The Current State of Nuclear Nephrology in Modern Medicine.

Glomerular filtration rate (GFR) is the most reliable parameter of renal function. Regarding the complexity of the gold standard inulin clearance, different estimating equations have been developed with CKD-EPI creatinine equation recommended as the most reliable one. In some clinical situations where creatinine based equations might not be valid, alternative methods are needed. Nuclear medicine methods for measuring GFR with 51Cr EDTA and 99mTc DTPA have been widely used for decades. There are different methodologies for the measurement of kidney function with radiopharmaceuticals: urinary clearance, plasma clearance, multiple plasma sampling, slope intercept, single sample plasma equation, slope only, and the gamma camera-based method. Greater precision of measuring GFR is needed in certain clinical situations. The most common are diagnosis and follow up of chronic kidney disease and definition of the beginning of replacement therapy. The assessment of renal function is also important for potential kidney donors. In recent years, with the introduction of new chemotherapeutic drugs and targeted therapy, oncologic patients treated with nephrotoxic drugs have become more commonly referred for measuring GFR. The monitoring of renal function is important during treatment in order to detect the transformation from reversible acute kidney injury to irreversible chronic kidney disease as well as in the cases of renal insufficiency reduce the dosage and prevent accumulation of the drug and avoid dosage related toxic effects. Assessment of kidney function using measured mGFR will be an important milestone in the creation of more accurate and expanding personalized medicine principle in current onconephrology practice.

Predictive Admission Risk Factors, Clinical Features and Kidney Outcomes in Covid-19 Hospitalised Patients with Acute Kidney Injury.

Introduction: In COVID-19 patients, acute kidney injury (AKI) is recognized as a cause of high mortality. The aim of our study was to assess the rate and the predictors of AKI as well as survival among COVID-19 patients. Methods: We analyzed clinical and laboratory admission data, predictors of AKI and outcomes including the need for renal replacement therapy (RRT) and mortality at 30 days. Results: Out of 115 patients, 62 (53.9%) presented with AKI: 21 (33.9%) at stage 1, 7(11.3%) at stage 2, and 34 (54.8%) at stage 3. RRT was required in 22.6% of patients and was resolved in 76%. Pre-existing CKD was associated with a 13-fold risk of AKI (p= 0.0001). Low albumin (p = 0.017), thrombocytopenia (p = 0.022) and increase of creatine kinase over 350UI (p = 0.024) were independently associated with a higher risk for AKI. Mortality rates were significantly higher among patients who developed AKI compared to those without (59.6% vs 30.2%, p= 0.003). Low oxygen blood saturation at admission and albumin were found as powerful independent predictors of mortality (OR 0.937; 95%CI: 0.917 - 0.958, p = 0.000; OR 0.987; 95%CI: 0.885-0.991, p= 0.024, respectively). Longer survival was observed in patients without AKI compared to patients with AKI (22.01± 1.703 vs 16.69 ± 1.54, log rank p= 0.009). Conclusion: Renal impairment is significant in hospitalized COVID-19 patients. The severity of the disease itself is emphasized as main contributing mechanism in the occurrence of AKI, and lower blood saturation at admission is the strongest mortality predictor, surpassing the significance of the AKI itself.

Comorbid Conditions in a Cohort of Inpatients with SARS-CoV-2 and their Association with In-Hospital Mortality During the Early Phases of the Pandemic.

Introduction: Studies determined that age and associated comorbidities are associated with worse outcomes for COVID-19 patients. The aim of the present study is to examine previous electronic health records of SARS-CoV-2 patients to identify which chronic conditions are associated with in-hospital mortality in a nationally representative sample. Materials and Methods: The actual study is a cross-sectional analysis of SARS-CoV-2 infected patients who were treated in repurposed hospitals. The study includes a cohort of patients treated from 06-11-2020 to 15-03-2021 for COVID-19 associated pneumonia. To examine the presence of comorbidities, electronic health records were examined and analyzed. Results: A total of 1486 in-patients were treated in the specified period, out of which 1237 met the criteria for case. The median age of the sample was 65 years. The overall in-hospital mortality in the sample was 25.5%, while the median length of stay was 11 days. From whole sample, 16.0% of the patients did not have established diagnoses in their electronic records, while the most prevalent coexisting condition was arterial hypertension (62.7%), followed by diabetes mellitus (27.3%). The factors of age, male gender, and the number of diagnoses showed a statistically significant increase in odds ratio (OR) for in-hospital mortality. The presence of chronic kidney injury was associated with the highest increase of OR (by 3.37) for in-hospital mortality in our sample. Conclusion: The study reaffirms the findings that age, male gender, and the presence of comorbidities are associated with in-hospital mortality in COVID-19 treated and unvaccinated patients. Our study suggests that chronic kidney injury showed strongest association with the outcome, when adjusted for age, gender, and coexisting comorbidities.

Comparative analysis of different nuclear medicine techniques in evaluation of renal function.

INTRODUCTION: Nuclear medicine (NM) methods play an important role in the evaluation of renal function in a wide range of clinical indications. The aim of our study was to evaluate the correlation between measured GFR (mGFR) obtained by the three-plasma sample slope-intercept NM method (TPSM) - reference method vs. estimated GFR (eGFR) using Fleming's single plasma sample method (SPSM) at 120 min, 180 min, and 240 min and correlation of reference method with eGFR with camera-based Gates' protocol. MATERIAL AND METHODS: A total of 82 subjects (33 male/49 female) with a mean age of 54.87 ± 15.65 years were included and mGFR value was obtained by the three-plasma sample slope-intercept NM method and eGFR was obtained with Fleming's single sample method. eGFR was also quantified with the camera-based Gates' protocol after i.v. application of [99mTc]Tc-DTPA. RESULTS: Our study revealed a very strong positive significant correlation between all three SPSMs with the TPSM as the reference method. Between the Gates' method and the TPSM in the group of patients with mGFR ≥ 61-84 mL/min/1.73 m2 and mGFR ≥ 84 mL/min/1.73 m2, a moderate positive statistically significant correlation was obtained. CONCLUSIONS: The SPSM method shows a very strong correlation with the reference and low bias in all three groups of patients and can be routinely used for GFR estimation.

Glomerulopathies with Fibrillary Deposits.

The glomerulopathies associated with the deposition of extracellular fibrils in the glomeruli are subdivided into Congo red positive (amyloidosis) and Congo red negative (non-amyloidotic glomerulopathies) based on Congo red staining. The non-amyloidotic glomerulopathies are divided into immunoglobulin-derived and non-immunoglobulin-derived glomerulopathies. The immunoglobulin-derived glomerulopathies: fibrillary glomerulopathy (FGn) and immunotactoid glomerulopathy (ITG) are rare glomerulopathies. The diagnosis of fibrillary-immunotactoid glomerulopathy depends on electron microscopy, which shows the presence of microfibrils in the glomeruli. The microfibrils in FGn are randomly arranged with diameters less than 30 nm. The microfibrils in ITG are larger than 30 nm with a visible lumen (microtubules), focally arranged in parallel bundles. Patients with fibrillary-immunotactoid glomerulopathy present with proteinuria (usually in the nephrotic range), microscopic hematuria, arterial hypertension, and chronic kidney disease that progresses to kidney failure over months to years. Currently, there are no guidelines for the treatment of fibrillary-immunotactoid glomerulopathy, although immunotactoid glomerulopathy could be associated with underlying hematologic disorders with the need for clone-directed therapy.

Percutaneous Onsite Insertion of Catheter for Peritoneal Dialysis - A New Method Introduction in the Country.

Peritoneal dialysis (PD) is one of the options for renal replacement therapy (RRT) in the end stage renal disease (ESRD) patients. Compared to hemodialysis (HD), patients on PD experience a greater sense of well-being, an improved steady state in terms of extracellular fluid volume shifts and hemodynamics and it is preferred method for patients with problematic vascular access, bleeding tendencies, heart failure and elderly patients. In order to perform PD, a tunneled catheter should be placed through the abdominal wall and into peritoneal space, with positioning of the catheter within the most dependent portion of pelvis. Currently, there are several techniques available for PD catheter placement: open surgery, laparoscopic and percutaneous. We present for the first time in our country a case of 65 year old male patient to whom percutaneous onsite insertion of peritoneal catheter was performed. The idea is to emphasize that sometimes this should be a method of choice for RRT, especially in patients where general anesthesia should be avoid. Compared to other methods, percutaneous insertion is a simple procedure with no need for general anesthesia, and the benefits of quick recovery, earlier ambulation, and less delay in catheter placement.

Salivary Markers in Patients with Chronic Kidney Disease.

Aim of the study: To determine the possibility of using saliva as a diagnostic and prognostic tool for screening and monitoring kidney function. Methods: This study included 32 patients with different stages of chronic kidney disease (CKD) and 20 healthy examinees for the control group. Saliva was collected using the spitting method, and on the same day blood was also drawn from the examinees to determine serum concentrations of urea and creatinine. The salivary values of uric acid, urea, creatinine and albumin were determined with a spectrophotometer, as well as the serum concentrations of urea and creatinine. Results: Our results showed a statistically significant positive correlation between salivary and serum levels of urea and creatinine in patients with CKD (Pearson's correlation coefficient for urea was r =0.6527, p = 0.000, while for creatinine it was r = 0.5486, p = 0.001). We detected a statistically significant positive correlation between the salivary levels of urea and the clinical stage of CKD (r = 0.4667, p = 0.007). We did not register a significant correlation between the salivary levels of creatinine and the clinical stage of CKD (r = 0.1643, p = 0.369). Conclusion : Salivary urea is a valid marker for determining kidney function and a potential salivary marker for screening and monitoring kidney function. Salivary creatinine can be used as a qualitative marker, only indicating the existence of a disease.

Using a Catheter for Hemodialysis Placed in the Inferior Vena Cava for the First Time in N. Macedonia - Translumbar Approach.

Maintenance of vascular access for hemodialysis remains a challenge for every doctor. Exhausted conventional vascular access is the cause for the placement of the central venous catheter in unconventional sites such as enlarged collateral vessels, hepatic veins, hemiazygos, azygos, renal veins, and the inferior vena cava. The percutaneous translumbar catheter for hemodialysis in the inferior vena cava was described over 20 years ago. In this article, we report on the procedure and complications arising from the percutaneous translumbar approach of a hemodialysis catheter. This was done for the first time in N. Macedonia. This approach is a potential option in adults and children when conventional approaches are limited.

The blood flow rate on the first day after arteriovenous fistula creation is a predictor of successful fistula maturation.

BACKGROUND: The determination of blood flow rate (BFR) is a useful tool for assessing the function of arteriovenous fistula (AVF). METHODS: Eighty patients with a newly created radio cephalic AVF were analyzed. Hemodynamics and morphological characteristics of the blood vessels were assessed by Doppler ultrasound. RESULTS: The mean age of patients was 59.9 ± 13.5 years. A successful rate of AVF maturation was 62.5% at 8 weeks. Six adjusted models of multivariate analysis showed that BFR at Day 1 was a predictor for AVF maturation both at 4 weeks (p < 0.001) and 8 weeks (p < 0.001). Receiver operating characteristic analysis showed an optimal cut-off point for BFR at Day 1 of 395 ml/min for successful maturation at 4 weeks (sensitivity 0.714, specificity 0.889) and 344 ml/min for successful maturation at 8 weeks (sensitivity 0.860, specificity 0.867). CONCLUSION: BFR at Day 1 is a powerful predictor for successful AVF maturation at 4 and 8 weeks.

Rhabdomyolysis Associated with Recent SARS-COV-2 Infection in a Patient with Carnitine Palmitoyltransferase II Deficiency.

Carnitine palmitoyltransferase II deficiency (CPT II) is an autosomal recessive inherited disorder of long-chain fatty acid oxidation in the mitochondrial matrix, resulting in an inability to utilize fat for energy in cells. The most frequent myopathic form occurs in young adults and is associated with recurrent episodes of exercise-induced rhabdomyolysis. The myopathic form is caused by the Ser113Leu mutation of the CPT II gene. Rarely, massive rhabdomyolysis could be complicated by acute kidney injury (AKI), cardiomyopathy, and respiratory insufficiency. We present a case of an 18-year old male with myalgia, muscular weakness, and dark-colored urine after prolonged exercise and a recent mildSARS-CoV-2infection. Massive rhabdomyolysis was diagnosed with markedly increased serum concentrations of myoglobin and creatine kinase, with normal kidney function. The patient experienced two similar episodes in the years 2017 and 2018, with rhabdomyolysis and AKI treated with hemodialysis. After excluding autoimmune and infectious diseases as causes of recurrent rhabdomyolysis, the patient was genetically tested and Ser113Leu mutation of the CPT II gene was confirmed. When a patient presents with myalgia and dark-colored urine triggered by minor physical activities, genetic testing for possible CPT II deficiency should be initiated. TheSARS-CoV-2infection could be a factor that triggers the occurrence of rhabdomyolysis and aggravates the severity of the attack in patients with CPT II deficiency.

Percutaneous Nephrostomy in the Treatment of Hydronephrosis in Renal Transplant Patients - Case Report.

Percutaneous nephrostomy is a first-line minimal invasive treatment option for ureteral obstruction following kidney transplantation, with high effectiveness and a low complication rate. Percutaneous nephrostomy might be used as a temporary salvage therapy, providing acute decompression of the kidney collecting system and preventing graft loss. It can also function as a permanent and sometimes only possible option in transplant patients with frequent recurrences of ureteral stenosis who either fail an open surgical reconstruction or who are not good candidates for these procedures. We present two patients with acute decline in urine output after renal transplantation with radiologically verified hydroureteronephrosis of the transplanted kidney (graft) caused by stenosis of distal ureter. In both cases, nephrostomy was placed within 48 hours as a temporary salvage treatment that ameliorates renal function and prevents graft loss. The permanent nephrostomy was the only possible solution for the preservation of the graft's function in the first case because of the recurrences of ureteral stenosis after several percutaneous interventions and open-surgery ureteral reconstruction. A few episodes of nephrostomy tube-related infections were resolved with antibiotics in the first case. The second case was treated with open ureteroneocystostomy with resection of stenotic segment and reinsertion of the ureter into the bladder (ureterocystoneostomy) because of the length of the involved ureteral segment. Both patients had stable graft function in the follow-up period.

Pharmacotherapeutic options for the prevention of kidney transplant rejection: the evidence to date.

INTRODUCTION: Although early rejection episodes are successfully controlled, the problem of unrecognized production of de novo anti-HLA antibodies and associated chronic rejection still persists. AREAS COVERED: In addition to the standard induction and maintenance therapy, we present a couple of new drugs as induction (Alemtuzumab), CNI-free protocol (Belatacept, Sirolimus, and Everolimus), and maintenance treatment in transplant patients with various types of malignancies (T cell-targeted immunomodulators blocking the immune checkpoints CTLA-4 and PD1/PDL1) and TMA (aHUS)-eculizumab and IL6 receptor antagonists in antibody-mediated rejection (AMR). EXPERT OPINION: There are a couple of issues still preventing improvement in kidney transplant long-term outcomes with current and anticipated future immunosuppression: patients more susceptible to infection and CNI nephrotoxicity in kidneys obtained from elderly donors and highly sensitized patients with limited chances to get appropriate kidney and a higher risk for late AMR. A lower rate of CMV/BK virus infections has been observed in everolimus-treated patients. Belatacept use has been justified only in EBV-seropositive kidney transplants due to the increased risk of PTLD. Eculizumab upon recurrence of aHUS is a sole cost-effective option. A new IL-6 blocking drug (clazakizumab/tocilizumab) is a promising option for prevention/treatment of AMR. Clinical experience in tailoring immunosuppression for improving as long as possible graft and patient survival is inevitable.

Association of the chronic kidney disease urinary proteomic predictor CKD273 with clinical risk factors of graft failure in kidney allograft recipients.

BACKGROUND: Kidney transplantation is the best treatment option for end-stage kidney disease but is still associated with long-term graft failure. In this study, we evaluated the application of urinary proteomics to identify grafts with high failure risk before initial decline of estimated glomerular filtration rate (eGFR) with irreversible graft changes. METHODS: Fifty-two living donor kidney transplant recipients (KTR) with 8-year follow-up were enrolled. All patients underwent clinical examination and had a routine laboratory screening at 3, 6, 12, 24, 36, 48 and 96 months post-transplantation, including creatinine, urea, albumin and 24-h proteinuria. Graft function was estimated according to Nankivell. Urine samples at Month 24 were analysed by capillary electrophoresis coupled mass spectrometry followed by classification with the chronic kidney disease classifier CKD273. RESULTS: CKD273 showed significant correlation with serum creatinine at every time point and moderate inverse correlation for the slope in glomerular filtration rates by Nankivell (r = -0.29, P = 0.05). Receiver operating characteristics analysis for graft loss and death within the next 6 years after proteomic analysis resulted in an area under curve value of 0.89 for CKD273 being superior to 0.67 for Nankivell eGFR. Stratification into CKD273-positive and -negative patient groups revealed a hazard ratio of 16.5 for prevalence of graft loss in case of CKD273 positivity. CONCLUSIONS: Using a representative KTR cohort with 8-year follow-up, we could demonstrate significant value of CKD273 for risk stratification of graft loss. This study provides the conceptual basis for further evaluation of CKD273 as a prognostic tool for long-term graft function risk stratification by large prospective clinical trials.

High Risk Percutaneous Coronary Intervention of Left Main Bifurcation Stenosis in a Peritoneal Dialysis Patient.

Complex coronary artery disease is the leading cause of death in patients with end-stage renal disease. We report a case of a patient on peritoneal dialysis, preloaded with Prasugrel and acetylsalicylic acid as а potent dual antiplatelet therapy (DAPT). The patient underwent a high-risk percutaneous coronary intervention (PCI) due to bifurcation stenosis of the left main stem branch. A "double kiss crush" bifurcation stenting technique was performed. This case provides additional data about the treatment of this group of patients, a group that is often excluded from randomized control trials, but is frequently encountered in cardiovascular practice. Furthermore, it helps to advance PCI treatment along with exploring the safety of potent DAPT in a group that is susceptible to both ischemia and bleeding, thus presenting a great challenge in the decision for treatment.

The Importance of the World Kidney Day World Kidney Day - 11 March 2021 - Living Well with Kidney Disease.

World Kidney Day (WKD) is a global campaign to raise awareness of the importance of our kidneys to overall health and to reduce the frequency and impact of kidney disease and associated health problems worldwide. Kidney disease is a non-communicable disease (NCD) and currently affects around 850 million people worldwide. One in ten adults has chronic kidney disease (CKD). The global burden of CKD is increasing, and is projected to become the 5th most common cause of years of life lost globally by 2040. CKD is a major cause of catastrophic health expenditure. The costs of dialysis and transplantation consume 2-3% of the annual healthcare budget in high-income countries. Crucially, kidney disease can be prevented and progression to end-stage kidney disease can be delayed with appropriate access to basic diagnostics and early treatment. This year World Kidney Day continues to raise awareness of the increasing burden of kidney diseases worldwide and to strive for kidney health for everyone, everywhere. During the pandemic with COVID 19 patients kidneys are also damaged, apart from the respiratory tract and other organs. It can lead to an increase in acute renal failure and consequent chronic kidney insufficiency, as well as number of deaths. Therefore, it is important to evaluate the renal function in each patient with COVID 19 virus. In the Republic of North Macedonia from 2006 to present day nephrologists and other medical personnel devoted to the early diagnosis, prevention and treatment of renal disease have participated in the activities of the World Kidney Day. These activities were supported by the Macedonian Society of Nephrology, Dialysis, Transplantation and Artificial Organs, the Department of Nephrology at the Medical Faculty, the Macedonian Academy of Sciences and Arts, the Government of the Republic of North Macedonia, non-governmental nephrology organizations (NEFRON) and the media. There were lectures and presentation devoted to the various theme of the WKD, publications in journals, as well as activities for examination of the renal function of patients in the medical centers. The activities during the WKD contributed to the improvement of the nephrological protection of the citizens of the Republic of N. Macedonia.

Urinary Proteomics in Kidney Transplantation.

Although kidney transplantation is the best treatment option for end stage kidney disease, it is still associated with long-term graft failure. One of the greater challenges for transplant professionals is the ability to identify grafts with a high risk of failure before initial decline of eGFR with irreversible graft changes. Transplantation medicine is facing an emerging need for novel disease end point-specific biomarkers, with practical application in preventive screening, early diagnostic, and improved prognostic and therapeutic utility. The aim of our review was to evaluate the clinical application of urinary proteomics in kidney transplant recipients at risk for any type of future graft failure.

COVID 19 Pneumonia and a Rare Form of Fungal Peritonitis in a Patient Survivor on Peritoneal Dialysis.

Peritoneal dialysis (PD) related peritonitis is usually caused by bacteria, but viruses and fungi could also affect the peritoneal membrane and cause cloudy effluent with negative bacterial cultures. We present a case of a PD patient who survived fungal peritonitis caused by Geotrichum klebahnii (March 2015) and COVID-19 pneumonia (April 2021) with peritonitis probably caused by the SARS-CoV-2 virus. The fungal peritonitis followed one episode of exit-site infection and two episodes of bacterial peritonitis treated with a wide-spectrum antibiotic. The patient's PD catheter was removed immediately upon the diagnosis of fungal peritonitis, and an antifungal treatment was continued for 3 weeks after catheter removal. The new peritoneal catheter was reinserted 8 weeks after complete resolution of peritonitis, and the patient continued treatment with PD. The patient developed severe Covid-19 pneumonia with a sudden appearance of cloudy peritoneal effluent. There was no bacterial or fungal growth on the effluent culture. A PCR test for SARS-CoV-2 in peritoneal effluent was not performed. The peritoneal effluent became transparent with the resolution of the severe symptoms of Covid-19 pneumonia.

Peritoneal Dialysis-Related Peritonitis: Rate, Clinical Outcomes and Patient Survival.

Peritoneal dialysis-related peritonitis remains the major complication and primary challenge to the long-term success of peritoneal dialysis (PD). The study aimed to analyze the peritonitis rate, the cause, the outcomes, and the association of peritonitis with the survival of patients on peritoneal dialysis. Patient data were collected retrospectively from medical charts. A total of 96 patients received peritoneal dialysis in the PD center from 1 January 1999 to 31 December 2018. Episodes of peritonitis (n=159) were registered in 54 (56.3%) patients. The study population was divided into two groups, a group of patients (n=54) who experienced peritonitis and a group of patients free of peritonitis (n=42). The peritonitis rate was 0.47 episodes per patient year. The majority of causative microorganisms were gram-positive bacteria (53.5%). Outcomes of the episodes of peritonitis were resolved infection in 84.9% of episodes, catheter removal in 11.3% of episodes, and death in 3.8% of the episodes of peritonitis. A Kaplan-Meier analysis and log-rank test revealed that the group with peritonitis tended to survive significantly longer than the peritonitis-free group. A 67% reduction rate in the risk of patient mortality was observed for the peritonitis group compared with the peritonitis-free group (hazard ratio: 0.33, 95% CI 0.19-0.57, P=0.000). The prevention and management of PD-related infections, resulted in their worldwide reduction, supporting the use of PD as a first-line dialysis modality.

Impact of preoperative arterial and venous diameter on achievement of the adequate blood flow in arteriovenous fistula for hemodialysis.

An arteriovenous fistula (AVF) remains the best choice of vascular access (VA) for hemodialysis (HD). The aim of the study was to determine the factors associated with the achievement of adequate blood flow (BF) of AVFs at the 4th week after creation. Created AVFs in 63 patients with chronic kidney disease (CKD) stage 4/5 and CKD stage 5 on hemodialysis (CKD5D) were analyzed in a prospective study. Doppler ultrasound (DUS) was used for measuring the diameter of the radial artery, the brachial artery and the cephalic vein before AVF creation. The BF of AVF was calculated by DUS at the 4th week after creation and adequate BF was defined as ≥ 600 mL/min. The average age of patients was 61.31 ± 12.9 years. An adequate BF of AVF at the 4th week after creation was achieved in 43.54% of patients. The BF of AVF measured in male patients was significantly higher compared to the BF of AVF obtained in females (576.03 mL/min vs 375.12 mL/min, P = 0.004). The diameter of the blood vessels with achieved adequate BF was significantly larger compared to the diameter of the blood vessels without adequate BF (radial artery: 2.45 mm vs 2.03 mm, P = 0.000; brachial artery: 4.78 mm vs 4.06 mm, P = 0.001 and cephalic vein: 3.12 mm vs 2.83 mm P = 0.018). The gender and the diameter of the blood vessels before AVF creation were significantly associated with achievement of adequate BF of AVF at the 4th week of creation.

Efficacy of Medium Cut-Off Dialyzer and Comparison with Standard High-Flux Hemodialysis.

BACKGROUND: A new medium cut-off (MCO) membranes has been designed to achieve better removal capacities for middle and large middle molecules in hemodialysis (HD) treatment. AIM: The aim of this study was to evaluate the removal efficacy of Theranova® in standard HD in comparison with standard high-flux HD. METHODS: Four HD patients (M/F 1/4) were included in 12-week observational pilot study in HD with Theranova® 400 and Theranova® 500 dialyzers. Each patient was assessed 4 times, T0 with high-flux dialyzers, T1 at 1 month, T2 at second month, and T3 at third month, by measuring pre- and post-HD samples of urea, Cr, ß2-microglobilin (ß2M), myoglobin, albumin, free light chains kappa (FLC-k), and free light chains lambda (FLC-λ). RESULTS: The data showed a higher average removal rate for all the uremic toxins with Theranova® dialyzers for ß2M, myoglobin, FLC-k, and FLC-λ (62.7, 56.9, 63.5, and 54.6%, respectively) during the 3 months. Albumin retention was observed and did not change between T0 and T3 (p = 0.379). CONCLUSION: Compared to high-flux membranes, MCO membranes show greater permeability for middle molecules in midterm report.