Immunomodulation Driven by Theranova Filter during a Single HD Session.

Uremic patients, especially those receiving regular hemodialysis (HD) treatment, are at high risk of oxidative damage by noxious free radicals and reactive oxygen species (ROS). The erythrocyte glutathione-defense system (GSH-DS) is one of the major enzymatic means of scavenging and detoxifying ROS. This study aimed to elucidate the effect of HD and dialyzer biocompatibility on erythrocyte GSH-DS in uremic patients on maintenance HD treatment. Twenty-five healthy volunteers and 42 HD patients were enrolled in this study. Blood samples were drawn immediately before and after HD session, and erythrocyte glutathione (GSH) level as well as the activities of the enzymes glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-Rd), and glutathione S-transferase (GST) were measured. To evaluate the effect of dialyzer type on the studied parameters the patients were were subdivided into two groups: those who had dialysis with cuprophane (CU) membranes (n=23) and those who received dialysis with the aid of polysulfone (PS) membranes (n=19). The activities of G6PD and GSH-Px as well as GSH level were significantly decreased in HD patients as compared with controls. On the other hand, the activities of GSSG-Rd and GST were significantly elevated among HD patients in comparison with control values. A single HD session, regardless of the type of dialyzer, did not induce any significant effect on any of the measured parameters, although G6PD activity increased significantly after dialysis. CU membrane did not result in any change in GSH or its metabolizing enzymes, while PS dialyzers exerted a minor but significant restoration in GSH-DS. The antioxidant pool, as represented by GSH-DS, is significantly affected by dialyzer type in HD patients being significantly corrected with polysulfone dialyzer.

Background: Haemodialysis (HD) superimposes additional circulatory stress on the microvasculature, leading to endothelial dysfunction, which plays a key role in the development of haemodialysis-associated multiorgan dysfunction. This study was undertaken to evaluate the effect of a single HD session on retinal and choroidal microcirculation, using optical coherence tomography angiography (OCTA) in relation to changes in the blood levels of selected biochemical modulators of endothelial function. Methods: The vessel density (VD) of 35 patients was evaluated before and after a single HD session, using OCTA in the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC). Retinal thickness (RT) and choroidal thickness (CT) were also assessed. Asymmetric dimethylarginine (ADMA), endothelin-1 (ET-1) and malondialdehyde (MDA) levels, oxidative stress (OS) status and systemic parameters were assessed before and after a single HD session. The correlation between changes in these parameters and changes in selected OCTA parameters was tested. Results: A single HD session resulted in a significant increase in RT and a decrease in CT. In addition to increased oxidative and osmotic stress resulting from a significant reduction in plasma osmolality, the HD session was associated with a significant increase in ET-1 levels and a decrease in ADMA levels. These biochemical changes correlated with changes in RT and CT, as well as with changes in VD in the retinal capillary plexuses and the CC. Increased ET-1 levels and decreased plasma osmolality were identified as predictors of RT increase, whereas increased MDA levels corrected serum creatinine-predicted CT reduction. Conclusions: Changes in ADMA and ET-1 and OS, as well as osmotic stress induced by a single HD session, affect the eye microcirculation and morphology of the retina and choroid. OCTA examination is a promising method for assessing microcirculation in HD patients.

Background and Aims Intradialytic hypoxemia is a common but often overlooked condition in patients undergoing maintenance hemodialysis (HD), potentially contributing to adverse clinical outcomes. Sleep apnea, a condition marked by intermittent "saw-tooth patterns" (STP) in arterial oxygen saturation (SaO2), may underlie some cases of intradialytic hypoxemia. Identifying these patterns during HD could provide critical insights into the prevalence of intradialytic sleep apnea and its clinical implications. This study aimed to estimate the distribution of SaO2 STPs based on the start time of HD treatments. Method We analyzed intradialytic SaO2 data from a large cohort of HD patients across the United States. SaO2 was continuously monitored during HD sessions using the Crit-Line Monitor (CLM; Fresenius Medical Care North America), an FDA-approved device for measuring oxygen saturation and hematocrit in the extracorporeal dialysis circuit. SaO2 data were recorded at 10-second intervals and transmitted to a secure cloud-based platform for analysis. Data was collected between January 14, 2021, and July 30, 2023. SaO2 levels were tracked continuously during the HD sessions. To construct the one-dimensional convolutional neural network (1D CNN), a random sample of HD sessions was chosen. The time series data from these sessions were segmented into consecutive 5-minute intervals, and each segment was independently reviewed by a physician and a researcher who categorized them as either containing a saw-tooth pattern or not. The trained 1D CNN was then applied to the entire dataset to classify each segment as exhibiting an STP or not. Figure 1 provides a visual example of SaO2 measurements during a single HD session, highlighting segments classified as STP by the 1D CNN. The timing of these segments was categorized based on the hour during which the HD treatment began. For example, all 5-minute segments from treatments starting between 6:00 and 6:59 were assigned to the 6 hours. The STP rate was then calculated for each hourly category. Results Following rigorous data cleaning, the dataset included more than 3 million HD sessions from over 49,000 patients treated at 714 clinics. Analysis revealed that 11% of the 5-minute segments were classified as STP, while 89% were non-STP. The proportion of 5-minute segments exhibiting STP exceeded 15% in treatments starting between 4:00 and 4:59 local time. Conversely, the lowest STP rates were observed in treatments beginning between 14:00 and 15:59. These findings were further detailed in Fig. 2A, which shows the total number of 5-minute segments analyzed alongside the number of STPs for each hourly category, and Fig. 2B, which illustrates the hourly STP rates. Night, defined as a start time between 20:00 and 5:00, was associated with a higher prevalence of STP at 13.36%, compared to 10.77% during the daytime. Patients who initiated HD at night exhibited a significantly greater occurrence of STP (P < 0.00001). Conclusion Our results indicate a high rate of STP in patients who have started HD during the nighttime. Since patients may be more likely to sleep during night and since STP of SaO2 are a hallmark of sleep apnea, we hypothesize that sleep apnea is a likely condition in these patients. As a next step, patients with a high rate of SaO2 STP should undergo formal testing for sleep apnea and, if confirmed, receive adequate treatment.

Systemic congestion and pulmonary congestion (PC) are common in hemodialysis (HD) patients. However, the relationship between these two entities is not quite clear. We study this relationship and attempt to uncover the factors that may affect it considering different inter-dialytic intervals. A prospective pilot observational and interventional study including 18 HD patients was conducted. The following were obtained: i) B-line score (BLS) by lung ultrasound (LUS) (reflecting significant pulmonary congestion if BLS > 5), ii) echocardiography, iii) bioelectrical impedance analysis (BIA) (reflecting global volume status), and iv) inferior vena cava (IVC) dynamics (reflecting systemic congestion) before and after the first two consecutive HD sessions of the week, with different inter-dialytic intervals (68 hours and 44 hours). Serum N-terminal pro-brain natriuretic peptide type B (NT-proBNP) levels were obtained before each session. Then, patients were randomized into two groups: the active group, where dry weight was reduced according to BLS + standard of care, and the control group, where dry weight was modified according to standard of care. All the measures were repeated on day 30. We found no correlation between pulmonary congestion represented by BLS and IVC dimensions and dynamics reflecting systemic congestion, independent of different inter-dialytic intervals. Pulmonary congestion was quite prevalent, as mean pre- and post-dialysis BLSs were quite elevated (16 ± 5.53 and 15.3 ± 6.63, respectively) in the first session compared with the second session (16.3 ± 5.26 and 13.6 ± 5.83, respectively). Systolic (left ventricular ejection fraction) and diastolic cardiac function (e/è ratio) parameters from one side and pulmonary congestion (BLS) from the other were not always correlated. BLS was correlated to e/è ratio before HD (session 1) (R 2 = 0.476, p = 0.002) and after HD (session 2) (R 2 = 0.193, p = 0.034). Pulmonary congestion reflected by BLS was correlated to the global volume state reflected by BIA only in the second HD session (HD2) (R 2 = 0.374, p = 0.007). NT-proBNP levels and BLS were correlated before both sessions (R 2 = 0.421, p = 0.004, and R 2 = 0.505, p = 0.001, respectively). Systemic congestion was quite prevalent, as mean pre- and post-dialysis IVC dimensions and dynamics were quite elevated in both sessions, with a higher level of systemic congestion in the first HD session (diameter and collapsibility of 2.1 cm and 23%, and 2.01 cm and 19%, respectively) compared with the second session (1.98 cm and 17.5%, and 1.9 cm and 22%, respectively) without reaching statistical significance. IVC dimensions and global volume status measured by BIA were correlated in the second dialysis session (R 2 = 0.260, p = 0.031). No correlation was found between IVC dimensions and diastolic cardiac function (e/è ratio) parameters or with NT-proBNP levels. On day 30, BLS was significantly reduced in the active group, whereas no difference was found in the control group. However, no real impact was observed on IVC dimensions and dynamics or in total volume status by BIA. Pulmonary congestion is common in HD patients even after reaching their dry weight at the end of two consecutive sessions, and it is not correlated to systemic congestion, suggesting a complex multifactorial pathophysiology origin. Global volume status reflected by BIA and cardiac function are not always related to either systemic congestion represented by IVC dimensions or pulmonary congestion represented by BLS. Fluid redistribution anomalies may allow pulmonary congestion accumulation independently from systemic congestion and global volume status (non-cardiogenic pulmonary congestion). We recommend a personalised approach when managing HD patients by integrating systemic and pulmonary congestion parameters. Dry weight modification guided by repeat LUS may safely reduce pulmonary congestion. However, no impact was observed on systemic congestion or global volume status.

Atherosclerosis is by far the leading cause of mortality and morbidity in patients with end stage renal disease undergoing chronic hemodialysis (HD). Vascular endothelial cell adhesion molecules like the intercellular adhesion molecule-1 (ICAM-1) and the vascular cell adhesion molecule-1 (VCAM-1) are involved in the pathogenesis of atherosclerosis. Their soluble forms (sICAM-1, sVCAM-1) are considered potential serum markers of endothelial activation and atherosclerosis. The aim of this study was to clarify the influence of the HD procedure on the levels of sICAM-1 and sVCAM-1 in patients with end stage renal disease. We evaluated 35 clinically stable patients (18 males, 17 females, mean age 61 ± 12) on chronic HD treatment. Diabetes mellitus coexisted in eight patients and arterial hypertension in 23 patients. Blood was drawn before, every hour during, and after a single HD session in each patient. Low-flux cuprophane dialyzers (GFS 12®, Gambro, Lund, Sweden) were used in 22 and high-flux polysulfone dialyzers (Hemoflow F 60S®, Fresenius, Oberursel, Germany) in 13 cases. At 30 min into the HD session (n = 31, 20 low-flux HD, 11 high-flux HD) blood was drawn simultaneously from the entrance and the exit line of the dialyzer. From all these samples, serum concentrations of sICAM-1 and sVCAM-1 were determined by commercially available enzyme immunoassays (ELISA, R&D Systems, Minneapolis, USA). Results were corrected according to hemoconcentration, where appropriate. Plasma levels of sVCAM-1 were elevated in patients with end stage renal disease before the beginning of the dialysis session when compared to healthy controls (1449 ± 497 ng/mL vs. 691 ± 118 ng/mL). On the contrary, such an elevation was not found in the case of sICAM-1 (231 ± 58.5 ng/mL vs. 236.4 ± 96.8 ng/mL in healthy controls). These levels remained stable in all measurements throughout the dialysis procedure. Furthermore, serum sICAM-1 and sVCAM-1 levels remained unaltered after the passage of the dialyzer. The levels of sICAM-1 and sVCAM-1 were not influenced by the existence of diabetes mellitus, hypertension, or by the utilization of biocompatible, high flux dialyzers. Our study confirms that in chronic HD patients serum levels for sVCAM-1 are elevated. The levels of adhesion molecules are not affected by the HD procedure. These findings probably can be attributed to a decreased renal clearance or catabolism of sICAM-1 and sVCAM-1 and to the different sources of the two molecules. Neither coexisting diabetes mellitus nor arterial hypertension influences the circulating levels of these adhesion molecules. The functional role of sVCAM-1 and sICAM-1, the exact renal contribution to their metabolism, and their role as markers of atherosclerosis in chronic renal disease need further evaluation.

To evaluate the effects of chronic kidney disease (CKD) and hemodialysis (HD) on the inner ear using the G width (the width between the bimodal peaks of the conductance (G) tympanogram at 2,000 Hz), which reflects the inner ear pressure and/or the existence of endolymphatic hydrops. We selected five patients (10 ears) from the patients with CKD who were hospitalized for creation of arteriovenous fistula prior to initiation of HD (non-HD group), and we selected seven patients (14 ears) from the patients with CKD who were undergoing HD (the HD group). As a control group, we selected 80 healthy individuals (160 ears); these were mainly the medical staff of the hospital. We measured the G width of the control group and that of patients with CKD using multifrequency tympanometry. The mean G widths of the HD (measured just before an HD session), non-HD, and control groups were 210.7, 128.4, and 97.0 daPa, respectively. The G width of the HD group was significantly greater than that of the control and non-HD groups (p<0.01 and p<0.01, respectively; Tukey-Kramer test after one-way analysis of variance). The non-HD group also had a greater G width than the control, but it was not significant (p=0.20; Tukey-Kramer). No significant changes were observed in the G widths of the HD group, just before and after a single HD session (p=0.423; paired t-test). The greater G width observed in hemodialyzed CKD patients suggests either an increased inner ear pressure or the existence of endolymphatic hydrops in these patients, which is probably related to their otologic symptoms.

Vascular access malfunction, usually presenting with an inadequate access flow (Qa), is the leading cause of morbidity and hospitalization in hemodialysis (HD) patients. Many methods of thermal therapy have been tried for improving Qa but with limited effects. This randomized trial was designed to evaluate the effect of far-infrared (FIR) therapy on access flow and patency of the native arteriovenous fistula (AVF). A total of 145 HD patients were enrolled with 73 in the control group and 72 in the FIR group. A WS TY101 FIR emitter was used for 40 min, and hemodynamic parameters were measured by the Transonic HD(02) monitor during HD. The Qa(1)/Qa(2) and Qa(3)/Qa(4) were defined as the Qa measured at the beginning/at 40 min later in the HD session before the initiation and at the end of the study, respectively. The incremental change of Qa in the single HD session with FIR therapy was significantly higher than that without FIR therapy (13.2 +/- 114.7 versus -33.4 +/- 132.3 ml/min; P = 0.021). In comparison with control subjects, patients who received FIR therapy for 1 yr had (1) a lower incidence (12.5 versus 30.1%; P < 0.01) and relative incidence (one episode per 67.7 versus one episode per 26.7 patient-months; P = 0.03) of AVF malfunction; (2) higher values of the following parameters, including Delta(Qa(4) - Qa(3)) (36.2 +/- 82.4 versus -12.7 +/- 153.6 ml/min; P = 0.027), Delta(Qa(3) - Qa(1)) (36.3 +/- 166.2 versus -51.7 +/- 283.1 ml/min; P = 0.035), Delta(Qa(4) - Qa(2)) (99.2 +/- 144.4 versus -47.5 +/- 244.5 ml/min; P < 0.001), and Delta(Qa(4) - Qa(2)) - Delta(Qa(3) - Qa(1)) (62.9 +/- 111.6 versus 4.1 +/- 184.5 ml/min; P = 0.032); and (3) a better unassisted patency of AVF (85.9 versus 67.6%; P < 0.01). In conclusion, FIR therapy, a noninvasive and convenient therapeutic modality, can improve Qa and survival of the AVF in HD patients through both its thermal and its nonthermal effects.

Predialysis Hyponatremia and Positive Change of Natremia Within Hemodialysis Sessions Are Strong Indicators of Poor Cardiovascular Outcome in Hemodialysis Patients

This study evaluated the effects of end stage chronic renal failure (CRF) on auditory function and changes in auditory function following a single session of hemodialysis. The experimental group included 31 patients with end-stage renal failure on chronic hemodialysis. The control group consisted of 31 healthy volunteers. The patients were examined prior to and following a session of hemodialysis. Measurements included pure tone audiometry, tympanometry and acoustic reflex measurements, auditory brainstem responses (ABR), and blood now chemistry parameters. Controls underwent the same test battery, with the exception of biochemical and hematological assessment. Prior to hemodialysis sessions, all ABR latencies except interpeak latency I–III were significantly prolonged in the experimental group. A comparison between controls and the experimental group following hemodialysis indicated that wave V absolute latency and interpeak latencies III–V and I–V were significantly prolonged in the slow repetition rate paradigm. In the fast repetition rate, absolute latencies of waves I and V and III–V interpeak latencies were prolonged in the experimental group. Comparison of ABR recordings prior to and following hemodialysis showed overall significant difference between the measures. Post hoc analysis showed a significant improvement in wave I and V latencies in the slow repetition rate and wave V latency in the fast repetition rate. This study showed that neural conduction along the auditory pathway is delayed in patients with end stage CRF as compared to healthy subjects. Dialysis sessions improve overall neural auditory function. However, patients with end stage CRF show delayed conduction even after a session of hemodialysis.

Monocyte chemotactic and activating factor (MCAF) is a novel inflammatory cytokine belonging to the chemokine superfamily and stimulates chemotaxis and activation of monocytes. Increased production of inflammatory cytokines has been shown in patients with end-stage renal disease (ESRD). This study was thus conducted to determine plasma MCAF in patients with ESRD. Plasma levels of MCAF were determined by ELISA. Gene expression of MCAF in PBMC was assessed by RT-PCR followed by southern blot hybridization. Plasma MCAF in 72 patients with long-term haemodialysis (HD) (162.4 +/- 58.2 pg/ml) and eight uraemic patients not yet dialysed (167.6 +/- 57.7 pg/ml) was found to exceed significantly the level in 24 normal subjects (86.0 +/- 19.4 pg/ml). MCAF before HD session in long-term HD patients was the same whether HD was carried out with either cellulosic (CUP) or synthetic (PMMA) membrane dialysers. Intradialytic increase in plasma MCAF during a single HD session was observed in both patient groups dialysed with CUP or PMMA membranes. The results of RT-PCR analysis indicated that haemodialysis stimulates the gene expression of MCAF in PBMC in vivo. The present results indicate that increased levels of plasma MCAF may promote the activation of monocytes in patients with ESRD.

Background: Peptide-linked degradation products of advanced glycation end products (AGE peptides) accumulate in chronic haemodialysis (HD) patients and may contribute to a number of HD-related long-term complications, such as accelerated atherosclerosis. Methods: The influence of a single HD session versus long-term HD on serum AGE peptides was determined. The patients were randomized to HD with a low-flux polysulfone (PS; F 6HPS), a high-flux PS (F 60S), a superflux PS (F 500S), or a superflux cellulose triacetate (CTA; Tricea 150G) dialyzer. Results: During a single HD session, both AGE peptides and reference peptides decreased significantly (AGE peptides: Tricea 150G –37.0 ± 2.9%; F 6HPS –35.5 ± 2.4%; F 60S –39.5 ± 4.7%, and F 500S –43.3 ± 2.1%, p = 0.005; reference peptides: Tricea 150G –73.2 ± 8.8%; F 6HPS –73.2 ± 7.9%; F 60S –72.5 ± 8.2%, and F 500S –74.1 ± 7.3%, p = 0.005). After 12 weeks of HD with the superflux CTA, the AGE peptide levels decreased significantly (week 1: 2.7 ± 1.1 arbitrary units, week 12: 2.5 ± 1.2 arbitrary units, decrease 7.4%; p = 0.01), whereas the AGE peptide levels remained unchanged after HD with each of the other three modalities. The reference peptide levels did not change after 12 weeks of HD. Conclusion: Although AGE peptides can be effectively removed during a single HD session, superflux CTA seems to be the only modality capable of reducing AGE peptides in the long term.

Hypotension commonly occurs during hemodialysis (HD). Hypotension can result from an absolute reduction in plasma volume following excessive ultrafiltration or from a reduction in vascular tone. We hypothesized that changes in vascular tone could occur during dialysis. Aortic pulse wave velocity (aPWV) was measured in 197 HD patients, mean age 63.3 ± 16.6 years, 62% male, 49% diabetic, during a single HD session. aPWV did not change (9.6 ± 2.2 vs. 9.6 ± 2.2 m/s) with HD. Systolic blood pressure (SBP) declined from 151 ± 31 to 147 ± 32 after 20 min and to 140 ± 36 mm Hg on completion of HD (P < 0.05), with an ultrafiltration volume of 2.2 ± 0.9 L over a 3.9 ± 0.4 h HD session. Aortic SBP declined from 154 ± 32 to 146 ± 29 after 20 min and 143 ± 35 at the end of HD, P < 0.001. Aortic augmentation index (Aortic Aix) decreased from 65% (52-79%) to 36.7% (23.3-52.9%) by 20 min and to 34.3 (15.1-49.1%) on completion of HD (P < 0.05), and brachial augmentation index (brachial Aix) from 5.7% (-25.2 to 27.5%) to -1.9% (-2.2 to 30.1%) and -6.6% (-44 to 22.7%), respectively, P < 0.05. Diastolic reflection area (DRA) increased from 36.7 (27.9-46.3) to 40.4 (32.2-51) after 20 min and 47.1 (34.2-60.5) on completion of HD, P < 0.05. We report changes in arterial tone within 20 min of starting HD, when minimal ultrafiltration has occurred, suggesting that volume changes may not be the only predisposing cause of intradialytic hypotension. The combination of a fall in SBP and a rise in DRA would suggest a reduction in coronary blood flow in keeping with reports of "myocardial stunning" during HD.

Hemodialysis (HD) prolongs the survival of patients with end-stage chronic kidney disease (CKD), but mortality remains high due to malnutrition and inflammation. This study aimed to investigate whether low albumin levels and a reduced phase angle (PA) predict higher mortality in HD patients. This prospective cohort study followed 82 HD patients for 36 months. Biological markers, including albumin and oxidative stress indicators, were measured before and after a single HD session upon study enrollment (time zero). PA was determined by bioimpedance analysis. Kaplan-Meier survival curves and Cox regression analyses were performed to assess the association between albumin, PA, and mortality. Patients with PA <4 had a mean survival of 11.6 months, compared to 27.0 months for those with PA ≥ 4 (HR = 5.66; 95% CI: 2.44-13.12). Similarly, patients with albumin <3.9 g/dL had significantly lower survival rates at 6, 12, and 36 months compared to those with albumin ≥3.9 g/dL (HR = 4.39; 95% CI: 1.81-10.63). Low albumin levels and a reduced PA are strong predictors of mortality in HD patients. Routine monitoring and targeted interventions to improve these markers could enhance survival outcomes.

Background/Objective: Systemic inflammation is a hallmark of end-stage renal disease (ESRD) and contributes to the high burden of cardiovascular morbidity and mortality in hemodialysis (HD) patients. The systemic immune–inflammation index (SII), derived from peripheral neutrophil, lymphocyte, and platelet counts, has emerged as a promising biomarker of immune–inflammatory status. This study aimed to assess the acute effect of a single HD session on systemic inflammation and to identify metabolic predictors associated with this response. Methods: In this single-center observational before–after study, 44 chronic HD patients were enrolled. Blood samples were collected immediately before and after a single HD session. SII was calculated as platelet count × neutrophil count/lymphocyte count. Subgroup analyses were conducted based on renal disease etiology and diabetic status. Multivariable linear regression models identified baseline predictors of SII variation. Results: Median SII significantly decreased post-HD in the overall cohort (from 553.4 [342.6–847.5] to 449.1 [342.6–866.6], p = 0.001), with a more pronounced reduction in patients with cardiometabolic etiologies (from 643.4 [353.3–1360.0] to 539.1 [324.8–1083.4], p = 0.007) and diabetes (from 671.1 [408.7–1469.1] to 458.3 [285.7–1184.4], p = 0.028), but not in those with nephroangiosclerosis (p = 0.182). Baseline total cholesterol (p = 0.001) and gamma-glutamyl transferase (p = 0.034) were positively associated with smaller reductions in SII, while higher baseline glycaemia predicted a greater decrease in post-dialysis SII (p = 0.021). Conclusions: HD acutely modulates systemic inflammation, as reflected by reduction in SII. The magnitude of this response is significantly influenced by individual metabolic profiles. These findings highlight the relevance of metabolic–immune crosstalk in ESRD and suggest that SII may serve as a dynamic biomarker integrating inflammatory and metabolic signals, deserving further validation in larger, outcome-driven studies.

Background and Aims Tregs regulate immune responses and maintain self-tolerance, while Natural Killer cells (NK) are cytotoxic lymphocytes critical for both adaptive and innate immunity. The presence of chronic kidney disease (CKD) is often characterized by disturbances in immune responses, including dysregulation between tolerance and cytotoxicity. Aim of the present study was to evaluate the influence of CKD on the Tregs (CD4+CD25+FoxP3+) and NK cells, as well as the effect of hemodialysis (HD) and peritoneal dialysis (PD) on these subtypes. Method A total of 40 CKD Stage V patients and 15 healthy volunteer subjects were recruited into our study. Peripheral Tregs and NK cells were isolated from whole blood samples using flow cytometry, and the results were compared to those of age and gender matched controls. The immunologic profile of CKD patients was repeated 6 months after HD initiation (n=20) and PD (n=20) in order to investigate the effect of different dialysis methods. Results Patients with CKD had significantly reduced populations of CD4+CD25+ FoxP3+ Tregs (47.5± 28.8 vs 71.5±24.7) p=0.01, while there was no difference in NK cells between patients and controls (16.4±8.1% vs. 13.4±9.1%), p=NS, respectively. There were no differences between patients started on HD or PD in terms of clinical and laboratory parameters. Frequencies and total numbers of Tregs were significantly reduced after 6 months of HD, from 7.6±2.1% to 5.2±2.3%, p=0.009, and from 53.6±26K/μL to 36.9±19K/μL, p=0.02, respectively, while showed no differences on PD patients, from 5.3±3.3% to 5.6±2%, p=NS and 33.2±27K/μL to 45.6±28K/μL, p=NS, respectively. NK cells were increased in HD patients, not reaching statistical significance (245±156K/μL to 261±128K/μL). Frequencies of NK cells were positively correlated with CRP (r=0.56, p=0.009) and Intimal media thickness (IMT) (r=0.48, p=0.03) Conclusion The results of our study show that initiation of hemodialysis (HD) seems to reduce the expression of CD4+CD25+FoxP3+ T cells while peritoneal dialysis (PD) doesn’t seem affect this cell population. The immune alterations observed in hemodialysis patients may have a clinical impact on chronic inflammation and atheromatosis.