Peritoneal dialysis related peritonitis: insights from a long-term analysis of an Italian center.

BACKGROUND: Peritonitis is a common and severe complication of peritoneal dialysis (PD). For comparative analysis standardized definitions as well as measurements and outcomes are crucial. However, most PD-related peritonitis studies have been using heterogenous definitions and variable methods to measure outcomes. The ISPD 2022 guidelines have revised and clarified numerous definitions and proposed new peritonitis categories and outcomes. METHODS: Between 1st January 2009 and 31st May 2023, 267 patients who started PD at our institution were included in the study. All PD-related peritonitis episodes that occurred in our unit during the study period were collected. The new definitions and outcomes of ISPD 2022 recommendations were employed. RESULTS: The overall peritonitis rate was 0.25 episode/patient year. Patient cumulative probability of remaining peritonitis-free at one year was 84.2%. The medical cure and refractory peritonitis rates were equal to 70.3 and 22.4%, respectively. Culture-negative peritonitis accounted for 25.6% of all specimens. The rates of peritonitis associated death, hemodialysis transfer, catheter removal and hospitalization were 6.8%, 18.3%, 18.7% and 64.4%, respectively. Relapsing, repeat, recurrent and enteric peritonitis accounted for 7.8%, 6.8%, 4.1% and 2.7% of all episodes, respectively. Catheter insertion, catheter related and pre-PD peritonitis were 4.2, 2.1 and 0.5%. CONCLUSIONS: The implementation of PD-related peritonitis reports using standardized definitions and outcome measurements is of paramount importance to enhance clinical practice and to allow comparative studies.

Tunnel ultrasound can guide the use of peritoneal dialysis catheter exit site relocation by external splicing and cuff removal in refractory tunnel infection.

BACKGROUND: Peritoneal dialysis (PD) catheter related infections continue to be a major cause of morbidity and transfer to hemodialysis (HD) in PD patients. The treatment of tunnel infection (TI) could be challenging, especially when the infection involves the superficial cuff requiring the removal of the catheter. To spare the patient the loss of the catheter and the transfer to HD, several mini-invasive surgical techniques have been proposed as rescue therapy. Furthermore, nowadays, the rapid growth of digital technology has enormously increased the diagnostic sensibility of the echo signal allowing to accurately defines the extent of the infectious process along the PD catheter tunnel. METHODS: Between 1st January 2020 and 31st December 2021 seven patients who underwent exit-site relocation by external splicing and cuff removal at our institution due to refractory TI were included in the study. All patients were followed until 12 months after the procedure. As soon as TI was defined refractory to the medical therapy, an ultrasonographic examination of the catheter tunnel was performed to define the extent of the infectious episode. RESULTS: Among the 7 infectious episodes, 4 were caused by P. aeruginosa, and 3 by S. aureus. Around the superficial cuff the hypo/anechoic collections detected by ultrasounds showed a mean diameter of 3.05 ± 0.79 mm. The exit-site relocation by external splicing and cuff removal was successful in all cases (7/7, 100%). CONCLUSIONS: In our experience the use of exit site relocation by external splicing and cuff removal as rescue therapy for TI with positive ultrasounds for TI limited to superficial cuff involvement and without secondary peritonitis, yielded to promising results with a success rate of 100%. This preliminary experience underlines the paramount usefulness of tunnel echography in accurately defining the extent of TI and, consequently, guiding the choice of the therapeutical approach in refractory TI.

Relationship between number of daily exchanges at CAPD start with clinical outcomes.

BACKGROUND: Peritoneal dialysis (PD) continues to be demanding for patients affected by kidney failure. In kidney failure patients with residual kidney function, the employment of incremental PD, a less onerous dialytic prescription, could translate into a decrease burden on both health systems and patients. METHODS: Between 1st January 2009 and 31st December 2021, 182 patients who started continuous ambulatory peritoneal dialysis (CAPD) at our institution were included in the study. The CAPD population was divided into three groups according to the initial number of daily CAPD exchanges prescribed: one or two (50 patients, CAPD-1/2 group), three (97 patients, CAPD-3 group) and four (35 patients, CAPD-4 group), respectively. RESULTS: Multivariate analysis showed a difference in term of peritonitis free survival in CAPD-1/2 in comparison to CAPD-3 (hazard ratio (HR): 2.20, p = 0.014) and CAPD-4 (HR: 2.98, p < 0.01). A tendency towards a lower hospitalisation rate (CAPD-3 and CAPD-4 vs. CAPD-1/2, p = 0.11 and 0.13, respectively) and decreased mortality (CAPD-3 and CAPD-4 vs. CAPD-1/2, p = 0.13 and 0.22, respectively) in patients who started PD with less than three daily exchanges was detected. No discrepancy of the difference of the mean values between baseline and 24 months residual kidney function was observed among the three groups (p = 0.33). CONCLUSIONS: One- or two-exchange CAPD start was associated with a lower risk of peritonitis in comparison to three- or four-exchange start. Furthermore, an initial PD prescription with less than three exchanges may be associated with an advantage in term of hospitalisation rate and patient survival.

Simultaneous removal and replacement of the peritoneal catheter in CAPD patient with refractory peritonitis sustained by P. aeruginosa: A case-report.

Pseudomonas peritonitis is often severe and associated with less than 50% complete cure rate, often requiring catheter removal, and transfer to HD. International guidelines recommend that peritoneal catheter should be removed if peritoneal dialysis (PD) effluent does not clear after 5 days of appropriate antibiotic therapy defining the episode as refractory peritonitis. To avoid the shift to hemodialysis (HD), the simultaneous removal and replacement of the peritoneal catheter (SCR) has been employed to treat recurrent peritonitis or tunnel infections associated with peritonitis, obtaining satisfactory outcomes. However, the use of SCR is still controversial in refractory episodes. At present there is growing evidence that refractory peritonitis can be sustained by bacterial adherence along the intraperitoneal portion of the catheter, especially when Pseudomonas species are involved. We describe a case of refractory peritonitis sustained by P. aeruginosa that after a partial response to antibiotics has been successfully treated by SCR.

The Impact of Antiviral Treatment of Hepatitis B Virus after Kidney Transplant and the Latest Insights.

BACKGROUND: The current frequency of hepatitis B virus infection in patients with advanced chronic kidney disease (CKD) (including patients on maintenance dialysis and kidney transplant recipients) is low but not negligible worldwide. HBV has a deleterious effect on survival after a kidney transplant; antiviral treatments improved the short-term outcomes of kidney transplant recipients, but their long-term impact remains uncertain. AIM: The aim of this review is to assess the role of antiviral therapy for HBV in improving survival after a kidney transplant. The recent publication of large surveys has prompted us to update the available evidence on the impact of HBV on patient and graft survival after a kidney transplant. METHODS: We have conducted an extensive review of the medical literature, and various research engines have been used. RESULTS: We retrieved several studies (n = 11; n = 121,436 unique patients) and found an association between positive serologic HBsAg status and diminished patient and graft survival after a kidney transplant; the adjusted relative risk (aRR) of all-cause mortality and graft loss was 2.85 (95% CI, 2.36; 3.33, p < 0.0001) and 1.26 (95% CI, 1.02; 1.51, p < 0.0001), respectively. To our knowledge, at least six studies reported improved patient and graft survival after the adoption of antiviral therapies for HBV (this result was reported with both survival curves and multivariable regression). According to novel clinical guidelines, entecavir has been suggested as a 'first line' antiviral agent for the treatment of HBV after a kidney transplant. CONCLUSIONS: The recent availability of safe and effective antiviral drugs for the treatment of HBV has meant that the survival curves of HBsAg-positive patients on antiviral therapy and HBsAg-negative patients after a kidney transplant can be comparable. Antiviral therapy should be systematically proposed to HBV-positive kidney transplant recipients and candidates to avoid the deleterious hepatic and extra-hepatic effects of chronic HBV replication.

Recent Information on Pan-Genotypic Direct-Acting Antiviral Agents for HCV in Chronic Kidney Disease.

BACKGROUND: Hepatitis C virus (HCV) is still common in patients with chronic kidney disease. It has been recently discovered that chronic HCV is a risk factor for increased incidence of CKD in the adult general population. According to a systematic review with a meta-analysis of clinical studies, pooling results of longitudinal studies (n = 2,299,134 unique patients) demonstrated an association between positive anti-HCV serologic status and increased incidence of CKD; the summary estimate for adjusted HR across the surveys was 1.54 (95% CI, 1.26; 1.87), (p < 0.0001). The introduction of direct-acting antiviral drugs (DAAs) has caused a paradigm shift in the management of HCV infection; recent guidelines recommend pan-genotypic drugs (i.e., drugs effective on all HCV genotypes) as the first-choice therapy for HCV, and these promise to be effective and safe even in the context of chronic kidney disease. AIM: The purpose of this narrative review is to show the most important data on pan-genotypic DAAs in advanced CKD (CKD stage 4/5). METHODS: We recruited studies by electronic databases and grey literature. Numerous key-words ('Hepatitis C' AND 'Chronic kidney disease' AND 'Pan-genotypic agents', among others) were adopted. RESULTS: The most important pan-genotypic combinations for HCV in advanced CKD are glecaprevir/pibrentasvir (GLE/PIB) and sofosbuvir/velpatasvir (SOF/VEL). Two clinical trials (EXPEDITION-4 and EXPEDITION-5) and some 'real-world' studies (n = 6) reported that GLE/PIB combinations in CKD stage 4/5 gave SVR12 rates ranging between 86 and 99%. We retrieved clinical trials (n = 1) and 'real life' studies (n = 6) showing the performance of SOF/VEL; according to our pooled analysis, the summary estimate of SVR rate was 100% in studies adopting SOF/VEL antiviral combinations. The drop-out rate (due to AEs) in patients on SOF/VEL ranged between 0 and 4.8%. CONCLUSIONS: Pan-genotypic combinations, such as GLE/PIB and SOF/VEL, appear effective and safe for HCV in advanced CKD, even if a limited number of studies with small sample sizes currently exist on this issue. Studies are under way to assess whether successful antiviral therapy with DAAs will translate into better survival in patients with advanced CKD.

Peritoneal Dialysis for Potential Kidney Transplant Recipients: Pride or Prejudice?

Kidney transplantation (KT) is recognized as the gold-standard of treatment for patients with end-stage renal disease. Additionally, it has been demonstrated that receiving a pre-emptive KT ensures the best recipient and graft survivals. However, due to an overwhelming discrepancy between the organs available and the patients on the transplant waiting list, the vast majority of transplant candidates require prolonged periods of dialysis before being transplanted. For many years, peritoneal dialysis (PD) and hemodialysis (HD) have been considered competitive renal replacement therapies (RRT). This dualistic vision has recently been questioned by evidence suggesting that an individualized and flexible approach may be more appropriate. In fact, tailored and cleverly planned changes between different RRT modalities, according to the patient's needs and characteristics, are often needed in order to achieve the best results. While home HD is still under scrutiny in this particular setting, current data seems to favor the use of PD over in-center HD in patients awaiting a KT. In this specific population, the demonstrated advantages of PD are superior quality of life, longer preservation of residual renal function, lower incidence of delayed graft function, better recipient survival, and reduced cost.

Vitamin D Status and SARS-CoV-2 Infection in a Cohort of Kidney Transplanted Patients.

BACKGROUND: Recently the protective role of 25-hydroxyvitamin D (25(OH)D) against viral infections has been hypothesized. We evaluated the association between vitamin D status and SARS-CoV-2 infection susceptibility and severity in a cohort of kidney transplanted patients (KTxp). METHODS: A total of 61 KTxp with SARS-CoV-2 infection (COV+) were matched with 122 healthy KTxp controls (COV-). Main biochemical parameters at 1, 6, and 12 months before SARS-CoV-2 infection were recorded. Vitamin D status was considered as the mean of two 25(OH)D measures obtained 6 ± 2 months apart during the last year. The severity of SARS-CoV-2 infection was based on the need for hospitalization (HOSP+) and death (D+). RESULTS: 25(OH)D levels were lower in COV+ than in controls [19(12-26) vs. 23(17-31) ng/mL, p = 0.01]. No differences among the other biochemical parameters were found. The SARS-CoV-2 infection discriminative power of 25(OH)D was evaluated by ROC-curve (AUC 0.61, 95% CI 0.5-0.7, p = 0.01). 25(OH)D was not significantly different between HOSP+ and HOSP- [17(8-25) vs. 20(15-26) ng/mL, p = 0.19] and between D+ and D- [14(6-23) vs. 20(14-26) ng/mL, p = 0.22] and had no significant correlation with disease length. CONCLUSIONS: During the year preceding the infection, 25(OH)D levels were lower in COV+ KTxp in comparison with controls matched for demographic features and comorbidities. No significant association between vitamin D status and SARS-CoV-2 infection related outcomes was found.

HBV vaccination with Fendrix is effective and safe in pre-dialysis CKD population.

BACKGROUND: Patients with chronic kidney disease have a poor response to hepatitis B vaccine due to the immunodeficiency conferred from chronic uremia. A recombinant HB vaccine containing an improved adjuvant system AS04 (HBV-AS04) has been manufactured but scarce evidence exists on HBV-AS04 use among patients with CKD. AIM: To assess efficacy and safety of an adjuvanted recombinant vaccine (HBV-AS04) in a large cohort of CKD patients at pre-dialysis stage (with susceptibility to HBV infection). METHODS: Patients were prospectively enrolled to receive four 20-mcg doses of HBV-AS04 by intramuscular route (deltoid muscle) at months 1, 2, 3, and 4. Anti-HBs surface antibody concentrations were tested at intervals of 1, 2, 3, 4, and 12months. Multivariate analyses were performed to assess the parameters, which predicted immunologic response to HBV-AS04 vaccine. RESULTS: One hundred and seven patients were included and 102 completed the study. At completion of vaccine schedule, the frequency of responders (anti-HBs titers≥10mIU/mL) was 95% (97/102) (mean anti-HBs antibody titers, 688.9±385mIU/mL), according to per-protocol analysis. Serum haemoglobin levels were greater in responder than non- or low-responder patients to HBV-AS04 (P=0.04) and this was confirmed by multivariate analysis. The seroprotection rate at month 50 was 88% (30/34) with lower anti-HBs antibody titers (218.5±269.6mIU/mL, P=0.001). No major side effects were observed. CONCLUSIONS: Our prospective study performed in a real-world setting showed a high immunogenicity and safety of HBV-AS04 vaccine in patients with CKD not yet on maintenance dialysis. Studies provided with longer follow-ups are under way to assess the durability of seroprotection in responders.

Membranous Nephropathy (MN) Recurrence After Renal Transplantation.

Primary membranous nephropathy (MN) is a frequent cause of NS in adults. In native kidneys the disease may progress to ESRD in the long term, in some 40-50% of untreated patients. The identification of the pathogenic role of anti-podocyte autoantibodies and the development of new therapeutic options has achieved an amelioration in the prognosis of this disease. MN may also develop in renal allograft as a recurrent or a de novo disease. Since the de novo MN may have some different pathogenetic and morphologic features compared to recurrent MN, in the present paper we will deal only with the recurrent disease. The true incidence of the recurrent form is difficult to assess. This is mainly due to the variable graft biopsy policies in kidney transplantation, among the different transplant centers. Anti-phospholipase A2 receptor (PLA2R) autoantibodies are detected in 70-80% of patients. The knowledge of anti-PLA2R status before transplant is useful in predicting the risk of recurrence. In addition, the serial survey of the anti-PLA2R titers is important to assess the rate of disease progression and the response to treatment. Currently, there are no established guidelines for prevention and treatment of recurrent MN. Symptomatic therapy may help to reduce the signs and symptoms related to the nephrotic syndrome. Anecdotal cases of response to cyclical therapy with steroids and cyclophosphamide have been published. Promising results have been reported with rituximab in both prophylaxis and treatment of recurrence. However, these results are based on observational data, and prospective controlled trials are still missing.