Researcher:
Akyıldız, Murat

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Murat

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Akyıldız

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Akyıldız, Murat

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2019 - 201932020 - 202323

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Now showing 1 - 10 of 27
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    Graft versus host disease after liver transplantation: a case report
    (Kare Yayıncılık, 2022) Acar, Sencan; Arat, Mutlu; Tecimer, Tulay; Polat, Kamil Yalcin; Akyıldız, Murat; Faculty Member; School of Medicine; 123080
    Graft Versus Host Disease (GVHD) is a severe immunological-clincopathological condition mediated by healthy T-lymphocytes in donor tissue against the immunosuppressed host tissue and rarely seen after solid organ transplantation (SOT). A 72-year old male patient underwent cadaveric liver transplantation. On day 34 of the postoperative follow-up, the patient developed fever, generalized skin rash and hemorrhagic lesions in the oropharynx. Skin biopsy was consistent with GVHD. Despite high-dose corticosteroid treatment, he died on postoperative day 51. Although it is seen rarely after liver transplantation, GVHD is an important clinical entity for which early diagnosis is critical due to its high rates of mortality.
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    Functional cure with lonafarnib-based therapy in chronic hepatitis delta
    (Wiley, 2022) Yurdcu, Esra; Gumussoy, Mesut; Keskin, Onur; Zeybel, Mujdat; Idilman, Ramazan; Bozdayi, Mithat; Choong, Ingrid; Glenn, Jeffrey; Gençdal, Genco; Yurtaydın, Süleyman Cihan; Akyıldız, Murat; Zeybel, Müjdat; Doctor; Faculty Member; Faculty Member; 0000-0001-5440-4623; N/A; School of Medicine; School of Medicine; School of Medicine; Koç University Hospital; N/A; 189330; 123080; 214694
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    Co-infection with HBV and HDV increases immune exhaustion when compared to HBV monoinfection
    (Wiley, 2022) Khanam, Arshi; Abutaleb, Ameer; Byambabaatar, Sumiya; Dashdorj, Naranjargal; Kottilil, Shyam; Akyıldız, Murat; Yurtaydın, Süleyman Cihan; Faculty Member; Faculty Member; School of Medicine; School of Medicine; 123080; 189330
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    Recurrence of extrahepatic hepatocellular carcinoma after liver transplantation
    (Sakarya Üniversitesi, 2020) Acar, Şencan; Akyıldız, Murat; Faculty Member; School of Medicine; 123080
    Hepatocellular carcinoma is the most common primary malignancy and the only curative treatment option is liver transplantation. A 67-year-old man who underwent living donor liver transplantation due to decompensated liver cirrhosis due to chronic viral hepatitis B and a 5-cm hepatocellular carcinoma focus. In the second postoperative year, although all biochemical data, abdominal and thoracic CT were normal, a dorsal MRI of back pain revealed a recurrence of 2.5 cm at D7 level. Radiotherapy and subsequent surgery were performed. Recurrences after liver transplantation often develop in extrahepatic areas. Rarely, it should be kept in mind in patients with bone pain. It is possible to treat early relapse with early diagnose / Hepatoselüler karsinom en sık primer karaciğer malignitesi olup küratif tek tedavi seçeneği karaciğer transplantasyonudur. Kronik viral hepatit B’ye bağlı dekompanse karaciğer sirozu ve 5 cm.lik hepatoselüler karsinom odağı nedeniyle canlı vericili karaciğer transplantasyonu uygulanmış olan 67 yaşında erkek hastanın post-transplant 2. yılında tüm biyokimyasal verileri, abdominal ve toraks BT’si normal olmasına rağmen sırt ağrısı nedeniyle çekilen dorsal MR’da D7 seviyesinde 2.5 cm.lik nüks gelişmiştir. Radyoterapi ve sonrasında cerrahi uygulanmıştır. Karaciğer transplantasyonu sonrası nüksler sıklıkla ekstrahepatik alanlarda gelişmektedir. Nadiren de olsa kemik ağrısı olanlarda akılda bulundurulmalıdır. Erken tanı ile erken nüks tedavisi mümkün olmaktadır.
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    Predictive value of protein induced by absence of vitamin K absence or antagonist II, alpha-fetoprotein and gamma-glutamyltransferase/aspartate aminotransferase ratio for the diagnosis of hepatocellular carcinoma in transplantation candidates
    (Lippincott Williams and Wilkins (LWW), 2021) Ekmen, Nergis; Akalın, Çağrı; Akyıldız, Murat; Faculty Member; School of Medicine; Koç University Hospital; 123080
    Objectives Alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) are used as tumour markers for the diagnosis of hepatocellular carcinoma (HCC). We investigate whether combined liver function marker such as gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST) with alpha-fetoprotein (AFP) and PIVKA-II increase their diagnostic predictive value in diagnosis of HCC.
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    Standard immunosuppressive treatment reduces regulatory B cells in children with autoimmune liver disease
    (Frontiers, 2023) Polat, Esra; N/A; Yüksel, Muhammed; Nazmi, Farinaz; Alwardat, Dima; Akgül, Sebahat Usta; Akyıldız, Murat; Arıkan, Çiğdem; Researcher; PhD Student; Researcher; Doctor; Faculty Member; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Koç University Transplant Immunology Research Centre of Excellence (TIREX) Inaugurated; N/A; Graduate School of Health Sciences; N/A; N/A; School of Medicine; School of Medicine; Koç University Hospital; Koç University Hospital; N/A; Koç University Hospital; Koç University Hospital; Koç University Hospital; N/A; N/A; N/A; N/A; 123080; 240198
    Introduction: Autoimmune hepatitis (AIH) is a chronic liver disease caused by a perturbed immune system. The scarcity of short- and long-term immune monitoring of AIH hampered us to comprehend the interaction between immunosuppressive medication and immune homeostasis. Methods and Patients: We recruited children with AIH at the time of diagnosis and at the 1st, 3rd, 6th, 12th, 18th, and 24th months of immunosuppression (IS). We also enrolled children with AIH being on IS for >2 years. Children with drug-induced liver injury (DILI), and those receiving tacrolimus after liver transplantation (LT), were enrolled as disease/IS control subjects. Healthy children (HC) were also recruited. Peripheral blood mononuclear cells (PBMCs) were isolated from all participants. Healthy liver tissue from adult donors and from livers without inflammation were obtained from children with hepatoblastoma. By using flow cytometry, we performed multi-parametric immune profiling of PBMCs and intrahepatic lymphocytes. Additionally, after IS with prednisolone, tacrolimus, rapamycin, or 6-mercaptopurine, we carried out an in vitro cytokine stimulation assay. Finally, a Lifecodes SSO typing kit was used to type HLA-DRB1 and Luminex was used to analyze the results. Results: Untreated AIH patients had lower total CD8 T-cell frequencies than HC, but these cells were more naïve. While the percentage of naïve regulatory T cells (Tregs) (CD4+FOXP3lowCD45RA+) and regulatory B cells (Bregs, CD20+CD24+CD38+) was similar, AIH patients had fewer activated Tregs (CD4+FOXP3highCD45RA-) compared to HC. Mucosal-associated-invariant-T-cells (MAIT) were also lower in these patients. Following the initiation of IS, the immune profiles demonstrated fluctuations. Bregs frequency decreased substantially at 1 month and did not recover anymore. Additionally, the frequency of intrahepatic Bregs in treated AIH patients was lower, compared to control livers, DILI, and LT patients. Following in vitro IS drugs incubation, only the frequency of IL-10-producing total B-cells increased with tacrolimus and 6MP. Lastly, 70% of AIH patients possessed HLA-DR11, whereas HLA-DR03/DR07/DR13 was present in only some patients. Conclusion: HLA-DR11 was prominent in our AIH cohort. Activated Tregs and MAIT cell frequencies were lower before IS. Importantly, we discovered a previously unrecognized and long-lasting Bregs scarcity in AIH patients after IS. Tacrolimus and 6MP increased IL-10+ B-cells in vitro.
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    Varicella-zoster virus-induced hepatitis in a liver transplant recipient: a case report
    (Elsevier, 2019) Acar, S.; Gencdal, G.; Kirimlioglu, H.; Polat, K. Y.; Cagatay, A. A.; Akyıldız, Murat; Faculty Member; School of Medicine; 123080
    Infections after solid organ transplantation are a major cause of mortality and morbidity. Varicella-zoster virus (VZV) infection after solid organ transplantation is rare. Here we present a case presenting with acute hepatitis and shingles after a liver transplantation (LT). A 36-year-old male patient underwent a liver transplantation; 7 months later his liver function tests increased. An examination and test results revealed that he had VZV-induced hepatitis. After VZV treatment, his test results returned to normal levels. Hepatic involvement of VZV infection is rare, but it may be fatal in immunocompromised individuals. Early diagnosis and early initiation of antiviral therapy is important in the control of hepatitis and rare hepatotropic viruses in immunocompromised individuals.
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    Determination of Turkish norms of psychometric tests for diagnosing minimal hepatic encephalopathy and proposal of a high sensitive screening test battery
    (Springer, 2021) Ozbas, Burak; Keskin, Onur; Hecker, Hartmut; Karahan, Irfan; Ozbas, Cansu; Kalkan, Cagdas; Kartal, Aysun; Onder, Fatih Oguz; Oncu, Burcu Kahveci; Gunsar, Fulya; Idilman, Ramazan; Weissenborn, Karin; Ozutemiz, Omer; Gençdal, Genco; Akyıldız, Murat; Yurtaydın, Süleyman Cihan; Doctor; Faculty Member; Faculty Member; N/A; School of Medicine; School of Medicine; Koç University Hospital; N/A; 123080; 189330
    Background Psychometric hepatic encephalopathy score (PHES) needs local standardization. Aims This study aimed at standardizing PHES for Turkish patients and compare them with German norms; to determine minimal hepatic encephalopathy (mHE) prevalence with two different methods [PHES battery and Critical Flicker Frequency (CFF)] and to assess whether sub-tests of the battery can be used for screening for mHE. Methods Healthy volunteers (n = 816; 400 male) and cirrhotics (n = 124; 58 male) were included. For mHE diagnosis PHES score threshold was set at <= - 5 points and that of CFF at < 39 Hz. For comparing German and Turkish norms, datasets were combined. Multiple backward procedure was applied to assess effects of age, sex and education on single tests of the battery. Receiver operating characteristic (ROC) curves were created for assessing diagnostic capabilities of subtests of the battery. Results PHES norms for Turks were developed. MHE prevalence in compensated cirrhotics was 29.8% and 27.4% with PHES and CFF tests, respectively, with low compatibility (kappa coefficient 0.389); mHE prevalence decreased to 16% when both tests were combined. Turks performed worse vs Germans in the digit symbol (DS) and serial dotting (SD) subtests but performed better in other subtests. In ROC analyzes of subtests, the combination of DS + SD tests achieved an AUROC of 0.974 versus PHES. Conclusions Use of two methods for diagnosing mHE is important for research purposes. From a clinical perspective, sensitivity with acceptable specificity may suffice for screening instruments for mHE. Combined use of DS and SD subtests of the PHES battery appears suitable for this purpose.
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    Course of vitamin D levels before and after liver transplantation in pediatric patients
    (Wiley, 2021) N/A; N/A; N/A; N/A; N/A; N/A; Yüksel, Muhammed; Demir, Barış; Mızıkoğlu, Özlem; Akyıldız, Murat; Baygül, Arzu Eden; Arıkan, Çiğdem; Researcher; Doctor; Researcher; Faculty Member; Faculty Member; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); N/A; N/A; N/A; School of Medicine; School of Medicine; School of Medicine; Koç University Hospital; N/A; N/A; N/A; 123080; 272290; 240198
    Background: 25-hydroxy VD insufficiency is known in children undergoing LT but the serial post-transplant VD course and supplementation modalities in the peri-transplant period are lacking. We aimed to determine the pre-VD status and the post-transplant VD status course following VD supplementation and to elucidate its relationship with post-transplant outcome parameters such as infection and survival. Methods: Pre- and post-VD levels were monitored in parallel with interventions to adjust VD levels in LT patients. VD status was categorized as circulating levels <30–21 ng/ml (insufficiency), 20–10 ng/ml (deficiency), and <10 ng/ml (severe deficiency). Patients received stoss (300000IU) VD3 within the pretransplant period if serum levels were <20 ng/ml. Results: 135 transplanted children were included. The age at LT was 22 months (IQR: 8–60). The pretransplant median VD level was 14 ng/ml. Despite stoss dose, post-transplant median VD level was 1.8 ng/ml (day one), 4 ng/ml (week one), 19 ng/ml (month one), 33 ng/ml (month three), 38 ng/ml (months 6–12), and 40 ng/ml (month 24). After 6 months, VD status reached >30 ng/ml in 98% of patients. Only at pre-LT, higher infection rate (18.7%) in the severe VD deficiency group was observed compared to the VD deficiency group (2.9%, p = .04). Survival was not affected by serum VD levels. Conclusion: VD levels fell substantially after LT but are rectifiable by stoss dose, which was well tolerated. Only the infection rate was associated with the VD status.
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    Hepatocellular carcinoma and liver transplantation: a single-center experience
    (2020) Polat, Kamil Yalçın; Acer, Şencan; Gençdal, Genco; Yazar, Şerafettin; Kargı, Ahmet; Dönmez, Ramazan; Aslan, Serdar; Kavlak, Mustafa Emre; Arıkan, Çiğdem; Akyıldız, Murat; Faculty Member; Faculty Member; School of Medicine; School of Medicine; Koç University Hospital; Koç University Hospital; 240198; 123080
    Background: Liver transplantation(LT) is thebest treatment inselectedpatients with hepatocellular carcinoma(HCC). Morphologic criteriaalone are not sufficient topredict survival. In this study,we investigated theclinical, biochemical, andpathologic factors affecting survival inpatients who under wentLT due to HCC. Methods: Between October2011 and January 2018,165 of 749 LT for HCC cases performedat the Memorial Atasehir Hospital were evaluated retrospectively. Survival, demographic characteristic sandetiology, preoperative alpha-fetoprotein(AFP) level, Model for End-StageLiver Disease (MELD) score, prognostic staging, and morphologic and histologic properties were evaluated. Results: Onehundredandthirty-nine cases of 165 were living donor liver transplantation (LDLT). Theme anage was 57.7 7.3 years, the mean follow-upperiodwas 27.8 20 months, and 41 patients(24%)died before follow-up. Recurrence of HCC was detected in 23 (14%) cases. Overall survival was 85%, 71%, and 64% for 1, 3, and 5 years, respectively. Intermsof 1-, 3-, and 5-year survival within vs beyond Milancriteria was 90%, 80%, and 76%vs 75%, 66%, and 44%, respectively. In the University of California SanFrancisco criteria, it was 86%, 76%, and70%vs 76%, 60%, and30% compared with1-, 3-, and5-year survival. While histopathological poor differentiation and AF Pelevation affected the coursenegatively. Good differentiation did not have a significant effecton survival. It was determined that poor differentiation, lymphovascular invasion, and an increased number of nodules significantly affected survival in both withinandbeyondcases. Conclusion: Atransplantdecisioniscontroversial inpatients with HCC with other than previously defined morphologic criteria. In these cases, AFP level and histologic differentiation determine survival. The results were not satisfactory in both highand/orpoorly differentiated cases.