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Yelken, Berna

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Berna

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Yelken

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Yelken, Berna

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2019 - 201912020 - 202315

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    Improving the urine spot protein/creatinine ratio by the estimated creatinine excretion to predict proteinuria in pediatric kidney transplant recipients
    (Wiley, 2021) Palaoğlu, Kerim Erhan; N/A; İncir, Said; Taşdemir, Mehmet; Koçak, Burak; Yelken, Berna; Arpalı, Emre; Akyollu, Başak; Baygül, Arzu Eden; Bilge, İlmay; Türkmen, Aydın; Doctor; Faculty Member; Faculty Member; Doctor; Doctor; Doctor; Faculty Member; Faculty Member; Doctor; N/A; School of Medicine; School of Medicine; N/A; N/A; N/A; School of Medicine; School of Medicine; N/A; Koç University Hospital; N/A; N/A; Koç University Hospital; Koç University Hospital; Koç University Hospital; N/A; N/A; Koç University Hospital; 175430; 175867; 220671; N/A; N/A; N/A; 272290; 198907; N/A
    Background Since the daily creatinine excretion rate (CER) is directly affected by muscle mass, which varies with age, gender, and body weight, using the spot protein/creatinine ratio (Spot P/Cr) follow-up of proteinuria may not always be accurate. Estimated creatinine excretion rate (eCER) can be calculated from spot urine samples with formulas derived from anthropometric factors. Multiplying Spot P/Cr by eCER gives the estimated protein excretion rate (ePER). We aimed to determine the most applicable equation for predicting daily CER and examine whether ePER values acquired from different equations can anticipate measured 24 h urine protein (m24 h UP) better than Spot P/Cr in pediatric kidney transplant recipients. Methods This study enrolled 23 children with kidney transplantation. To estimate m24 h UP, we calculated eCER and ePER values with three formulas adapted to children (Cockcroft-Gault, Ghazali-Barratt, and Hellerstein). To evaluate the accuracy of the methods, Passing-Bablok and Bland-Altman analysis were used. Results A statistically significant correlation was found between m24 h UP and Spot P/Cr (p < .001, r = 0.850), and the correlation was enhanced by multiplying the Spot P/Cr by the eCER equations. The average bias of the ePER formulas adjusted by the Cockcroft-Gault, Ghazali-Barratt, and Hellerstein equations were -0.067, 0.031, and 0.064 g/day, respectively, whereas the average bias of Spot P/Cr was -0.270 g/day obtained by the Bland-Altman graphics. Conclusion Using equations to estimate eCER may improve the accuracy and reduce the spot urine samples' bias in pediatric kidney transplantation recipients. Further studies in larger populations are needed for ePER reporting to be ready for clinical practice.
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    Living related kidney donation for alternative complement pathway diseases: long-term outcomes
    (Wiley, 2022) Caliskan, Y.; Safak, S.; Dirim, A. B.; Velioglu, A.; Oto, O. A.; Yildiz, A.; Garayeva, N.; Yazici, H.; Ersoy, A.; Lentine, K. L.; Yelken, Berna; Türkmen, Aydın; Doctor; Doctor; Koç University Hospital; Koç University Hospital; N/A; N/A
    Purpose: Atypical hemolytic-uremic syndrome (aHUS) and C3 glomerulopathy (C3G) are rare conditions that cause severe kidney disease. Data to guide the evaluation of living related donor (LRD) candidates for aHUS and C3G are very limited. We examined the clinical course of LRDs to recipients with aHUS and C3G to understand the challenges and outcomes after donation. Methods: The cohort of recipients and their living donors (LD) was retrospectively identified from data at 5 transplant centers (1987-2021). LD were followed for postdonation kidney function measured by eGFR, proteinuria, cardiac events and death. Recipient graft outcomes were also examined. Results: The cohort comprised 24 LD to recipients with aHUS (46%) and C3G (54%) including 18 LRD, where relationship to recipient included father (7, 29%), mother (5, 21%), sibling (3, 12.5%), son (1, 4%), aunt (1, 4%) and unrelated (6, 25%). Outcomes were evaluated in 22 LRD over 5 years (IQR, 2.5-11) follow-up. None of the donors developed kidney failure (eGFR<15 ml/min/1.73m2 or dialysis). Last follow up serum mean (SD) creatinine, eGFR and proteinuria levels were 1.05 (0.16) mg/dL, 78.4 (15.7) ml/min/1.73m2, and 0.13 (0.22) g/g, respectively (Table 1). During follow up, 5 (23%) donors developed hypertension, but none developed cardiac events. One donor developed gastric cancer and another donor developed a brain tumor and died at 4th year after donation. Regarding recipients, 2 (18.2%) of aHUS and 8 (61.5%) of C3G recipients lost allografts at a median 11 (IQR 6-14.5) years after transplant (p=0.03).
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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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    Living related kidney donation for alport syndrome spectrum: long-term outcomes
    (Wiley, 2022) Caliskan, Y.; Dirim, A. B.; Safak, S.; Velioglu, A.; Yildiz, A.; Oto, O. A.; Guller, N.; Yazici, H.; Ersoy, A.; Lentine, K. L.; Yelken, Berna; Türkmen, Aydın; Doctor; Doctor; Koç University Hospital; Koç University Hospital; N/A; N/A
    Purpose: Data to guide the evaluation of living related donor (LRD) candidates for kidney transplant recipients with Alport syndrome (AS) spectrum are limited. We examined a cohort of LRD to recipients with AS to improve understanding of the clinical course and outcomes of living donation in this context. Methods: The cohort of recipients and their LRD was retrospectively identified from data at 5 transplant centers (1987-2021). LRD were followed for postdonation kidney function measured by estimated glomerular filtration rate (eGFR), proteinuria, major cardiac events (MACE) and death. Results: The cohort comprised 33 LD, where relationship to recipient included mother (14, 42%), father (10, 30%), sibling (5, 32%), grandparent (1, 3%), uncle (1, 3%) and unrelated (2, 6%). Long term outcomes were evaluated in 27 LRD during a follow up of 12 years (IQR, 5-16). None of the donors developed kidney failure (eGFR<15 ml/min/1.73m2 or dialysis) during follow up. Last follow up serum mean (SD) creatinine, eGFR and proteinuria levels were 1.1 (0.2) mg/dL, 68.3 (16.0) ml/min/1.73m2, and 0.19 (0.36) g/g, respectively (Table 1). During follow up, 13 (48%) and 6 (22%) donors developed hypertension and diabetes mellitus, respectively. Five donors (19%) developed MACE [acute coronary ischemia, n=4 (15%), severe congestive heart failure, n=1, (4%)] at a median 5.5 (IQR, 4.5-10.3) years after donation. MACE rate was significantly higher in patients who developed hypertension compared to normotensives after donation (0% vs 35.7%, p=0.017) (Fig. 1). Three donors died during follow-up at median 14 (5-15) years after donation.
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    Case report: a kidney transplant patient with mild COVID-19
    (Wiley, 2020) N/A; N/A; N/A; N/A; N/A; N/A; Arpalı, Emre; Akyollu, Başak; Yelken, Berna; Tekin, Süda; Türkmen, Aydın; Koçak, Burak; Doctor; Doctor; Doctor; Faculty Member; Doctor; Faculty Member; N/A; N/A; N/A; School of Medicine; N/A; School of Medicine; Koç University Hospital; N/A; N/A; N/A; 42146; N/A; 220671
    Coronavirus Disease 2019 (COVID-19) is currently a pandemic with a mortality rate of 1%-6% in the general population. However, the mortality rate seems to be significantly higher in elderly patients, especially those hospitalized with comorbidities, such as hypertension, diabetes, or coronary artery diseases. Because viral diseases may have atypical presentations in immunosuppressed patients, the course of the disease in the transplant patient population is unknown. Hence, the management of these patients with COVID-19 is an area of interest, and a unique approach is warranted. Here, we report the clinical features and our treatment approach for a kidney transplant patient with a diagnosis of COVID-19. We believe that screening protocols for SaRS-Cov-2 should be re-evaluated in patients with solid-organ transplants.
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    Outcome of renal transplantation in patients with diabetes mellitus: a single-center experience
    (Elsevier, 2022) Akagün, Tülin; Usta, Murat; Türkmen, Aydın; N/A; Yelken, Berna; Doctor; N/A; Koç University Hospital; N/A
    Background: An increasing proportion of kidney recipients have diabetes mellitus (DM). Some concerns have been raised about the kidney transplantation results in diabetic patients. Therefore, we assessed the effect of DM on morbidity and mortality of diabetic patients with renal transplantation. Methods: We retrospectively studied adult patients with and without DM who underwent living donor transplantation between 2007 and 2016. Information concerning demographic and clinical data were retrospectively analyzed by reviewing the patient files. Results: Of the 1536 transplant recipients, 126 (8%) had diabetes mellitus (mean age 49.4 +/- 11.8) and 525 patients were evaluated in the non-diabetic control group (mean age 36.2 +/- 15.9). The diabetic and non-diabetic patient groups had a mean follow-up after kidney transplantation 42.5 months (0.27-101.7 months) and 58.8 +/- 10.6 months, respectively. In the diabetic patient group, only 3 patients had lost graft and 13 patients were exitus. Three patients had lost graft and 5 patients were exitus in non-diabetic patient group. Cardiac death (54.5%) was the most common cause of mortality in diabetic group. The 6-year patient and graft survival rates are 84.9% and 95.3%; 97.5% and 97.2% in the diabetic and non-diabetic patient groups, respectively. Conclusions: Both infection and cardiovascular diseases increase morbidity and mortality in renal transplant patients with diabetes mellitus. The mortality risk of diabetic patients after renal transplantation is higher than the non-diabetic kidney recipients. Therefore, diabetic patients need meticulous cardiac evaluation before renal transplantation and a close follow-up, in terms of infection, after transplantation.
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    Long-term outcomes of living-related kidney donation for alport syndrome spectrum: a propensity score-matched analysis
    (Karger Publishers, 2022) Oto, Ozgur Akin; Safak, Seda; Mirioglu, Safak; Velioglu, Arzu; Dirim, Ahmet Burak; Guller, Nurana; Yildiz, Abdulmecit; Ersoy, Alparslan; Turkmen, Aydin; Yazici, Halil; Lentine, Krista L. L.; Caliskan, Yasar; Yelken, Berna; Doctor; Koç University Hospital; N/A
    Introduction: Data to guide the evaluation of living-related donor candidates for kidney transplant recipients with Alport syndrome (AS) spectrum are limited. We aimed to examine a cohort of living-related donors to recipients with AS and compare their outcomes with a control group to improve understanding of the clinical course and outcomes of living donation in this context. Methods: Living donors (LDs) of AS recipients and propensity score-matched control LDs without any family history of AS (control group) were followed for major cardiac events, death, post-donation estimated glomerular filtration rate (eGFR), and proteinuria. Results: There were 31 LDs (48.4% male), in whom relationship to AS recipient included mother (45.2%), father (32.3%), sibling (16.1%), grandparent (3.2%), and uncle (3.2%). Long-term outcomes over 10.0 (IQR, 3.0-15.0) years were evaluated in 25 and 25 LDs from study and control groups, respectively. During follow-up, 5 LDs (20.0%) in study group developed major cardiac event (acute coronary ischemia [n = 4] and severe congestive heart failure [n = 1]) after 5.5 (IQR, 4.5-10.3) years, whereas only 2 (8.0%) LDs in control group developed major cardiac events (p = 0.221). New-onset hypertension was higher in study group (56.0%) compared to the control group (16.0%) (p = 0.003). Three donors in study and 2 donors in control group who developed new-onset hypertension died during follow-up (p = 0.297). Major cardiac event rate was significantly higher in donors who developed hypertension after donation (0 vs. 28.0%, p < 0.001). There were no differences between study groups regarding last eGFR and proteinuria levels (p = 0.558 and p = 0.120, respectively). Discussion/Conclusion: Although the risk of kidney disease can be minimized by careful donor evaluation, our findings suggest that hypertension risk after the donation is higher than expected in related donors of recipients with AS.
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    Mortality analysis of COVID-19 infection in chronic kidney disease, haemodialysis and renal transplant patients compared with patients without kidney disease: A nationwide analysis from Turkey
    (Oxford University Press, 2021) Ozturk S.; Turgutalp K.; Arici M.; Odabas A.R.; Altiparmak M.R.; Aydin Z.; Cebeci E.; Basturk T.; Soypacaci Z.; Sahin G.; Ozler T.E.; Kara E.; Dheir H.; Eren N.; Suleymanlar G.; Islam M.; Ogutmen M.B.; Sengul E.; Ayar Y.; Dolarslan M.E.; Bakirdogen S.; Safak S.; Gungor O.; Sahin I.; Mentese I.B.; Merhametsiz O.; Oguz E.G.; Genek D.G.; Alpay N.; Aktas N.; Duranay M.; Alagoz S.; Colak H.; Adibelli Z.; Pembegul I.; Hur E.; Azak A.; Taymez D.G.; Tatar E.; Kazancioglu R.; Oruc A.; Yuksel E.; Onan E.; Turkmen K.; Hasbal N.B.; Gurel A.; Sahutoglu T.; Gok M.; Seyahi N.; Sevinc M.; Ozkurt S.; Sipahi S.; Bek S.G.; Bora F.; Demirelli B.; Oto O.A.; Altunoren O.; Tuglular S.Z.; Demir M.E.; Ayli M.D.; Huddam B.; Tanrisev M.; Bozaci I.; Gursu M.; Bakar B.; Tokgoz B.; Tonbul H.Z.; Yildiz A.; Sezer S.; Ates K.; N/A; Yelken, Berna; Doctor; N/A; Koç University Hospital; N/A
    Background: Chronic kidney disease (CKD) and immunosuppression, such as in renal transplantation (RT), stand as one of the established potential risk factors for severe coronavirus disease 2019 (COVID-19). Case morbidity and mortality rates for any type of infection have always been much higher in CKD, haemodialysis (HD) and RT patients than in the general population. A large study comparing COVID-19 outcome in moderate to advanced CKD (Stages 3-5), HD and RT patients with a control group of patients is still lacking. Methods: We conducted a multicentre, retrospective, observational study, involving hospitalized adult patients with COVID-19 from 47 centres in Turkey. Patients with CKD Stages 3-5, chronic HD and RT were compared with patients who had COVID-19 but no kidney disease. Demographics, comorbidities, medications, laboratory tests, COVID-19 treatments and outcome [in-hospital mortality and combined in-hospital outcome mortality or admission to the intensive care unit (ICU)] were compared. Results: A total of 1210 patients were included [median age, 61 (quartile 1-quartile 3 48-71) years, female 551 (45.5%)] composed of four groups: Control (n = 450), HD (n = 390), RT (n = 81) and CKD (n = 289). The ICU admission rate was 266/ 1210 (22.0%). A total of 172/1210 (14.2%) patients died. The ICU admission and in-hospital mortality rates in the CKD group [114/289 (39.4%); 95% confidence interval (CI) 33.9-45.2; and 82/289 (28.4%); 95% CI 23.9-34.5)] were significantly higher than the other groups: HD = 99/390 (25.4%; 95% CI 21.3-29.9; P<0.001) and 63/390 (16.2%; 95% CI 13.0-20.4; P<0.001); RT = 17/81 (21.0%; 95% CI 13.2-30.8; P = 0.002) and 9/81 (11.1%; 95% CI 5.7-19.5; P = 0.001); and control = 36/450 (8.0%; 95% CI 5.8-10.8; P<0.001) and 18/450 (4%; 95% CI 2.5-6.2; P<0.001). Adjusted mortality and adjusted combined outcomes in CKD group and HD groups were significantly higher than the control group [hazard ratio (HR) (95% CI) CKD: 2.88 (1.52- 5.44); P = 0.001; 2.44 (1.35-4.40); P = 0.003; HD: 2.32 (1.21- 4.46); P = 0.011; 2.25 (1.23-4.12); P = 0.008), respectively], but these were not significantly different in the RT from in the control group [HR (95% CI) 1.89 (0.76-4.72); P = 0.169; 1.87 (0.81-4.28); P = 0.138, respectively]. Conclusions: Hospitalized COVID-19 patients with CKDs, including Stages 3-5 CKD, HD and RT, have significantly higher mortality than patients without kidney disease. Stages 3-5 CKD patients have an in-hospital mortality rate as much as HD patients, which may be in part because of similar age and comorbidity burden. We were unable to assess if RT patients were or were not at increased risk for in-hospital mortality because of the relatively small sample size of the RT patients in this study.
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    Effects of rituximab on atherosclerotic biomarkers in kidney transplant recipients
    (Elsevier Science Inc, 2019) Aliyeva, N.; Demir, E.; Akgul, S. U.; Temurhan, S.; Ucar, A. R.; Dirim, A. B.; Bayraktar, A.; Catikkas, N. M.; Erol, A.; Caliskan, Y.; Yazici, H.; Savran, F. O.; Turkmen, A.; N/A; Yelken, Berna; Doctor; School of Medicine; Koç University Hospital; N/A
    Introduction: Cardiovascular disease is the leading cause of mortality in kidney transplant recipients. Rituximab is widely used in kidney transplantation for a variety of situations, and rituximab may inhibit some cytokines and antibodies that may play an active role in the atherosclerotic process. The aim of the study was to evaluate the efficacy of rituximab on atherosclerosis biomarkers in kidney transplant recipients. Methods: All patients, 18 years of age and older, who underwent kidney transplantation and received at least 1 dose of 375 mg/m(2) rituximab were considered for participation in this study. The primary study endpoint was the development of cardiovascular diseases after rituximab therapy. The secondary endpoint was the onset of cytomegalovirus (CMV) disease or biopsy-confirmed BK virus nephropathy. In addition, comparison of atherosclerosis biomarkers was performed between study and control groups. Results: There were no cardiovascular events observed during follow up. Only 8 patients in the study group suffered from CMV disease during follow up. Serum interleukin 10 levels were significantly higher in the rituximab group compared with the control group, although antieoxidized low-density lipoprotein levels were lower in the rituximab group compared with the control group, though this did not achieve statistical significance. Discussion: Rituximab treatment may increase the risk of CMV reactivation and decrease lymphocyte counts and interleukin 10 levels; however, significant decreases in all atherosclerotic-related biomarkers have not been shown in our study.
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    Propensity score-matched analysis of long-term outcomes for living kidney donation in alternative complement pathway diseases: a pilot study
    (Springer Science and Business Media Deutschland GmbH, 2023) Caliskan, Yasar; Safak, Seda; Oto, Ozgur Akin; Velioglu, Arzu; Mirioglu, Safak; Dirim, Ahmet Burak; Yildiz, Abdulmecit; Guller, Nurana; Yazici, Halil; Ersoy, Alparslan; Turkmen, Aydin; Lentine, Krista L.; Yelken, Berna; Doctor; Koç University Hospital; N/A
    Background: Atypical hemolytic syndrome (aHUS) and C3 glomerulopathy (C3G) are complement-mediated rare diseases with excessive activation of the alternative pathway. Data to guide the evaluation of living-donor candidates for aHUS and C3G are very limited. The outcomes of living donors to recipients with aHUS and C3G (Complement disease-living donor group) were compared with a control group to improve our understanding of the clinical course and outcomes of living donation in this context. Methods: Complement disease-living donor group [n = 28; aHUS(53.6%), C3G(46.4%)] and propensity score-matched control-living donor group (n = 28) were retrospectively identified from 4 centers (2003–2021) and followed for major cardiac events (MACE), de novo hypertension, thrombotic microangiopathy (TMA), cancer, death, estimated glomerular filtration rate (eGFR) and proteinuria after donation. Results: None of the donors for recipients with complement-related kidney diseases experienced MACE or TMA whereas two donors in the control group developed MACE (7.1%) after 8 (IQR, 2.6–12.8) years (p = 0.15). New-onset hypertension was similar between complement disease and control donor groups (21.4% vs 25%, respectively, p = 0.75). There were no differences between study groups regarding last eGFR and proteinuria levels (p = 0.11 and p = 0.70, respectively). One related donor for a recipient with complement-related kidney disease developed gastric cancer and another related donor developed a brain tumor and died in the 4th year after donation (2, 7.1% vs none, p = 0.15). No recipient had donor-specific human leukocyte antigen antibodies at the time of transplantation. Median follow-up period of transplant recipients was 5 years (IQR, 3–7). Eleven (39.3%) recipients [aHUS (n = 3) and C3G (n = 8)] lost their allografts during the follow-up period. Causes of allograft loss were chronic antibody-mediated rejection in 6 recipients and recurrence of C3G in 5. Last serum creatinine and last eGFR of the remaining patients on follow up were 1.03 ± 038 mg/dL and 73.2 ± 19.9 m/min/1.73 m2 for aHUS patients and 1.30 ± 0.23 mg/dL and 56.4 ± 5.5 m/min/1.73 m2 for C3G patients. Conclusion: The present study highlights the importance and complexity of living related-donor kidney transplant for patients with complement-related kidney disorders and motivates the need for further research to determine the optimal risk-assessment for living donor candidates to recipients with aHUS and C3G.