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Inherited platelet disorders (IPDs) are a group of rare conditions featured by reduced circulating platelets and/or impaired platelet function causing variable bleeding tendency. Additional hematological or non hematological features, which can be congenital or acquired, distinctively mark the clinical picture of a subgroup of patients. Recognizing an IPD is challenging, and diagnostic delay or mistakes are frequent. Despite the increasing availability of next-generation sequencing, a careful phenotyping of suspected patients—concerning the general clinical features, platelet morphology, and function—is still demanded. The cornerstones of IPD diagnosis are clinical evaluation, laboratory characterization, and genetic testing. Achieving a diagnosis of IPD is desirable for several reasons, including the possibility of tailored therapeutic strategies and individual follow-up programs. However, detailed investigations can also open complex scenarios raising ethical issues in case of IPDs predisposing to hematological malignancies. This review offers an overview of IPD diagnostic workup, from the interview with the proband to the molecular confirmation of the suspected disorder. The main implications of an IPD diagnosis are also discussed.

Vaccination is crucial in combatting the severe acute respiratory syndrome coronavirus 2 pandemic. The rare complication of thrombocytopenia and thrombotic complications at unusual sites after ChAdOx1 nCov-19 vaccination is caused by platelet-activating antibodies directed against platelet factor 4 (PF4). We present a widely applicable whole-blood standard flow cytometric assay to identify the pathogenic antibodies associated with vaccine-induced immune-mediated thrombotic thrombocytopenia (VITT) after ChAdOx1 nCov-19 vaccination. This assay will enable rapid diagnosis by many laboratories. This trial was registered at www.clinicaltrials.gov as #NCT04370119.

MYH9 -related disease patients with mutations in the contractile protein nonmuscle myosin heavy chain IIA display, among others, macrothrombocytopenia and a mild-to-moderate bleeding tendency. In this study, we used three mouse lines, each with one point mutation in the Myh9 gene at positions 702, 1424, or 1841, to investigate mechanisms underlying the increased bleeding risk. Agonist-induced activation of Myh9 mutant platelets was comparable to controls. However, myosin light chain phosphorylation after activation was reduced in mutant platelets, which displayed altered biophysical characteristics and generated lower adhesion, interaction, and traction forces. Treatment with tranexamic acid restored clot retraction in the presence of tPA and reduced bleeding. We verified our findings from the mutant mice with platelets from patients with the respective mutation. These data suggest that reduced platelet forces lead to an increased bleeding tendency in patients with MYH9 -related disease, and treatment with tranexamic acid can improve the hemostatic function.

Cytoskeleton is composed of more than 100 proteins and represents a dynamic network of the cellular cytoplasm. Cytoskeletal functions include spatial organization of cellular components, structural connection of the cell with external environment, and biomechanical force generation. Cytoskeleton takes part, at different levels, in all phases of platelet biogenesis: megakaryocyte (MK) differentiation, MK maturation, and platelet formation. In addition, it also plays a major role in each stage of platelet function. Inherited platelet disorders (IPDs) are a group of rare diseases featured by low platelet count and/or impaired platelet function. Over the past decade, the investigation of platelet biomechanics has become a major and highly relevant theme of research due to its implications at every stage of development of human life. The initial use of diverse biophysical techniques (e.g., micropipette aspiration, atomic force and scanning ion conductance microscopy, real-time deformability cytometry) started unraveling biomechanical features of platelets that are expected to provide new explanations for physiological and pathological mechanisms. Although the impact of cytoskeletal alterations has been largely elucidated in various IPDs' pathogenesis, the understanding of their impact on biomechanical properties of platelets represents an unmet need. Regarding IPDs, improving biomechanical studies seems promising for diagnostic and prognostic implications. Potentially, these characteristics of platelets may also be used for the prediction of bleeding risk. This review addresses the current available methods for biophysical investigations of platelets and the possible implementations in the field of IPDs.

Genetic variants in growth factor-independent 1B (GFI1B), encoding transcription factor GFI1B, are causative of platelet-type bleeding disorder-17. Presently, 53 cases of GFI1B associated inherited thrombocytopenia (IT) have been published, however only three were homozygous. The bleeding- and platelet phenotypes of these patients depend on location and inheritance pattern of the GFI1B variant. We report a novel homozygous GFI1B (Thr174Ile) variant located in the first Zinc finger domain of GFI1B in two sisters of Palestinian ancestry born to consanguineous parents. They experienced severe bleeding tendency at moderately reduced platelet counts. Flow cytometry and immunofluorescent microscopy confirmed the diagnostic features of GFI1B associated IT: a reduced content of alpha granules and aberrant expression of the stem cell marker CD34 on platelets. Transcription factor GFI1B is differentially expressed during hemato- and lymphopoiesis. In addition, to platelet function investigations, we present results of lymphoid subgroup analyses and deformability of red cells measured by ektacytometry.

MYH9-related disease patients with mutations in the contractile protein non-muscle myosin heavy chain IIA display, among others, macrothrombocytopenia and a mild to moderate bleeding tendency. In this study, we used three mouse lines, each with one point mutation in the Myh9 gene at positions 702, 1424, or 1841, to investigate mechanisms underlying the increased bleeding risk. Agonist-induced activation of Myh9 mutant platelets was comparable to controls. However, myosin light chain phosphorylation after activation was reduced in mutant platelets, which displayed altered biophysical characteristics and generated lower adhesion, interaction, and traction forces. Treatment with tranexamic acid restored clot retraction and reduced bleeding. We verified our findings from the mutant mice with platelets from patients with the respective mutation. These data suggest that reduced platelet forces lead to an increased bleeding tendency in MYH9-related disease patients, and treatment with tranexamic acid can improve the hemostatic function.TeaserImpaired hemostasis in Myh9 mutant mice due to reduced platelet forces can be improved by tranexamic acid.

Src-related thrombocytopenia (SRC-RT) is a rare autosomal dominant, inherited platelet disorder resulting from the p.E527K heterozygous germline gain-of-function variant of Src. To date, genetic diagnosis of the disease has only been reported in 7 patients from 3 unrelated families. The clinical features ranged from isolated thrombocytopenia to complex syndromic manifestations characterized by thrombocytopenia, bleeding, myelofibrosis, splenomegaly, and bone disease. We report a new 3-generation kindred with the Src p.E527K variant. Patients presented with rather variable platelet counts (38-139 × 109/L), mildly impaired platelet function, >15% immature platelet fraction, and with a significant proportion of large-giant platelets. Four adults from the family were diagnosed with immune thrombocytopenia (ITP) and underwent splenectomy, achieving sustained platelet counts >75 × 109/L for several years; increases in platelet counts were also observed after corticosteroid therapy. Four of 7 Src p.E527K variant carriers showed immune defects and recurrent infections. In addition, a range of neurological symptoms, from specific language impairment to epilepsy, was seen in some family members. Patient platelets exhibited constitutive Src, Bruton tyrosine kinase, and phospholipase Cγ2 activation, and after stimulating CD19 cells by crosslinking surface immunoglobulin M, phosphorylated extracellular signal-regulated kinase (ERK) was significantly increased in B cells from individuals carrying the Src p.E527K substitution. In summary, in addition to causing impaired platelet production, SRC-RT may associate immune dysregulation and increased platelet consumption. In families in whom several members are responsive to ITP-directed therapies, an underlying Src p.E527K variant should be excluded.

Platelet disorders comprise heterogeneous diseases featured by reduced platelet counts and/or impaired platelet function causing variable bleeding symptoms. Despite their bleeding diathesis, patients with platelet disorders can develop transient or permanent prothrombotic conditions that necessitate prophylactic or therapeutic anticoagulation. Anticoagulation in patients with platelet disorders is a matter of concern because the bleeding risk could add to the hemorrhagic risk related to the platelet defect. This review provides an overview on the evidence on anticoagulation in patients with acquired and inherited thrombocytopenia and/or platelet dysfunction. We summarize tools to evaluate and balance bleeding— and thrombotic risks and describe a practical approach on how to manage these patients if they have an indication for prophylactic or therapeutic anticoagulation.

MYH9-related disease (MYH9-RD) is a rare, autosomal dominant disorder caused by mutations in MYH9, the gene encoding the actin-activated motor protein non-muscle myosin IIA (NMIIA). MYH9-RD patients suffer from bleeding syndromes, progressive kidney disease, deafness, and/or cataracts, but the impact of MYH9 mutations on other NMIIA-expressing tissues remains unknown. In human red blood cells (RBCs), NMIIA assembles into bipolar filaments and binds to actin filaments (F-actin) in the spectrin-F-actin membrane skeleton to control RBC biconcave disk shape and deformability. Here, we tested the effects of MYH9 mutations in different NMIIA domains (motor, coiled-coil rod, or non-helical tail) on RBC NMIIA function. We found that MYH9-RD does not cause clinically significant anemia and that patient RBCs have normal osmotic deformability as well as normal membrane skeleton composition and micron-scale distribution. However, analysis of complete blood count data and peripheral blood smears revealed reduced hemoglobin content and elongated shapes, respectively, of MYH9-RD RBCs. Patients with mutations in the NMIIA motor domain had the highest numbers of elongated RBCs. Patients with mutations in the motor domain also had elevated association of NMIIA with F-actin at the RBC membrane. Our findings support a central role for motor domain activity in NMIIA regulation of RBC shape and define a new sub-clinical phenotype of MYH9-RD.

Background: The classic Bernard-Soulier syndrome (BSS) is a rare inherited thrombocytopenia (IT) associated with severe thrombocytopenia, giant platelets, and bleeding tendency caused by homozygous or compound heterozygous variants in GP1BA, GP1BB, or GP9. Monoallelic BSS (mBSS) associated with mild asymptomatic macrothrombocytopenia caused by heterozygous variants in GP1BA or GP1BB may be a frequent cause of mild IT. Objective: We aimed to examine the frequency of mBSS in a consecutive cohort of patients with IT and to characterize the geno- and phenotype of mBSS probands and their family members. Additionally, we set out to examine if thrombopoietin (TPO) levels differ in mBSS patients. Patients/Methods: We screened 106 patients suspected of IT using whole exome- or whole genome sequencing and performed co-segregation analyses of mBSS families. All probands and family members were phenotypically characterized. Founder mutation analysis was carried out by certifying that the probands were unrelated and the region around the variant was shared by all patients. TPO was measured by solid phase sandwich ELISA. Results: We diagnosed 14 patients (13%) with mBSS associated with heterozygous variants in GP1BA and GP1BB. Six unrelated probands carried a heterozygous variant in GP1BA (c.58T>G, p.Cys20Gly) and shared a 2.0 Mb region on chromosome 17, confirming that it is a founder variant. No discrepancy of TPO levels between mBSS patients and wild-type family members (P >.05) were identified. Conclusion: We conclude that the most frequent form of IT in Denmark is mBSS caused by the Copenhagen founder variant.

Background: Careful assessment of bleeding history is the first step in the evaluation of patients with mild/moderate bleeding disorders, and the use of a bleeding assessment tool (BAT) is strongly encouraged. Although a few studies have assessed the utility of the ISTH-BAT in patients with inherited platelet function disorders (IPFD) none of them was sufficiently large to draw conclusions and/or included appropriate control groups. Objectives: The aim of the present study was to test the utility of the ISTH-BAT in a large cohort of patients with a well-defined diagnosis of inherited platelets disorder in comparison with two parallel cohorts, one of patients with type-1 von Willebrand disease (VWD-1) and one of healthy controls (HC). Patients/Methods: We enrolled 1098 subjects, 482 of whom had inherited platelet disorders (196 IPFD and 286 inherited platelet number disorders [IT]) from 17 countries. Results: IPFD patients had significantly higher bleeding score (BS; median 9) than VWD-1 patients (median 5), a higher number of hemorrhagic symptoms (4 versus 3), and higher percentage of patients with clinically relevant symptoms (score > 2). The ISTH-BAT showed excellent discrimination power between IPFD and HC (0.9

Genetic variants in growth factor-independent 1B (

Thrombocytopenic disorders have been treated with the Thrombopoietin-receptor agonist Eltrombopag. Patients with the same apparent form of thrombocytopenia may respond differently to the treatment. We describe a miniaturized bone marrow tissue model that provides a screening bioreactor for personalized, pre-treatment response prediction to Eltrombopag for individual patients. Using silk fibroin, a 3D bone marrow niche was developed that reproduces platelet biogenesis. Hematopoietic progenitors were isolated from a small amount of peripheral blood of patients with mutations in ANKRD26 and MYH9 genes, who had previously received Eltrombopag. The ex vivo response was strongly correlated with the in vivo platelet response. Induced Pluripotent Stem Cells (iPSCs) from one patient with mutated MYH9 differentiated into functional megakaryocytes that responded to Eltrombopag. Combining patient-derived cells and iPSCs with the 3D bone marrow model technology allows having a reproducible system for studying drug mechanisms and for individualized, pre-treatment selection of effective therapy in Inherited Thrombocytopenias., eLife digest Platelets are tiny cell fragments essential for blood to clot. They are created and released into the bloodstream by megakaryocytes, giant cells that live in the bone marrow. In certain genetic diseases, such as Inherited Thrombocytopenia, the bone marrow fails to produce enough platelets: this leaves patients extremely susceptible to bruising, bleeding, and poor clotting after an injury or surgery. Certain patients with Inherited Thrombocytopenia respond well to treatments designed to boost platelet production, but others do not. Why these differences exist could be investigated by designing new test systems that recreate the form and function of bone marrow in the laboratory. However, it is challenging to build the complex and poorly understood bone marrow environment outside of the body. Here, Di Buduo et al. have developed an artificial three-dimensional miniature organ bioreactor system that recreates the key features of bone marrow. In this system, megakaryocytes were grown from patient blood samples, and hooked up to a tissue scaffold made of silk. The cells were able to grow as if they were in their normal environment, and they could shed platelets into an artificial bloodstream. After treating megakaryocytes with drugs to stimulate platelet production, Di Buduo et al. found that the number of platelets recovered from the bioreactor could accurately predict which patients would respond to these drugs in the clinic. This new test system enables researchers to predict how a patient will respond to treatment, and to tailor therapy options to each individual. This technology could also be used to test new drugs for Inherited Thrombocytopenias and other blood-related diseases; if scaled-up, it could also, one day, generate large quantities of lab-grown blood cells for transfusion.

Inherited platelet disorders (IPDs) are rare diseases featured by low platelet count and defective platelet function. Patients have variable bleeding diathesis and sometimes additional features that can be congenital or acquired. Identification of an IPD is desirable to avoid misdiagnosis of immune thrombocytopenia and the use of improper treatments. Diagnostic tools include platelet function studies and genetic testing. The latter can be challenging as the correlation of its outcomes with phenotype is not easy. The immune-morphological evaluation of blood smears (by light- and immunofluorescence microscopy) represents a reliable method to phenotype subjects with suspected IPD. It is relatively cheap, not excessively time-consuming and applicable to shipped samples. In some forms, it can provide a diagnosis by itself, as for MYH9-RD, or in addition to other first-line tests as aggregometry or flow cytometry. In regard to genetic testing, it can guide specific sequencing. Since only minimal amounts of blood are needed for the preparation of blood smears, it can be used to characterize thrombocytopenia in pediatric patients and even newborns further. In principle, it is based on visualizing alterations in the distribution of proteins, which result from specific genetic mutations by using monoclonal antibodies. It can be applied to identify deficiencies in membrane proteins, disturbed distribution of cytoskeletal proteins, and alpha as well as delta granules. On the other hand, mutations associated with impaired signal transduction are difficult to identify by immunofluorescence of blood smears. This review summarizes technical aspects and the main diagnostic patterns achievable by this method.

Major surgery is associated with an increased risk of venous thromboembolism, thus the application of mechanical or pharmacologic prophylaxis is recommended. The incidence of venous thromboembolism in patients with inherited platelet disorders undergoing surgical procedures is unknown and no information on the current use and safety of thromboprophylaxis, particularly of low-molecular-weight-heparin in these patients is available. Here we explored the approach to thromboprophylaxis and thrombotic outcomes in inherited platelet disorders patients undergoing surgery at venous thromboembolism-risk participating in the multicenter SPATA study. We evaluated 210 surgical procedures carried out in 155 patients with well-defined forms of inherited platelet disorders (venous thromboembolism-risk: 31% high, 28.6% intermediate, 25.2% low, 15.2% very low). The use of thromboprophylaxis was low (23.3% of procedures), with higher prevalence in orthopedic and gynecological surgeries, and was related to venous thromboembolism-risk. The most frequently employed thromboprophylaxis was mechanical and appeared to be effective, as no patients developed thrombosis, including patients belonging to the highest venous thromboembolism-risk classes. Low-molecular-weight-heparin use was low (10.5%) and it did not influence the incidence of post-surgical bleeding or of antihemorrhagic prohemostatic interventions. Two thromboembolic events were registered, both occurring after high venous thromboembolism-risk procedures in patients who did not receive thromboprophylaxis (4.7%). Our findings suggest that venous thromboembolism incidence is low in patients with inherited platelet disorders undergoing surgery at venous thromboembolism-risk and that it is predicted by the Caprini score. Mechanical thromboprophylaxis may be of benefit in patients with inherited platelet disorders undergoing invasive procedures at venous thromboembolism-risk and low-molecular-weight-heparin should be considered for major surgery. Fil: Paciullo, Francesco. Università di Perugia; Italia Fil: Bury, Loredana. Università di Perugia; Italia Fil: Noris, Patrizia. Universita Degli Studi Di Pavia; Italia Fil: Falcinelli, Emanuela. Università di Perugia; Italia Fil: Melazzini, Federica. Universita Degli Studi Di Pavia.; Italia Fil: Orsini, Sara. Università di Perugia; Italia Fil: Zaninetti, Carlo. Universita Degli Studi Di Pavia.; Italia Fil: Abdul Kadir, Rezan. Haemophilia Centre And Haemostasis Unit, Royal Free Fou; Reino Unido Fil: Obeng Tuudah, Deborah. Haemophilia Centre And Haemostasis Unit, Royal Free Fou; Reino Unido Fil: Heller, Paula Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentina Fil: Glembotsky, Ana Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentina Fil: Fabris, Fabrizio. Università di Padova; Italia Fil: Rivera, Jose. Universidad de Murcia; España Fil: Lozano, Maria Luisa. Universidad de Murcia; España Fil: Butta, Nora. Hospital Universitario la Paz; España Fil: Favier, Remi. French Reference Centre For Inherited Platelet Disorder; Francia Fil: Cid, Ana Rosa. Hospital Universitario y Politecnico la Fe; España Fil: Fouassier, Marc. French Reference Centre For Inherited Platelet Disorder; Francia Fil: Podda, Gian Marco. Università degli Studi di Milano; Italia Fil: Santoro, Cristina. Università degli studi di Roma "La Sapienza"; Italia Fil: Grandone, Elvira. Casa Sollievo Della Sofferenza,s.giovanni Rotondo; Italia Fil: Henskens, Yvonne. Maastricht University Medical Centre; Países Bajos Fil: Nurden, Paquita. French Reference Centre For Inherited Platelet Disorder; Francia Fil: Zieger, Barbara. Albert Ludwigs University of Freiburg; Alemania Fil: Cuker, Adam. University of Pennsylvania; Estados Unidos Fil: Devreese, Katrien. University of Ghent; Bélgica Fil: Tosetto, Alberto. Hospital San Bortolo; Italia Fil: De Candia, Erica. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; Italia Fil: Dupuis, Arnaud. French Reference Centre For Inherited Platelet Disorder; Francia Fil: Miyazaki, Koji. Kitasato University School Of Medicine; Japón Fil: Othman, Maha. Queens University; Canadá Fil: Gresele, Paolo. Università di Perugia; Italia

La malattia MYH9-correlata è una rara sindrome genetica caratterizzata da piastrinopenia congenita associata al rischio di sviluppare, durante l’infanzia o l’età adulta, ipoacusia neurosensoriale, nefropatia e cataratta presenile ad andamento evolutivo. Furono inclusi in uno studio retrospettivo tutti i casi con sordità da severa a profonda arruolati consecutivamente nel Registro Italiano dei pazienti affetti da malattia MYH9-correlata. La popolazione esaminata coinvolse 147 pazienti Italiani con malattia MYH9-correlata: l’ipoacusia fu identificata nel 52% dei casi e solo 4 pazienti (6%) presentarono un quadro di sordità da severa a profonda all’età media di 33 anni. In tutti i 4 pazienti, la sordità fu associata ad un lieve sanguinamento spontaneo e in 3 pazienti fu accompagnata da un coinvolgimento renale. L’impianto cocleare fu eseguito in 3 casi, con beneficio, in assenza di complicanze maggiori. La diagnosi di malattia MYH9-correlata fu eseguita circa 28 anni dopo la prima manifestazione clinica della malattia che non fu mai sospettata da un otorinolaringoiatra. Saranno discussi gli aspetti clinici e diagnostici di 4 pazienti con sordità da severa a profonda affetti da malattia MYH)-correlata, focalizzando anche le implicazioni terapeutiche.

Patients with inherited thrombocytopenias often require platelet transfusions to raise their platelet count before surgery or other invasive procedures; moreover, subjects with clinically significant spontaneous bleeding may benefit from an enduring improvement of thrombocytopenia. The hypothesis that thrombopoietin-mimetics can increase platelet count in inherited thrombocytopenias is appealing, but evidence is scarce. We conducted a prospective, phase II clinical trial to investigate the efficacy of the oral thrombopoietin-mimetic eltrombopag in different forms of inherited thrombocytopenia. We enrolled 24 patients affected by MYH9-related disease, ANKRD26-related thrombocytopenia, X-linked thrombocytopenia/ Wiskott-Aldrich syndrome, monoallelic Bernard-Soulier syndrome, or ITGB3-related thrombocytopenia. The average pre-treatment platelet count was 40.4 ×109/L. Patients received a 3- to 6-week course of eltrombopag in a dose-escalated manner. Of 23 patients evaluable for response, 11 (47.8%) achieved a major response (platelet count >100 ×109/L), ten (43.5%) had a minor response (platelet count at least twice the baseline value), and two patients (8.7%) did not respond. The average increase of platelet count compared to baseline was 64.5 ×109/L (P

MYH9-assoziierte Erkrankung (MYH9-RD) ist eine autosomal-dominante Thrombozytopenie, die durch Mutationen im Gen für die Nicht-Muskel-Myosin schwere Kette IIA (NMMHC-IIA) verursacht wird. Die Patienten weisen eine kongenitale Makrothrombozytopenie und Einschlüsse von NMMHC-IIA in Leukozyten auf und haben ein variables Risiko, Nierenschäden, sensorineurale Taubheit, präsenile Katarakte und / oder Leberenzyme zu entwickeln. Das Spektrum der bei MYH9-RD-Patienten gefundenen Mutationen ist begrenzt und die Inzidenz und der Schweregrad der nicht-kongenitalen Merkmale werden durch die verursachende MYH9-Variante prognostiziert. Insbesondere assoziieren verschiedene Veränderungen der C-terminalen Schwanzdomäne von NMMHC-IIA mit einer bemerkenswert unterschiedlichen Krankheitsentwicklung. Wir berichten über vier neue MYH9-Mutationen, die die Schwanzdomäne von NMMHC-IIA betreffen und in vier Familien für MYH9-RD verantwortlich sind. Zwei Varianten verursachen Aminosäuresubstitutionen in der Coiled-Coil-Region von NMMHC-IIA, während die anderen beiden eine Splicing-Variante und eine Einzelnucleotid-Deletion sind, die beide zu Frameshift-Veränderungen des kurzen nicht-helikalen Schwanzstückes führen. Die Charakterisierung der Phänotypen betroffener Individuen zeigt, dass alle diese neuen Varianten mit einer milden klinischen Entwicklung der Erkrankung einhergehen.

Syncope is defined as a transient loss of consciousness (T-LOC) due to temporary global cerebral hypoperfusion. It is characterized by rapid onset, short duration, loss of postural tone possibly causing patient fall, and spontaneous full recovery. Syncope has a high prevalence and incidence within the general population with a relevant impact on both quality of life and health care costs. The diagnosis of syncope is often inaccurate and subject to delay, and management is greatly variable. The main objective of this monograph is to discuss a methodological diagnostic approach to signs and symptoms suggestive of syncope, aiming for a management optimization. The present work is based on a systematic review of recent international guidelines.

Background Several studies have documented a linear growth of the prevalence of anemia with aging. Especially in hospitalized elderly patients, anemia can aggravate the course of chronic disorders, and ultimately get worse the clinical outcomes. Methods To evaluate the distribution, the main causes, and the possible correlations of anemia with comorbidities and length of hospitalization in a population of internal medicine inpatients, we carried out an observational study on a cohort of 923 consecutive admissions relative to 856 subjects. Results Anemia was observed in 58.4% of patients, with an increase of the prevalence with increasing age regardless gender difference. In more than one-half of anemic patients, anemia was mild. Chronic inflammation and chronic renal failure were the most frequent causes of anemia in our population, and in > 35% of patients a multifactorial anemia was diagnosed. Age, chronic renal failure, chronic liver disease, hematological malignancies, solid tumors, and antiplatelet therapy showed a significantly independent association with the presence of anemia. Hemoglobin levels were influenced by the presence of chronic lung disease, chronic renal failure, hematological malignancies, solid tumors, and antiplatelet therapy. The presence and the degree of anemia also correlated with a significantly longer hospital stay. Conclusions Our data confirm the high prevalence of anemia in patients hospitalized in an Internal Medicine Department, with a remarkable burden of mild forms, and of chronic inflammation's pathogenic mechanism. Correlations with comorbidities and duration of hospital stay highlight the crucial part played by anemia in determining the clinical complexity of such patients.

Essentials Extramedullary hematopoiesis (EMH) represents a pathologic finding in adult life. We report a mass-like EMH in the presacral space in a patient with ANKRD26-related thrombocytopenia. We found possible correlation between EMH and conditions causing lifelong thrombocytopenia. EMH can cause masses of unknown origin in patients with inherited thrombocytopenias. Summary Most commonly located in the liver and spleen, extramedullary hematopoiesis (EMH) is the presence of hematopoietic tissue outside the bone marrow. MYH9-related thrombocytopenia (MYH9-RD) and ANKRD26-related thrombocytopenia (ANKRD26-RT) are two of the most frequent forms of inherited thrombocytopenia (IT). Until recently, EMH has been associated with neoplastic and non-neoplastic hematologic conditions in which ITs were not included. We describe a case of mass-like EMH in the presacral space in a patient affected with ANKRD26-RT, comparing it with another case of paravertebral EMH we recently described in a subject with MYH9-RD. The surprisingly similitude of such a finding in the context of a group of rare disorders induces us to speculate about the possible pathogenic relationship between EMH and conditions causing lifelong thrombocytopenia, particularly the entity of ITs. Finally, we suggest that EMH has to be taken into consideration in the diagnostic work-up of masses of unknown origin in subjects affected with ITs.

Essentials Thrombocytopenia 2 (THC2) is an inherited thrombocytopenia (IT) with dysmegakaryopoiesis. Physicians often do not suspect the genetic origin of thrombocytopenia in patients with THC2. We report two THC2 patients misdiagnosed with myelodysplasia and treated with chemotherapy. IT should be always considered in patients with isolated thrombocytopenia and dysmegakaryopoiesis. Summary Thrombocytopenia 2 (THC2) is an autosomal-dominant disorder caused by point substitutions in the 5′UTR of the ANKRD26 gene. Patients have congenital thrombocytopenia, normal platelet morphology and function, and dysmegakaryopoiesis. Thrombocytopenia is frequently discovered only in adulthood and physicians often do not suspect its genetic origin. We describe two unrelated patients referred to two different institutions for investigation of thrombocytopenia. Based on the finding of dysmegakaryopoiesis at bone marrow examination, patients were diagnosed with myelodysplastic syndrome (MDS) (refractory thrombocytopenia) and treated with several courses of 5-azacytidine. Subsequently, demonstration of thrombocytopenia in their relatives eventually led to molecular diagnosis of THC2 in both families. These cases highlight that patients with THC2 are at risk of being misdiagnosed with MDS and receiving undue myelosuppressive treatments. Because dysmegakaryopoiesis is a feature also of other forms of inherited thrombocytopenia, a genetic disorder must always be considered when a patient presents with isolated thrombocytopenia and dysmegakaryopoiesis.

Bleeding diathesis has been considered for a long time the main clinical issue impacting the lives of patients affected by inherited thrombocytopaenias. However, the number of known inherited thrombocytopaenias greatly increased in recent years, and careful evaluation of hundreds of patients affected by these 'new' disorders revealed that most of them are at risk of developing additional life-threatening disorders during childhood or adult life. These additional disorders are usually more serious and dangerous than low platelet count. For instance, it is known that mutations in RUNX1, ANKRD26 and ETV6 cause congenital thrombocytopaenia, but we now know that they also predispose to haematological malignancies. Similarly, MYH9 mutations result in congenital thrombocytopaenia and increase the risk of developing kidney failure, cataracts and hearing loss at a later stage, while MPL mutations cause a congenital thrombocytopaenia that almost always evolves into deadly bone marrow failure. Thus, identification of patients with these disorders is essential for evaluation of their prognosis, enabling effective genetic counselling, personalizing follow-up and giving appropriate treatments in case of development of additional diseases. Careful clinical evaluation and peripheral blood film examination are extremely useful tools in guiding the diagnostic process and identifying the candidate genes to be sequenced.

The reference range for any blood test is defined as the set of values which 95% of the normal population falls within. When the value of a parameter varies according to specific physiological characteristics of investigated individuals, a single reference range is not sufficient, and personalized

Inherited thrombocytopenias (ITs) are a group of disorders characterized by different degrees of complexity and severity, which, in turn, result from a wide genetic heterogeneity. To date, at least 25 genes responsible for ITs have been identified. Moreover, known genetic defects account for only 50% of patients, indicating that not all the existing forms have yet been recognized. The development of next generation sequencing is favoring the discovery of novel genes causative for IT, and characterization of these “new” forms is important for improving patients’ management as well as for gaining novel information on mechanisms of platelet production. Recently, Fletcher and colleagues identified by exome analysis monoallelic mutations in the SLFN14 gene as a novel cause of IT. SLFN14-related thrombocytopenia (SLFN14-RT) was described in three pedigrees as a non-syndromic thrombocytopenia associated with excessive bleeding phenotype and defective platelet ATP secretion. The reported families carried three different mutations predicted to result in substitutions hitting consecutive residues (Lys218, Lys219, and Val220) within the ATPase-AAA-4 domain of the SLFN14 protein. The function of SLFN family of proteins is poorly known: they have been associated with regulation of cell proliferation and differentiation, and recently SLFN14 has been shown to have endoribonuclease activity in rabbit reticulocytes. However, the role of SLFN14 in platelet biogenesis or survival is completely unknown. Here we report a fourth family with IT caused by a novel SLFN14 mutation.