Missense mutation in RPS7 causes Diamond-Blackfan anemia via alteration of erythrocyte metabolism, protein translation and induction of ribosomal stress.

Diamond-Blackfan anemia (DBA) is predominantly underlined by mutations in genes encoding ribosomal proteins (RP); however, its etiology remains unexplained in approximately 25 % of patients. We previously reported a novel heterozygous RPS7 mutation hg38 chr2:g.3,580,153G > T p.V134F in one female patient and two asymptomatic family members, in whom mild anemia and increased erythrocyte adenosine deaminase (eADA) activity were detected. We observed that altered erythrocyte metabolism and oxidative stress which may negatively affect the lifespan of erythrocytes distinguishes the patient from her asymptomatic family members. Pathogenicity of the RPS7 p.V134F mutation was extensively validated including molecular defects in protein translational activity and ribosomal stress activation in the cellular model of this variant.

Acute portal vein thrombosis in noncirrhotic patients - different prognoses based on presence of inflammatory markers: a long-term multicenter retrospective analysis.

Background: Portal vein thrombosis (PVT) is a partial or complete thrombotic occlusion of the portal vein and is rare in noncirrhotic patients.Patients and methods: 78 adult patients with noncirrhotic acute PVT without known malignity were evaluated. Patients with initial CRP level 61-149 mg/l were excluded.Results: Patients were divided into two groups - the first one (33 patients) was characterized with signs of inflammation and CRP over 149 mg/l. The second group (45 patients) was without signs of inflammation and CRP level less than 61 mg/l. The frequency of prothrombotic hematologic factors was statistically significantly different in levels of factor VIII and MTHFR 677 C mutation. All patients from both groups underwent the same oncologic and hemato-oncologic screening which was positive in 23 patients (51.1%) in the group without signs of inflammation. In the group of patients with clinical and laboratory signs of inflammation oncologic and hemato-oncologic screening was positive only in 1 patient (3.0%). Complete portal vein recanalization was achieved in 19.2%, partial recanalization in 26.9%.Conclusions: Patients with clinical signs of inflammation and acute PVT have a low risk of malignancy in contrast to patients without signs of inflammation and acute PVT, which have a high risk of oncologic or hemato-oncologic disease. Patients with negative hemato-oncologic screening should be carefully observed over time because we expect they are at higher risk for the development of hemato-oncologic disease, independent from the presence and number of procoagulation risk factors.

Impact of CYP2C19 Polymorphisms on Clinical Outcomes and Antiplatelet Potency of Clopidogrel in Caucasian Poststroke Survivors.

BACKGROUND: Variable response after clopidogrel is well documented and may affect major adverse clinical events after stroke. Impact of CYP2C19 genetic polymorphisms is an established marker linked to variable response after clopidogrel. However, the association of certain genetic polymorphisms with prediction of major adverse clinical events following stroke still remains controversial, especially in Caucasians. STUDY QUESTION: The primary aim was to evaluate the impact of CYP2C19 allele *2 in heterozygote form on major adverse clinical events in Caucasian poststroke survivors treated with clopidogrel. The secondary aim was to analyze the potential link between CYP2C19 genetic polymorphism and variable response after clopidogrel. STUDY DESIGN: One hundred thirty patients of Caucasian origin following documented ischemic stroke were included. Platelet reactivity was assessed by light transmittance aggregometry (LTA) and matched with various CYP2C19 loss-of-function genetic polymorphisms and major adverse clinical events (composite of vascular deaths, stroke/transient ischemic attack, and myocardial infarction). RESULTS: Over the mean follow-up of 14.9 months, 19 patients experienced major adverse clinical events. The risk of major adverse clinical events was nearly 3-fold in loss-of-function allele carriers (hazard ratio = 2.904; 95% confidence interval, 1.083-7.786; P = 0.013), whereas the risk of ischemic stroke or transient ischemic attack alone was also higher (hazard ratio = 3.170; 95% confidence interval, 1.281-7.849; P = 0.034). Platelet activity was strongly associated with allele *2 status (rs = 0.21, P = 0.016) but not with other genetic polymorphisms. Carriers of allele*2 exhibited lower platelet response to adenosine diphosphate-mean LTA (30.1% vs. 42.0%; P = 0.017). There were no significant differences in LTA results with other agonists. Strong association of increase in adenosine diphosphate-induced aggregation with diabetes mellitus (rs = 0.20, P = 0.023), increasing age (rs = 0.23, P = 0.008), and conversely diminishing over increased weight (rs = 0.23, P = 0.009) was also detected. The carriers of other gene allele variants lack uniformed impact on variable response after clopidogrel. CONCLUSIONS: Even heterozygous CYP2C19*2 allele carriers among Caucasian patients after ischemic stroke had a higher risk of major adverse clinical events. The LTA, however, did not predict major adverse clinical events. The exact clinical utility of these findings is still uncertain and requires large outcome-driven randomized trial in Caucasians for proof of concept.

Endogenous Heparinoids May Cause Bleeding in Mucor Infection and can be Detected by Nonactivated Thromboelastometry and Treated by Recombinant Activated Factor VII: A Case Report.

Mucormycosis is an aggressive fungal infection, which invades endothelial cells of blood vessels. This condition might lead to destruction of endothelium and release of heparin-like substances to the bloodstream and cause life-threatening bleeding, which is not well described in the literature.We present a patient with mucormycosis who experienced life-threatening bleeding, although no standard laboratory test could detect any coagulopathy.The cause of bleeding-coagulopathy was detected only by nonactivated thromboelastometry (NATEM), which revealed the presence of heparin-like substances. After treatment with recombinant activated FVII rotational thromboelastometry, results improved and the patient stopped bleeding. Regular application of the drug was necessary during acute phase of infection to prevent further bleeding.In this case report, we show that NATEM can detect the presence of heparin-like substances in bleeding patient with mucormycosis infection and that recombinant activated FVII can be used to stop and prevent bleeding until infection resolves.

Does asymptomatic carriage of FV Leiden and FII prothrombin mutations in heterozygous configuration pose an increased risk of thrombembolic complications in the course of pregnancy, labor and puerperium?

OBJECTIVE: To evaluate the course of pregnancy and puerperium in asymptomatic carriers of FV Leiden and FII prothrombin mutation in heterozygous configuration in terms of risk of thrombembolic disease (TED) and late pregnancy complications. To evaluate whether global prophylactic LMWH administration during pregnancy benefits these women. METHODS: We monitored the incidence of thrombembolic events and severe late pregnancy complications in 473 asymptomatic carriers of FV Leiden and FII prothrombin mutation in heterozygous configuration. In 253 women, preventive LMWH application was introduced already during pregnancy. In 220 women, the application of LMWH was commenced as late as on the delivery day. In both groups application of LMWH continued during the puerperium. RESULTS: The incidence of TED in the whole group of carriers of thrombophylic mutations accounted for 0.19%. The incidence of severe late pregnancy complications was low - 2.5% compared with general population of pregnant women (6.4%). CONCLUSIONS: No direct causal relationship was established between asymptomatic carriage of Leiden and prothrombin mutation in heterozygous configuration and the occurrence of severe late pregnancy complications. There was no benefit from general LMWH prophylaxis started as early as pregnancy in these women and thus we consider it unnecessary.

Arteriovenous differences of hematological and coagulation parameters in patients with sepsis.

In critically ill patients, either arterial or venous blood is usually available for sampling and measurement of basic coagulation parameters. The aim of this study was to examine whether in these patients the values of coagulation parameters differ significantly with respect to the source of the blood samples. In a group of 44 patients with severe sepsis, we compared the values of coagulation, thromboelastography and selected hematological parameters between the arterial and venous blood. In most of the investigated parameters (international normalized ratio, activated partial thromboplastin time, fibrinogen concentration, erythrocyte count, leukocyte and platelet count, hemoglobin level and thromboelastography parameters), we did not find significant differences (P > 0.1). However, we found a significantly lower antithrombin activity and a significantly higher D-dimer concentration in venous blood compared to arterial blood (P < 0.05). This could be associated with increased consumption of antithrombin and generation of D-dimer as a consequence of microthrombi formation in the capillaries. We therefore conclude that for the purpose of assessment of coagulation status in septic patients, arterial and venous blood cannot be treated as equivalent.