Olga Meltem Akay
Eskişehir Osmangazi University
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Publication
Featured researches published by Olga Meltem Akay.
Platelets | 2013
Hava Üsküdar Teke; Eren Gündüz; Olga Meltem Akay; Zafer Gulbas
Primer immunologic defect in patients with idiopathic thrombocytopaenic purpura (ITP) result from autoreactive B-lymphocytes secreting antiplatelet antibodies. Dysfunctional cellular immunity has also great importance in ITP pathogenesis. CD4+CD25+ regulatory T-cells have immunoregulatory features and it is able to inhibit CD4+CD25− and CD8+ responses. ITP is also an autoimmune disease; the CD4+CD25+ T-cell levels of the patients decrease during the active state. According to our findings, immunosuppressive treatments increase the CD4+CD25+ Treg cell levels in the non-remission ITP patients. However, this level is not enough to overcome the resistance. CD4+CD25−Foxp3+ and CD4+Foxp3+ Treg cells are responsible for the pathogenesis of the non-remission ITP patients and other factors exist, which are responsible for the resistance of ITP treatment.
Platelets | 2011
Eren Gündüz; Olga Meltem Akay; Cengiz Bal; Zafer Gulbas
Thrombelastography (TEG) analyses the status of blood coagulation including abnormalities associated with low platelet count. The aim of this study was to investigate the changes in TEG parameters in idiopathic thrombocytopenic purpura (ITP) patients. Thirty nine patients with ITP (platelet count < 100 × 103 µl−1) were included in the study. Age-matched 17 patients with thrombocytopenia due to chemotherapy were selected as a control group. Platelet count was positively correlated with maximum clot formation (MCF) in INTEM (r = 0.716, p < 0.001) and MCF in EXTEM (r = 0.679, p < 0.001); negatively correlated with clot formation time (CFT) in INTEM (r = −0.755, p < 0.001) and CFT in EXTEM (r = −0.585, p < 0.001) in ITP patients. Platelet count was positively correlated with MCF in INTEM (r = 0.776, p < 0.001) and MCF in EXTEM (r = 0.878, p < 0.001); negatively correlated with CFT in INTEM (r = −0.627, p < 0.001) in control group. Receiver operating characteristic curves to describe the critical platelet count and fibrinogen level that affect MCF revealed 31 × 103 µl−1 and 375 mg dl−1 as cut-off values, respectively. In conclusion, ROTEM determines the contribution of fibrinogen and platelets to clot strength in patients with ITP. MCF appears to be the most important TEG parameter in predicting bleeding in ITP patients that makes TEG superior to other hemostatic tests.
Renal Failure | 2009
Garip Sahin; Olga Meltem Akay; Esin Kuş; Cengiz Bal; Ahmet Ugur Yalcin; Zafer Gulbas
Background/aim. Post-transplant cardiovascular events are associated with increased morbidity and mortality after renal transplantation. Though renal transplantation eliminates cardiovascular disease risk factors by restoring renal function, it introduces new cardiovascular risks derived partly from immunosuppressive medications. In this study, to assess the effects of various immunosuppressive drugs on platelet function of renal transplant patients, we measured soluble P selectin levels (sP-selectin) and performed platelet aggregation studies in patients who have undergone renal transplantation. Methods. sP-selectin levels and platelet aggregation induced by 5 μM adenosine diphosphate (ADP), 5 μM epinephrine, 1.25 mg/mL ristocetin, and 2 μg/mL collagen were studied by whole blood platelet lumi-aggregometer in 40 renal transplant patients. Patients in group 1 (n = 24) were treated with cyclosporine/mycophenolate mofetil/methylprednisolone, and group 2 (n = 16) were treated with tacrolimus/mycophenolate mofetil/methylprednisolone. Effects were compared with those in control groups of hypertensive subjects and healthy subjects. Results. Platelet aggregation values induced by ADP, epinephrine, ristocetin, and collagen were lower in cyclosporine-treated patients than tacrolimus-treated patients, hypertensive subjects, and healthy subjects, though the difference was not statistically significant (p > 0.05). sP-selectin levels were appreciably higher in cyclosporine-treated patients, and statistically significant differences were observed compared with those of tacrolimus-treated patients (p < 0.05), hypertensive subjects (p < 0.01), and healthy subjects (p < 0.05). Conclusion. We conclude that cyclosporine-treated renal transplant patients show enhanced platelet activation in which anti-platelet therapy should be considered, in addition to management of other conventional cardiovascular risk factors, to decrease the cardiovascular morbidity and mortality in this high risk population.
Cancer Genetics and Cytogenetics | 2014
Olga Meltem Akay; Beyhan Durak Aras; Serap Işıksoy; Cigdem Toprak; Fezan Mutlu; Sevilhan Artan; Ülkü Öner; Zafer Gulbas
The purpose of this study was to determine the frequency of BCL2, BCL6, IGH, TP53, and MYC protein expression and rearrangements of the respective genes in diffuse large B-cell lymphoma (DLBCL) patients and to assess their prognostic values. Samples from 44 patients with DLBCL were evaluated using fluorescence in situ hybridization and immunohistochemical analyses. BCL6 was the most rearranged gene (63.6%), followed by MYC (31.8%), TP53 (22.7%), and BCL2 (18.2%). Multiple rearrangements were detected in 40.9% of the cases. BCL6 was the most expressed protein (78.6%), followed by TP53 (69.04%), BCL2 (59.5%) and MYC (14.3%). Expression of multiple proteins was detected in 67.4% of the cases. BCL2 (P = .003) expression had a significant negative influence on overall survival,whereas BCL6 (P = .014) expression had a significant positive influence. Our results with a different pattern of gene rearrangements and associated protein overexpression indicate the molecular genetic complexity of DLBCLs, which reflects the morphologic, biologic, and clinical heterogeneity of these lymphomas.
Turkish journal of haematology : official journal of Turkish Society of Haematology | 2015
Hava Üsküdar Teke; Eren Gündüz; Olga Meltem Akay; Cengiz Bal; Zafer Gulbas
Objective: Pro-inflammatory and pro-angiogenic cytokines play an important role in the pathogenesis of lymphoma, and recent studies have shown that cytokines can be used as prognostic markers. Non-Hodgkin lymphoma (NHL) patients with high levels of serum interleukin-6 (s-IL6) and serum vascular endothelial growth factor (s-VEGF) have poor prognosis and shorter survival time. We aimed to determine pre-treatment levels of s-IL6 and s-VEGF and their relation with known prognostic markers, especially International Prognostic Index (IPI) scores, and to examine their effects on overall survival in newly diagnosed, untreated aggressive NHL patients. Materials and Methods: The study included 51 newly diagnosed NHL patients and 17 healthy controls. Blood samples were obtained to study s-IL6 and s-VEGF cytokine levels. Results: Patients with aggressive NHL diagnosis had higher s-VEGF and s-IL6 levels than the healthy population. If the s-IL6 levels of patients were above the cut-off levels, the overall survival time was shorter. There was no relation between s-VEGF and overall survival time. Conclusion: s-IL6 is an independent prognostic factor that may be included in IPI risk classification. In addition to the s-IL6 level, age, erythrocyte sedimentation rate, beta-2 microglobulin, WHO performance status, and IPI score are independent prognostic factors that are effective, especially for overall survival, in the clinical follow-up of NHL patients.
Mycoses | 2015
Müge Aslan; Yasemin Oz; Filiz Aksit; Olga Meltem Akay
The incidence of invasive aspergillosis (IA) has increased over the last years, especially in immuncompromised patients with high mortality rates. Because of difficulties about the diagnosis; serological methods [galactomannan (GM) antigen test] and polymerase chain reaction (PCR) developed in recent years. MycAssay Aspergillus PCR performance in the diagnosis of IA was evaluated and compared with the GM and in‐house PCR. This study was conducted with 358 serum samples obtained from 99 patient with febrile neutropenic episodes who were followed in haematology and bone marrow transplantation units. Patients were classified by the European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria, 18 of them is proven and probable IA. GM antigen test and two different real‐time PCR; one of them is fist commercial PCR for IA; Mycassay Aspergillus and the other one is in‐house real‐time PCR performed. Sensitivity values were Mycassay Aspergillus PCR, in‐house PCR, and GM 65.38%, 11.53% and 23.07%, respectively. The high sensitivity obtained from Mycassay Aspergillus PCR and sensitivity is increased by using a combination of diagnostic methods. GM antigen test and real‐time PCR could be beneficial for early diagnosis and treatment of IA. For routine usage of PCR as diagnostic assay more studies needed in future.
Renal Failure | 2014
Sultan Ozkurt; Mustafa Fuat Acikalin; Gokhan Temiz; Olga Meltem Akay; Mehmet Soydan
Abstract Hereditary hemochromatosis leads to the accumulation of iron in many organs including the liver, spleen and heart and results in injury and dysfunction of these organs. On the other hand, iron accumulation and functional impairment in kidney is extremely rare. We report a 61-year-old male patient with hereditary hemochromatosis, in whom the renal function was deteriorated rapidly. Renal biopsy revealed crescentic glomeruli and hemosiderin accumulation in tubular epithelial cells.
Transfusion and Apheresis Science | 2010
Eren Gündüz; Olga Meltem Akay; Hava Üsküdar Teke; Zafer Gulbas
Antigen D incompatibility between mother and fetus is the most frequent cause of red-cell alloimmunization. However there are surface antigens capable of producing hemolytic disease other than antigen D. Populational antigen frequencies may be country specific. The aim of this retrospective study was to evaluate the incidence of red-cell alloimmunization due to non-anti-D antibodies during pregnancy. We evaluated the indirect antiglobulin test results of 535 pregnant women performed between March 2003 and 2009. The incidence of non-anti-D antibodies was found 1.21%, similar with reported in literature, but the spectrum of non-anti-D antibodies was different from other countries.
Pathophysiology of Haemostasis and Thrombosis | 2007
Olga Meltem Akay; Enver Akın; Fezan Mutlu; Zafer Gulbas
This study was performed to evaluate the effect of iron therapy on platelet function among women with unexplained menorrhagia in order to better understand possible interactions between iron deficiency anemia and platelet behavior and menorrhagia. Platelet aggregation and adenosine triphosphate (ATP) release induced by 5.0 mM adenosine diphosphate (ADP), 0.5 mM arachidonic acid (AA), 1.0 mg/ml ristocetin and 2 μg/ml collagen were studied by whole-blood platelet lumi-aggregometer in 50 menorrhagic women before and after oral iron therapy and in 22 women of the control group. There was a significant increase in AA- induced platelet aggregation (p < 0.05) and a decrease in ristocetin-induced platelet aggregation (p < 0.01) after treatment. Pre- and posttreatment platelet aggregation responses to ADP and collagen were not significantly different (p > 0.05). Pre- and posttreatment platelet secretion responses to all agonists disclosed no significant difference (p > 0.05). There was no significant difference between the study group after treatment and the control group in respect to platelet aggregation and ATP secretion values induced by all agonists (p > 0.05). We conclude that iron deficiency anemia in women causes AA-induced platelet dysfunction, which may give rise to increased menstrual blood loss and can be reversed by iron repletion.
Platelets | 2014
Neslihan Andıç; Eren Gündüz; Olga Meltem Akay; Deniz Gören Şahin; Hava Üsküdar Teke
Glucocorticosteroids, intravenous immunoglobulins, vincristine, danazol, and eltrombopag are used in refractory chronic idiopathic thrombocytopenic purpura (ITP). All those treatment modalities are susceptible for thrombosis generation. There is an increased risk of thrombosis in the diseases’ natural course. The case we present is a resistant chronic ITP patient who developed pulmonary and intracardiac thrombosis during multidrug treatment. Risk of concomitant usage of drugs and rapid increase in platelet count are discussed.