Browsing by Author "Sayin, Burak"

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ANGIOTENSIN RECEPTOR BLOCKERS PROVIDE BETTER GLOMERULAR FILTRATION RATES THAN ANGIOTENSIN CONVERTING ENZYME INHIBITORS IN KIDNEY TRANSPLANT RECIPIENTS WITH PROTEINURIA
(2020) Etlik, Zeynep Melekoglu; Sayin, Burak; Erdogmus, Siyar; Colak, Turan; Akdur, Aydincan; Haberal, Mehmet A.
ASSESSMENT OF MIDDLE EAR MECHANICS, INTERNAL EAR ACOUSTICAL EMISSION MEASUREMENTS AND HEARING IN RENAL TRANSPLANT RECIPIENTS
(2020) Oz, Isilay; Soy, Ebru H. Ayvazoglu; Sayin, Burak; Ozluoglu, Levent; Haberal, Mehmet
Assessment of Myocardial Mechanics in Patients with End-Stage Renal Disease and Renal Transplant Recipients Using Speckle Tracking Echocardiography
(2015) Pirat, Bahar; Bozbas, Huseyin; Simsek, Vahide; Sade, L. Elif; Sayin, Burak; Muderrisoglu, Haldun; Haberal, Mehmet; 0000-0002-9635-6313; 0000-0003-4576-8630; 0000-0003-3737-8595; 0000-0002-3462-7632; 0000-0001-8287-6572; 25894162; AAG-8233-2020; AAI-8897-2021; AAQ-7583-2021; AAJ-8097-2021; J-3707-2015
Objectives: Velocity vector imaging allows quantitation of myocardial strain and strain rate from 2-dimensional images based on speckle tracking echocardiography. The aim of this study was to analyze the changes in myocardial strain and strain rate patterns in patients with end-stage renal disease and renal transplant recipients. Materials and Methods: We studied 33 patients with end-stage renal disease on hemodialysis (19 men; mean age, 36 +/- 8 y), 24 renal transplant recipients with functional grafts (21 men; mean age, 36 +/- 7 y) and 26 age- and sex-matched control subjects. Longitudinal peak systolic strain and strain rate for basal, mid, and apical segments of the left ventricular wall were determined by velocity vector imaging from apical 4- and 2-chamber views. The average longitudinal strain and strain rate for the left ventricle were noted. From short-axis views at the level of papillary muscles, average circumferential, and radial strain, and strain rate were assessed. Results: Mean heart rate and systolic and diastolic blood pressure during imaging were similar between the groups. Longitudinal peak systolic strain and strain rate at basal and mid-segments of the lateral wall were significantly higher in renal transplant recipients and control groups than end-stage renal disease patients. Average longitudinal systolic strain from the 4-chamber view was highest in control subjects (-14.5% +/- 2.9%) and was higher in renal transplant recipients (-12.5% +/- 3.0%) than end-stage renal disease patients (-10.2% +/- 1.6%; P <= .001). Radial and circumferential strain and strain rate at the level of the papillary muscle were lower in patients with end-stage renal disease than other groups. Conclusions: Differences in myocardial function in patients with end-stage renal disease, renal transplant recipients, and normal controls can be quantified by strain imaging. Myocardial function is improved in renal transplant recipients compared with end-stage renal disease patients.
CLINICAL CHARACTERISTICS AND OUTCOME OF HERPES ZOSTER IN SOLID ORGAN TRANSPLANT PATIENTS: A SINGLE CENTER CASE SERIES
(2020) Altunel, Cemile Tugba; Seckin, Deniz; Sayin, Burak; Sezgin, Atilla; Akdur, Aydincan; Haberal, Mehmet A.
CLINICAL FEATURES AND SENSITIZATION RISK FACTORS IN PATIENTS AWAITING KIDNEY TRANSPLANTATION: A SINGLE CENTER EXPERIENCE
(2020) Erdogmus, Siyar; Celebi, Zeynep Kendi; Sayin, Burak; Acar, F. Nurhan Ozdemir; Karakaya, Emre; Haberal, Mehmet A.
Early Conversion to mTOR Inhibitors Prevents Kidney Function Better Than Late Conversion
(2018) Atay, Gokhan; Sayin, Burak; Colak, Turan; Acar, Nurhan Ozdemir; Sezer, Siren; Haberal, Mehmet; 0000-0001-8287-6572; 0000-0002-8372-7840; 0000-0002-3462-7632; J-3707-2015; AAJ-8554-2021; AAJ-8097-2021
Incidence and Immunologic Analysis of Coronavirus Disease (COVID-19) in Hemodialysis Patients: A Single-Center Experience
(2020) Arslan, Hande; Musabak, Ugur; Soy, Ebru H. Ayvazoglu; Azap, Ozlem Kurt; Sayin, Burak; Akcay, Sule; Haberal, K. Murat; Akdur, Aydincan; Yildirim, Sedat; Haberal, Mehmet; 0000-0001-8287-6572; 0000-0003-1511-7634; 0000-0002-5735-4315; 0000-0002-0993-9917; 0000-0002-8726-3369; 0000-0002-3171-8926; 0000-0002-8360-6459; 0000-0002-3462-7632; 0000-0002-8211-4065; 32519618; J-3707-2015; AAU-1810-2020; AAF-4610-2019; AAC-5566-2019; AAA-3068-2021; AAK-4089-2021; AAB-5175-2021; AAJ-8097-2021; R-9398-2019
Objectives: COVID-19 is a great threat to the modern world and significant threat to immunocompromised patients, including patients with chronic renal failure. We evaluated COVID-19 incidence among our hemodialysis patients and investigated the most probable immune mechanisms against COVID-19. Materials and Methods: Baskent University has 21 dialysis centers across Turkey, with 2420 patients on hemodialysis and 30 on peritoneal dialysis. Among these, we retrospectively evaluated 602 patients (257 female/345 male) with chronic renal failure receiving hemodialysis as renal replacement therapy; 7 patients (1.1%) were infected with SARS-CoV-2. We retrospectively collected patient demographic characteristics, clinical data, and immunological factors affecting the clinical course of the disease. We divided patients into groups and included 2 control groups ( individuals with normal renal functions): group I included COVID-19-positive patients with normal renal function, group II included COVID-19-positive hemodialysis patients, group III included COVID-19-negative hemodialysis patients, and group IV included COVID-19-negative patients with normal renal function. Lymphocyte subsets in peripheral blood and typing of human leukocyte antigens were analyzed in all groups, with killer cell immunoglobulin-like receptor genes analyzed only in COVID-19-positive patients and healthy controls. Results: No deaths occurred among the 7 COVID-19-positive hemodialysis patients. Group I patients were significantly older than patients in groups II and III ( P = .039, P = .030, respectively) but not significantly different from group IV (P = .060). Absolute counts of natural killer cells in healthy controls were higher than in other groups (but not significantly). Activated T cells were significantly increased in both COVID-19-positive groups versus COVID-19-negative groups. Groups showed significant differences in C and DQ loci with respect to distribution of alleles in both HLA classes. Conclusions: Although immunocompromised patients are at greater risk for COVID-19, we found lower COVID-19 incidence in our hemodialysis patients, which should be further investigated in in vitro and molecular studies.
INCIDENCE AND RISK FACTORS OF NEW ONSET DIABETES AFTER SOLID ORGAN TRANSPLANTATION: BASKENT UNIVERSITY EXPERIENCE
(2020) Kaban, Gokturk; Iyidir, Ozlem Turhan; Sayin, Burak; Turgut, Didem; Karakaya, Emre; Haberal, Mehmet A.
Is Hyperuricemia Related to Morning Blood Pressure Surge and Non-Dipper Hypertension
(2015) Gurlekdemirci, Bahar; Sezer, Siren; Sayin, Burak; Erkmenuyar, Mehtap; Colak, Turan; Haberal, Mehmet; 0000-0002-8372-7840; 0000-0002-3462-7632; 0000-0001-8287-6572; AAJ-8554-2021; AAJ-8097-2021; IAO-2608-2023; J-3707-2015
Long-Term Follow-up of Over 600 Living Related Kidney Donors: Single-Center Experience
(2022) Sayin, Burak; Akdur, Aydincan; Karakaya, Emre; Soy, Ebru H. Ayvazoglu; Haberal, Mehmet; https://orcid.org/0000-0002-4879-7974; https://orcid.org/0000-0002-3462-7632; 35384802; AAD-5466-2021; AAJ-8097-2021
Objectives: Kidney transplant is the treatment of choice in patients with end-stage renal disease because it offers improved survival and better quality of life. Although most epidemiologic studies have suggested that living kidney donors have a minimal lifetime risk of developing end-stage renal disease, long-term complications and physiologic and psychologic sequelae resulting from donation remain unclear. Here, we examined the long-term results of living-related kidney donors who donated kidneys at the Baskent University Ankara Hospital over the past 25 years. Materials and Methods: We were able to examine 607 kidney transplant donors (mean age of 52.03 +/- 11.54 years) who were seen at our center from 1986 to 2021 and who agreed to a general health evaluation. Collected data included donor age, sex, blood type, body mass index, duration after donation, blood pressure measurements, biochemical parameters, abdominal ultrasonograph for size, structure, and renal blood flow of the solitary kidney, comorbid conditions, chronic drug use, and surgical procedures after donation. Results: Mean time after donation was 10.4 +/- 3.2 years. Twenty-four donors (3.9%) were diagnosed with diabetes and 21 (3.4%) with thyroid disease, 64 (10.5%) developed hypertension, and 48 (8.8%) developed atherosclerotic cardiovascular disease. Obesity was found to be an increasing problem in our donor population, with 174 (28.6%) developing mild to moderate obesity (body mass index >25 kg/m2). Older age, obesity, smoking, and hyperlipidemia were found to be the major and independent risk factors of both hypertension and atherosclerotic cardiovascular disease in donors. None of our donors developed endstage renal disease. Conclusions: Obesity and hypertension were the most common comorbidities that developed in our kidney donor population. Our principle is to avoid unrelated and nondirected donors because of the possible long-term complications. Unrelated donors may be desperate if a family member needs donation in the future.
Long-Term Results of Kidney Transplantation in Patients with Familial Mediterranean Fever
(2023) Bitik, Berivan; Hatipoglu, Bugra; Sayin, Burak; Kanbur, Aysenur Yalcintas; Bursa, Nurbanu; Oygur, Cagdas Sahap; Ozdemir, Handan; Colak, Turan; Haberal, Mehmet; Yucel, Ahmet Eftal; 0000-0001-5803-915X; 0000-0002-7528-3557; 0000-0002-3462-7632; 0000-0002-0168-2993; 36544375; AAI-9195-2021; X-8540-2019; AAJ-8097-2021
IntroductionLong-term kidney transplantation (KT) results in patients with familial Mediterranean fever (FMF)-related amyloidosis are not well studied. This study reviewed the long-term survival outcomes of FMF patients who underwent KT. MethodsWe compared the outcomes of 31 patients who underwent (KT) for biopsy-proven amyloidosis secondary to FMF with 31 control patients (five with diabetes mellitus and 26 with nondiabetic kidney disease) undergoing KT between 1994 and 2021 at Baskent University Hospital. All data were recorded retrospectively from patients' files. Results: The median age (quartile deviationQD) at the time of KT in the FMF and control group were 31 (6.7) and 33 (11), respectively. The median follow-up period (QD) after KT was 108 (57) months in the FMF and 132 (72) months in the control group. In the FMF group, graft and patient survivals were 71% and 84% at 5 years and 45% and 48% at 10 years, respectively. In the control group, graft and patient survivals were 79% and 100% at 5 years and 63% and 71% at 10 years, respectively. Patient survival in the FMF group at 5 years was significantly lower than in the control group (p = .045). There was no statistically significant difference between the FMF and control groups in terms of graft and patient survival, and serum creatinine levels at 10 years. All patients were given triple immunosuppressive treatment with cyclosporine, mycophenolate mofetil, and prednisolone. Three patients received anakinra and one received canakinumab in addition to colchicine treatment. One FMF patient also underwent heart transplantation due to AA amyloidosis. Of the FMF patients, 11 died during follow-up. ConclusionWe have found that the long-term outcome of KT in patients with FMF amyloidosis is numerically worse but not statistically different from the control group. However, short- and long-term complications still need to be resolved.
Microvascular Injury With Macrophage, Neutrophil, And Hla-dr Positive Inflammatory Infiltrate, either in dsa Positive or Negative abmr, Determines the Prognosis in Renal Allografts
(2022) Ozdemir, B. Handan; Basturk, Bilkay; Terzi, Aysen; Sayin, Burak; Haberal, Mehmet; 0000-0002-3462-7632; AAJ-8097-2021
Obesity and Loss of Kidney Function: Two Complications to Face for Older Living Kidney Donors
(2017) Kaya, Demet Firat; Sayin, Burak; Saglam, Hatice; Demirci, Bahar Gurlek; Colak, Turan; https://orcid.org/0000-0001-8287-6572; https://orcid.org/0000-0002-8372-7840; 28260454; J-3707-2015; AAJ-8554-2021
Objectives: Although living kidney donors have a minimal lifetime risk of developing end-stage renal disease, long-term complications and physiologic and psychologic sequelae resulting from donation remain unclear because of lack of optimum follow-up after transplant. Here, we evaluated renal function, complications, and physical and mental performance of living kidney donors. Materials and Methods: We evaluated 147 patients who donated living kidneys between 1981 and 2012 at Baskent University Hospital. We collected data on donor age, sex, body mass index, smoking status, hypertension before and after nephrectomy, proteinuria, estimated glomerular filtration rate according to the Modification of Diet in Renal Disease formula, and duration after donation. All donors answered the Medical Outcomes Study short-form general health survey; results were evaluated according to answers to 11 questions totaling 22 points. Results: Body mass index of donors showed that 31 (21.1%) were in normal range, 66 (44.9%) had mild obesity (body mass index of 26-30 kg/m(2)), and 30 (34%) had moderate to high obesity (body mass index > 30 kg/m(2)). Results from the general health survey showed that 117 donors (80%) had no loss, 13 (9%) had mild loss, 12 (8%) had moderate loss, and 5 (3%) had high loss of ability. When we compared estimated glomerular filtration rates according to donor age, donors who were 18 to 34 years had a mean estimated glomerular filtration rate of 113.5 +/- 40, donors 35 to 49 years had a mean rate of 95.01 +/- 23.4, donors 50 to 64 years had a mean rate of 87.43 +/- 25.4, and donors older than 65 years had a mean rate of 63.76 +/- 11.35 mL/min/1.73 m(2), revealing a statistically significant loss of kidney function with aging (P = .001). Conclusions: Careful evaluation of kidney donors before and after donation is essential for the most common risk factors, such as obesity, and for loss of kidney function, especially in older donors.
Over 5 Years of Excellent Graft Kidney Function Determinants: Baskent University Experience
(2019) Sayin, Burak; Ozdemir, Aydan; Soy, Ebru H. Ayvazoglu; Kirnap, Mahir; Akdur, Aydincan; Moray, Gokhan; Haberal, Mehmet; https://orcid.org/0000-0001-8287-6572; https://orcid.org/0000-0002-0993-9917; https://orcid.org/0000-0002-8726-3369; https://orcid.org/0000-0003-2498-7287; https://orcid.org/0000-0002-3462-7632; 30777527; J-3707-2015; ABH-7372-2020; AAC-5566-2019; AAH-9198-2019; AAA-3068-2021; AAE-1041-2021; AAJ-8097-2021
Objectives: Kidney graft survival may be evaluated according to the duration of time with a functioning graft. Survival alone may not satisfy expectations of a successful kidney transplant if the graft kidney does not show excellent function. In our study, we analyzed the characteristics of kidney transplant recipients who showed excellent graft function after 5 to 10 years of follow-up in an aim to improve graft survival and to ensure the best kidney function in the long term. Materials and Methods: We retrospectively evaluated graft function and demographic characteristics of 288 patients who underwent kidney transplant between January 2008 and December 2012. Results: We found that 149 patients (51.7%) had excellent graft function, 88 patients (30.5%) had a functioning graft with a glomerular filtration rate lower than 60 mL/min and/or had signs of graft kidney dysfunction, and 45 patients (15.6%) experienced graft loss. Of 288 kidney transplant recipients enrolled in the study, most were male (56%), and mean age was 30.47 +/- 14.36 years at time of transplant. Median time on dialysis was 39.09 +/- 59.30 months. The overall graft survival rate in the patient group was 82.2% after 5 to 10 years of follow-up. Multivariate analysis showed that excellent graft survival predictors beyond 5 years were negative panel reactive antibody levels, lower donor age, shorter duration on dialysis, absence of acute rejection episodes, 3 or less HLA mismatches, lower immunosuppressive levels, and lower recipient age at transplant. Conclusions: Lower panel reactive antibody levels, lower donor age, shorter duration on dialysis, absence of acute rejection episodes, 3 or less HLA mismatches, and lower recipient age at transplant are major determinants of excellent graft survival in our kidney transplant recipients.
Oxidative Stress in Maintenance Hemodialysis Patients
(2014) Uyar, Mehtap Erkmen; Bal, Zeynep; Bayraktar, Nilufer; Demirci, Bahar Gurlek; Sayin, Burak; Sezer, Siren; https://orcid.org/0000-0002-7886-3688; https://orcid.org/0000-0001-8287-6572; https://orcid.org/0000-0002-7326-8388; IAO-2608-2023; AAZ-5795-2021; Y-8758-2018; J-3707-2015; JYQ-2550-2024
PAIRED KIDNEY EXCHANGE TRANSPLANTATION EXPERIENCE IN OUR CENTER
(2020) Soy, Ebru H. Ayvazoglu; Akdur, Aydincan; Sayin, Burak; Karakayali, Feza; Moray, Gokhan; Haberal, Mehmet A.
Pregnancy Outcomes in Kidney Transplant Recipients And Their Newborns
(2022) Sayin, Burak; Akdur, Aydincan; Dogan, Berna; Karakas, Latife Atasoy; Karakaya, Emre; Soy, Ebru H. Ayvazoglu; Haberal, Mehmet; 0000-0002-3462-7632; 0000-0002-4879-7974; AAJ-8097-2021; AAD-5466-2021
Renin-Angiotensin System Blockage and Avoiding High Doses of Calcineurin Inhibitors Prevent Interstitial Fibrosis and Tubular Atrophy in Kidney Transplant Recipients
(2017) Sayin, Burak; Canver, Burak; Demirci, Bahar Gurlek; Colak, Turan; Ozdemir, Binnaz Handan; Haberal, Mehmet; https://orcid.org/0000-0001-8287-6572; https://orcid.org/0000-0002-8372-7840; https://orcid.org/0000-0002-7528-3557; https://orcid.org/0000-0002-3462-7632; 28260428; J-3707-2015; AAJ-8554-2021; X-8540-2019; AAJ-8097-2021
Objectives: Chronic allograft dysfunction is a complex and multifactorial process characterized by progressive interstitial fibrosis and tubular atrophy. The finding of interstitial fibrosis and tubular atrophy is prevalent among kidney transplant patients receiving a calcineurin inhibitor-based immunsuppressive regimen and may be considered as a surrogate of allograft survival. Both immune (acute rejection episodes, sensitization, and HLA incompatibility) and nonimmune (donor age, delayed graft function, calcineurin inhibitor toxicity, infections, and hypertension) mechanisms play a role in chronic allograft dysfunction, and different causes all lead to similar histologic and clinical final pathways, with the end result of graft loss. In our study, we aimed to compare the outcomes of kidney transplant recipients with or without interstitial fibrosis and tubular atrophy in protocol biopsies to determine the conditions that may affect allograft survival. Materials and Methods: We divided 192 kidney transplant recipients into 2 groups (96 patients with interstitial fibrosis and tubular atrophy; 96 patients without interstitial fibrosis and tubular atrophy) according to protocol biopsy at 6 months. Patient groups were compared according to their risk factors for chronic allograft dysfunction (cold ischemia time, delayed graft function, donor age, infections, mean blood calcineurin levels, and hypertension). Results: Cold ischemia time, delayed graft function, high 24-hour proteinuria levels, and higher mean blood calcineurin levels were found to be major risk factors for poor graft function in kidney transplant recipients with interstitial fibrosis and tubular atrophy. Renin-angiotensin system blockage with either angiotensin-converting enzyme inhibitors or angio tensin receptor blockers was found to be preventive for interstitial fibrosis and tubular atrophy after kidney transplant. Conclusions: Preventing prolongation of cold ischemia time, lowering blood cholesterol levels, angiotensin-converting enzyme inhibitors and angiotensin receptor blocker treatment even without existing proteinuria and avoiding higher doses of calcineurin inhibitors should be major approaches in kidney transplant recipients.
Risk Factors and Treatment Options for Persistent Hyperparathyroidism After Kidney Transplantation
(2020) Kirnap, Nazli Gulsoy; Kirnap, Mahir; Sayin, Burak; Akdur, Aydincan; Tutuncu, Neslihan Bascil; Haberal, Mehmet; 0000-0002-8726-3369; 0000-0002-3462-7632; 0000-0002-1816-3903; 0000-0001-8287-6572; 31924405; AAA-3068-2021; AAJ-8097-2021; ABG-5027-2020; J-3707-2015
Background. Kidney transplantation (KT) corrects secondary hyperparathyroidism. However, persistent hyperparathyroidism (pHPT) may be observed in some patients post-KT. This study aims to evaluate the risk factors and treatment options for pHPT. Materials and methods. The study population comprises 1054 patients who underwent KT between January 2001 and May 2019. Serum samples were analyzed for calcium (Ca), phosphorus, creatinine, intact parathyroid hormone (iPTH) and estimated glomerular filtration rate. Results. The prevalence of pHPT following KT is 14%. Ninety pHPT patients were compared with 550 non-pHPT patients. The median duration of pre-KT dialysis was longer, and pre-KT serum Ca, P, and iPTH levels were significantly higher in the pHPT group than the non-HPT group. The pHPT of 46 patients (51%) received medical treatment. The remaining 44 patients (49%) had parathyroidectomy (PTx) if symptoms or signs (or both) of pHPT continued. Subtotal PTx was performed in 35 patients, and minimally invasive PTx was performed in 9 patients. Conclusion. Based on our study results, the most important risk factors for post-KT pHPT are long dialysis duration and high pre-KT iPTH levels. In patients who underwent KT, if pHPT lasts longer than 1 year, surgical treatment is the recommended approach. Based on our experience, the treatment method to be performed in pHPT should be 3+1/2 PTx.
Sensitization Status of Patients on the Deceased Donor Kidney Transplant Waiting List: A Single-Center Experience
(2022) Erdogmus, Siyar; Celebi, Zeynep Kendi; Turgut, Didem; Sayin, Burak; Ozdemir, Fatma Nurhan; Colak, Turan; Haberal, Mehmet; 0000-0002-3462-7632; AAJ-8097-2021
Objectives: This study aimed to analyze the features of patients on the deceased donor kidney transplant waiting list and risk factors associated with sensitization that affect panel reactive antibody status in our center. Methods: Patients' data were collected retrospectively. Panel reactive antibody screening and definition tests were studied for class I (A, B, and C) and class II (DR, DP, DQ) antigens with Luminex every 6 months. Patients with panel reactive antibody >5% and antibody strength >1000 median fluorescence intensity were considered panel reactive antibody-positive. Based on the panel reactive antibody status, the patients were divided into 2 groups: the panel reactive antibody-positive group and -negative group. Results: A total of 338 patients (60% male, mean age: 52.6 +/- 14.6 years) were included in the analysis. Panel reactive antibody positivity was detected in 117 (34.6) patients on the waiting list. Compared with the panel reactive antibody-negative patient group, the panel reactive antibody-positive patient group had higher rate of women and lower age (P <.001 and P <.001, respectively). The patients in the panel reactive antibody-positive group also had longer dialysis vintage (P =.027), higher rate of blood transfusion history (P <.001), organ transplant (P <.001), and higher number of blood transfusion (P <.001). Female gender (odd ratio:4.094, 95% CI:2.275-7.368, P <.001), history of blood transfusion (odds ratio:2.027, 95% CI:1.131-3.633, P =.018), and organ transplant (odds ratio:16.894, 95% CI:7.212-39.578, P <.001) were independent risk factors associated with panel reactive antibody positivity. Conclusion: Updates of the organ allocation system to consider sensitized patients and new strategies to expand the donor pool and donation rates are needed in Turkiye.