Elias Kyriakou

Prognostic value of serum free light chain ratio at diagnosis in multiple myeloma

The prognostic value of baseline serum free light chain ratio (sFLCR) was investigated in 94 multiple myeloma (MM) patients. sFLCR was calculated as κ/λ or λ/κ, depending on the patients’ dominating monoclonal light chain. Median baseline sFLCR was 3·57 in κ‐MM patients, 45·09 in λ‐MM. ‘High’ sFLCR (≥ the observed median value for κ‐ and λ‐MM respectively) correlated with elevated serum creatinine and lactate dehydrogenase, extensive marrow infiltration and light chain type MM. The 5‐year disease‐specific survival was 82% and 30% in patients with sFLCR lower than and equal or greater than the median, respectively (P = 0·0001). sFLCR was an independent prognostic factor.

Fondaparinux for the Treatment of Acute Heparin-Induced Thrombocytopenia: A Single-Center Experience:

Heparin-induced thrombocytopenia (HIT) is a life-threatening immune response to heparin that is associated with a high risk of thromboembolic complications. The syndrome is caused by antibodies that are reactive against complexes of platelet factor 4/heparin (PF4/H). For patients with HIT, the discontinuation of heparin alone is not sufficient and the diagnosis necessitates the administration of an alternative anticoagulant. Fondaparinux is a synthetic pentasaccharide that binds to antithrombin and potentiates inhibition of factor Xa. Data have shown that fondaparinux is structurally too short to induce an antibody response and could be a useful agent to treat HIT. In our hospital, we retrospectively analyzed the use of fondaparinux in the treatment of 24 patients with acute HIT during unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) administration and compared the results to a similar population of 20 patients who were treated with lepirudin. The treated patients had a complete platelet count recovery, and none experienced a new thromboembolic complication or major bleeding. The development of limb gangrene (2 patients who received lepirudin and 1 who received fondaparinux) likely resulted from a delay in diagnosis and treatment initiation. Our data suggest that fondaparinux may be considered a safe and an effective alternative treatment in HIT complicated with or without thrombosis.

Serial determination of FLT3 mutations in myelodysplastic syndrome patients at diagnosis, follow up or acute myeloid leukaemia transformation: incidence and their prognostic significance

The incidence of FLT3 mutations (internal tandem duplication and Asp835) was investigated in bone marrow samples from 97 patients with myelodysplastic syndrome [(MDS); excluding cases with refractory anaemia with excess blasts in transformation] at the time of diagnosis and several time points thereafter. Three patients had FLT3 mutations at presentation. Forty‐two patients progressed to acute myeloid leukaemia (AML), including the three patients with FLT3 mutations at MDS diagnosis. Three additional patients acquired FLT3 mutations and progressed to AML in 1  month. FLT3 mutations seem to be a critical additional genetic event that transforms a minority of MDS patients to AML.

Impact of the proton pump inhibitors and CYP2C19*2 polymorphism on platelet response to clopidogrel as assessed by four platelet function assays

BACKGROUND Previous studies suggested a possible negative interference of proton pump inhibitors (PPIs) on clopidogrels antiplatelet effect because of the competitive inhibition of the CYP 2C19 isoenzyme. Moreover, carriers of the loss-of-function allele of CYP2C19 polymorphism (CYP2C19*2) display significantly lower responses to clopidogrel. In this study, we investigated the association between CYP2C19*2 genotype, PPI intake and clopidogrel resistance in patients with coronary artery disease (CAD) and their effect on clinical outcome. METHODS We recruited 95 patients with CAD receiving chronic clopidogrel therapy in combination with aspirin. Platelet reactivity was simultaneously assessed by INNOVANCE PFA-100 P2Y, ADP-induced light transmission aggregometry (LTA), flow-cytometric vasodilator-stimulated phosphoprotein (VASP)-phosphorylation assay and multiple electrode aggregometry (Multiplate). Cardiovascular outcomes were recorded during 1-year follow-up period. RESULTS Only platelet reactivity assessed by measuring platelet phosphorylated-VASP demonstrated a significant higher platelet reactivity in carriers of CYP2C19*2 (p=0.023). The other methods displayed higher - but not statistically significant - platelet reactivity in patients carrying the CYP2C19*2 variant as compared with non-carriers. Patients on PPIs demonstrated almost similar suppression of platelet reactivity in comparison with those not treated with PPIs by all platelet function assays. In logistic regression analysis none of the platelet function assays measurements were related with clinical outcomes. Similarly neither CYP2C19*2 genetic variant nor PPI treatment were associated with adverse clinical events. CONCLUSIONS PPI co-administration did not influence clopidogrels antiplatelet effect on laboratory testing by all platelet function assays used. On the contrary, patients carrying CYP2C19*2 genotype had significantly higher residual platelet reactivity as estimated by VASP-phosphorylation assay.

Laboratory Assessment of the Anticoagulant Activity of Dabigatran

Background: Our aim was to identify laboratory assays in order to assess the anticoagulant effects of dabigatran etexilate (DE). Methods: Twenty patients with nonvalvular atrial fibrillation treated on DE (110 mg per os twice daily) and 20 on acenocoumarol were studied. Conventional coagulation tests, endogenous thrombin potential (ETP), thromboelastometry (ROTEM), epinephrine-induced light transmission aggregometry (LTA), and Hemoclot Thrombin Inhibitors (HTI) were performed in all patients. Results: In ROTEM analysis, the lysis index at 60 minutes was significantly lower in patients receiving DE (P = .011). In LTA, patients on DE showed decreased aggregation compared to those on acenocoumarol, marginally insignificant (P = .068). Regarding ETP, acenocoumarol affected thrombin generation more than dabigatran (area under the curve [AUC], P < .001), while statistically significant associations were detected between dabigatran levels, as determined by the HTI assay, and almost all parameters of ETP assay (AUC, P < .001). Conclusion: The role of ETP in estimating anticoagulant activity of dabigatran possibly requires further research.

Impact of dabigatran on platelet function and fibrinolysis

BACKGROUND We sought to evaluate the potential enhanced fibrinolytic and antiplatelet activity of dabigatran etexilate (DE) due to decreased thrombin levels in patients with stroke or transient ischemic attack and non-valvular atrial fibrillation (NVAF). METHODS Consecutive patients with cerebrovascular diseases and NVAF that were treated with DE in a tertiary university hospital. Fibrinolysis and platelet function were assessed by thromboelastometry (ROTEM) and platelet function analyzer (PFA)-100, respectively, before and after treatment with DE. Conventional coagulation tests, endogenous thrombin potential (ETP) and hemoclot thrombin inhibitors (HTI), were also performed in order to detect any possible correlation between dabigatran plasma levels, its anticoagulant activity and the intensity of platelet dysfunction or fibrinolysis. RESULTS A total of nineteen patients fulfilled our inclusion criteria (mean age 62.3±7.2years; 47% males; median CHADS2-score: 3; interquartile range: 2-4). DE treatment was associated with a significant reduction of the lysis index (LI60) at 60min (p=0.036), and prolongation of the PFA-100 CEPI closure time (p=0.024). After dabigatran treatment, abnormal PFA-100 results were obtained in two patients (11%, 95% CI: 2%-33%). DE levels (determined by HTI) were strongly inversely correlated (rho=-0.85; p<0.001) with the area under the curve (AUC) values in ETP assay. Νo association was found between HTI and PFA-100 CEPI CT (p=0.64), or LI60 measurements (p=0.60). CONCLUSIONS Our findings indicate that DE might affect platelet function and fibrinolysis and highlight the potential role of ETP as an alternative option in DE monitoring. The intensity and clinical relevance of DE antiplatelet and fibrinolytic effects require further investigation.

Cost-effectiveness of leucoreduction for prevention of febrile non-haemolytic transfusion reactions

BACKGROUND The cost-effectiveness of universal leucoreduction of blood components remains unclear. When using leucoreduced red blood cells, the decrease in the rate of febrile non-haemolytic transfusion reactions (FNHTR) is the only proven, meaningful clinical benefit, whose relationship to costs can be calculated relatively easily. The aim of this study was to evaluate the cost-effectiveness of leucoreduction in avoiding FNHTR. MATERIALS AND METHODS Data were obtained from two large tertiary hospitals in Athens, Greece, over a 4-year period (2009-2012). The incidence of FNHTR in patients transfused with leucoreduced or non-leucodepleted red blood cells, the additional cost of leucoreduction and the cost to treat the FNHTR were estimated. The incremental cost-effectiveness ratio (ICER), which is the ratio of the change in costs to the incremental benefits of leucoreduction, was calculated. RESULTS In total, 86,032 red blood cell units were transfused. Of these, 53,409 were leucodepleted and 32,623 were non-leucoreduced. Among patients transfused with leucodepleted units, 25 cases (0.047%) met the criteria for having a FNHTR, while in patients treated with non-leucoreduced components, 134 FNHTR were observed (0.411%). The ICER of leucoreduction was € 6,916 (i.e., the cost to prevent one case of FNHTR). CONCLUSIONS Leucoreduction does not have a favourable cost-effectiveness ratio in relation to the occurrence of FNHTR. However, many factors, which could not be easily and accurately assessed, influence the long-term costs of transfusion. It is imperative to undertake a series of large, meticulously designed clinical studies across the entire spectrum of blood transfusion settings, to investigate most of the parameters involved.

Quantitative and qualitative analysis of regulatory T cells in B cell chronic lymphocytic leukemia

Accumulated data indicate a significant role of T cell dysfunction in the pathogenesis of chronic lymphocytic leukemia. In CLL, regulatory T cells are significantly higher and show lower apoptotic levels compared to healthy donors. We demonstrate that CLL derived CD4+CD25-CD127- and CD4+CD25lowCD127- subpopulations share a common immunophenotypic profile with conventional Tregs and are associated with advanced stage disease. We further provide evidence that the increased number of Tregs contributes indirectly to the proliferation of the CLL clone, by suppressing the proliferation of Teffs which in turn suppress CLL cells. These data are further supported by our observations that CLL derived Tregs appear rather incapable of inducing apoptosis of both normal B cells and CLL cells, in contrast to normal Tregs, suggesting an immunoediting effect of CLL cells on Tregs which negatively affects the functionality of the latter and contributes to the failure of Tregs in CLL to efficiently eliminate the abnormal clone.

Red Blood Cell Transfusions in Greece: Results of a Survey of Red Blood Cell Use in 2013

Objective: Greece is ranked as the second highest consumer of blood components in Europe. For an effective transfusion system and in order to reduce variability of transfusion practice by implementing evidence-based transfusion guidelines it is necessary to study and monitor blood management strategies. Our study was conducted in order to evaluate the use of red blood cell units (RBC-U) in nationwide scale mapping parameters that contribute to their proper management in Greece. Materials and Methods: The survey was conducted by the Working Committee of Transfusion Medicine&Apheresis of the Hellenic Society of Hematology from January to December 2013. The collected data included the number, ABO/D blood group, patients’ department, and storage age of RBC-U transfused. Results: The number of RBC-U evaluated was 103,702 (17.77%) out of 583,457 RBC-U transfused in Greece in 2013. RBC-U transfused by hospital department (mean percentage) was as follows: Surgery 29.34%, Internal Medicine 29.48%, Oncology/Hematology 14.65%, Thalassemia 8.87%, Intensive Care Unit 6.55%, Nephrology 1.78%, Obstetrics/Gynecology 1.46%, Neonatal&Pediatric 0.31%, Private Hospitals 8.57%. RBC-U distribution according to ABO/D blood group was: A: 39.02%, B: 12.41%, AB: 5.16%, O: 43.41%, D+: 87.99%, D-: 12.01%. The majority of RBC-U (62.46%) was transfused in the first 15 days of storage, 25.24% at 16 to 28 days, and 12.28% at 29-42 days. Conclusion: Despite a high intercenter variability in RBC transfusions, surgical and internal medicine patients were the most common groups of patients transfused with an increasing rate for internal medicine patients. The majority of RBC-U were transfused within the first 15 days of storage, which is possibly the consequence of blood supply insufficiency leading to the direct use of fresh blood. Benchmarking transfusion activity may help to decrease the inappropriate use of blood products, reduce the cost of care, and optimize the use of the voluntary donor’s gift.

Cerebral Venous Thrombosis due to Heparin-Induced Thrombocytopenia in a 17- Year Old Female Trauma Patient: Successful Treatment with Fondaparinux

Thrombosis of cerebral veins and sinuses (CVST) is a rare condition seldom affecting young adults and children. The development of cerebral sinus thrombosis as a complication of heparin-induced thrombocytopenia/thrombosis syndrome (HIT/HITT) is even rarer. We describe a case of a 17-year old female with multiple fractures, who developed CVST secondary to HIT, while being under thromboprophylaxis with low molecular weight heparin (LMWH). The patient was successfully treated afterwards with 7.5 mg fondaparinux once daily subcutaneously. Our patient’s outcome was excellent, without recurrent thrombotic or bleeding events throughout her therapy. Fondaparinux is a synthetic pentasaccharide selectively inhibiting activated factor X. Published data have shown that due to its short structure, the drug almost never causes clinical HIT/HITT, therefore it could be a useful alternative anticoagulant agent for treating HIT/HITT patients.