Increased Frequency of Circulating Activated FOXP3+ Regulatory T Cell Subset in Patients with Chronic Lymphocytic Leukemia Is Associated with the Estimate of the Size of the Tumor Mass, STAT5 Signaling and Disease Course during Follow-Up of Patients on Therapy.

INTRODUCTION: Advanced chronic lymphocytic leukemia (CLL) is accompanied by increased circulating regulatory T cells (Tregs) and increased susceptibility to severe infections, which were also shown to entail a striking induction of FOXP3 expression in Tregs. As homeostasis of the most suppressive CD45RA-FOXP3high activated Treg (aTreg) subset differs, it is critical to analyse homeostatic signalling in Treg subsets. MATERIALS AND METHODS: In this study, by using conventional and imaging flow cytometry, we monitored STAT5 signalling/phosphorylation (pSTAT5) and investigated Treg subsets in relation to the Binet stage, the total tumor mass score (TTM) and the disease course during a follow-up of 37 patients with CLL. RESULTS: The aTreg percentage was significantly increased among CD4+ T cells from patients with advanced disease and significantly correlated with the TTM. A subgroup of patients with higher aTreg percentages among CD4+FOXP3+ T cells at the start of therapy was characterised by more frequent episodes of severe infections during follow-up. CONCLUSIONS: The results suggesting that an aTreg fraction could represent a possible marker of a severe disease course with infectious complications. Augmented homeostatic STAT5 signalling could support aTreg expansion, as higher pSTAT5 levels were significantly correlated with an increased aTreg frequency among CD4+FOXP3+ T cells during the follow-up of patients on therapy, as well as following SARS-CoV-2 antigen-specific stimulation in vitro.

Clinical Properties and Non-Clinical Testing of Mineralocorticoid Receptor Antagonists in In Vitro Cell Models.

Mineralocorticoid receptor antagonists (MRAs) are one of the renin-angiotensin-aldosterone system inhibitors widely used in clinical practice. While spironolactone and eplerenone have a long-standing profile in clinical medicine, finerenone is a novel agent within the MRA class. It has a higher specificity for mineralocorticoid receptors, eliciting less pronounced adverse effects. Although approved for clinical use in patients with chronic kidney disease and heart failure, intensive non-clinical research aims to further elucidate its mechanism of action, including dose-related selectivity. Within the field, animal models remain the gold standard for non-clinical testing of drug pharmacological and toxicological properties. Their role, however, has been challenged by recent advances in in vitro models, mainly through sophisticated analytical tools and developments in data analysis. Currently, in vitro models are gaining momentum as possible platforms for advanced pharmacological and pathophysiological studies. This article focuses on past, current, and possibly future in vitro cell models research with clinically relevant MRAs.

Iohexol plasma clearance measurement protocol standardization for adults: a consensus paper of the European Kidney Function Consortium.

International consensus supports the development of standardized protocols for measured glomerular filtration rate (mGFR) to facilitate the integration of mGFR testing in both clinical and research settings. To this end, the European Kidney Function Consortium convened an international group of experts with relevant experience in mGFR. The working group performed an extensive literature search to inform the development of recommendations for mGFR determination using 1-compartment plasma clearance models and iohexol as the exogenous filtration marker. Iohexol was selected as it is non-radio labeled, inexpensive, and safe, can be assayed at a central laboratory, and the other commonly used non-radio-labeled tracers have been (inulin) or are soon to be (iothalamate) discontinued. A plasma clearance model was selected over urine clearance as it requires no urine collection. A 1 compartment was preferred to 2 compartments as it requires fewer samples. The recommendations are based on published evidence complemented by expert opinion. The consensus paper covers practical advice for patients and health professionals, preparation, administration, and safety aspects of iohexol, laboratory analysis, blood sample collection and sampling times using both multiple and single-sample protocols, description of the mGFR mathematical calculations, as well as implementation strategies. Supplementary materials include patient and provider information sheets, standard operating procedures, a study protocol template, and support for mGFR calculation.

Treatment of acute kidney injury with continuous renal replacement therapy and cytokine adsorber (CytoSorb®) in critically ill patients with COVID-19.

INTRODUCTION: This retrospective study aimed to evaluate the 30 and 60-day survival of critically ill patients with COVID-19 and AKI. METHODS: Inflammatory and biochemical biomarkers, length of intensive care unit (ICU) stay and mortality at Day 30 and Day 60 after ICU admission were analyzed. A total of 44 patients treated with continuous renal replacement therapy (CRRT) with cytokine adsorber (CA group) were compared to 58 patients treated with CRRT alone (non-CA group). RESULTS: Patients in CA group were younger, had better preserved kidney function prior to the beginning of CRRT and had higher levels of interleukin-6. There were no statistically significant differences in their comorbidities and in other measured biomarkers between the two groups. The number of patients who died 60 days after ICU admission was statistically significantly higher in non-CA group (p = 0.029). CONCLUSION: Treatment with CRRT and cytokine adsorber may have positively influenced 60-day survival in our COVID-19 ICU patients with AKI.

Renal Disease in Metabolic Syndrome: the Hidden Role of Intrarenal Ischemia.

Introduction: The pathogenesis of renal disease in obesity and metabolic syndrome (MS) is mostly unknown. This is in part because of the limited information about renal morphological changes in these conditions. We evaluated renal histology in subjects with MS and those without MS, who are participants in the European Nephrectomy Biobank (ENBiBA) project. Methods: MS was defined with at least 3 of the following criteria: (i) body mass index (BMI) ≥27 kg/m2; (ii) prediabetes: fasting glucose of 100-125 mg/dl or HbA1c >5.7%; (iii) systolic or diastolic blood pressure >140/90 mm Hg or the use of medications; and (iv) triglycerides >150 mg/dl or high-density lipoprotein cholesterol <40 (in men) or 50 mg/dl (in women). The absence of these criteria defined patients without MS. Exclusion criteria were diabetes or known causes of renal disease. Results: A total of 157 cases were evaluated: 49 without and 108 with MS. Those with MS were older (54 ± 16 vs. 66 ± 11, P < 0.0001), had more prevalent chronic kidney disease (CKD, estimated glomerular filtration rate [eGFR] <60 ml/min): 24% (23%) versus 4% (8%) (P = 0.02), and had higher albumin-to-creatinine ratio (10 [4-68] vs. 4.45 [0-27], P = 0.05) than those without MS. Global sclerosis (3% [1-7] vs. 7% [3-13], P < 0.0001), nodular sclerosis, mesangial expansion, glomerulomegaly; moderate + severe hyalinosis, and arteriosclerosis were more frequent in those with MS than in those without (88 [82] vs. 29 [59]; 83 [77] vs. 30 [61]; P < 0.05). These vascular changes were independent of differences in age. Conclusion: In MS, ischemic renal disease may play a role in renal disease. In addition, some patients may develop lesions compatible with diabetic nephropathy such as increased mesangial expansion and nodular sclerosis. Further analyses are needed to study the consequences of the pandemic of obesity on renal health.

Finerenone: From the Mechanism of Action to Clinical Use in Kidney Disease.

Diabetic kidney disease is a frequent microvascular complication of diabetes and is currently the leading cause of chronic kidney disease and end-stage kidney disease worldwide. Although the prevalence of other complications of diabetes is falling, the number of diabetic patients with end-stage kidney disease in need of kidney replacement therapy is rising. In addition, these patients have extremely high cardiovascular risk. It is more than evident that there is a high unmet treatment need in patients with diabetic kidney disease. Finerenone is a novel nonsteroidal mineralocorticoid receptor antagonist used for treating diabetic kidney disease. It has predominant anti-fibrotic and anti-inflammatory effects and exhibits several renal and cardiac protective effects. This review article summarizes the current knowledge and future prospects of finerenone in treating patients with kidney disease.

Psychometric Testing of the Slovene Version of the Perceived Inventory of Technological Competency as Caring in Nursing.

The Perceived Inventory of Technological Competency as Caring in Nursing (PITCCN) questionnaire has been designed to measure technological competency as caring in nursing practice. It incorporates the use of technology with the fundamental principles of caring that are central to nursing. As there were no psychometrically sound instruments to quantify the concept of technological competency as caring in the Slovene language, we adapted the English version of the questionnaire to the local environment. The goal was to assess the level of psychometric properties of the PITCCN investigated in Slovene hospitals. METHODS: Content validity was conducted with eight experts and quantified by the content validity index (CVI) and the modified Cohen's kappa index. Face validity was assessed through discussions with participants from the target culture in the pilot study. To assess construct validity and internal consistency, a cross-sectional research methodology was used on a convenience sample of 121 nursing personnel from four hospitals. Principal component analysis (PCA) was used to examine construct validity, while Cronbach's alpha and adjusted item-total correlations were used to measure internal consistency. RESULTS: The content and face validity of PITCCN were adequate. The scale validity index (S-CVI) was 0.97. Cronbach's α was 0.92, and subscale reliabilities ranged from 0.810 to 0.925. PCA showed four components, which explained more than 73.49% of the variance. CONCLUSIONS: The Slovenian version of PITCCN (PITCCN_SI) has good psychometric properties.

Simply adding oral nutritional supplementation to haemodialysis patients may not be enough: a real-life prospective interventional study.

Introduction: Protein-energy wasting (PEW) is a common and serious co-morbidity in haemodialysis (HD) patients. Its importance as a prognostic factor has been increasingly recognised during the past decades. Much effort has been invested in the improvement of nutritional status and amelioration of consequences through different therapeutic approaches, either intradialytic parenteral nutrition or more commonly oral nutritional supplementation. In the article, we present the results of a prospective study in HD patients after 12 months of therapeutic intervention with oral nutritional supplements (ONS). Methods: A total of 92 HD adult patients were enrolled in the study after 3 months of wash-out period. Baseline nutritional status was assessed using composite scores, laboratory markers, bioelectrical impedance analysis, and hand-grip strength test. Patients recognised as undernourished or at high risk for undernutrition received renal-specific commercially available ONS on HD day in addition to their regular diet. After 12 months, the effect of ONS on surrogate markers of undernutrition, serum albumin level, phase angle, and hand-grip strength was analysed in 71 surviving patients. Results: After 12 months, data for 71 patients, 39 (54.9%) men, 62.4 ± 12.9 years, and median haemodialysis vintage 53.3 (IQR 27.5-92.8) months, were available. Patients were divided into three groups: group A patients were with normal nutritional status at baseline not necessitating ONS; group B patients received ONS; and group C patients were entitled to receive but refused to take ONS. The baseline results showed statistically significant differences between the groups in serum albumin levels and phase angle but not hand-grip strength. Differences between the groups remained statistically significant at month 12; we did not find any statistically significant positive changes within the groups, indicating no positive effect of intervention with ONS. Conclusion: In a prospectively designed interventional single-centre study, we did not find a statistically significant change in surrogate markers of PEW in our cohort of HD patients, receiving ONS for 12 months. Since PEW is an independent risk factor influencing the survival of HD patients, efforts should be directed towards a timely and comprehensive nutritional approach, including intensive, personalised dietary counselling, increase in protein and energy intake and advocating tight control of nutritional status during HD treatment, possibly providing psychological support and motivation.

The Role of Oxidative Stress in Kidney Injury.

Acute kidney injury and chronic kidney disease are among the most common non-communicable diseases in the developed world, with increasing prevalence. Patients with acute kidney injury are at an increased risk of developing chronic kidney disease. One of kidney injury's most common clinical sequelae is increased cardiovascular morbidity and mortality. In recent years, new insights into the pathophysiology of renal damage have been made. Oxidative stress is the imbalance favoring the increased generation of ROS and/or reduced body's innate antioxidant defense mechanisms and is of pivotal importance, not only in the development and progression of kidney disease but also in understanding the enhanced cardiovascular risk in these patients. This article summarizes and emphasizes the role of oxidative stress in acute kidney injury, various forms of chronic kidney disease, and also in patients on renal replacement therapy (hemodialysis, peritoneal dialysis, and after kidney transplant). Additionally, the role of oxidative stress in the development of drug-related nephrotoxicity and also in the development after exposure to various environmental and occupational pollutants is presented.

Higher Body Mass Index is associated with increased arterial stiffness prior to target organ damage: a cross-sectional cohort study.

BACKGROUND: Obesity is associated with several neurohumoral changes that play an essential role in organ damage. Increased arterial stiffness causes functional vessel wall changes and can therefore lead to accelerated target organ damage as well. Whether obesity causes an independent increase in central arterial stiffness is, however, not yet fully known. METHODS: One hundred thirty-three patients (63.2% male) were included. Body Mass Index (BMI) was defined as body weight in kilograms, divided by the square of body height in meters. Chronic Kidney Disease Epidemiology Collaboration creatinine 2009 equation was used to estimate the glomerular filtration rate (eGFR). Non-invasive applanation tonometry was used for arterial stiffness measurements (Sphygmocor Atcor Medical, Sydney, Australia). All patients underwent coronarography. RESULTS: The mean age of our patients was 65.0 ± 9.2 years. Their mean BMI was 28.5 ± 4.4 kg/m2, eGFR 75.5 ± 17.2 ml/min/1.73 m2 and ankle-brachial index (ABI) 1.0 ± 0.1. Their arterial stiffness measurements showed mean carotid-femoral pulse wave velocity (cfPWV) 10.3 ± 2.7 m/s, subendocardial viability ratio (SEVR) 164.4 ± 35.0%, and pulse pressure (PP) 47.8 ± 14.5 mmHg. Spearman's correlation test revealed a statistically significant correlation between BMI and SEVR (r = -0.193; p = 0.026), BMI and cfPWV (r = 0.417; p < 0.001) and between BMI and PP (r = 0.227; p = 0.009). Multiple regression analysis confirmed an independent connection between BMI and cfPWV (B = 0.303; p < 0.001) and between BMI and SEVR (B = -0.186; p = 0.040). There was no association between BMI and kidney function, ABI, or coronary artery disease. CONCLUSION: Increased BMI is independently associated with augmented central arterial stiffness and reduced subendocardial perfusion but not with coronary artery disease, kidney function, or ABI.

Atherosclerosis and Epigenetic Modifications in Chronic Kidney Disease.

Chronic kidney disease (CKD) is one of the most common chronic diseases worldwide, with prevalence currently projected at 10% and rising. Cardiovascular disease is the leading cause of morbidity and mortality in CKD patients and is integrally linked with atherogenesis and vascular stiffness. Estimated glomerular filtration rate and the level of proteinuria are not only markers of kidney function but of cardiovascular risk, as well. Despite the efforts, CKD patients still experience excessive cardiovascular burden. MicroRNAs (miRNAs) are small (18-24 nucleotides), single-stranded non-coding RNAs that regulate gene expression by blocking messenger RNA (mRNA) translation and initiating degradation of mRNA. Studies have confirmed the imperative role of miRNA dysregulation in the pathophysiology of several diseases, including atherosclerosis and CKD. This article summarizes what is currently known about the role of miRNAs in CKD patients.

Renal Proximal Tubular Epithelial Cells: From Harvesting to Use in Studies.

The kidneys are the body's main excretion organ with several additional functions, and the nephron represents their central structural unit. It is comprised of endothelial, mesangial, glomerular, and tubular epithelial cells, as well as podocytes. Treatment of acute kidney injury or chronic kidney disease (CKD) is complex due to broad etiopathogenic mechanisms and limited regeneration potential as kidney cells finish their differentiation after 34 weeks of gestation. Despite the ever-increasing prevalence of CKD, very limited treatment modalities are available. The medical community should therefore strive to improve existing treatments and develop new ones. Furthermore, polypharmacy is present in most CKD patients, while current pharmacologic study designs lack effectiveness in predicting potential drug-drug interactions and the resulting clinically relevant complications. An opportunity for addressing these issues lies in developing in vitro cell models based on patient-derived renal cells. Currently, several protocols have been described for isolating desired kidney cells, of which the most isolated are the proximal tubular epithelial cells. These play a significant role in water homeostasis, acid-base control, reabsorption of compounds, and secretion of xenobiotics and endogenous metabolites. When developing a protocol for the isolation and culture of such cells, one must focus on several steps. These include harvesting cells from biopsy specimens or after nephrectomies, using different digestion enzymes and culture mediums to facilitate the selective growth of only the desired cells. The literature reports several existing models, from simple 2D in vitro cultures to more complex ones created with bioengineering methods, such as kidney-on-a-chip models. While their creation and use depend on the target research, one should consider factors such as equipment, cost, and, even more importantly, source tissue quality and availability.

Chronic Kidney Disease and Obesity.

There is a pandemic of obesity worldwide and in Europe up to 30% of the adult population is already obese. Obesity is strongly related to the risk of CKD, progression of CKD, and end-stage renal disease (ESRD), also after adjustment for age, sex, race, smoking status, comorbidities, and laboratory tests. In the general population, obesity increases the risk of death. In nondialysis-dependent CKD patients, the association between body mass index and weight with mortality is controversial. In ESRD patients, obesity is paradoxically associated with better survival. There are only a few studies investigating changes in weight in these patients and in most weight loss was associated with higher mortality. However, it is not clear if weight change was intentional or unintentional and this is an important limitation of these studies. Management of obesity includes life-style interventions, bariatric surgery, and pharmacotherapy. In the last 2 years, a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist and GLP-1 and glucose-dependent insulinotropic polypeptide receptor agonist were shown to be effective in managing weight loss in non-CKD patients, but we are awaiting results of more definitive studies in CKD patients.

New Flow Cytometric Methods for Monitoring STAT5 Signaling Reveal Responses to SARS-CoV-2 Antigen-Specific Stimulation in FOXP3+ Regulatory T Cells also in Patients with Advanced Chronic Lymphocytic Leukemia.

Increased frequency of CD4+CD25+ regulatory T-cells (Treg) has been associated with disease progression in chronic lymphocytic leukemia (CLL). Flow cytometric methods, which allow for the simultaneous analysis of their specific transcription factor Foxp3 and activated STAT proteins, together with proliferation can help to elucidate the signaling mechanisms driving Treg expansion and suppression of FOXP3- conventional CD4+T-cells (Tcon). Herein, we first report a novel approach in which STAT5 phosphorylation (pSTAT5) and proliferation (BrdU-FITC incorporation) could be analyzed specifically in FOXP3+ and FOXP3- responding cells after CD3/CD28 stimulation. The addition of magnetically purified CD4+CD25+ T-cells from healthy donors to cocultured autologous CD4+CD25- T-cells resulted in suppression of Tcon cell cycle progression accompanied by a decrease in pSTAT5. Next, a method using imaging flow cytometry is presented for the detection of cytokine-dependent pSTAT5 nuclear translocation in FOXP3-expressing cells. Finally, we discuss our experimental data obtained by combining Treg pSTAT5 analysis and antigen-specific stimulation with SARS-CoV-2 antigens. Applying these methods on samples from patients revealed Treg responses to antigen-specific stimulation and significantly higher basal pSTAT5 in CLL patients treated with immunochemotherapy. Thus, we speculate that through the use of this pharmacodynamic tool, the efficacy of immunosuppressive drugs and their possible off-target effects can be assessed.

Serum zinc values, ankle brachial index and mortality in hemodialysis patients.

INTRODUCTION: The atherosclerotic state of haemodialysis (HD) patients may be influenced by heavy metals. The purpose of our study was to assess the relationship between serum zinc (Zn) ankle brachial index (ABI) as a non-invasive diagnostic tool for atherosclerosis, and mortality in chronic haemodialysis (HD) patients. METHODS: Sixty one HD patients were included (mean age 61.2 ± 13.8 years). The ABI was measured with an automated measuring device (ABPI MD, MESI®, Slovenia). Two groups of patients were formed based on the median value of Zn (14.1 mcmol/l). The average observation time was 2.8 years. Comorbidities (arterial hypertension (AH), diabetes mellitus (DM), dyslipidaemia), smoking and oral nutritional supplements (ONS) consumption were noted. Survival rates were analysed by Kaplan-Meier and Cox regression was used to determine the influence of Zn, ABI, AH, DM, dyslipidaemia, smoking and ONS. RESULTS: Zn values were between 9.2 and 23.5 mcmol/l (14.4 ± 2.34), ABI values ranged from 0.8 to 1.4 (1.14 ± 0.12). Patients with lower Zn values had lower ABI (p = 0.036). Mean survival time of patients with higher Zn values was 985 days ± 277 days and with lower Zn values 1055 ± 143 days. Six (19.4%) patients with lower Zn and five (16.7%) patients with higher Zn died. We found statistically insignificant lower survival in patients with higher Zn. We failed to find any predictor of all-cause mortality, except for ONS consumption (95% CI 1.6-33.3; p = 0.012). CONCLUSIONS: Lower Zn is associated with lower ABI in HD patients, but we found no impact of Zn on patient survival.

Polypharmacy and Mental Health Issues in the Senior Hemodialysis Patient.

Hemodialysis (HD) is the most common method of chronic kidney failure (CKF) treatment, with 65% of European patients with CKF receiving HD in 2018. Regular two to three HD sessions weekly severely lower their quality of life, resulting in a higher incidence of depression and anxiety, which is present in one third to one half of these patients. Additionally, the age of patients receiving HD is increasing with better treatment and care, resulting in more cognitive impairment being uncovered. Lastly, patients with other mental health issues can also develop CKF during their life with need for kidney replacement therapy (KRT). All these conditions need to receive adequate care, which often means prescribing psychotropic medications. Importantly, many of these drugs are eliminated through the kidneys, which results in altered pharmacokinetics when patients receive KRT. This narrative review will focus on common issues and medications of CKF patients, their comorbidities, mental health issues, use of psychotropic medications and their altered pharmacokinetics when used in HD, polypharmacy, and drug interactions, as well as deprescribing algorithms developed for these patients.

Technological Competency As Caring in Nursing: a Description, Analysis and Evaluation of The Theory.

Introduction: When introducing and using technology in nursing, there is a danger that too much focus is placed on technology over caring for patients. The 'Technological competency as caring in nursing' theory can facilitate technology in caring, but the theory needs to be described, analysed and evaluated before it is used. The purpose of the literature review was to determine the possibility of applying the theory in education, research and practice, and whether the theory could be used to guide research into the use of electronic nursing record systems. Methods: A literature search was conducted in PubMed, CINAHL, ScienceDirect, Google Scholar and Google Books, and supplemented with manual searching using the keywords 'Locsin', 'technology', 'caring' and 'nursing theory'. The criteria for inclusion were fully accessible articles and books in English on the relevant topics. The review process is shown in a PRISMA diagram. A hierarchy of evidence was used to evaluate the relative strength of the results. Pajnkihar's model was used to describe, analyse and evaluate the theory. Results: A total of 26 hits were included in the final analysis. The theory in question meets the criteria of clarity, simplicity and complexity, adequacy, importance and significance; it can be tested; and it is useful in patient care that employs technology. Discussion and conclusion: The theory is useful in nursing education, research and practice. The theory will be used to guide research on the perception of technological competency and care of internal medicine patients by nurses when using the electronic nursing record system in three Slovenian hospitals.

Early Detection of Arteriovenous Fistula Stenosis in Hemodialysis Patients through Routine Measurements of Dialysis Dose (Kt/V).

BACKGROUND: Monitoring of arteriovenous (AV) fistula to detect hemodynamically important stenosis is crucial for the prevention of AV fistula thrombosis. The aim of our study was to analyze the importance of dialysis dose (Kt/V) during online postdilution hemodiafiltration (HDF) for early detection of AV fistula stenosis. METHODS: Hemodialysis patients with AV fistula were included in this study. We compared a group of 44 patients who have undergone fistulography and subsequently percutaneous transluminal angioplasty (PTA) of significant AV fistula stenosis (active group) with a group of 44 age- and sex-matched patients without PTA (control group). Observational time in both groups was the same. RESULTS: All patients had postdilution online HDF using a F5008 dialysis machine, which can measure online single-pool Kt/V. All data were analyzed during the performance of 2056 HDF procedures. In the active group, we found statistically significantly lower values of Kt/V, all 8 weeks before PTA. In the active group, there was a significant improvement in Kt/V in the first (p < 0.001) and second week (p = 0.049) after PTA. Three and 8 weeks after PTA, we did not find any statistically significant difference in Kt/V between both groups (p = 0.114; p = 0.058). Patients in the active group had statistically significantly lower substitution volumes and blood pump flow rates during HDF over the whole observation period before and after PTA. In contrast, there were no differences in venous pressure in the dialysis circuit between both groups throughout the observation period. CONCLUSION: In hemodialysis patients with AV fistula, treated with online HDF, routine measurements of Kt/V during each HDF are a beneficial, quick, and straightforward method for early detection of hemodynamically significant AV fistula stenosis.

The role of kidney function on patient survival after percutaneous coronary intervention for acute coronary syndrome in left main coronary artery disease.

BACKGROUND: The prevalence of chronic kidney disease (CKD) is increasing on a global scale. Patients with CKD have a reduced quality of life and are more likely to develop significant cardiovascular disease, most commonly coronary artery disease (CAD). Left main coronary artery disease (LMCAD) is one of the most severe forms of CAD, where revascularization is needed. The aim of the study was to determine the impact of CKD on the mortality of patients after undergoing percutaneous coronary intervention (PCI) for the acute coronary syndrome (ACS) due to LMCAD. MATERIALS AND METHODS: 210 Caucasian patients (142 male; 67.6%, mean age 69.2 ± 11.3 years) with ACS due to LMCAD who underwent primary PCI were included in this retrospective study. Basic demographic and laboratory data were recorded. Patients were divided into two groups by their estimated glomerular filtration rate (eGFR). Those in the CKD group had eGFR ≤ 60 mL/min/1.73m2 (n = 82), and those in the non-CKD group had eGFR > 60 mL/min/1.73m2 (n = 128). RESULTS: The mean survival time of patients in the CKD group was 1,550 ± 1,393 days, compared to the non-CKD group of 2,149 ± 1,235 days. Kaplan-Meier survival analysis showed a statistically significant (log-rank, p < 0.0005) difference in mortality for patients in the CKD group compared to those in the non-CKD group. Cox-regression analysis showed a correlation between CKD and mortality (B = 0.541, p = 0.036), independent of arterial hypertension, diabetes mellitus, total cholesterol, and triglycerides. CONCLUSION: CKD is an independent risk factor for increased mortality after PCI due to an ACS in LMCAD.