Effect of Pretransplant Dialysis Method and Vintage on Early Clinical Outcomes of Kidney Transplantation.

BACKGROUND: Pre-transplantation dialysis duration and modality may affect patients' long-term (mortality and graft failure) and short-term (delayed graft function) outcomes after kidney transplantation. We aimed to assess the impact of the method and duration of dialysis therapy on the graft function in the first 6 months post-transplant. METHODS: The analysis included 122 kidney transplant patients (109 from a deceased donor and 13 from a living donor). Before transplantation, 91 were on hemodialysis (HD), 19 were on peritoneal dialysis (PD), and 9 received preemptive transplants. The incidence of delayed graft function (DGF) and creatinine levels at discharge and 6 months after transplantation were assessed. RESULTS: PD and HD patients did not differ in age, number of mismatches, and cold ischemia time (CIT), but they had a significantly shorter dialysis vintage (18.3 ± 25.7 vs 39.6 ± 34.3 months, P = .01) and a lower incidence of DGF (5% vs 37%, P = .006). The duration of hospitalization and creatinine concentration at discharge and after 6 months were similar. Preemptively transplanted patients had a significantly shorter CIT (ND vs DO - 576 ± 362 vs 1113 ± 574, P = .01; ND vs HD - 576 ± 362 vs 1025 ± 585 minutes, P = .01). DGF did not occur in any of the patients transplanted preemptively. They had slightly shorter hospitalization times and, compared to HD, better graft function at discharge. After 6 months, creatinine levels were comparable to HD and PD. Patients dialyzed for less than 12 months, regardless of the method, had a lower incidence of DGF. CONCLUSIONS: Peritoneal dialysis and a short duration of pre-transplant dialysis may improve the early results of kidney transplantation.

Iron status and anemia control are related to peritoneal membrane properties in peritoneally dialyzed patients.

Background: Characteristics of peritoneal membrane is unique and individually different in peritoneal dialysis patients. Relationship between specific nature of peritoneal transport, anemia and inflammation has not yet been extensively studied. We attempted to outline the complex interplay of several biomarkers of iron status and their association with peritoneal transport, degree of inflammation and residual renal function. Methods: A total of 58 patients treated with peritoneal dialysis either CAPD or APD for at least 3 months were enrolled in this study. Full blood count, traditional markers of iron status (transferrin saturation-TSAT and ferritin), serum erythroferrone-ERFE, soluble transferrin receptor (sTfR), hepcidin, zonulin, growth differentiation factor -15 (GDF15), IL-16, hsCRP and hypoxia-inducible factor-α (HIF-1-α; in serum and dialysate) were measured using commercially available tests. We also performed Peritoneal Equilibrium Test and assessed GFR level. Results: Hb levels above 10 g/dL was found in 74% of patients. Hb levels positively correlated with residual renal function and nutritional status. Adequate iron status was diagnosed in 69% of subjects, only in 9% of patients, criteria for absolute iron deficiency were met. Serum ERFE correlated inversely with hepcidin levels but was not associated with erythropoietin stimulating agent dose. Peritoneal transport had strong correlation with dialysate sTfR (p < 0.05), dialysate hepcidin (p < 0.05), dialysate GDF15 (p < 0.01) and dialysate zonulin (p < 0.001) levels, as well as serum IL6 (p = 0.03), serum hs-CRP (p = 0.04) and dialysate hs-CRP (p = 0.04). Conclusion: Residual kidney function contributes considerably to better control of anemia. Various degree of inflammation is inherent to PD patients. Additionally, fast-average peritoneal transport is associated with greater degree of inflammation and higher concentration of markers of iron status, GDF15 and zonulin in dialysate. This finding may indicate more effective clearance of higher-range middle molecules in fast-average transporters. The role of ERFE as a marker of erythropoiesis in PD patients requires further investigation.

Prevalence of Cognitive Impairment in Peritoneal Dialysis Patients and Associated Factors.

BACKGROUND: Cognitive impairment (CI) in patients with chronic kidney disease, including those treated with renal replacement therapy, is a growing problem worldwide. OBJECTIVES: The study aimed to assess the prevalence of CI and associated factors in patients undergoing peritoneal dialysis (PD). METHODS: In this cross-sectional study, 18 consecutive patients with PD therapy and 15 controls were evaluated for CI using the Addenbrooke's Cognitive Examination III (ACE III) test. RESULTS: The prevalence of CI was 33% in patients and 27% in the control group and was not statistically significant. A higher prevalence of CI was found in subjects aged ≥65 years old than in those <65 years old (p = 0.02), but only in the control group. The prevalence of CI in PD patients over and under 65 years of age did not differ statistically significantly (p = 0.12). Memory and verbal fluency were the most affected cognitive domain in PD patients with CI (p = 0.00, p = 0.04, respectively). There was a significant correlation between higher educated PD patients and the ACE III test results. The duration of dialysis did not affect the results of the cognitive screening test. CONCLUSIONS: CI is a growing problem in the course of chronic kidney disease and dialysis therapy. It seems that cognitive problems may occur in patients undergoing PD at a younger age than in the general population with particularly affected memory and verbal fluency. Higher educated patients score better on the cognitive screening test.

Transplant Renal Artery Stenosis: Underrecognized, Not So Rare, but Curable Complication.

Transplant renal artery stenosis (TRAS) constitutes 75% of all vascular complications in kidney transplant recipients, being a significant source of graft dysfunction and loss. TRAS is a heterogeneous disease with different risk factors and causes. The incidence differs greatly, and it is likely it will increase because of the aging population of potential recipients and donors of renal grafts and the expanding use of extended-criteria donors. Prompt diagnosis and treatment of TRAS can prevent irreversible allograft dysfunction and loss. Current evidence of risk factors, diagnostic challenges, and therapeutic options are presented in this short review.

Malignancy Prevalence in the Dialyzed Population and in Waitlisted Potential Kidney Transplant Recipients.

Malignancy is the second cause of death in the dialyzed population. However, data on the prevalence of cancer are very scarce. Kidney transplantation improves quality of life, prolongs survival, and is cost-effective but bears some serious complications including malignancy. Therefore, active screening for cancer is of utmost importance. The aim of this study was to assess the prevalence of malignancy in dialyzed patients in relation to status on the on the waiting list and type of dialysis. This cross-sectional study was conducted in 108 hemodialyzed patients (mean age 65 years, 47 women) and 47 peritoneally dialyzed patients (mean age 51 years, 25 women). Among the population studied, 20 patients were actively waitlisted, including 14 peritoneal dialysis patients. Patients who had been active on the cadaver kidney waiting list and not listed did not differ in regard to sex, dialysis vintage, and causes of end-stage renal failure, but were significantly younger. Among hemodialysis patients, 24 of them had a history of malignancy and 10 in the peritoneal dialysis population. The most common were renal cell carcinoma in 6, breast cancer in 4, lung cancer in 3, prostate cancer in 3, hepatocellular cancer in 2, colorectal cancer in 2, esophageal cancer in 2, and others 14. In waitlisted patients, only 2 hemodialysis patients had a history of malignancy. Waitlisted patients represent a very selected and healthier dialyzed population. Malignancy has become a more common comorbidity in dialyzed patients, which may have important clinical implication regarding therapy. Guidelines for cancer screening in potential transplant recipients should be developed, as nowadays there are scarcity of data in this matter.

Kidney Transplant Recipients Have Higher Malignancy Prevalence Than Hemodialyzed Patients.

BACKGROUND: Kidney transplant is the preferred therapy for end-stage kidney disease; however, it has been associated with some serious complications, including malignancy, which became the second leading cause of death among kidney allograft recipients. The aim of this study was to assess the prevalence of malignancy in hemodialyzed patients and in kidney transplant recipients. METHODS: A cross-sectional study was conducted in 114 prevalent hemodialyzed patients, including 7 on the waiting list and 350 kidney allograft recipients. Hemodialyzed patients and kidney allograft recipients did not differ in regard to sex, dialysis vintage, and cause of end-stage renal failure, but were significantly older. RESULTS: Among wait-listed patients, only 1 had a history of malignancy (gastric cancer stage G1). Among kidney allograft recipients, in 70 patients, malignancy developed (in total 20% of the studied population). The leading malignancy was skin cancer (18 cases), followed by post-transplant lymphoproliferative disorder (PTLD) in 10 cases, lung cancer (small cell and non-small cell lung cancer; 4 cases), renal cell carcinoma (3 cases), brain cancer (glioma; 3 cases), colorectal cancer (3 cases), Kaposi sarcoma (2 cases), Merkel carcinoma (2 cases), metastatic disease of unknown origin (2 cases), and other 23 malignancies were in a single patient (including 1 leukemia and 1 multiple myeloma). Twenty-six deaths were recorded in kidney allograft recipients with malignancy, mainly in PTLD, Kaposi sarcoma, Merkel carcinoma, sarcoma, glioma, and melanoma. CONCLUSIONS: Despite the lower prevalence of malignancy on hemodialyzed population, cancer screening in both potential transplant recipients and kidney allograft recipients is a prerequisite, because nowadays there is a scarcity of data in this area. It may be due to previous immunosuppression, long-term dialysis vintage, immunocompromised status, and immunosuppressive therapy after transplant, in particular in high-risk patients.

Influence of formalized Predialysis Education Program (fPEP) on the chosen and definitive renal replacement therapy option.

BACKGROUND: It is widely accepted that patients with chronic kidney disease (CKD) should play an active role in the selection of renal replacement therapy (RRT) option. However, patients' knowledge about CKD and treatment options is limited. The implementation of structured education program and shared decision-making may result in a better preparation to RRT, more balanced choice of dialysis modalities and better access to kidney transplantation (TX). OBJECTIVES: The aim of this long-term study was to assess the impact of formalized Predialysis Education Program (fPEP) on knowlege on RRT options, as well as on selected and definitive therapy. MATERIAL AND METHODS: The study included 435 patients (53% men, mean age 60 years) with CKD stage 4 and 5, participating in fPEP at our center. The program included at least 3 visits, during which balanced information about all RRT options was presented and self-care and informed decision-making were encouraged. The knowledge about RRT options before and after fPEP attendance, and selected and definitive RRT options were assessed. RESULTS: Ninety-two percent of patients received prior nephrology care. After fPEP completion, in most patients, the knowledge about CKD and RRT options and selected preferred modality improved - 40% of participants chose hemodialysis (HD), 32% peritoneal dialysis (PD) and 18% TX. During the observation period, 4% of patients died before commencement of dialysis, 2.7% received preemptive kidney transplant, 8.6% were placed on transplant waiting list, and 94% started dialysis (30% PD and 70% HD). Among those who chose PD, 69% started PD and 24% started HD; the leading causes of the discrepancy between choosing and receiving PD was the deterioration in clinical condition (50%) and change of decision (32%). CONCLUSIONS: The fPEP increases CKD patients' knowledge on RRT methods. The implementation of a decision-making process based on fPEP leads to a satisfying distribution between modalities, with a good concordance between chosen and definitive modality.

Potential Effects of Immunosuppression on Oxidative Stress and Atherosclerosis in Kidney Transplant Recipients.

Chronic kidney disease is a public health problem that, depending on the country, affects approximately 8-13% of the population, involving both males and females of all ages. Renal replacement therapy remains one of the most costly procedures. It is assumed that one of the factors influencing the course of chronic kidney disease might be oxidative stress. It is believed that the main mediators of oxidative stress are reactive oxygen species (ROS). Transiently increased concentrations of ROS play a significant role in maintaining an organism's homeostasis, as they are part of the redox-related signaling, and in the immune defense system, as they are produced in high amounts in inflammation. Systemic oxidative stress can significantly contribute to endothelial dysfunction along with exaggeration of atherosclerosis and development of cardiovascular disease, the leading cause of mortality in patients with kidney disease. Moreover, the progression of chronic kidney disease is strictly associated with the atherosclerotic process. Transplantation is the optimal method for renal replacement therapy. It improves better quality of life and prolongs survival compared with hemodialysis and peritoneal dialysis; however, even a successful transplantation does not correct the abnormalities found in chronic kidney disease. As transplantation reduces the concentration of uremic toxins, which are a factor of inflammation per se, both the procedure itself and the subsequent immunosuppressive treatment may be a factor that increases oxidative stress and hence vascular sclerosis and atherosclerotic cardiovascular disease. In the current work, we review the effect of several risk factors in kidney transplant recipients as well as immunosuppressive therapy on oxidative stress.

Uremic Toxins, Oxidative Stress, Atherosclerosis in Chronic Kidney Disease, and Kidney Transplantation.

Patients with chronic kidney disease (CKD) are at a high risk for cardiovascular disease (CVD), and approximately half of all deaths among patients with CKD are a direct result of CVD. The premature cardiovascular disease extends from mild to moderate CKD stages, and the severity of CVD and the risk of death increase with a decline in kidney function. Successful kidney transplantation significantly decreases the risk of death relative to long-term dialysis treatment; nevertheless, the prevalence of CVD remains high and is responsible for approximately 20-35% of mortality in renal transplant recipients. The prevalence of traditional and nontraditional risk factors for CVD is higher in patients with CKD and transplant recipients compared with the general population; however, it can only partly explain the highly increased cardiovascular burden in CKD patients. Nontraditional risk factors, unique to CKD patients, include proteinuria, disturbed calcium, and phosphate metabolism, anemia, fluid overload, and accumulation of uremic toxins. This accumulation of uremic toxins is associated with systemic alterations including inflammation and oxidative stress which are considered crucial in CKD progression and CKD-related CVD. Kidney transplantation can mitigate the impact of some of these nontraditional factors, but they typically persist to some degree following transplantation. Taking into consideration the scarcity of data on uremic waste products, oxidative stress, and their relation to atherosclerosis in renal transplantation, in the review, we discussed the impact of uremic toxins on vascular dysfunction in CKD patients and kidney transplant recipients. Special attention was paid to the role of native and transplanted kidney function.

Iron and Chronic Kidney Disease: Still a Challenge.

Anemia is a clinical feature of chronic kidney disease (CKD). Most common causes are iron and erythropoietin deficiency. The last two decades have yielded significant advances in understanding iron balance's physiology, including iron trafficking and the crosstalk between iron, oxygen, and erythropoiesis. This knowledge sheds new light on the regulation and disturbance of iron homeostasis in CKD and holds the promise for developing new diagnostic and therapeutic tools to improve the management of iron disorders. Hepcidin-ferroportin axis has a central role in regulating body iron balance and coordinating communication between tissues and cells that acquire, store, and utilize iron. Recent research has revealed a bidirectional relationship between fibroblast growth factor 23 (FGF23) and iron status, anemia, and inflammation, as well as the role of erythroferrone (ERFE) in iron homeostasis. However, ERFE concentrations and actions are not well-characterized in CKD patients. Studies on ERFE in CKD are limited with slightly conflicting results. Despite general interest in iron metabolism in kidney diseases, studies on the less prevalent renal replacement therapy mode, such as peritoneal dialysis or hemodiafiltration, are scarce. Slightly more was published on hemodialysis. There are several novel options on the horizon; however, clinical data are limited. One should be aware of the potential risks and benefits of the novel, sophisticated therapies. An inhibition of hepcidin on the different pathways might be also a viable adjunctive therapeutic option in other clinical situations.

[Hyperkalemia - current therapuetic strategies].

Hyperkalemia is a medical emergency that requires immediate therapy, followed by interventions aimed at preventing its recurrence. Hyperkalemia occurs especially frequently in patients with chronic kidney disease (CKD), in part because of impaired kidney function and in part due to coexisting comorbidities such as diabetes or heart failure and the medications used to treat them, first of all the inhibitors of renin-angiotensin-aldosterone system (RAASi). Both acute and chronic management of hyperkalemia are equally important, though, with currently available therapeutic possibilities, the effective restoration of potassium homeostasis are in fact limited to the correction of its triggers. The emergence of new medications (patiromer and ZS-9) could lead to a therapeutic paradigm shift from intermittent treatment of incidentally discovered hyperkalemia toward preventive measures preventing fluctuations in serum potassium levels and enabling the continuation of beneficial, but hyperkalemia inducing agents.

[Toxic alcohol poisonings].

Accidental or intentional poisonings with ethylene glycol or methanol constitute a serious toxicological problem in many countries. Both alcohols are quickly metabolized by alcohol dehydrogenase to toxic metabolites responsible for high anion gap severe metabolic acidosis and profound neurological, cardiopulmonary, renal disturbances and death. In the early period, the competing inhibition the alcohol dehydrogenase with ethanol or fomepizol may successfully prevent the formation of the toxic metabolites. Once severe acidosis develops an emergency hemodialysis is required.

[Managing hypertension in patients with chronic kidney disease - implications of the SPRINT study].

Optimal blood pressure control is a key measure in slowing the progression of kidney disease and reducing the cardiovascular risk in patients with chronic kidney disease, although the target BP remain controversial. The SPRINT (Systolic Blood Pressure Intervention Trial) demonstrated that intensive treatment of hypertension brings a spectacular reduction in the risk of major cardiovascular events and all-cause mortality in older non-diabetic patients at high cardiovascular risk and chronic kidney disease and mild proteinuria.

[Kidney diseases in cardiology]. / Choroby nerek w kardiologii.

A close relationship between renal dysfunction and heart failure has been demonstrated with a huge impact on the patients outcomes. To describe the relationship, the term cardio-renal syndrome (CRS) has been increasingly used in recent years. Medical management of patients with CRS remains tremendously challenging. The integration of cardiology and nephrology communities providing with a more holistic and complete clinical presentation of patients seems to be a necessary strategy to treat this vulnerable population.

[Cardiac surgery associated acute kidney injury]. / Ostre uszkodzenie nerek po zabiegach kardiochirurgicznych.

Acute kidney injury (AKI) is a common postoperative complication of cardiac surgery and the second most common cause of this syndrome in the intensive care units. The etiology is multifactorial and related to the surgery itself, as well as to intra- and postoperative management. To date, there is scarce evidence supporting specific measures to prevent AKI in this clinical situation, and whether the patients may benefit from early institution of some pharmacologic agents or early renal replacement therapy initiation. Further studies are essential to determine how to optimize cardiac surgical procedures and intra- and postoperative management.