distinct Epitopes and Inhibition of Virus Attachment to Cells.

Human astrovirus is an important cause of viral gastroenteritis worldwide. Young children, the elderly, and the immunocompromised are especially at risk for contracting severe disease. However, no vaccines exist to combat human astrovirus infection. Evidence points to the importance of antibodies in protecting healthy adults from reinfection. To develop an effective subunit vaccine that broadly protects against diverse astrovirus serotypes, we must understand how neutralizing antibodies target the capsid surface at the molecular level. Here, we report the structures of the human astrovirus capsid spike domain bound to two neutralizing monoclonal antibodies. These antibodies bind two distinct conformational epitopes on the spike surface. We add to existing evidence that the human astrovirus capsid spike contains a receptor-binding domain and demonstrate that both antibodies neutralize human astrovirus by blocking virus attachment to host cells. We identify patches of conserved amino acids which overlap or border the antibody epitopes and may constitute a receptor-binding site. Our findings provide a basis for developing therapies to prevent and treat human astrovirus gastroenteritis. IMPORTANCE Human astroviruses infect nearly every person in the world during childhood and cause diarrhea, vomiting, and fever. Despite the prevalence of this virus, little is known about how antibodies block astrovirus infection. Here, we determined the crystal structures of the astrovirus capsid protein in complex with two virus-neutralizing antibodies. We show that the antibodies bind to two distinct sites on the capsid spike domain, however, both antibodies block virus attachment to human cells. Importantly, our findings support the use of the human astrovirus capsid spike as an antigen in a subunit-based vaccine to prevent astrovirus disease.

European Delphi panel to build consensus on tapering and discontinuing thrombopoietin receptor agonists in immune thrombocytopenia.

To establish pan-European consensus on tapering and discontinuing thrombopoietin receptor agonists (TPO-RAs) in patients with immune thrombocytopenia (ITP), we applied a three-step Delphi technique consisting of a one-to-one interview round and two online survey rounds. Three healthcare professionals (HCPs) from Italy, Spain, and the United Kingdom formed the Steering Committee (SC), which advised on study design, panelist selection, and survey development. A literature review also informed the development of the consensus statements. Likert scales were used to collect quantitative data on panelists' level of agreement. Twelve hematologists representing nine European countries assessed 121 statements spanning three categories: (1) patient selection; (2) tapering and discontinuation strategies; (3) post-discontinuation management. Consensus was reached on approximately half of the statements in each category (32.2%; 44.6%; 66%). Panelists agreed on patients' main selection criteria, patients' involvement in decision-making, tapering strategies, and follow-up criteria. Areas not reaching consensus were risk factors and predictors of successful discontinuation, monitoring intervals, and rates of successful discontinuation or relapse. This lack of consensus signals knowledge and practice gaps among European countries and suggests the need for the development of clinical practice guidelines that outline a pan-European, evidence-based approach to tapering and discontinuing TPO-RAs.

Immune thrombocytopenia (ITP) is a condition that may cause extensive bruising and excessive bleeding. Another sign is a pattern of small reddish-purple dots resembling a rash. ITP is treated with a class of medications known as thrombopoietin receptor agonists (TPO-RAs), which include eltrombopag, avatrombopag, and romiplostim. Sometimes the beneficial effects of the medication last even after the patient stops taking it, which means that some patients can be tapered off it. This paper presents the results of a Delphi panel­a method of research that gathers insights from experts­about tapering and discontinuing TPO-RAs. There were 12 physicians from nine European countries on the Delphi panel, all practicing hematologists with expertise in tapering and discontinuing TPO-RAs in patients with ITP. Panelists were presented with a total of 130 statements over three survey rounds. At the end of Round Three, 52 statements (40%) achieved consensus (response pattern of ≥80% "Agree"), and six statements (4.6%) achieved dissensus (response pattern of ≥80% "Disagree"). Consensus was achieved on the appropriateness of tapering the dose of the TPO-RA for two to three months prior to attempting discontinuation. The panel also reached consensus on considering tapering in a slower fashion (six to 12 months) for patients showing suboptimal response to TPO-RAs. More than half the survey's statements did not achieve consensus or dissensus. This signals that knowledge gaps exist and highlights the importance of conducting prospective, real-world evidence studies to identify best practices and develop pan-European guidelines for tapering and discontinuing TPO-RAs.

Effects of Static Contemporary Western Yoga vs. a Dynamic Stretching Exercise Program on Body Composition, Balance, and Flexibility.

ABSTRACT: Chapman-Lopez, TJ, Moris, JM, Petty, G, Timon, C, and Koh, Y. Effects of static contemporary western yoga vs. a dynamic stretching exercise program on body composition, balance, and flexibility. J Strength Cond Res 37(5): 1064-1069, 2023-Essentrics is a dynamic full-body stretching workout, which has recently earned its popularity in the field of yoga because of its potential for improvement in balance, flexibility, and weight loss while adding enjoyment to the workout without any discomfort and pain. However, the effects of Essentrics on overall health have not been well studied, particularly in a younger, physically healthy population. Thirty-five subjects (27 females and 8 males, age = 20.4 ± 0.2 years, and body mass index = 22.58 ± 0.55 kg·m-2) were assigned to 2 groups-contemporary western yoga (CWY, n = 20) and Essentrics (ESS, n = 15). Each group met 3 times per week for a total of 45-50 minutes per day for 6 weeks. Anthropometric measurements, body composition (dual-energy x-ray absorptiometry), flexibility (sit-and-reach), and balance (lower extremity Y-balance) were assessed before and after the 6-week program. The balance test included 3 reaches (anterior, posteromedial [PM], and posterolateral [PL] and composite reach distance). Each reach was averaged for the right and left sides and then normalized to leg length. Data were analyzed using an analysis of variance with repeated measures (p ≤ 0.05), and a post hoc test was performed for any significant interactions. There were no significant group differences between CWY and ESS in balance and flexibility. Following the 6-week yoga programs, balance was improved as follows: PM (87.13 ± 11.64 cm to 92.25 ± 9.91 cm, p = 0.001), PL (82.88 ± 11.28 to 88.62 ± 9.62 cm, p = 0.002), composite reach distance (CRD) (225.96 ± 27.17 to 238.26 ± 22.98 cm, p = 0.001), normalized PM (98.31 ± 11.68 to 104.27 ± 11.14%, p = 0.001), normalized PL (93.60 ± 11.98 to 100.15 ± 10.70%, p = 0.001), and normalized CRD (255.12 ± 27.89 to 269.21 ± 25.07%, p = 0.001). Flexibility was also improved from 51.42 ± 8.24 to 53.38 ± 7.04 cm (p = 0.010) following the 6-week workout programs. Total body fat percentage was significantly reduced only in the CWY group (24.44 ± 6.73 to 23.51 ± 6.32%, p = 0.002). Regardless of the type of stretching workout, both dynamic and static workouts improved flexibility and balance. Thus, individuals seeking to improve balance and flexibility can benefit from either dynamic or static yoga program.

Sustained Remission Off-Treatment (SROT) of TPO-RAs: The Burgos Ten-Step Eltrombopag Tapering Scheme.

Background and Objectives: TPO-RAs (romiplostim/eltrombopag/avatrombopag) have broadly demonstrated high efficacy rates (59-88%), durable responses (up to three years) and a satisfactory safety profile in clinical trials. The effect of TPO-RAs is classically considered to be transient because platelet numbers usually dropped rapidly to baseline unless therapy was maintained. However, several groups have reported the possibility of successfully discontinuing TPO-RAs in some patients without further need for concomitant treatments. This concept is usually referred as sustained remission off-treatment (SROT). Materials and Methods: Unfortunately, we still lack predictors of the response to discontinuation even after the numerous biological, clinical and in vitro studies performed to study this phenomenon. The frequency of successful discontinuation is matter of controversy, although a percentage in the range of 25-40% may probably be considered a consensus. Here, we describe all major routine clinical practice studies and reviews that report the current position on this topic and compare them with our own results in Burgos. Results: We report our Burgos ten-step eltrombopag tapering scheme with which we have achieved an elevated percentage rate of success (70.3%) in discontinuing treatment. Conclusions: We hope this protocol may help successfully taper and discontinue TPO-RAs in daily clinical practice.

Current Concepts in the Diagnosis and Management of Adult Primary Immune Thrombocytopenia: Our Personal View.

Primary immune thrombocytopenia (ITP) is an acquired blood disorder that causes a reduction in circulating platelets with the potential for bleeding. The incidence of ITP is slightly higher in adults and affects more women than men until 60 years, when males are more affected. Despite advances in basic science, primary ITP remains a diagnosis of exclusion. The disease is heterogeneous in its clinical behavior and response to treatment. This reflects the complex underlying pathophysiology, which remains ill-understood. Platelet destruction plays a role in thrombocytopenia, but underproduction is also a major contributing factor. Active ITP is a proinflammatory autoimmune disease involving abnormalities within the T and B regulatory cell compartments, along with several other immunological abnormalities. Over the last several years, there has been a shift from using immunosuppressive therapies for ITP towards approved treatments, such as thrombopoietin receptor agonists. The recent COVID-19 pandemic has hastened this management shift, with thrombopoietin receptor agonists becoming the predominant second-line treatment. A greater understanding of the underlying mechanisms has led to the development of several targeted therapies, some of which have been approved, with others still undergoing clinical development. Here we outline our view of the disease, including our opinion about the major diagnostic and therapeutic challenges. We also discuss our management of adult ITP and our placement of the various available therapies.

Use of thrombopoietin receptor agonists for immune thrombocytopenia in pregnancy: results from a multicenter study.

Management of immune thrombocytopenia (ITP) during pregnancy can be challenging because treatment choices are limited. Thrombopoietin receptor agonists (Tpo-RAs), which likely cross the placenta, are not recommended during pregnancy. To better assess the safety and efficacy of off-label use of Tpo-RAs during pregnancy, a multicenter observational and retrospective study was conducted. Results from 15 pregnant women with ITP (pregnancies, n = 17; neonates, n = 18) treated with either eltrombopag (n = 8) or romiplostim (n = 7) during pregnancy, including 2 patients with secondary ITP, were analyzed. Median time of Tpo-RA exposure during pregnancy was 4.4 weeks (range, 1-39 weeks); the indication for starting Tpo-RAs was preparation for delivery in 10 (58%) of 17 pregnancies, whereas 4 had chronic refractory symptomatic ITP and 3 were receiving eltrombopag when pregnancy started. Regarding safety, neither thromboembolic events among mothers nor Tpo-RA-related fetal or neonatal complications were observed, except for 1 case of neonatal thrombocytosis. Response to Tpo-RAs was achieved in 77% of cases, mostly in combination with concomitant ITP therapy (70% of responders). On the basis of these preliminary findings, temporary off-label use of Tpo-RAs for severe and/or refractory ITP during pregnancy seems safe for both mother and neonate and is likely to be helpful, especially before delivery.

Incidence, characteristics and clinical profile of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in patients with pre-existing primary immune thrombocytopenia (ITP) in Spain.

Infections are one of the well-known precipitating factors for relapses in patients with immune thrombocytopenia (ITP). Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection can sometimes lead to or be associated with thrombocytopenia due to an increase in peripheral platelet destruction from inflammatory hyperactivation. Currently, we do not know if SARS-CoV-2 infection modifies the natural evolution of chronic or persistent ITP or if previous immunosuppression of patients with ITP influences the incidence and severity of coronavirus disease 2019 (COVID-19) in this group. The present study was an observational, multicentre, national series of 32 adult patients with pre-existing ITP and subsequent SARS-CoV-2 infection, collected by the Spanish ITP Group [Grupo Español de Trombocitopenia Inmune (GEPTI)].

A decade of changes in management of immune thrombocytopenia, with special focus on elderly patients.

BACKGROUND: Ten years after their availability, thrombopoietin receptor agonists (TPO-RA) have heralded a paradigm shift in the treatment of immune thrombocytopenia (ITP). This study was aimed to analyze the implementation of current recommendations in the standard practice of adult ITP patients, and how age may influence those changes. METHODS: We included 121 adult patients (> 65 years, n = 54; younger individuals, n = 67) who initiated treatment with TPO-RA between January 2012 and December 2014. RESULTS: Patients older than 65 years treated with TPO-RA presented at diagnosis with significantly higher platelet counts, less bleeding, and a more prothrombotic profile than younger ones. The high efficacy rates of TPO-RA, preferentially used during the last decade in non-chronic phases, precluded from further therapies in the majority of ITP patients. Their administration was associated with a sharp decline in the last decade in the use of splenectomy and intravenous immunoglobulin, especially in younger ITP individuals. CONCLUSION: These results confirm (1) that there is a preferential use of TPO-RAs in elderly ITP patients with fewer bleeding complications but more unfavorable prothrombotic conditions than in younger individuals, and (2) that early use of these agents has been established as an effective therapeutic alternative to other second line therapies.

Isolation of Neutralizing Monoclonal Antibodies to Human Astrovirus and Characterization of Virus Variants That Escape Neutralization.

Human astroviruses (HAstVs) cause severe diarrhea and represent an important health problem in children under two years of age. Despite their medical importance, the study of these pathogens has been neglected. To better understand the astrovirus antigenic structure and the basis of protective immunity, in this work we produced a panel of neutralizing monoclonal antibodies (Nt-MAbs) to HAstV serotypes 1, 2, and 8 and identified the mutations that allow the viruses to escape neutralization. We first tested the capacity of the recombinant HAstV capsid core and spike domains to elicit Nt-Abs. Hyperimmunization of animals with the two domains showed that although both induced a potent immune response, only the spike was able to elicit antibodies with neutralizing activity. Based on this finding, we used a mixture of the recombinant spike domains belonging to the three HAstV serotypes to immunize mice. Five Nt-MAbs were isolated and characterized; all of them were serotype specific, two were directed to HAstV-1, one was directed to HAstV-2, and two were directed to HAstV-8. These antibodies were used to select single and double neutralization escape variant viruses, and determination of the amino acid changes that allow the viruses to escape neutralization permitted us to define the existence of four potentially independent neutralization epitopes on the HAstV capsid. These studies provide the basis for development of subunit vaccines that induce neutralizing antibodies and tools to explore the possibility of developing a specific antibody therapy for astrovirus disease. Our results also establish a platform to advance our knowledge on HAstV cell binding and entry.IMPORTANCE Human astroviruses (HAstVs) are common etiological agents of acute gastroenteritis in children, the elderly, and immunocompromised patients; some virus strains have also been associated with neurological disease. Despite their medical importance, the study of these pathogens has advanced at a slow pace. In this work, we produced neutralizing antibodies to the virus and mapped the epitopes they recognize on the virus capsid. These studies provide the basis for development of subunit vaccines that induce neutralizing antibodies, as well as tools to explore the development of a specific antibody therapy for astrovirus disease. Our results also establish a platform to advance our knowledge on HAstV cell binding and entry.

Use of eltrombopag for patients 65 years old or older with immune thrombocytopenia.

BACKGROUND: Eltrombopag is useful for immune thrombocytopenia (ITP). However, results of clinical trials may not accurately mirror clinical practice reality. Here we evaluated eltrombopag for primary and secondary ITP in our ≥65-year-old population. METHODS: A total of 106 primary ITP patients (16 with newly diagnosed ITP, 16 with persistent ITP, and 74 with chronic ITP) and 39 secondary ITP patients (20 with ITP secondary to immune disorders, 7 with ITP secondary to infectious diseases, and 12 with ITP secondary to lymphoproliferative disorders [LPD]) were retrospectively evaluated. RESULTS: Median age of our cohort was 76 (interquartile range, IQR, 70-81) years. 75.9% of patients yielded a platelet response including 66.2% complete responders. Median time to platelet response was 14 (IQR, 8-21) days. Median time on response was 320 (IQR, 147-526) days. Sixty-three adverse events (AEs), mainly grade 1-2, occurred. The most common were hepatobiliary laboratory abnormalities (HBLAs) and headaches. One transient ischemic attack in a newly diagnosed ITP and two self-limited pulmonary embolisms in secondary ITP were the only thrombotic events observed. CONCLUSION: Eltrombopag showed efficacy and safety in ITP patients aged ≥65 years with primary and secondary ITP. However, efficacy results in LPD-ITP were poor. A relatively high number of deaths were observed.