Peritoneal Dialysis Exit-Site Care Protocols in Portugal and Its Association with Catheter-Related Infections.

INTRODUCTION: Exit-site infection (ESi) prevention is a key factor in lowering the risk of peritonitis. This study aimed to evaluate the associations between exit-site (ES) care protocols and the annual incidence rates of ESi and peritonitis in Portugal. METHODS: We performed a national survey using two questionnaires: one about the incidence of catheter-related infections and the other characterizing patients' education and ES care protocols. RESULTS: In 2017 and 2018, 14 Portuguese units followed 764 and 689 patients. ESi incidence rate was 0.41 episodes/year, and the peritonitis incidence rate was 0.37. All units monitor catheter-related infections on a yearly basis, use antibiotic prophylaxis at the time of catheter placement, and treat nasal carriage of S. aureus, although with different approaches. Screening for nasal carriage of S. aureus is performed by 12 units, and daily topical antibiotic cream is recommended by 6 out of 14 of the units. We did not find statistical differences in ESi/peritonitis, comparing these practices. The rate of ESis was lower with nonocclusive dressing immediately after catheter insertion, bathing without ES dressing, with the use of colostomy bags in beach baths and was higher with the use of bath sponge. The peritonitis rate was lower with bathing without ES dressing and if shaving of the external cuff was performed in the presence of chronic ESi. CONCLUSIONS: We found potential proceedings associated with ESi and peritonitis. A regular national audit of peritoneal dialysis units is an important tool for clarifying the best procedures for reduction of catheter-related infections.

Different kidney function trajectory patterns before dialysis in elderly patients: clinical implications and outcomes.

Background. Identifying trajectories of kidney disease progression in chronic kidney disease (CKD) patients may help to deliver better care. We aimed to identify and characterize trajectories of renal function decline in CKD patients and to investigate their association with mortality after dialysis.Methods. This retrospective cohort study included 378 CKD patients who initiated dialysis (aged 65 years and over) between 2009 and 2016. Were considered mixed models using linear quadratic and cubic models to define the trajectories, and we used probabilistic clustering procedures. Patient characteristics and care practices at and before dialysis were examined by multivariable multinomial logistic regression. The association of these trajectories with mortality after dialysis was examined using Cox models.Results. Four distinct groups of eGFR trajectories decline before dialysis were identified: slower decline (18.3%), gradual decline (18.3%), early rapid decline (41.2%), and rapid decline (22.2%). Patients with rapid eGFR decline were more likely to have diabetes, more cognitive impairment, to have been hospitalized before dialysis, and were less likely to have received pre-dialysis care compared to the patients with a slower decline. They had a higher risk of death within the first and fourth year after dialysis initiation, and after being more than 4 years in dialysis.Conclusions. There are different patterns of eGFR trajectories before dialysis initiation in the elderly, that may help to identify those who are more likely to experience an accelerated decline in kidney function, with impact on pre ESKD care and in the mortality risk after dialysis.

Predicting 6-Month Mortality in Incident Elderly Dialysis Patients: A Simple Prognostic Score.

AIM: Mortality in end-stage renal disease (ESRD) remains high, particularly among elderly, who represents the most rapidly growing segment of the ESRD population in wealthier countries. We developed and validated a risk score in elderly patients to predict 6-month mortality after dialysis initiation. METHODS: We used data from a cohort of 421 patients, aged 65 years and over who started dialysis between 2009 and 2016, in our Nephrology department. The predictive score was developed using a multivariable logistic regression analysis. A bootstrapping technique was used for internal validation. RESULTS: The overall mortality within 6 months was 14.0%. Five independent predictors were identified, and a points system was constructed: age 75 years or older (2 points), coronary artery disease (2), cerebrovascular disease with hemiplegia (2), time of nephrology care before dialysis (<3.0 months [2]; ≥3 to <12 months [1]), and serum albumin levels (3.0-3.49 g/dL [1]; <3.0 g/dL [2]). A score of 6 identified patients with a 70% risk of 6-month mortality. Model performance was good in both discrimination (area under the curve of 0.793; [95% CI 0.73-0.86]) and validation (concordance statistics of 0.791 [95% CI 0.73-0.85]). CONCLUSIONS: We developed a simple prediction score based on readily available clinical and laboratory data that can be a practical and useful tool to assess short-term prognosis in elderly patients starting dialysis. It may help to inform patients and their families about ESRD treatment options and provide a more patient-centered overall approach to care.

A Step Forward in Breast Cancer Research: From a Natural-Like Experimental Model to a Preliminary Photothermal Approach.

Breast cancer is one of the most frequently diagnosed malignancies and common causes of cancer death in women. Recent studies suggest that environmental exposures to certain chemicals, such as 7,12-Dimethylbenzanthracene (DMBA), a chemical present in tobacco, may increase the risk of developing breast cancer later in life. The first-line treatments for breast cancer (surgery, chemotherapy or a combination of both) are generally invasive and frequently associated with severe side effects and high comorbidity. Consequently, novel approaches are strongly required to find more natural-like experimental models that better reflect the tumors' etiology, physiopathology and response to treatments, as well as to find more targeted, efficient and minimally invasive treatments. This study proposes the development and an in deep biological characterization of an experimental model using DMBA-tumor-induction in Sprague-Dawley female rats. Moreover, a photothermal therapy approach using a near-infrared laser coupled with gold nanoparticles was preliminarily assessed. The gold nanoparticles were functionalized with Epidermal Growth Factor, and their physicochemical properties and in vitro effects were characterized. DMBA proved to be a very good and selective inductor of breast cancer, with 100% incidence and inducing an average of 4.7 tumors per animal. Epigenetic analysis showed that tumors classified with worst prognosis were hypomethylated. The tumor-induced rats were then subjected to a preliminary treatment using functionalized gold nanoparticles and its activation by laser (650-900 nm). The treatment outcomes presented very promising alterations in terms of tumor histology, confirming the presence of necrosis in most of the cases. Although this study revealed encouraging results as a breast cancer therapy, it is important to define tumor eligibility and specific efficiency criteria to further assess its application in breast cancer treatment on other species.

Deleterious effect of anti-angiotensin II type 1 receptor antibodies detected pretransplant on kidney graft outcomes is both proper and synergistic with donor-specific anti-HLA antibodies.

AIM: Both donor-specific antibodies (DSA) and anti-angiotensin II type 1 receptor antibodies (AT1R-abs) have been associated with poor graft outcomes after kidney transplantation (KT). We aimed to understand the impact of pretransplant AT1R-abs with or without concomitant DSA on KT outcomes. METHODS: Seventy-six patients transplanted in 2009 were studied. DSA (MFI > 1000) and/or AT1R-abs (>10UI) were detected by solid-phase assays in pre-KT sera. Multivariable Cox regression models were used to determine independent predictors of outcomes: acute rejection (AR) and graft failure. RESULTS: At transplant, 48 patients were AT1R-abs (-)/DSA (-), 12 AT1R-abs (+)/DSA (-), 9 AT1R-abs (-)/DSA (+) and 7 AT1R-abs (+)/DSA (+). Incidence of acute rejection at 1-year increased from 6% in AT1R-abs (-)/DSA (-), to 35% in AT1R-abs (+)/DSA (-), 47% in AT1R-abs (-)/DSA (+) and 43% in AT1R-abs (+)/DSA (+) (P < 0.001). No difference in DSA strength and C1q-binding ability was observed between AT1R-abs (-) /DSA (+) and AT1R-abs (+)/DSA (+) patients. Graft survival at 6-years was the lowest in AT1R-abs (+)/DSA (+) (57%), followed by AT1R-abs (+)/DSA (-) (67%), and higher in AT1R-abs (-)/DSA (-) (94%) and AT1R-abs (-)/DSA (+) (89%) patients (P = 0.012). AT1R-abs (+)/DSA (-) (HR = 6.41, 95% CI: 1.43-28.68; P = 0.015) and AT1R-abs (+)/DSA (+) (HR = 7.75, 95% CI: 1.56-38.46; P = 0.012) were independent predictors of graft failure. CONCLUSION: Acute rejection incidence and graft failure were associated with both DSA and AT1R-abs. These results demonstrate a proper negative effect of AT1R-abs on graft outcomes, besides a synergistic one with DSA. Pretransplant AT1R-abs should be acknowledged to better stratify patients' immunological risk.

Determining donor-specific antibody C1q-binding ability improves the prediction of antibody-mediated rejection in human leucocyte antigen-incompatible kidney transplantation.

Detrimental impact of preformed donor-specific antibodies (DSAs) against human leucocyte antigens on outcomes after kidney transplantation are well documented, however, the value of their capacity to bind complement for predicting antibody-mediated rejection (AMR) and graft survival still needs to be confirmed. We aimed to study DSA characteristics (strength and C1q binding) that might distinguish harmful DSA from clinically irrelevant ones. We retrospectively studied 60 kidney-transplanted patients with preformed DSA detected by single antigen bead (SAB) assays (IgG and C1q kits), from a cohort of 517 kidney graft recipients (124 with detectable anti-HLA antibodies). Patients were divided into DSA strength (MFI < vs. ≥ 15 000) and C1q-binding ability. AMR frequency was high (30%) and it increased with DSA strength (P = 0.002) and C1q+ DSA (P < 0.001). The performance of DSA C1q-binding ability as a predictor of AMR was better than DSA strength (diagnostic odds ratio 16.3 vs. 6.4, respectively). Furthermore, a multivariable logistic regression showed that C1q+ DSA was a risk factor for AMR (OR = 16.80, P = 0.001), while high MFI DSAs were not. Graft survival was lower in high MFI C1q+ DSA in comparison with patients with C1q- high or low MFI DSA (at 6 years, 38%, 83% and 80%, respectively; P = 0.001). Both DSA strength and C1q-binding ability assessment seem valuable for improving pretransplant risk assessment. Since DSA C1q-binding ability was a better predictor of AMR and correlated with graft survival, C1q-SAB may be a particularly useful tool.

Impact of de novo donor-specific anti-HLA antibodies on grafts outcomes in simultaneous pancreas-kidney transplantation.

De novo donor-specific antibodies (dDSA) relevance in simultaneous pancreas-kidney (SPK) transplantation has been scarcely investigated. We analyzed dDSA relationship with grafts outcomes in a long-term follow-up SPK-transplanted cohort. In 150 patients that received SPK transplant between 2000 and 2013, post-transplant anti-human leukocyte antigen (HLA) antibodies were screened and identified using Luminex-based assays in sera collected at 3, 6, and 12 months, then yearly. dDSA were detected in 22 (14.7%) patients at a median 3.1 years after transplant. Pretransplant anti-HLA sensitization (OR = 4.64), full HLA-DR mismatch (OR = 4.38), and previous acute cellular rejection (OR = 9.45) were significant risk factors for dDSA. dDSA were significantly associated with kidney (in association with acute rejection) and pancreas graft failure. In dDSA+ patients, those with at least one graft failure presented more frequently dDSA against class II or I + II (P = 0.011) and locusDQ (P = 0.043) and had a higher median dDSA number (P = 0.014) and strength (P = 0.030). Median time between dDSA emergence and pancreas and kidney graft failure was 5 and 12 months, respectively. Emergence of dDSA increased the risk of grafts failure in SPK-transplanted patients. Full HLA-DR mismatch was associated with dDSA emergence. dDSA characteristics might help identify patients at a higher risk of graft failure.

Health-related quality of life may improve after transplantation in pancreas-kidney recipients.

Pancreas-kidney transplantation (PKT) may significantly improve quality of life (HRQOL) in patients with type 1 diabetes. We have assessed the changes felt by PKT patients, using the Gastrointestinal Quality of Life Index (GIQLI) and EuroQol-5D questionnaires. Patients were asked to compare how their HRQOL had changed from pre-transplantation to the last visit. The 60 men and 66 women enrolled had a mean follow-up of five yr; 84.1% with both grafts, 15.9% with one graft functioning. In all domains of EuroQol-5D scores improved after PKT, as well as the visual analogue scale health state (from 38% to 84%, p < 0.001; effect size 3.34). In GIQLI, physical function was felt better after PKT than before (14.83 ± 3.86 vs. 7.86 ± 4.43, p < 0.001; effect size 1.68); the same was observed for psychological status, social function, and GI complaints. Concerning the burden of medical treatment, the score significantly improved (from 1.31 to 3.63, p < 0.001, effect size 2.02). The rate of unemployed patients decreased after PKT (from 50.8% to 36.5%, p < 0.001). Multivariate analysis showed that having only one functioning graft was associated with worse HRQOL scores (B = -5.157, p = 0.015). In conclusion, for all assessed domains, patients reported a significant improvement in HRQOL after PKT. Maintenance of the two grafts functioning predicted higher improvement of HRQOL scores.

Pancreas-Kidney transplantation: Impact of dialysis modality on the outcome.

It remains controversial whether dialysis modality prior to SPKT (simultaneous pancreas-kidney transplantation) affects the outcome. We analyzed outcomes in type 1 diabetic patients undergoing SPKT, comparing peritoneal dialysis (PD) and hemodialysis (HD) groups: 119 had been on HD; 39 on PD. They were comparable except regarding dialysis time, higher in HD patients (30 ± 23 vs. 21 ± 15 months, P = 0.003). Thrombosis-driven relaparotomy was more frequent in PD patients (12.8% vs. 1.7%, P = 0.014). Pancreas loss due to infection was higher in PD patients (12.8% vs. 3.4%, P = 0.042). Thrombosis-related kidney loss was more frequent in PD patients (5.1%, vs. 0% in HD patients, P = 0.058). Thirteen deaths occurred, more within the PD group (17.9% vs. 5%; P = 0.011), being infection the leading cause (13.5%, vs. 1.7% in HD patients, P = 0.010). Patient survival was inferior in PD patients. Besides PD, cardiovascular disease and graft failure were independent predictors of patient death. In conclusion, PD patients more frequently complicated with intra-abominal infection leading to pancreatic loss and with renal thrombosis, with adverse impact on survival. As a PD first strategy in end-stage renal disease patients is generally associated with good outcomes, these gloomier results after SPKT urge for careful adjustment of infection and thrombosis prophylactic protocols in PD patients.

Pancreatic autoantibodies after pancreas-kidney transplantation - do they matter?

Type 1 diabetes recurrence has been documented in simultaneous pancreas-kidney transplants (SPKT), but this diagnosis may be underestimated. Antibody monitoring is the most simple, noninvasive, screening test for pancreas autoimmune activity. However, the impact of the positive autoimmune markers on pancreas graft function remains controversial. In our cohort of 105 SPKT, we studied the cases with positive pancreatic autoantibodies. They were immunosuppressed with antithymocyte globulin, tacrolimus, mycophenolate, and steroids. The persistence or reappearance of these autoantibodies after SPKT and factors associated with their evolution and with graft outcome were analyzed. Pancreatic autoantibodies were prospectively monitored. Serum samples were collected before transplantation and at least once per year thereafter. At the end of the follow-up (maximum 138 months), 43.8% of patients were positive (from pre-transplant or after recurrence) for at least one autoantibody - the positive group. Antiglutamic acid decarboxylase was the most prevalent (31.4%), followed by anti-insulin (8.6%) and anti-islet cell autoantibodies (3.8%). Bivariate analysis showed that the positive group had higher fasting glucose, higher glycated hemoglobin (HbA1c), lower C-peptide levels, and a higher number of HLA-matches. Analyzing the sample divided into four groups according to pre-/post-transplant autoantibodies profile, the negative/positive group tended to present the higher HbA1c values. Multivariate analysis confirmed the significant association between pancreas autoimmunity and HbA1c and C-peptide levels. Positivity for these autoantibodies pre-transplantation did not influence pancreas survival. The unfavorable glycemic profile observed in the autoantibody-positive SPKT is a matter of concern, which deserves further attention.

Hepatocyte growth factor signalizes peritoneal membrane failure in peritoneal dialysis.

BACKGROUND: Hepatocyte growth factor (HGF) counteracts peritoneal fibrosis in animal models and in-vitro studies, but no study explored effluent HGF in peritoneal dialysis (PD) patients with ultrafiltration failure (UFF). Our aim was to assess the relationship between effluent HGF with UF profile, free water transport (FWT) and small-solute transport. METHODS: We performed 4-hour, 3.86% PET with additional UF measurement at 60 minutes in 68 PD patients. MTACcreatinine, FWT, small-pore ultrafiltration, and effluent HGF were quantified. RESULTS: Effluent HGF negatively correlated with UF (r=-0.80, p=0.009) and FWT (r=-0.69, p=0.04). Patients with UFF had higher dialysate HGF (103 pg/mL vs 77 pg/mL, p=0.018) and, although not statistically significant, those with FWT compromise had also higher dialysate HGF compared with subgroup of UFF without FWT compromise (104 pg/mL vs 88 pg/mL, p=0.08). FWT≤45% without clinical UFF was documented in some patients who also had increased effluent HGF. CONCLUSIONS: Dialysate HGF concentration is significantly higher among patients with UFF, specially, if FWT is impaired, being a sign of peritoneal membrane deterioration.

In Vitro Characterization of Reversine-Treated Gingival Fibroblasts and Their Safety Evaluation after In Vivo Transplantation.

Reversine is a purine derivative that has been investigated with regard to its biological effects, such as its anticancer properties and, mostly, its ability to induce the dedifferentiation of adult cells, increasing their plasticity. The obtained dedifferentiated cells have a high potential for use in regenerative procedures, such as regenerative dentistry (RD). Instead of replacing the lost or damaged oral tissues with synthetic materials, RD uses stem cells combined with matrices and an appropriate microenvironment to achieve tissue regeneration. However, the currently available stem cell sources present limitations, thus restricting the potential of RD. Based on this problem, new sources of stem cells are fundamental. This work aims to characterize mouse gingival fibroblasts (GFs) after dedifferentiation with reversine. Different administration protocols were tested, and the cells obtained were evaluated regarding their cell metabolism, protein and DNA contents, cell cycle changes, morphology, cell death, genotoxicity, and acquisition of stem cell characteristics. Additionally, their teratoma potential was evaluated after in vivo transplantation. Reversine caused toxicity at higher concentrations, with decreased cell metabolic activity and protein content. The cells obtained displayed polyploidy, a cycle arrest in the G2/M phase, and showed an enlarged size. Additionally, apoptosis and genotoxicity were found at higher reversine concentrations. A subpopulation of the GFs possessed stem properties, as supported by the increased expression of CD90, CD105, and TERT, the existence of a CD106+ population, and their trilineage differentiation capacity. The dedifferentiated cells did not induce teratoma formation. The extensive characterization performed shows that significant functional, morphological, and genetic changes occur during the dedifferentiation process. The dedifferentiated cells have some stem-like characteristics, which are of interest for RD.

Update on the challenging role of biofilms in peritoneal dialysis.

Biofilms are commonly associated with an increased risk of patient infection. In peritoneal dialysis (PD), catheter associated infection, especially peritonitis, remains a clinically relevant problem. Although the presence of a biofilm is recognized in relapsing, repeat, and catheter-related peritonitis, it remains poorly characterized. In this review, an update on the role of biofilms in PD infections is presented. The emerging concept that host cells and tissue associated biofilms, in addition to the biofilms on the catheters themselves, contribute to the recalcitrance of infections is discussed. Furthermore, the evidence of biofilms on PD catheters, their developmental stages, and the possible influence of the PD environment are reviewed. The focus is given to ex vivo and in vitro studies that contribute to the elucidation of the interplay between host, microbial, and dialysis factors. The key issues that are still to be answered and the challenges to clinical practice are discussed.

Modelling competing risks in nephrology research: an example in peritoneal dialysis.

BACKGROUND: Modelling competing risks is an essential issue in Nephrology Research. In peritoneal dialysis studies, sometimes inappropriate methods (i.e. Kaplan-Meier method) have been used to estimate probabilities for an event of interest in the presence of competing risks. In this situation a competing risk analysis should be preferable. The objectives of this study are to describe the bias resulting from the application of standard survival analysis to estimate peritonitis-free patient survival and to provide alternative statistical approaches taking competing risks into account. METHODS: The sample comprises patients included in a university hospital peritoneal dialysis program between October 1985 and June 2011 (n = 449). Cumulative incidence function and competing risk regression models based on cause-specific and subdistribution hazards were discussed. RESULTS: The probability of occurrence of the first peritonitis is wrongly overestimated using Kaplan-Meier method. The cause-specific hazard model showed that factors associated with shorter time to first peritonitis were age (≥55 years) and previous treatment (haemodialysis). Taking competing risks into account in the subdistribution hazard model, age remained significant while gender (female) but not previous treatment was identified as a factor associated with a higher probability of first peritonitis event. CONCLUSIONS: In the presence of competing risks outcomes, Kaplan-Meier estimates are biased as they overestimated the probability of the occurrence of an event of interest. Methods which take competing risks into account provide unbiased estimates of cumulative incidence for each specific outcome experienced by patients. Multivariable regression models such as those based on cause-specific hazard and on subdistribution hazard should be used in this competing risk setting.

Is Erythrocytosis More Common After Simultaneous Pancreas Kidney Transplantation? A Single-Center Experience.

Post-transplant erythrocytosis (PTE) is reported in 8% to 22% of kidney transplant recipients. Few studies have evaluated the prevalence of PTE in simultaneous kidney-pancreas transplantation (SPKT). This study aimed to evaluate the prevalence of PTE in a cohort of SPKT and same-donor single kidney transplant patients and find predictive factors for erythrocytosis development. A single-center retrospective cohort study was performed with 65 SPKT recipients and 65 same-donor single kidney transplant patients. Post-transplant erythrocytosis was defined as a hematocrit persistently >51% without a known cause of erythrocytosis. The PTE prevalence was 23.1% and was more frequent in SPKT patients than in single donor patients (38.5% vs 7.7%; P < .001). The mean time for PTE development was 11.2 ± 13.3 months. In the multivariate model, SPKT was the only predictor for PTE development. De novo hypertension was more frequent in the PTE group (P = .002), but there was no difference in stroke and pancreatic or kidney thrombosis occurrence. Post-transplant erythrocytosis is more common after SPKT than after single kidney transplantation. De novo hypertension was more frequent in the erythrocytosis group, but allograft thrombosis rates.

Cost analysis of renal replacement therapy by transplant in a system of bundled payment of dialysis.

Renal replacement therapies (RRT) for patients with end-stage renal failure represent a high burden on European countries' healthcare budget. Our purpose was to report and compare the costs of RRT by hemodialysis (HD) or peritoneal dialysis (PD) and renal transplantation (RT) after introduction of a bundled payment system of dialysis. We analyzed average annual cost of RT in a public national health system hospital - surgical/anesthesiologist team and material, induction and maintenance immunosuppression therapy, hospital stay, diagnostic examinations (DE), and post-transplant office visits (including DE). Incentives paid to hospitals performing RT were included. Annual cost of HD or PD was estimated by bundled payment established in a recently revised law - 537.25 €/wk. Total first year cost or RT is 61 658.14 € and from the second year forth 543.86 €/month. Dialysis costs 28 033.71 €/yr. Break-even point for cost is at 32 months, and from there on, RT is less expensive. Strategies aimed at increasing RT are needed as it confers better survival than RRT by dialysis with lower costs to Portuguese health system.

Temporal trends in peritonitis rates, microbiology and outcomes: the major clinical complication of peritoneal dialysis.

Peritonitis remains a common complication of peritoneal dialysis (PD). The aim of this study was to analyze, in a PD center, long-term temporal trends in peritonitis rates, microbiology and outcomes. We treated 588 cases of peritonitis that occurred during 11,833.6 months at risk. Y-set and twin-bag disconnecting systems were introduced in 1990, mupirocin at the exit site in 2000 and fluconazole prophylaxis in 2005. Vancomycin and ceftazidime were the empiric protocol. Global and 5-year cohort rates were expressed as episodes/patient-year (ep/p-y). A global peritonitis rate reduction was found from 1.02 to 0.47 ep/p-y (p = 0.008). Poisson analyses performed in each of the subgroups of Gram-positive and Gram-negative peritonitis revealed no significant changes over time. No case of vancomycin resistance was identified. There was a downward trend in peritonitis-related hospitalization over time to 0.11 ep/p-y (p ≤ 0.001). Trend analysis showed a favorable, but changing evolution, highlighting the importance of accurate longitudinal PD center registry data and quality control.

A Case of Peritoneal Dialysis-Related Peritonitis Caused by Ewingella americana.

Peritoneal dialysis (PD)-related peritonitis is a frequent complication. PD units should be aware of all possible pathogens and share their experience about prevention and optimal management. Uncommon bacteria, a special group with crescent incidence in PD practice, may require singular considerations. A case of peritonitis due to Ewingella americana, a rare human pathogen, is reported, with a favorable outcome. To date, only three other cases have been described in the literature. New evidence is necessary for a better understanding of this pathogen and its consequences in PD modality.

COVID-19 in kidney transplant recipients: what have we learned one year later? A cohort study from a tertiary center.

INTRODUCTION: Kidney transplant (KT) recipients have a high risk for adverse outcomes from infections, such as COVID-19. METHODS: We have retrospectively reviewed all KT recipients with documented COVID-19 between March 1, 2020, and March 15, 2021, and analyzed patients' characteristics, clinical course, treatment, and outcomes. RESULTS: We identified 123 patients, 72% were male, with a mean age of 54.5±13.0 years. Twenty percent were asymptomatic, 7% had a nosocomial transmission, and 36% of the remainder required hospitalization. Almost all admitted patients received oxygen, 30% required invasive mechanical ventilation (IMV), more than a half had acute kidney injury, with 10% requiring dialysis, and 20% died. Incidence was comparable to that of the Portuguese population, but the mortality rate was almost four times higher (SMR of 3.768 (95% CI:1.723-7.154). Higher body mass index (OR 1.275, P=0.001), lower baseline graft function (OR 0.968, P=0.015), and nosocomial transmission (OR 13.836, P=0.019) were associated with oxygen demand, whereas female gender (OR 3.801, P=0.031) and lower baseline kidney graft function (OR 0.955, P=0.005), but not body mass index, were associated with IMV and/or death. CONCLUSION: Mortality rate in KT patients was higher than in the general population and lower baseline kidney function was the most consistent marker for adverse outcomes.

Association between severe chronic kidney disease defined by cystatin-c and creatinine and clinical outcomes in an elderly population - an observational study.

INTRODUCTION: Estimated glomerular filtration rate (eGFR) based on serum cystatin-C (sCys) seems as accurate as when based on serum creatinine (sCr), but sCys seems a better predictor of adverse outcomes. We aimed to study whether sCys could be a reliable tool for the prediction of adverse outcomes in elderly patients with severe chronic kidney disease (CKD). METHODS: A group of 348 elderly patients with non-end-stage CKD (stages 1-4, according to eGFR-EPI sCr and/or sCys), referred to our consultation unit during 2016, was retrospectively studied and divided into four exclusive categories: CKD_stage4_neither (eGFR-sCr≥30mL/min; eGFR-sCys≥30mL/min), CKD_stage4_sCr_only (eGFR-sCr<30mL/min), CKD_stage4_sCys_only (eGFR-sCys<30mL/min) and CKD_stage4_combined (eGFRsCr<30mL/min; eGFR-sCys<30mL/min). Baseline characteristics, predictors of death, and clinical events (cardiovascular events and admissions for cardiovascular, acute kidney injury or infectious events) were explored until December 2018. RESULTS: A 77±7.4 year-old cohort, with a modified Charlson Comorbidty Index (mCCI) of 3 (IQR:1-4), was followed-up during 29 (IQR: 26-33) months. There were no significant differences between the characteristics of the stage 4 groups. Survival analysis was stratified by follow-up at 12 months, and in the first year, survival curves of CKD_stage4_sCys_only and CKD_stage4_combined groups were significantly lower than the other groups (p=0.028). Adjusting for age, sex, and mCCI, CKD_stage4_sCys_only, conversely to CKD_stage4_sCr_only, had higher rates of clinical events (p<0.05) than CKD_stage4_neither group. CONCLUSION: In elderly patients with discordant CKD staging, sCys-based eGFR seems to be a better predictor of adverse outcomes than sCr-based eGFR. Patients with stage 4 CKD defined by sCr alone seem to behave similar to those with less severe CKD.