Abstract Background and Aims Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare cause of glomerulonephritis and clinical presentation can be diverse. Despite recent developments in immunosuppressive treatments, AAV with renal involvement is still associated with poor renal prognosis and a high risk of end-stage renal disease (ESRD). Kidney biopsy confirms the diagnosis, details the degree of active inflammation and chronicity of disease, also informing of renal prognosis. Berden histological classification categorizes renal histological findings into four classes but the ability to accurately predict renal outcomes varies among studied cohorts. In 2018 Brix et al developed and validated a new risk score, ANCA Renal Risk Score (ARRS), to determine renal outcomes based on histopathological and clinical indicators, with accurate ESRD prediction at 36 months. This study aims to assess the predictive value of ARRS in renal survival on a Portuguese cohort with newly diagnosed AAV with kidney involvement. Method We designed a retrospective study examining ANCA vasculitis in native kidney biopsies evaluated in a Portuguese kidney histomorphology-dedicated center between 2004 and 2023. Data collected from biopsies included percentage of normal glomeruli (PNG) and interstitial fibrosis/tubular atrophy (IFTA). Clinical and demographical data was also collected, including age, sex, estimated glomerular filtration rate (eGFR) at presentation, date of diagnosis, ESRD and date of death. We calculated ARRS based on eGFR, PNG and IFTA, and patients were classified as being at low, intermediate and high risk of developing ESRD by 36 months. Primary endpoint was established as difference in kidney survival at 36 months. Secondary endpoint included difference in overall survival at 36 months and the contribution of each of the ARRS parameters in a Cox regression model. Results A total of 143 patients were obtained, 46.2% female, with a mean age at diagnosis of 67.1 years. There was a predominancy of MPO-related disease (77.2%) and 69% presented with rapidly progressive renal insufficiency. Median ARRS was 6.5, with 10.8%, 44.3% and 44.9% classified as low, intermediate, and high risk, respectively. Kaplan Meier estimates for renal survival computed at 36 months revealed an overall mean time to dialysis of 20 months, which decreased with an increase in risk category [33.4 (low risk), 24.7 (intermediate risk), 12.7 months (high risk), Log-R test: χ2(2) = 24.9, p < 0.001] with an ESRD survival of 92.9%, 63.6% and 29.7% at 36 months, respectively. Regarding secondary endpoints, overall survival at 36 months was not different between groups [33.7 (low risk) vs. 33.2 (intermediate risk) vs. 32.2 months (high risk), Log-R test: χ2(2) = 0.3, p = 0.9]. Cox regression, plotted for ESRD at 36 months using the three score variables, revealed eGFR at presentation as the strongest predictor of kidney survival (HR: 0.96, 95% CI: 0.93-0.99, p = 0.004) whereas PNG and IFTA did not achieve significance (p = 0.189 and p = 0.066, respectively). Conclusion Our results corroborate Brix et al ARRS, accurately predicting ESRD in a Portuguese cohort of patients with renal involvement by ANCA vasculitis. Patients assessed as high-risk of developing ESRD had a lower mean time to dialysis, although overall survival did not differ between groups. Contrary to Brix et al findings, which revealed PGN as the only independent predictor of ESRD, in our study lower eGFR at the time of diagnosis was an independent risk factor. Type of immunosuppression used in each patient was not considered in this study and could maybe alter results of renal and overall survival. Despite this, Brix et al reported that, in their population, validity of ARRS was not influenced by immunosuppressive treatment. This new scoring system still requires validation in a larger cohort, but results seem promising and, in the future, may aid clinicians with treatment decisions. This is relevant since full immunosuppression induction schemes may be halted in patients with high probability of ESRD, diminishing infectious complications and potentially decreasing morbidity and mortality associated with AAV.

A kidney transplant is the best option for patients with end-stage renal disease. The waiting list period can be long, especially for highly sensitized patients. We describe a 60-year-old woman who received a second transplant and was highly sensitized to vascular access exhaustion, anuric, and performing peritoneal dialysis. At 27 days post-transplant, the patient developed thrombosis of the allograft vein, oliguria, and elevated serum creatinine. Fibrinolysis was attempted, but the patient remained oliguric and with acute graft dysfunction. She had a suction thrombectomy using the Penumbra System, allowing the removal of all thrombi and repermeabilization of the vein graft, resolving the acute graft dysfunction.

Objective: Despite technical advances, hypertension (HT) in peritoneal dialysis (PD) patients remains highly prevalent, with 24-hour ambulatory blood pressure monitoring (ABPM) allowing for a better understanding of the blood pressure profile. Recent studies suggest a close relationship between T helper (Th)1 and Th17 cells and non-dipping HT. In this setting, we aimed to evaluate the relationship between dipping profile and peripheral Th1 and Th17 cells and IL-17A levels in chronic PD patients. Design and method: Cross-sectional study of 26 PD patients with history of HT and 10 healthy controls. Peripheral blood frequencies of TCD4+, TCD8+, Th1 and Th17 cells were quantified by flow cytometry and IL-17A concentrations measured by enzyme-linked immunosorbent assay. All patients were examined by ABPM on the same day as the blood collection. Results: Table 1 summarizes patient characteristics. The frequency of Th1 cells in PD patients was lower than in healthy controls (p=0.001). A lower percentage of Th17 cells was also observed, although not statistically significant (p=0.061). According to ABPM, 10 PD patients were classified as dippers and the remaining as non-dippers. There were no significant differences in age, PD duration, office systolic and diastolic pressures, body mass index, lipid profile and hemoglobin A1c between dippers and non-dippers. All patients with diabetic nephropathy (n=7) were non-dippers. The average number of prescribed anti-hypertensive medication classes in dipper patients was 2.20 ± 1.14 and in non-dippers was 2.81 ± 0.91. Non-dippers presented lower frequencies of Th17 cells than dippers (p=0.018), and frequencies were also lower than the observed in healthy controls (p=0.008). These differences were not accompanied by a significant difference in IL-17A levels across the three groups. Both dipper and non-dippers had lower frequencies of Th1 cells when compared to the controls. Conclusions: Non-dipping is a frequent characteristic in PD patients, although higher frequencies of Th1 and Th17 cells, as well as IL-17A levels were not documented in these patients. Whether these cells may be the link between immunity and poorer blood pressure control in PD patients should be further evaluated in larger cohorts.

Abstract Background and Aims Chronic kidney disease (CKD) is a complex and heterogeneous disease and is increasingly becoming a global public health concern. It is is characterized by a persistent inflammation state which appear to be caused by cytokines, grown factors and hormones. Peritoneal dialysis (PD) accounts for 9% of all kidney replacement therapy (KRT) and over time, some changes are expected to occur in the peritoneal membrane mainly due to exposure to PD solutions, infectious processes and non-infectious complications. This inflammatory process is poorly understood and needs further clarification, but Th17 cells and Th1 cells seem to be involved. Therefore, we aimed to quantify the frequency of peripheral immune cells and the concentration of IL-17A in peripheral blood (PB) and peritoneal effluent (PE) and compare to a healthy control group. Method In a cross-sectional study of 26 PD patients and 10 healthy, age and sex-matched controls we evaluated PB and PE frequencies of T lymphocytes, T CD4, T CD8 and Th1 cells by flow cytometry as well as IL-17 concentrations using enzyme-linked immunosorbent assay. Comparisons were performed between PD patients and controls and between the different groups of PD patients according to PD modality, number of exchanges, dialysate tonicity, extraneal use, infusion and daily total volumes, type of peritoneal transport and volume indexes. Statistical analyses were performed using the SPSS statistics version 26. Results Table 1 summarizes the main characteristics of PD patients and controls. Overall, in comparison with the control group, the frequency of Th1 cells in PB of PD patients was significantly lower (P = 0.001). On the other hand, frequency of Th1 cells substantially expanded in the PE, as compared to the PB (P = 0.001). PD patients also presented lower Th17 cells frequencies (P = 0.061) and those prescribed Extraneal had the lowest frequencies of Th17 (P = 0.030). IL-17A concentration was significantly higher in PE vs PB of PD patients (P = 0.012). Finally, the frequency of total lymphocytes in high PD transporters was significantly higher in comparison with high-average transporters (P = 0.021). Conclusion In our cohort, PE presented high concentrations of proinflammatory cells and cytokines. Th1 cells rather than Th17 cells were increased, pointing to a predominant cytolytic activity but IL-17 was also increased. Treatment with Extraneal associated with a lower frequency of these cells, somehow counterbalancing the inflammatory millieu associated with high glucose concentrations.

Pembrolizumab is an immune checkpoint inhibitor used as a cancer therapy. The incidence of immune related adverse events in patients receiving immune checkpoint inhibitors can be as high as 59%–85%. Renal adverse effects are uncommon, but the incidence of kidney toxicity related to pembrolizumab is rising as the use of this agent becomes more frequent. We present an uncommon case of biopsy-proven acute interstitial nephritis secondary to pembrolizumab in a patient with metastatic squamous cell carcinoma at the time of his fourth scheduled cycle. Despite the good initial tumor response, pembrolizumab had to be suspended and the patient started on corticosteroids with an initial good response. On his own initiative, the patient stopped prednisolone early, leading to a rebound acute kidney injury. Pembrolizumab was not reintroduced for the risk of further renal function worsening. His clinical status declined due to the progression of the neoplastic disease, and he was referred for palliative care. This case illustrates the importance of systematizing some key points in the approach to acute interstitial nephritis secondary to pembrolizumab: the role of the differential diagnosis of acute kidney injury in a patient under an immune checkpoint inhibitor, the role of glucocorticoids and the controversy about rechallenging this drug after a related acute interstitial nephritis.

Wunderlich syndrome is a rare condition characterized by atraumatic spontaneous renal hemorrhage that can have serious associated complications, especially in chronic kidney disease and end-stage kidney disease patients due to their complexity. Diagnosis requires a high index of suspicion, since its classical presentation with Lenk’s triad is only seen in less than a quarter of patients. Early detection is of outmost importance because of this syndrome potential for causing hemodynamic instability and shock. Spontaneous renal hemorrhage has been reported much less frequently in peritoneal dialysis as compared to hemodialysis. To our knowledge, only 3 single-cases involving peritoneal dialysis patients were published since the year 2000. We describe an uncommon case report of a 68-year-old male undergoing continuous ambulatory peritoneal dialysis for 5 years and taking warfarin for permanent atrial fibrillation who developed Wunderlich syndrome presenting with Lenk’s triad. The patient was managed with percutaneous drainage of the renal hemorrhage and was able to continue peritoneal dialysis in the acute phase of disease. Unfortunately, he subsequently developed peritoneal membrane failure having to transition to hemodialysis 2.5 months after the WS episode. The authors will review literature on Wunderlich syndrome on end-stage kidney disease patients, discuss oral anticoagulation on peritoneal dialysis patients, maintenance of the technique, and finally, address the consequences of Wunderlich syndrome on peritoneal membrane diffusion capacity.

The number of elderly patients initiating hemodialysis (HD) increased considerably over the past decade. Arteriovenous fistulas (AVFs) are the preferred vascular access (VA) type in most HD patients. Choice of VA for older hemodialysis patients presents a challenge. The higher incidence of comorbidities, longer AVF maturation times, risk of primary failure, risk of patency loss, and shorter life expectancy are important factors to consider. In this review we provide a comprehensive analysis on maturation rates, primary failure, patency, and mortality regarding vascular access in patients older than 75 years of age.

Hemodialysis (HD) is currently the most widely used renal replacement therapy for end-stage chronic renal disease. Native arteriovenous fistula (AVF) is the preferred access because of lower infectious and thrombotic risk, higher survival, shorter hospitalization time, lower mortality and associated morbidity. However, the risk of AVF infection, namely by methicillin-resistant staphylococcus aureus (MRSA), should not be underestimated. Especially when using the Buttonhole technique in which cannulation of the AVF is performed in exactly the same place in every dialysis session. We present an uncommon case of endocarditis with metastatic complications (multifocal septic arthritis, multiple pulmonary cavitations and disseminated purpuric rash), associated with presumed access-related S. aureus bacteremia in a patient undergoing regular HD program with an AVF cannulated with the buttonhole technique, with a surprising complete resolution of tricuspid valvular vegetation and all other secondary infections with 8 weeks of antibiotherapy.