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Article Citation - WoS: 2Citation - Scopus: 2Potential Role of SGLT-2 Inhibitors in Improving Allograft Function and Reducing Rejection in Kidney Transplantation(Wiley, 2025) Demir, Mehmet Emin; Helvaci, Ozant; Yildirim, Tolga; Merhametsiz, Ozgur; Sezer, SirenSodium-glucose cotransporter-2 inhibitors (SGLT-2i) have demonstrated renoprotective and cardioprotective benefits beyond their antiglycemic effects. Their potential utility in kidney transplant recipients (KTRs) for preserving graft function and reducing rejection risk is currently under active investigation. Preliminary studies indicate that SGLT-2i therapy stabilizes estimated glomerular filtration rate (eGFR), decreases glomerular hyperfiltration, and improves metabolic outcomes in KTRs. Emerging clinical evidence also suggests that SGLT-2i may be associated with reduced rates of acute rejection, although direct immunosuppressive actions remain unclear. Experimental findings further suggest that SGLT-2i modulates gene regulation pathways involved in inflammation, oxidative stress, and fibrosis, contributing to improved allograft outcomes. Current safety data in KTRs are reassuring, without significant increases in urinary tract infections or adverse graft events. Nevertheless, long-term prospective studies specific to transplant populations are lacking. This review summarizes available evidence regarding the mechanisms of action, clinical efficacy, and safety profile of SGLT-2i in kidney transplantation, emphasizing their metabolic, hemodynamic, inflammatory, and immunomodulatory effects.Article Evaluation of Anti-Tetanus IgG Antibody Levels and Influencing Factors in Patients Undergoing Hemodialysis(Frontiers Media Sa, 2025) Ozsoy, Metin; Ozturk, Hakki; Tuna, Aysegul; Varlibas, Artuner; Cesur, Salih; Aksoy, Altan; Demir, Mehmet EminAim: This study aimed to assess anti-tetanus IgG antibody levels and identify determinants of inadequate tetanus immunity among maintenance hemodialysis (HD) patients. Methods: In this cross-sectional study, anti-tetanus IgG levels were measured by quantitative ELISA in 162 adult HD patients from two dialysis centers in Ankara, Turkey. Protective immunity was evaluated using both international (>= 0.1 IU/mL) and robust (>= 0.5 IU/mL) cut-offs. Demographic and clinical factors associated with immunity were analyzed by multivariate logistic regression. Results: Only 16.7% of HD patients achieved robust protection (>= 0.5 IU/mL), whereas 49.8% had minimal protection (>= 0.1 IU/mL). Protective immunity was independently associated with younger age (OR 1.07 per year; p = 0.004), shorter dialysis duration (OR 1.07; p = 0.030), male sex (female OR 2.92; p = 0.048), and recent booster vaccination within 10 years (OR 0.11; p < 0.001). Diabetes mellitus was not an independent factor. Conclusion: Most HD patients lacked durable tetanus immunity, particularly older females on long-term dialysis. The findings highlight the need for regular antibody monitoring, early revaccination, and structured booster programs to maintain adequate protection in this high-risk population.Article Comparison of SARS-CoV IgG Responses in Hemodialysis Patients and Healthcare Workers After COVID-19 Vaccination(Frontiers Media S.A., 2025) Ozturk, Hakki; Ozsoy, Metin; Tuna, Aysegul; Varlibas, Artuner; Cesur, Salih; Aksoy, Altan; Demir, Mehmet EminAim: This study aimed to compare SARS-CoV-2 IgG antibody levels in hemodialysis (HD) patients and healthcare workers (HCWs) after COVID-19 vaccination and to identify factors influencing these levels. Materials and methods: A total of 193 participants were included: 104 HD patients and 89 age- and sex-matched HCWs as controls. All had completed a primary COVID-19 vaccination series (two doses of CoronaVac or BNT162b2) and a booster dose. SARS-CoV-2 anti-spike IgG was measured at least one month after the last vaccine dose using a commercial immunoassay (Abbott SARS-CoV-2 IgG II Quant, CMIA). Results in Arbitrary Units (AU/mL) were converted to WHO standard Binding Antibody Units (BAU/mL) (1 AU/mL = 0.142 BAU/mL). IgG titers >= 7.1 BAU/mL (equivalent to 50 AU/mL) were considered positive. Results: All participants had positive SARS-CoV-2 IgG antibodies. There were no statistically significant differences in IgG levels between HD patients and HCWs at any individual time interval (<3 months, 3-6 months, or >6 months) or in the overall mean titers (HD: 1259 +/- 1112 BAU/mL; HCW: 1002 +/- 765 BAU/mL; p = 0.216). No individual in either group had an IgG titer below 7.1 BAU/mL. Vaccine type, dialysis vintage, and presence of comorbidities did not significantly impact antibody levels. In the HCWs group, those vaccinated only with CoronaVac had significantly lower IgG levels than those receiving only BNT162b2 or a heterologous regimen (CoronaVac followed by BNT162b2). However, among HD patients, IgG levels did not differ by vaccine regimen. Conclusion: HD patients mounted a SARS-CoV-2 IgG antibody response comparable to that of healthy HCWs, with no participant falling below the positivity threshold. Dialysis duration and comorbid conditions did not significantly affect post-vaccination IgG levels. While HCWs who received only CoronaVac showed lower antibody titers than those who received BNT162b2 or a heterologous schedule, this difference was not observed in HD patients. These results suggest that COVID-19 vaccination elicits a robust humoral immune response in the HD population, underscoring the benefit of vaccination in this high-risk group.Article Citation - WoS: 1Citation - Scopus: 1Factors Affecting Influenza and Pneumococcal Vaccination Rates in Hemodialysis Patients: a Multicenter Study(Dove Medical Press Ltd, 2025) Selen, Tamer; Merhametsiz, Ozgur; Onec, Kuersad; Ercan, Zafer; Islam, Mahmud; Altun, Gulsah; Demir, Mehmet EminPurpose: In patients with end-stage renal disease (ESRD), infections, particularly pneumonias, are the most common cause of hospital admissions and death after cardiovascular diseases. It is recommended that dialysis patients receive the pneumococcal vaccine every five years and the influenza vaccine annually. Our study aims to determine the awareness and factors affecting influenza and pneumococcal vaccination rates in hemodialysis patients. Patients and Methods: This cross-sectional study was conducted on patients undergoing regular hemodialysis treatment in 10 different hemodialysis centers across 4 cities. After excluding patients with less than one year of hemodialysis duration and those under 18 years of age, 548 patients were included in the study. Patients were administered a 20-item survey via face-to-face interview and electronic medical records. Results: Out of the 548 patients, only 19 (3.5%) had knowledge about the pneumococcal vaccine, while 238 (43.4%) had knowledge about the influenza vaccine. There were 220 patients (20.1%) who had knowledge about both vaccines. Among the patients, 95 (17.3%) had received the pneumococcal vaccine, with 41.1% of them having received it five years ago or more. A significant proportion (33.7%) of the patients could not recall the timing of their vaccination. While 183 (33.4%) patients had not received the influenza vaccine, only 140 (25.5%) had been vaccinated regularly every year. The reasons for not receiving the influenza and pneumococcal vaccines were stated as "I do not feel the need because I do not get the flu" (25%) and "I do not know about the pneumonia vaccine" (36.7%), respectively. The ROC curve analysis for the influenza questionnaire score showed an AUC of 0.822 (95% CI 0.787-0.856), with a p-value of <0.001. The statistically significant cutoff value for predicting influenza vaccination was determined to be 2.5. In the univariate analysis, dialysis duration (HD duration), diabetes mellitus (DM), and vascular access type were found to be statistically significant. In the multivariate logistic regression analysis, dialysis duration and DM were identified as independent factors predicting a higher level of knowledge about the influenza vaccine (p=0.009, 0.003, and p=0.041). The ROC curve analysis for the pneumococcal questionnaire score showed an AUC of 0.920 (95% CI 0.886-0.955), with a p-value of <0.001. The statistically significant cutoff value for predicting pneumococcal vaccination was determined to be 3.5. In the univariate analysis, residence, dialysis duration, and education level were found to be statistically significant. In the multivariate logistic regression analysis, dialysis duration and education level were identified as independent factors predicting a higher level of knowledge about the pneumococcal vaccine (p=0.038, 0.040, and p=0.010). physicians, nurses and nephrologists on this issue will increase vaccination rates.Article Citation - WoS: 14Citation - Scopus: 15The Results of Sglt-2 Inhibitors Use in Kidney Transplantation: 1-Year Experiences From Two Centers(Springer, 2023) Demir, Mehmet Emin; Ozler, Tuba Elif; Merhametsiz, Ozgur; Sozener, Ulas; Uyar, Murathan; Ercan, Zafer; Turkmen Sariyildiz, GulcinPurposeSodium-glucose co-transporter-2 inhibitor (SGLT-2i) administration is associated with some concerns in regard to the increased risk of genital and urinary tract infections (UTI) in kidney transplant recipients (KTR). In this study, we present the results of SGLT-2i use in KTR, including the early post-transplant period.MethodsParticipants were divided into two groups: SGLT-2i-free diabetic KTR (Group 1, n = 21) and diabetic KTR using SGLT-2i (Group 2, n = 36). Group 2 was further divided into two subgroups according to the posttransplant prescription day of SGLT-2i; < 3 months (Group 2a) and >= 3 months (Group 2b). Groups were compared for development of genital and urinary tract infections, glycated hemoglobin a1c (HgbA1c), estimated glomerular filtration rate (eGFR), proteinuria, weight change, and acute rejection rate during 12-month follow-up.ResultsUrinary tract infections prevalence was 21.1% and UTI-related hospitalization rate was 10.5% in our cohort. Prevalence of UTI and UTI-related hospitalization, eGFR, HgbA1c levels, and weight gain were similar between the SGLT-2i group and SGLT-2i-free group, at the 12-month follow-up. UTI prevalence was similar between groups 2a and 2b (p = 0.871). No case of genital infection was recorded. Significant proteinuria reduction was observed in Group 2 (p = 0.008). Acute rejection rate was higher in the SGLT-2i-free group (p = 0.040) and had an impact on 12-month follow-up eGFR (p = 0.003).ConclusionSGLT-2i in KTR is not associated with an increased risk of genital infection and UTI in diabetic KTR, even in the early posttransplant period. The use of SGLT-2i reduces proteinuria in KTR and has no adverse effects on allograft function at the 12-month follow-up.Article Investigation of Hepatitis E Virus Seroprevalence and Risk Factors in Hemodialysis Patients(Frontiers Media Sa, 2025) Ozturk, Hakki; Ozsoy, Metin; Tuna, Aysegul; Varlibas, Artuner; Cesur, Salih; Aksoy, Altan; Demir, Mehmet EminBackground: Hemodialysis patients are at increased risk for hepatitis E virus (HEV) infection due to their immunocompromised status and frequent exposure to invasive medical procedures. HEV can lead to chronic infections and severe complications, particularly in high-risk populations. This study aimed to determine HEV-IgG seroprevalence among hemodialysis patients in Ankara, Turkey, and evaluate associated risk factors. Methods: A total of 160 hemodialysis patients from three private dialysis centers in Ankara were included in this prospective, cross-sectional study. Anti-HEV-IgG antibodies were detected using the ELISA method. Demographic characteristics and potential risk factors, including dialysis duration, comorbidities, blood transfusion history, drinking water source, dietary habits, and involvement in animal husbandry, were assessed via structured surveys. Statistical analyses were conducted using SPSS Version 22.0, with Pearson's chi-square and Fisher's exact tests applied to categorical variables. Logistic regression analysis was performed to identify independent risk factors for HEV seropositivity. Results: HEV-IgG seropositivity was detected in 42 patients (26.25%). Seroprevalence increased significantly with age, rising from 6.7% in patients under 55 years to 47.4% in those over 65 years (p < 0.001). Extended dialysis duration (>5 years) was also significantly associated with HEV seropositivity (p = 0.02). However, no significant associations were found between HEV seropositivity and gender, blood transfusion history, source of drinking water, consumption of raw meat, or involvement in animal husbandry (p > 0.05). Conclusion: The HEV-IgG seroprevalence among hemodialysis patients in Ankara was higher than previously reported rates in Turkey. Age and prolonged dialysis duration emerged as significant risk factors, underscoring the importance of screening and preventive strategies in this vulnerable population. Further multi-regional studies are needed to better understand HEV transmission dynamics and improve management strategies in hemodialysis patients.Article Complex Multisource Sound Induces Greater Neurodegeneration in Neonatal Rat Brain than Single-Source Sound(Frontiers Media SA, 2026) Daltaban, Iskender Samet; Aydin, Mehmet Dumlu; Eyupoglu, Eylem Eren; Demirci, Elif; Okuyan, Aybike Aydin; Demir, Mehmet EminBackground: Excessive noise exposure is a known environmental health hazard linked to neurological injury and cognitive deficits. Whether complex sound waveforms from multiple sources exacerbate brain damage compared to a single-source noise of equal intensity remains unclear. We investigated the effects of identical music played either through one or four loudspeakers on the developing brain of newborn rats. Methods: Forty-one newborn Sprague-Dawley rat pups (both sexes), along with their dams, were randomly assigned to three groups: control (no noise, n = 6), single-speaker exposure (n = 15), and multi-speaker exposure (n = 20). From postnatal day 0 to 30, the exposure groups were subjected to an 8-min music track (similar to 85 dB SPL) either via one loudspeaker (simple waveform) or simultaneously via four loudspeakers (complex interfering waveform), six times daily at 4-h intervals. Sound intensity was calibrated at the cages with a sound-level meter. All procedures followed ARRIVE guidelines and the EU Directive 2010/63/EU for animal research, with institutional ethical approval. After 1 month, rat brains were examined histologically. Unbiased stereology was used to estimate neuronal densities in the temporal lobe (including amygdala and hippocampal dentate gyrus). Immunohistochemistry for neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP) and TUNEL assay (terminal deoxynucleotidyl transferase dUTP nick-end labeling) was performed to identify neuronal integrity, astroglial response, and apoptosis, respectively. Outcome measures were degenerated (TUNEL-positive) neuron densities and histopathological lesions. Statistical comparisons were made using Student's t-tests or ANOVA and chi-square tests (with p < 0.05 considered significant). Results: Eight of 20 pups (40%) in the multi-speaker group died during the exposure period, compared to 5/15 (33%) in the single-speaker group and 3/6 (50%) in controls (differences not statistically significant). Maternal rats exhibited agitation, stress behaviors, and weight loss under noise; some eventually ceased escape attempts (habituation/helplessness behavior) in both noise-exposed groups. Histologically, the multi-speaker exposure caused more severe brain injury than the single-speaker exposure. Pups in the multi-speaker group showed frequent subarachnoid hemorrhages and cortical microvascular bleeding in the temporal lobes, whereas these lesions were mild or infrequent in the single-speaker group and absent in controls. Neurons in noise-exposed brains displayed morphological signs of degeneration (shrunken, angulated cell bodies with pyknotic nuclei and condensed cytoplasm), which were markedly pronounced in the multi-speaker group. Stereological cell counting revealed a significant increase in apoptotic neuron density in both sound-exposed groups, with the multi-speaker group highest. For example, in the hippocampal dentate gyrus, the mean density of TUNEL-positive (degenerating) neurons was 13,450 +/- 1,560 per mm(3) in the multi-speaker group vs. 7,600 +/- 980 per mm(3) in the single-speaker group and only 200 +/- 34 per mm(3) in unexposed controls (p < 0.05). In the amygdala, apoptotic neuron density averaged 3,460 +/- 863 per mm(3) (multi-speaker) vs. 1,470 +/- 285 (single-speaker) and 1,321 +/- 234 (control), with the multi-speaker group showing a significantly higher burden of neuronal cell death (p < 0.005 for complex vs. simple waveforms). Correspondingly, multi-speaker exposed brains showed intense immunostaining for NSE and GFAP fragmentation, indicating widespread neuronal loss and reactive astroglial injury, whereas single-speaker exposure caused only moderate changes. Conclusion: Identical musical noise caused substantially more neurodegeneration in the developing brain when delivered as complex wave interference from multiple speakers rather than as a single-source sound of the same intensity. Complex multisource waveforms appear to amplify the harmful effects of noise on neonatal brain tissue, likely through interference-driven pressure fluctuations. These findings have clinical and public health implications, suggesting that current noise exposure guidelines should consider not only sound intensity and duration but also the acoustic complexity and source configuration, especially to protect vulnerable populations such as infants and children from high-intensity multisource noise environments.
