Researcher:
Akay, Olga Meltem

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Olga Meltem

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Akay

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Akay, Olga Meltem

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2016 - 2019202020 - 202219

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    Intravascular large B-cell lymphoma within the appendix presenting as acute abdomen: a challenging diagnosis for hematologists
    (Galenos Yayıncılık, 2021) N/A; N/A; N/A; N/A; N/A; N/A; Atalar, Semra Cemre; Akay, Olga Meltem; Osmanbaşoğlu, Emre; Masyan, Helin; Taşkın, Orhun Çığ; Ferhanoğlu, Ahmet Burhan; Undergraduate Student; Faculty Member; Doctor; Doctor; Faculty Member; Faculty Member; School of Medicine; School of Medicine; N/A; N/A; School of Medicine; School of Medicine; Koç University Hospital; 346260; 170966; N/A; N/A; 166686; 18320
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    Post-transplant recurrence of masked monoclonal gammopathy of renal significance in a patient with C3 glomerulonephritis: a case report
    (Lippincott Williams & Wilkins, 2022) N/A; N/A; N/A; N/A; N/A; N/A; N/A; Yelken, Berna; Arpalı, Emre; Akyollu, Başak; Koçak, Burak; Baydar, Dilek Ertoy; Akay, Olga Meltem; Türkmen, Aydın; Doctor; Doctor; Doctor; Faculty Member; Faculty Member; Faculty Member; Doctor; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine, School of Medicine; N/A; N/A; N/A; N/A; 8025; 170966; N/A
    Introduction: Monoclonal gammopathy of renal significance (MGRS) is a recently defined group of renal diseases caused by monoclonal immunoglobulin secreted by nonmalignant proliferative B cell or plasma cell causes renal damage. Here we report a case known as primary kidney disease C3 glomerulonephritis but after kidney transplant diagnosed MGRS. Case presentation: A 32-year old man underwent live related renal transplant in December 2020 for ESRF secondary C3 glomerulonephritis. At 2 months post-transplant, his serum kreatinin levels increased from a basaline creatinine of 1.2 mg/dl to 1.7mg/dl, and he developed proteinuria (1.2 gr/day). Renal biopsy showed monoclonal membranoproliferative glomerulonephritis. His serum and urine kappa/lambda light chain ratio was normal and he had no monoclonal protein in serum and urine immunfixation electrophoresis. After the patient was treated with Rituximab (4 cycles), his serum creatinin levels and proteinuria increased and repeat biopsy showed increase of monoclonal immun complexes in glomeruler capillers. The patient was treated bortezomib-based chemotherapy (4 cycles). Repeat biopsy showed no regression renal pathology. His renal functions and proteinuria continued to deteriorate. There were a rise in urine kappa/lambda light chain ratio. He received no further chemotherapy, a decision was taken to manage her kidney condition conservatively. Conclusions: Monoclonol immunoglobulin deposits may not be detectable in standart immunofluorescence techniques and can result missing the diagnosis of MGRS. Patiens with C3glomerulonephritis should be examined in detail for monoclonal gammapathy before kidney transplantation. 
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    Detection of clostridium difficile toxins on patients with hematolojical malignency
    (Eskişehir Osmangazi Üniversitesi, 2020) Durmaz, Gül; Heydarlou, Mehdi Meskini; N/A; Akay, Olga Meltem; Faculty Member; School of Medicine; 170966
    Clostridium difficile, asemptomatik taşıyıcılık, ılımlı diyare, psödomembransız kolit, psödomemranöz kolit (PMK), fulminantkolit/toksik megakolon gibi çok çeşitli klinik tablolara neden olabilen insan gastrointestinal sistem mikrobiyota üyesi, gram pozitif,sporlu anaerob çomakçıktır. Geniş spektrumlu antibiyotik kullanımı sonrası kolonda bulunan C.difficile suşları ekolojik avantajkazanıp çoğalmakta ve toksin sentezleyerek ishale neden olmaktadır. Son 20 yılda gerek hastane, gerekse toplum kaynaklıC.difficile enfeksiyonlarının insidans ve mortalitesinde belirgin bir artış olduğu göze çarpmaktadır. Bu çalışmada EskişehirOsmangazi Üniversitesi Hastanesi Hematoloji ve Onkoloji kliniklerinde terapötik veya proflaktik amaçlı geniş spektrumluantibiyotik kullanımı sonrasında ishal gelişen hastaların dışkısında toksijenik C.difficile varlığının iki farklı immündiagnostik testinyanısıra moleküler test kullanılarak araştırılması amaçlanmıştır. Ocak- Haziran 2015 tarihleri arasında Hematoloji ve Onkolojikliniklerinde yatan ve diyare gelişen 82 hastanın dışkı örnekleri incelenmiştir. Dışkı örnekleri kapaklı, sızdırmaz transport dışkıkaplarında bir saat içinde Mikrobiyoloji laboratuvarına ulaştırılmıştır. Glutamat dehidrogenaz enzimi (GDH) ve toksin A ve Bsaptamada EIA (enzim immunoassay) yöntemi (TECH LAB, Inc.), toksin B genini saptamada ise real-time PCR yöntemi (BDGeneOhm™ Cdiff Assay) kullanılmıştır. Elli altı örnekte her üç testle negatif sonuç elde edilmiş olup, dokuz hastada da yapılantestlerden en az iki tanesi pozitif olarak bulunmuştur. Üç hastada ise EIA (GDH, toksin A ve B) testleri pozitif iken moleküleryöntemle negatif sonuç alındı. Moleküler yöntem ile saptanan ve yalancı negatiflik olarak kabul ettiğimiz bu durumun tcdB genindegerçekleşen mutasyon veya sadece toksin B-/binary toksin sentezleyen suş nedeniyle olduğu düşünülmüştür. GDH EIA testininriskli hasta gruplarına uygulanacak güvenirlilikte bir tarama testi olduğu ve GDH pozitifliği durumunda ise toksin A ve B saptayanimmündiagnostik testler veya toksin B genini saptayan moleküler testlerden biriyle sonucun doğrulanmasının uygun bir yaklaşımolacağı sonucuna varıldı. Bu çalışmada Eskişehir Osmangazi Üniversitesi Tıp Fakültesi Hastanesi Hematoloji ve Onkolojikliniklerinde terapötik veya proflaktik amaçlı geniş spekturumlu antibiyotik kullanımı sonrasında ishal gelişen hastaların dışkısındatoksijenik C.difficile varlığının iki farklı immündiagnostik testin yanısıra moleküler test kullanılarak araştırılması amaçlanmıştır.Ocak-Haziran 2015 tarihleri arasında Hematoloji ve Onkoloji kliniklerde yatan ve diyaresi olan 82 hastanın dışkı örnekleriincelenmiştir. Dışkı örnekleri kapaklı, sızdırmaz transport dışkı kaplarında bir saat içinde Mikrobiyoloji laboratuvarınaulaştırılmıştır. Glutamat dehidrogenaz enzimi (GDH) ve toksin A ve B saptamada EIA (enzim immunoassay) yöntemi (TECH LAB,Inc.), toksin B genini saptamada ise Real-Time PCR yöntemi (BD GeneOhm™ CdiffAssay) kullanılmıştır. Elli altı örnekte her üçtestle negatif sonuç elde edilmiş olup, dokuz hastada da yapılan testlerden en az iki tanesi pozitif olarak bulunmuştur. Üç hastada iseEIA (GDH, toksin A ve B) testleri pozitif iken moleküler yöntemle negatif sonuç alındı. Moleküler yöntem ile saptanan ve yalancınegatiflik olarak kabul ettiğimiz bu durumun tcdB geninde gerçekleşen mutasyon veya sadece toksin B-/binary toksin sentezleyensuş nedeniyle olduğu düşünülmüştur. GDH EIA testinin riskli hasta gruplarına uygulanacak güvenirlilikte bir tarama testi olduğu veGDH pozitifliği durumunda ise toksin A ve B saptayan immündiagnostik testler veya toksin B genini saptayan moleküler testlerdenbiriyle sonucun doğrulanmasının uygun bir yaklaşım olacağı sonucuna varıldı.
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    Rituximab desensitization in three patients with severe rituximab allergy
    (Mosby-Elsevier, 2017) N/A; N/A; Öztürk, Erman; Özyiğit, Sabiha Leyla Pur; Öztürk, Ayşe Bilge; Akay, Olga Meltem; Çetiner, Mustafa; Ferhanoğlu, Ahmet Burhan; Doctor; Doctor; Faculty Member; Faculty Member; Faculty Member; Faculty Member; N/A; N/A; School of Medicine; School of Medicine; School of Medicine; School of Medicine; Koç University Hospital; Koç University Hospital; N/A; N/A; N/A; N/A; N/A; 214687; 147629; 170966; N/A; 18320
    Rituximab is a chimeric monoclonal antibody that targets CD20 positive B cells and has a positive effect on both overall and progression-free survival in B-cell lymphoid malignancies. Combination rituximab with chemotherapy treatment provide survival improvement. Although rituximab is an important treatment option in hematological malignancies, the risk of allergic reactions is high. These reactions are usually IgE-mediated and can be varied in regard of severity from urticaria to anaphylaxis. It is an option to interrupt the treatment and ommit rituximab therapy who had allergic reactions. Drug desensitization is another option and successful results have been reported by applying desensitization to such reactions. Drug desensitization alters the immune response to induce a state of temporary clinical tolerance to the allergic drug by giving gradual increasing of doses of drug at fixed time intervals. Herein, we present 3 cases successfully treated with rituximab desensitization. The cases were using rituximab with the diagnosis of Burkitt lymphoma, follicular lymphoma, and marginal zone lymphoma, respectively. Two cases had grade 2 and 1 case had grade 3 systemic allergic reaction with rituximab. There was no known allergy history in all 3 cases. All patients tolerated the desensitization protocol. The subsequent treatments of the patients were also given by desensitization protocol. A total of 12 desensitizations were administered to 3 cases. No severe or life-threating reactions were observed in subsequent applications. To date applying desensitization protocols ensure rituximab treatment safely. Rituximab desensitization can be performed at trained allergy centers, and it may be an appropriate option for rituximab allergic patients.
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    How i treat relapsed classical hodgkin lymphoma after autologous stem cell transplantation
    (Pergamon-Elsevier Science Ltd, 2016) N/A; Akay, Olga Meltem; Faculty Member; School of Medicine; 170966
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    Circulating endothelial cells in Behçet's disease: is there a relationship with vascular involvement?
    (Clinical and Experimental Rheumatology, 2019) Yaşar Bilge, Nazife Şule; Gunduz, Eren; Bilgin, Muzaffer; Kasifoglu, Timucin; N/A; Akay, Olga Meltem; Faculty Member; School of Medicine; 170966
    OBJECTIVES: Circulating endothelial cells (CEC) are identified in conditions with vascular damage such as systemic vasculitis. Our aim was to investigate if EPC, CEC, and/or its subgroups activated CEC (aCEC) or resting CEC (rCEC) related with vascular involvement in Behçet's disease (BD). METHODS: In total 60 patients were included in this study, divided into 4 groups: 1) Behçet patients with a history of vascular involvement: vascular BD; 2) Behçet patients with mucocutaneus involvement: mucocutaneus BD; 3) patients with history of thrombosis due to other causes: thrombosis; 4) 20 healthy controls were also included: control group. Percentages of CEC, aCEC, rCEC and EPCs in peripheral blood mononuclear cells were measured by flow cytometry. RESULTS: CEC (3.75 (1.80-7.20), 1.80 (0.70-3.53), 3.50 (1.83-7.23), 2.45 (1.28- 4.60)) and aCEC (2.40 (1.28-4.28), 1.10 (0.77-2.20), 3.15 (1.48-7.20), 3.20 (1.15-9.80) levels were did not show a statistically significant difference between groups (p:0.077 and p:0.054, respectively). EPC and rCEC levels were higher in vascular BD and thrombosis groups than mucocutaneus BD and control groups (EPC:10.5 (7.20-18.3), 11.6 (7.30-20.9) vs. 7.15 (5.55-8.25), 10.2 (5.93-18.6), rCEC: 5.35 (3.13-7.90), 6.45 (4.60-10.8) vs. 4.95 (3.05-7.55), 3.40 (1.88-4.30), p:0.042 and p:0.007, respectively). CONCLUSIONS: CEC, EPC, aCEC and rCEC may have role in the assessment of vascular involvement in BD. Longitudinal studies would be needed to identify the utility of these cells for the follow up and risk stratification of BD patients with vascular involvement for recurrences or identify BD patients at risk of vascular involvement.
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    A 52-year-old man with progressive weakness and incontinence
    (Sage, 2022) Danyeli, Ayca Ersen; Bozkurt, Subutay Berke; Uysal, Sanem Pinar; Akpek, Sergin; Kahyaoglu, Bulent; Peker, Selcuk; Altıntaş, Ayşe; Aygün, Murat Serhat; Akay, Olga Meltem; Üre, Ümit Barbaros; Ferhanoğlu, Ahmet Burhan; Faculty Member; Teaching Faculty; Faculty Member; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; Koç University Hospital; 11611; 291692; 170966; N/A; 18320
    Here we report a challenging case of a 52-year-old man presenting with subacute constipation, urinary retention, impotence, absent Achilles reflexes, and hypoesthesia in S2-S5 dermatomes. We review the clinical decision-making as the symptoms evolved and diagnostic testing changed over time. Once the diagnosis is settled, we discuss the sign and symptoms, additional diagnostic tools, treatment options and prognosis.
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    The relationship between thromboelastography and clinical outcome in acute stroke patients receiving thrombolytic therapy
    (Eskişehir Osmangazi Üniversitesi, 2020) Özakın, Engin; Özdemir Atilla Özcan; Şahin, Deniz Gören; Dinç, Yasemin; Çevik, Arif Alper; Acar, Nurdan; Kaya, Filiz Baloğlu; Bilgin, Muzaffer; N/A; Akay, Olga Meltem; Faculty Member; School of Medicine; 170966
    Thromboelastography (TEG) is a hemostatic test that measures the shear elasticity and the dynamics of clot formationand the strength and stability of formed clot. There are limited data about TEG in acute ischemic stroke who receives thrombolytictherapies. This study aimed to investigate the impact of coagulation parameters obtained by rotational thrombelastography(ROTEM) method on clinical outcome and intracerebral hemoorage in acute stroke patients receiving thrombolytic treatment. Thestudy included 29 patients with acute stroke who received rtPA treatment between June 2013 and March 2014. Blood samples weretaken from the patients before starting thrombolytic therapy. By ROTEM®; INTEM and EXTEM analysis, the parameters of CT(clotting time=sec), CFT (clot formation time=sec) and MCF (maximum clot firmness=mm) were tested. The demographicinformation of patients, NIHSS scores at the time and 24 hours after the admission and brain tomography results were recorded. Inaddition, the data obtained by ROTEM method were compared with the normal group. Compared to healthy group, ischemic strokepatients had lower intemCT (p<0.05), extemCT (p=0.01) and extemCFT (p<0.05) and higher extemMCF (p<0.05). These resultswere consistent with hypercoagulability. TEG parameters were not correlated with symptomatic hemorrhage, mortality and pooroutcome in patients who receive trombolytic treatment. Thrombelastography shows that patients with ischemic stroke are inhypercoagulable state. Further studies are needed to examine this observation and its relationship with clinical outcome.
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    Both imatinib and nilotinib treatment associated grade 3-4 skin rash, is it predictable before tyrosine kinase inhibitor treatment? a case report
    (Eskişehir Osmangazi Üniversitesi, 2018) Vasi, İbrahim; Taşdüzen, Sevda Keleş; Teke, Hava Üsküdar; Gündüz, Eren; Andıç, Neslihan; N/A; Akay, Olga Meltem; Faculty Member; School of Medicine; 170966
    Chronic myeloid leukemia (CML), characterized with the Philadelphia (Ph) chromosome, is a myeloproliferative disorder. Imatinib mesylate, the first selective tyrosine kinase inhibitor targeting Bcr-Abl protein. Nilotinib and dasatinib are second-generation tyrosine kinse inhibitors, that have been approved for imatinib resistant CML. Most common side effects of these tyrosine kinase inibitors are myelosuppression, nausea, vomiting, diarrhea and grade 1-2 skin rash. Due to imatinib treatment incidence of grade 3-4 skin rash is 3-5% and nilotinib treatment incidence grade 3-4 skin rash is <1% Philadelphia (Ph) chromosome positive chronic phase CML were diagnosed to 50-year-old female patient with leukocytosis, and started treatment with imatinib. In the third month of treatment with imatinib was seen itchy, raised skin lesions and skin biopsy was performed on the identification. It is evaluated as drug eruption associated imatinib, so imatinib interrupted and then nilotinib treatment 2*400 mg/day was started. In the third year of nilotinib treatment hyperemic lesions and itching was detected and nilotinib treatment dose reduced 2*200 mg/day and local steroid treatment started. In the eighth year of treatment with nilotinib was seen grade 3-4 rash and treatment was delayed and systemic steroid treatment was added. Because of development grade 3-4 skin rash, nilotinib could not resumed and was replaced with dasatinib treatment. Both two tyrosine kinase inhibitör treatment with in our patients with grade 3-4 skin rash, skin reactions under dasatinib continues to be closely monitored. / : Kronik miyeloid lösemi (KML), Philadelphia (Ph) kromozomu pozitifliği ile karakterize kronik miyeloproliferatif bir hastalıktır. İmatinib mesylate, Bcr-Abl proteinini hedef alan ilk seçici tirozin kinaz inhibitörüdür (TKI). Nilotinib ve dasatinib ise imatinib dirençli KML tedavisinde kullanılan 2.kuşak tirozin kinaz inhibitörleridir. Bu tirozin kinaz inhibitörlerinin en sık görülen yan etkileri miyelosupresyon, bulantı, kusma, ishal ve grade 1-2 cilt döküntüleridir. İmatinibe bağlı grade 3-4 cilt döküntüsünün görülme olasılığı %3-5, nilotinibe bağlı grade 3-4 cilt döküntüsünün görülme olasılığı ise <%1’dir. Olgumuz 50 yaşındaki kadın hastaya lökositoz nedenli Ph kromozomu pozitif kronik faz KML tanısı konuldu ve imatinib tedavisi başlandı. İmatinib tedavisinin 3. ayında kaşıntılı, ciltten kabarık lezyonlar saptanması üzerine cilt biyopsisi yapıldı ve ilaç erupsiyonu olarak değerlendirilerek imatinib tedavisi kesildi, nilotinib 2*400 mg/gün başlandı. Nilotinib tedavisinin 3.yılında ciltte hiperemik lezyonlar ve kaşıntı saptanması üzerine nilotinib tedavisi 2*200 mg/gün dozuna düşürüldü ve lokal tedavi başlandı. Nilotinib tedavisinin 8.yılında grade 3-4 cilt döküntüsü gelişen hastada tedaviye ara verildi ve sistemik steroid eklendi. Grade 3-4 döküntü gelişmesi nedeni ile nilotinib tekrar başlanamadı, ve tedavisi dasatinib ile değiştirildi. TKI ile grade 3-4 cilt döküntüsü gelişen hastamızda, dasatinib altında da cilt reaksiyonu gelişipgelişmeyeceği açısından yakın takip devam etmektedir.
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    Evaluation of the relationship between T regulatory cells and vitamin D levels in chronic spontaneous urticaria
    (Wolters Kluwer Medknow Publications, 2018) Bulur, Işıl; Erdoğan, Hilal Kaya; Yiğitaslan, Semra; Saraçoglu, Zeynep Nurhan; N/A; Akay, Olga Meltem; Faculty Member; School of Medicine; 170966
    Objective: T regulatory (Treg) cells play a role in autoimmunity and vitamin D is one of the factors involved in regulation of Treg cells. In this study, it is aimed to evaluate the relationship between Treg cells and disease-related parameters and serum vitamin D levels in chronic spontaneous urticaria (CSU) patients. Methods: The percentage of Treg cells were evaluated by flow cytometric analysis and serum 25 hydroxy vitamin D (25(OH)Vit D) levels were determined by commercial available ELISA kit. Results: Thirty eight CSU patients and 30 healthy controls were included in the study. The percentage of CD4(+)CD25(+) and CD4(+)FOXP3(+) T cells in the patient group were found lower than in the control group (p=0.018, p=0.000). No difference was detected between groups in terms of the percentage of CD4(+)CD25(+)FOXP3(+) T cells and the 25(OH) Vit D levels (p=0.192, p=0.218). There was no significant relationship between disease duration, weekly urticaria activity score, autologous serum skin test (ASST), serum 25(OH) Vit D levels and the percentage of Treg cells in CSU patients. Conclusion: The percentage of CD4(+)CD25(+) and CD4(+)FOXP3(+) T cells in CSU patients were observed to be lower than control group independent from the serum 25(OH)Vit D levels, ASST positivity, disease duration and severity. This result suggests that Treg cells are one of the factors involved in the pathogenesis of CSU.