Peracetic acid-based advanced oxidation processes for decontamination and disinfection of water: A review

Peracetic acid (PAA) has attracted growing attention as an alternative oxidant and disinfectant in wastewater treatment due to the increased demand to reduce chlorine usage and control disinfection byproducts (DBPs). These applications have stimulated new investigations on PAA-based advanced oxidation processes (AOPs), which can enhance water disinfection and remove micropollutants. The purpose of this review is to conduct a comprehensive analysis of scientific information and experimental data reported in recent years on the applications of PAA-based AOPs for the removal of chemical and microbiological micropollutants from water and wastewater. Various methods of PAA activation, including the supply of external energy and metal/metal-free catalysts, as well as their activation mechanisms are discussed. Then, a review on the usage of PAA-based AOPs for contaminant degradation is given. The degradation mechanisms of organic compounds and the influence of the controlling parameters of PAA-based treatment systems are summarized and discussed. Concurrently, the application of PAA-based AOPs for water disinfection and the related mechanisms of microorganism inactivation are also reviewed. Since combining UV light with PAA is the most commonly investigated PAA-based AOP for simultaneous pathogen inactivation and micropollutant oxidation, we have also focused on PAA microbial inactivation kinetics, together with the effects of key experimental parameters on the process. Moreover, we have discussed the advantages and disadvantages of UV/PAA as an AOP against the well-known and established UV/H₂O₂. Finally, the knowledge gaps, challenges, and new opportunities for research in this field are discussed. This critical review will facilitate an in-depth understanding of the PAA-based AOPs for water and wastewater treatment and provide useful perspectives for future research and development for PAA-based technologies.

Neutrophil Extracellular Traps in the Autoimmunity Context

The formation of neutrophil extracellular traps (NETs) is a strategy utilized by neutrophils for capturing infective agents. Extracellular traps consist in a physical net made of DNA and intracellular proteins externalized from neutrophils, where bacteria and viruses are entrapped and killed by proteolysis. A complex series of events contributes to achieving NET formation: signaling from infectious triggers comes first, followed by decondensation of chromatin and extrusion of the nucleosome components (DNA, histones) from the nucleus and, after cell membrane breakdown, outside the cell. NETs are composed of either DNA or nucleosome proteins and hundreds of cytoplasm proteins, a part of which undergo post-translational modification during the steps leading to NETs. There is a thin balance between the production and the removal of circulating NETs from blood where digestion of DNA by circulating DNases 1 and IL3 has a critical role. A delay in NET removal may have consequences for autoimmunity. Recent studies have shown that circulating NET levels are increased in systemic lupus erythematosus (SLE) for a functional block of NET removal mediated by anti-DNase antibodies or, in rare cases, by DNase IL3 mutations. In SLE, the persistence in circulation of NETs signifies elevated concentrations of either free DNA/nucleosome components and oxidized proteins that, in some cases, are recognized as non-self and presented to B-cells by Toll-like receptor 9 (TLR9). In this way, it is activated as an immunologic response, leading to the formation of IgG2 auto-antibody. Monitoring serum NET levels represents a potential new way to herald the development of renal lesions and has clinical implications. Modulating the balance between NET formation and removal is one of the objectives of basic research that are aimed to design new drugs for SLE. Clinical Trial Registration Number: The Zeus study was registered at https://clinicaltrials.gov (study number: NCT02403115).

Evaluation of the cutaneous inflammatory cells in dogs with leishmaniosis and in dogs without the disease that were naturally infected by Leishmania infantum (syn. L. chagasi)

BACKGROUND

Canine leishmaniosis (CanL) is associated with an aberrant cutaneous immune response. Few studies have compared cutaneous immune cells among dogs with leishmaniosis or infected without leishmaniosis, and noninfected dogs.

HYPOTHESIS/OBJECTIVE

Evaluate the number of neutrophils, histiocytes, T lymphocytes, T-bet-positive, GATA3-positive, FoxP3-positive and interleukin (IL)-17-positive cells, in lesional (Group A) and normal-looking (Group B) skin of nine dogs with stage II/III leishmaniosis; in normal-looking PCR-positive (Group C; n = 6) or PCR-negative (Group D; n = 6) skin of infected dogs; and in the normal-looking skin of 12 noninfected dogs (Group E).

METHODS AND MATERIALS

Diagnosis of CanL considered clinical signs, clinicopathological abnormalities, detection of Leishmania amastigotes in lymph nodes, and/or bone marrow and positive serological results. Paraffin-embedded skin biopsies were processed for routine immunofluorescence and positive cells were identified using commercially available anti-canine antibodies.

RESULTS

In Group A, there was a significantly higher number of neutrophils (P < 0.001), histiocytes (P = 0.012), T lymphocytes (P = 0.011), GATA3-positive (P = 0.02) and IL-17A-positive (P = 0.002) cells compared to Group E. In Group B, there was a significantly higher number of histiocytes (P = 0.02), T lymphocytes (P = 0.004), GATA3-positive (P = 0.006) and FoxP3-positive (P = 0.028) cells compared to Group E. There was no difference in between groups A and B and between groups C or D and E.

CONCLUSIONS AND CLINICAL IMPORTANCE

In the lesional and/or normal-looking skin of dogs with moderate/severe CanL there is an infiltration of neutrophils, histiocytes, T lymphocytes, GATA3-, FoxP3- and IL17A-positive cells. By contrast, the number of these cells is not increased in the normal-looking skin of infected dogs without CanL compared to the skin of noninfected dogs.

Maternal and Fetal Outcomes of Pregnancy in Nephrotic Syndrome Due to Primary Glomerulonephritis

Chronic kidney disease (CKD) affects 3% of pregnancies, impacting on maternal and fetal outcomes, and at the same time, a recurrent question in nephrology regards gestation impact on kidney function. Observational studies stated that CKD stage, pre-existent hypertension, and proteinuria are the main predictors of possible complications, such as maternal CKD progression, maternal or fetal death, prematurity, small for gestational age (SGA) newborn, or admission to the neonatal intensive care unit. In this regard, given the prominence of proteinuria among other risk factors, we focused on primary nephrotic syndrome in pregnancy, which accounts for 0.028% of cases, and its impact on materno-fetal outcomes and kidney survival. Data extracted from literature are scattered because of the small cohorts investigated in each trial. However, they showed different outcomes for each glomerular disease, with membranous nephropathy (MN) having a better maternal and fetal prognosis than focal and segmental glomerulosclerosis (FSGS), membranoproliferative glomerulonephritis (MPGN), or minimal change disease (MCD). Nephrotic syndrome does not have to discourage women to undertake a pregnancy, but the correct management may include a specific evaluation of risk factors and follow-up for adverse materno-fetal events and/or maternal kidney disease progression.

[Therapeutic options to reduce arterial stiffness in chronic kidney disease]

Chronic kidney disease is associated with an increased cardiovascular risk. Several uremic toxins are also vascular toxins and may contribute to the increase of the cardiovascular risk through the development of aortic stiffening. In this process, oxidative stress and endothelial dysfunction play an important role. Considering that aortic stiffness is a known cardiovascular risk factor and a vascular biomarker involved in the development of chronic cardiac dysfunction, and that the reduction of aortic stiffness is associated with an improved survival of patients with end-stage kidney disease, we aim at reviewing the therapeutic options to reduce aortic stiffness and potentially the cardiovascular risk.

Integrated fermentation and anaerobic digestion of primary sludges for simultaneous resource and energy recovery: Impact of volatile fatty acids recovery

This research assessed the impact of volatile fatty acids (VFA) recovery and biomethane potential in an integrated fermentation-digestion process with a single stage digestion of primary and rotating belt filtration (RBF) sludges. Implementing semi-continuous fermentation at 1, 2, and 4 days solids retention time (SRT) showed a direct impact on the hydrolysis and VFA recovery which increased as SRT increased, while also improving the dewaterability by reducing the concentrated sludge volume index of the processed sludge. pH-controlled fermentation was effective improving the VFA yields by up to 93% and 72% at pH 9 (relative to no pH control), for RBF and primary sludges, respectively; although fermentation at pH 6 (optimum) showed promise for enhancing VFAs while lowering the required chemicals significantly. Although cellulose constituted only 21.0% and 29.5% of the TSS in primary and RBF sludges, it contributed 38-41% of the methane production for the two sludges, respectively. Experimental results of integrated fermentation-digestion and single stage digestion processes were incorporated in techno-economic analysis. Results confirmed the economic viability of fermentation with payback periods of 2.7 ± 1.1 years (RBF), and 3.6 ± 2.7 years (PS), while also revealed that VFA recovery could save up to 7.2 ± 2.0% (RBF), and 7.6 ± 2.7% (PS) of the respective total sludge handling and disposal costs, despite an average of 12.7% and 8.4% decrease in biogas production due to VFA extraction in the integrated systems of RBF and primary sludges, respectively. Overall, the integrated fermentation-digestion system economically outperformed the single stage digestion for both sludge types under all studied scenarios.

Correction to: In search of potential predictors of erythropoiesis-stimulating agents (ESAs) hyporesponsiveness: a population-based study

An amendment to this paper has been published and can be accessed via the original article.

Clinical efficacy of spray-based heat-treated lactobacilli in canine atopic dermatitis: a preliminary, open-label, uncontrolled study

BACKGROUND

Canine atopic dermatitis (cAD) is a common inflammatory and pruritic skin disease, with various treatment options. The use of topical products containing natural ingredients has proven increasingly popular.

OBJECTIVE

To evaluate the effects of a spray solution containing heat-killed Lactobacillus rhamnosus and L. reuteri, on the clinical signs and cutaneous microbiota of atopic dogs.

ANIMALS

Ten privately owned, mildly affected, nonseasonally atopic dogs.

METHODS AND MATERIALS

The spray was applied to the ventrum every 24 h for 28 days. Clinical scores, skin barrier function and owner assessment were evaluated on day (D)0, D14, D28 and D42. The cutaneous microbiota was analysed on D0 and D28.

RESULTS

A reduction in the total clinical score was seen at each time point (D14, P = 0.03; D28, P = 0.04; D42, P = 0.001). A reduction in the regional clinical scores was seen after D28 (P = 0.01) and D42 (P = 0.003). A significant reduction in the pruritus score was seen on D42 (P = 0.01). A lower hydration value was seen on D28 (P = 0.02) and D42 (P = 0.02) on the pinnae. A good-to-excellent response and an easy-to-use administration was reported by owners. There were no significant changes in the cutaneous microbiota after 28 days.

CONCLUSIONS AND CLINICAL IMPORTANCE

There was a significant and rapid decrease in the clinical signs associated with cAD after use of the spray. Future larger, randomized, controlled studies are needed to confirm these results and to assess the effects on the cutaneous immunity and microflora of atopic dogs.

A chemical, microbiological and (eco)toxicological scheme to understand the efficiency of UV-C/H2O2 oxidation on antibiotic-related microcontaminants in treated urban wastewater

An assessment comprising chemical, microbiological and (eco)toxicological parameters of antibiotic-related microcontaminants, during the application of UV-C/H₂O₂ oxidation in secondary-treated urban wastewater, is presented. The process was investigated at bench scale under different oxidant doses (0-50 mg L^-1) with regard to its capacity to degrade a mixture of antibiotics (i.e. ampicillin, clarithromycin, erythromycin, ofloxacin, sulfamethoxazole, tetracycline and trimethoprim) with an initial individual concentration of 100 μg L^-1. The process was optimized with respect to the oxidant dose. Under the optimum conditions, the inactivation of selected bacteria and antibiotic resistant bacteria (ARB) (i.e. faecal coliforms, Enterococcus spp., Pseudomonasaeruginosa and total heterotrophs), and the reduction of the abundance of selected antibiotic resistance genes (ARGs) (e.g. bla_OXA, qnrS, sul1, tetM) were investigated. Also, phytotoxicity against three plant species, ecotoxicity against Daphnia magna, genotoxicity, oxidative stress and cytotoxicity were assessed. Apart from chemical actinometry, computational fluid dynamics (CFD) modelling was applied to estimate the fluence rate. For the given wastewater quality and photoreactor type used, 40 mg L^-1 H₂O₂ were required for the complete degradation of the studied antibiotics after 18.9 J cm^-2. Total bacteria and ARB inactivation was observed at UV doses <1.5 J cm^-2 with no bacterial regrowth being observed after 24 h. The abundance of most ARGs was reduced at 16 J cm^-2. The process produced a final effluent with lower phytotoxicity compared to the untreated wastewater. The toxicity against Daphnia magna was shown to increase during the chemical oxidation. Although genotoxicity and oxidative stress fluctuated during the treatment, the latter led to the removal of these effects. Overall, it was made apparent from the high UV fluence required, that the particular reactor although extensively used in similar studies, it does not utilize efficiently the incident radiation and thus, seems not to be suitable for this kind of studies.

Direct healthcare costs of chronic kidney disease management in Italy: What cost-savings can be achieved with higher biosimilar uptake and more appropriate use of erythropoiesis-stimulating agents?

PURPOSE

Erythropoiesis-stimulating agents (ESAs), are used for treating chronic kidney disease (CKD)-related anemia, contributing to CKD costs. The study was aimed at investigating direct healthcare costs of CKD patients treated with ESAs and the potential savings achievable by increasing the use of biosimilars and preventing inappropriate ESA use.

METHODS

A multi-center, cohort study was conducted using claims databases of five large Italian geographic areas. Yearly mean direct healthcare costs per patient were estimated, stratifying by CKD stage. The total yearly cost and potential savings related to ESA use were estimated: (a) considering 25/50/75% of originator ESA substitution with biosimilars; (b) eliminating inappropriate ESA dispensing.

RESULTS

During the study period, the ESA-related yearly mean cost represented 17% of total yearly costs in stage I-III, decreasing to 13% in stage IV-V and 6% in dialysis. Among originator users, assuming a 25% of biosimilar uptake, the annual cost-savings of ESA treatment would represent 10.5% of total ESA costs in CKD stage I-V and 7.7% in dialysis. Among incident ESA users for which hemoglobin levels were available, 9% started inappropriately ESA treatment, increasing to 62.0% during the first year of maintenance therapy. Hypothesizing prevention of the first inappropriate ESA dispensing, the total yearly cost-savings would amount to €35 772, increasing to €167 641 eliminating the inappropriate dispensing during maintenance therapy.

CONCLUSIONS

Higher use of lowest cost ESA, prevention of inappropriate ESA use as well as other strategies aimed at slowing down the progressive renal impairment are essential for minimizing clinical and economic burden of CKD.

Performic Acid Disinfection of Municipal Secondary Effluent Wastewater: Inactivation of Murine Norovirus, Fecal Coliforms, and Enterococci

Performic acid (PFA) is an emerging disinfectant to inactivate bacterial and viral microorganisms in wastewater. In this study, the inactivation kinetics of murine norovirus (MNV) by PFA, in phosphate buffer and municipal secondary effluent wastewater, are reported for the first time. PFA decay followed first-order kinetics and the inactivation of MNV was governed by the exposure of microorganisms to PFA, i.e., the integral of the PFA concentration over time (integral CT or ICT). The extension of the Chick-Watson model, in the ICT domain, described well the reduction of MNV by PFA, with determined ICT-based inactivation rate constants, k_d, of 1.024 ± 0.038 L/(mg·min) and 0.482 ± 0.022 L/(mg·min) in phosphate buffer and wastewater, respectively, at pH 7.2. Furthermore, the simultaneous PFA inactivation of MNV and fecal indicators indigenously present in wastewater such as fecal coliforms and enterococci showed that 1-log reduction could be achieved with ICT of 2, 1.5, and 3.5 mg·min/L, respectively. When compared with the most commonly used peracid disinfectant of municipal wastewater, peracetic acid (PAA), the ICT requirements determined using the fitted ICT-based kinetic models were ∼20 times higher for PAA than PFA, indicating a much stronger inactivation power of the PFA molecule.

Clinical Evaluation of the Safety, Efficacy and Tolerability of Lanthanum Carbonate in the Management of Hyperphosphatemia in Patients with End-Stage Renal Disease

Patients with progressive chronic kidney disease (CKD) commonly develop mineral and bone abnormalities and extraskeletal calcifications with following increased cardiovascular risk. A key pathophysiological role is played by hyperphosphatemia. Since diet and dialysis are often insufficient to control serum phosphorus levels, many patients require treatment with phosphate binders. Among them is lanthanum carbonate, an aluminum-free non-calcium-based compound. The present review summarizes the most recent literature data concerning the safety, efficacy and tolerability of lanthanum carbonate in patients with end-stage renal disease and hyperphosphatemia. The drug is taken orally as chewable tablets or powder with only minimal gastrointestinal absorption and resulting reduced risk of tissue deposition and systemic drug interactions. The dissociation of the drug in the acid environment of the upper gastrointestinal tract induces the release of lanthanum ions, which bind to dietary phosphate forming insoluble complexes then excreted in the feces. Even though there is no clear evidence that lowering serum phosphorus levels can improve patient-centered outcomes, a mortality benefit with all phosphate binders, especially non-calcium containing ones, is not excluded. Lanthanum carbonate has been suggested to decrease all-cause mortality but not cardiovascular event rate compared to other phosphate binders. It induces a lower suppression of bone turnover than calcium carbonate and calcium acetate and may improve systolic function and cardiac dimension compared to calcium carbonate. Moreover, the use of lanthanum carbonate has been associated with better nutritional status compared to other phosphate binders, lower risk for hypercalcemia than calcium-containing binders, and amelioration of mild metabolic acidosis contrary to sevelamer hydrochloride. Main adverse effects include nausea, alkaline gastric reflux, gastric deposition of lanthanum, gastrointestinal obstruction, subileus, ileus, perforation, fecal impaction, and reduction of gastrointestinal absorption of some drugs including statins, angiotensin-converting enzyme inhibitors and some antibiotics such as fluoroquinolones or tetracyclines.

Orchard grass allergy in an African spur-thighed tortoise (Centrochelys sulcata) confirmed via intradermal allergen testing and provocation testing

The humoral immune system of reptiles is not well-studied. To the best of the authors' knowledge, this case report describes the first case of a type I allergic conjunctivitis associated with orchard grass in an African spur-thighed tortoise (Centrochelys sulcata) supported by intradermal allergen testing and provocative testing. Further studies are needed to better characterize allergic reactions in reptiles.

Application of QMRA to MAR operations for safe agricultural water reuses in coastal areas

A pathogenic Escherichia coli (E.coli) O157:H7 and O26:H11 dose-response model was set up for a quantitative microbial risk assessment (QMRA) of the waterborne diseases associated with managed aquifer recharge (MAR) practices in semiarid regions. The MAR facility at Forcatella (Southern Italy) was selected for the QMRA application. The target counts of pathogens incidentally exposed to hosts by eating contaminated raw crops or while bathing at beaches of the coastal area were determined by applying the Monte Carlo Markov Chain (MCMC) Bayesian method to the water sampling results. The MCMC provided the most probable pathogen count reaching the target and allowed for the minimization of the number of water samplings, and hence, reducing the associated costs. The sampling stations along the coast were positioned based on the results of a groundwater flow and pathogen transport model, which highlighted the preferential flow pathways of the transported E. coli in the fractured coastal aquifer. QMRA indicated tolerable (<10^-6 DALY) health risks for bathing at beaches and irrigation with wastewater, with 0.4 infectious diseases per year (11.4% probability of occurrence) associated with the reuse of reclaimed water via soil irrigation even though exceeding the E. coli regulation limit of 10 CFU/100 mL by five times. The results show negligible health risk and insignificant impacts on the coastal water quality due to pathogenic E. coli in the wastewater used for MAR. However, droughts and reclaimed water quality can be considered the main issues of MAR practices in semiarid regions suggesting additional reclaimed water treatments and further stress-tests via QMRAs by considering more persistent pathogens than E. coli.

P1838THE CONTRIBUTION OF MICROSCOPE IN THE KNOWLEDGE OF KIDNEY DISEASES AS DESCRIBED BY GIULIO BIZZOZERO

Background and Aims

Giulio Bizzozero (20 March 1846 - 8 April 1901) was an eminent Italian scientist, the father of the modern microscopy. In 1879 he published his masterpiece “Manuale di Microscopia Clinica “(Handbook of Clinical Microscopy). Here he underlined how the microscopic examination of the urine gave to the physicians of the time indicative criteria of alteration of the kidney, often essential for diagnosis.

Method

Bizzozero operates in his book a detailed analysis of the methods of time, laying the foundations of microscopy and diagnosis of renal diseases. He proposed a classification of pathological urine and gave large space to the role of the presence of red blood as a great diagnostic sign in urinary sediment (Figure 1 and Figure 2).

The author emphasized the use of microscopy against the obsoleted vision of old academics and promulgated the experimental methods in opposition to the vitalistic philosophy of the time. Bizzozero underlined the idea of “teamwork” and the strong connection with his close collaborators, he says that on a laboratory “a mind should give the idea and the direction of work while other minds join together dealing with particular executions”.

Results

Bizzozero's revolutionary vision of medicine had the purpose to allow every scientist to reach new discoveries in their field, previously being the privilege of an elite, making him a model both as a doctor as a humanist. In one of his memorable speeches he declared: “We need to undress the science of the cloak of mystery and authority: the professor in the school must not offer a series of dogmas supported by the prestige of his name, he must instead expose science in the real state in which it is found, with its doubts and its unresolved mysteries”.

Conclusion

This Bizzozero’s masterpiece definitely represents a milestone of scientific literature, a witness of the radical evolution of modern medicine and experimental research.

SO034A NEW MARKER OF RESISTANT HYPERTENSION IN CKD PATIENTS

Background and Aims

Monocytes -HDL ratio (MHR), has emerged as a possible marker of inflammation and oxidative stress (OS), demonstrating its possible use in the population with Chronic Kidney Disease (CKD). These effects seem to be modulated by an increased lipid production, by reduced cellular catabolism of fatty acids and by the alteration of the antioxidant, anti-inflammatory mechanisms and the reverse cholesterol transport of HDL. The latter to exert favorable effects on inflammatory and oxidative pathway. The purpose of our research is to evaluate the link between MHR and resistant hypertension (RH) which, together with inflammation, OS and atherosclerosis, represents a widespread feature in the population with CKD and carries a greater risk of premature death due to cardiovascular disease.

Method

A retrospective study has been performed on 251 hypertensive patients, admitted in the last 6 months to the Unit of Nephrology and Dialysis of the Policlinic G. Martino of Messina, Italy. 80 patients were diagnosed with RH, defined as blood pressure that remains above 140/90 mmHg despite use of three different classes of antihypertensive medications (one of which must be a diuretic) at the maximum tolerated doses.

We evaluated the distribution of data with Kolmogorov-Smirnov test and, considering that MHR had a non-normal distribution, we expressed the values as medians and interquartile ranges (IQR). Moreover, differences between groups with Mann-Whitney test, correlations with Rank Correlation and Spearman's Rho coefficient were also considered in the analysis. Finally, we assessed the differences of variables between the means of different groups with ANOVA test using multiple regression to valuate independent relations between variables.

Results

MHR appeared to be positively correlated with serum creatinine levels (ρ=0.24; P=0.0001) (Figure 1). MHR correlated with the number of antihypertensive drugs per patient in the entire cohort of patients (F = 18.23; P &lt;0.001) (Figure 2). Patients with RH had a significantly higher MHR than patients without resistant hypertension (0.1493 [IQR 0.12 - 0.18] versus 0.11 [IQR 0.0 - 0.13], P &lt;0.0001) (Figure 3).

Conclusion

MHR has proven to be an accurate tool in quantifying inflammatory status and OS, whose effectiveness lies in the close correlation that exists between HDL and monocytes. HDL prevent and reverse the recruitment of monocytes in the arterial wall and their activation through a decrease in their F-actin content, thereby reducing the expression of CD11b on monocytes, and modulating their adhesion to the endothelium. Our study showed that MHR could be a useful and immediate tool to evaluate OS and inflammatory status in order to select high-risk patients and identify earlier and appropriate treatment strategies.

P0372RITUXIMAB IN IDIOPATHIC FOCAL SEGMENTAL GLOMERULOSCLEROSIS OF THE ADULT: A MULTICENTRE RETROSPECTIVE SURVEY OF 31 PATIENTS

Background and Aims

Idiopathic Focal Segmental Glomerulosclerosis (FSGS) is a rare glomerulonephritis often complicated by a chronic relapsing course frequently characterized by dependency or resistance to immunosuppressive treatment. Moreover, about half of the patients with active disease would develop end-stage renal disease within 10 years from the diagnosis, highlighting the need of novel therapeutic approaches. Rituximab (RTX), a chimeric monoclonal antibody against CD20, showed promising results in pediatric steroid-dependent/frequently relapsing FSGS and in post-transplantation recurrence. However, evidence about its role in the FSGS of the adult is still lacking with small case series suggesting conflicting results. In this study we assess the efficacy of RTX in the largest cohort of adults with FSGS currently available in literature.

Methods

Adults with biopsy proven idiopathic FSGS treated with RTX were retrospectively identified among several Italian nephrology units. Response to RTX was evaluated at 3, 6, 12 months and, when available, during the long-term follow-up. A positive response (POR) was defined as: (1) proteinuria &lt;3.5 g/die with a decrease &gt;50% compared to baseline, (2) stable renal function (3) decreased or stable dose of glucocorticoids and other immunosuppressants. Severe Adverse Events (SAEs) have been recorded.

Results

31 patients have been identified: 18 steroid-dependent, 11 steroid-resistant, and 2 patients with major contraindication to steroid therapy. RTX has been administered at a median of 87 months (IQR 54–96) from the diagnoses using heterogeneous schedules of administration. Overall, the POR rate at 6 months was 52% (steroid-dependent=69%; steroid-resistant=22%). At univariate analyses, POR to RTX at 6 months was associated to the steroid-dependent status (p=0.0347) and a proteinuria at RTX &lt;5 g/die (p=0.0173); a trend towards better response was observed in patients with IgG at RTX &lt;500 mg/dl (p=0.0774). Over the first year of follow-up, the proteinuria and serum albumin significantly improved (respectively, p=0.0021 and p=0.0277 at 12 months), while serum creatinine remained stable (figure). Among treated patients, the median dose of prednisone decreased from 15 mg/die (IQR 12.5–25) at baseline to 10 mg/die (IQR 5–15) at 12 months, while the proportion of patients free from glucocorticoids respectively increased from 42% to 54%. Six patients have been retreated within a year since the first RTX: of these only the 2 patients who have experienced a POR to the first administration obtained a further POR after retreatment. After the 12th month, 11 patients have been followed for a median time of 17 months (IQR 15–33.5): of the 5/11 with a POR at the 12th month, 2/5 maintained a POR without needing further immunosuppression, 2/5 maintained a POR with a pre-emptive RTX based maintenance treatment, 1/5 experienced a relapse successfully managed with RTX needing then a pre-emptive RTX based maintenance therapy able to allow a persistent POR. Overall, 9 SAEs have been recorded with requirement of hospital admission for clinical deterioration being the most frequent.

Conclusion

RTX may be an option in the FSGS of the adult, especially in the steroid-dependent patients and the ones with less severe nephrotic syndrome. In the responders, a RTX based maintenance therapy may be required.

Enzymatic pre-treatment for enhancement of primary sludge fermentation

This research showed the interrelated impact of cellulase enzyme, temperature, and SRT on enhancement of primary and rotating belt filter (PS, RBF) sludges fermentation. SRTs of 1, 2, and 4-days were tested at 25 °C and 35 °C. Enzymatic enhancement was examined using three different doses of enzyme (i.e. 0.5%, 1%, and 1.5% of the total solids in the feed). The results showed a positive impact of enzyme dose as well as temperature and SRT on VFA and soluble COD production. For the RBF sludge, enzyme addition enhanced the VFA yield of fermentation at room temperature (25 °C) from 52-103 mgCOD/g VS to 93-188 mgCOD/g VS, as compared with increase from 78-192 to 87-202 mgCOD/gVS in PS. Intensification of the fermentation process, particularly for the cellulose-rich RBF sludge, by enzyme addition confirms process viability as an alternative to the extraneous carbon sources for biological nutrient removal in wastewater treatment plants.

P0716RAAS INHIBITION MODULATES KYNURENINE LEVELS IN A CKD POPULATION WITH AND WITHOUT TYPE 2 DIABETES MELLITUS

Background and Aims

Kynurenine pathway of tryptophan metabolism is involved in the pathophysiology of chronic kidney disease (CKD) and diabetes mellitus (DM), mainly through the inflammation-induced activity of indoleamine 2,3-dioxygenase (IDO). Renin-angiotensin-aldosterone system inhibitors (RAASis) [angiotensin converting enzyme inhibitors (ACEis) and angiotensin II receptor antagonists (ARBs)] are recommended in these conditions to decrease proteinuria, slow CKD progression and reduce cardiovascular risk. The interactions between RAAS and the kynurenine pathway and the potential effects of RAASis have been reported in few experimental models but whether these drugs influence kynurenine levels in humans is unknown. We performed a single-centre cross-sectional observational study to evaluate tryptophan and kynurenine serum levels and IDO activity in CKD patients with and without type 2 DM, their correlations with markers of renal dysfunction, and their relationship with RAAS-inhibiting therapy.

Method

We enrolled 72 consecutive adult patients with CKD, of which 38 had DM, who were admitted to the Unit of Nephrology and Dialysis of our Hospital. Of them, 55 were receiving RAASis whereas 17 were not. Tryptophan was assessed by HPLC (high-performance liquid chromatography) analysis with an UltiMateTM 3000 chromatograph (Thermo Fisher Scientific, 168 Third Avenue Waltham, MA, USA); kynurenine was measured using an enzyme-linked immunosorbent assay (ELISA) kit (Catalogue n. K 7728; Immundiagnostik AG, Bensheim, Germany); IDO activity was calculated with the formula (kynurenine/tryptophan) x 100.

Results

Patients receiving RAASis and patients not under therapy only differed for frequency of arterial hypertension (100% vs 76.47%; P=0.002) and kynurenine levels, the latter being significantly lower in the treated group compared to the untreated one (1.56 ± 0.79 vs 2.16 ± 1.51 µmol/l; P=0.0378). Kynurenine did not correlate with estimated glomerular filtration rate (eGFR), proteinuria or albuminuria in the whole study cohort. Conversely, in patients not receiving RAASis it was inversely related to eGFR (r=-0.4862; P=0.0478) and directly related to proteinuria (ρ=0.493; P=0.0444) and albuminuria (ρ=0.542; P=0.0247); moreover, it varied across classes of albuminuria, being lower in patients with normoalbuminuria (0.98 ± 0.55 µmol/l) and higher in those with micro- (2.63 ± 1.53 µmol/l) and macroalbuminuria (3.09 ± 1.61 µmol/l) at the ANOVA test (F=4.008; P=0.042). In the same group, the relationship between IDO activity and eGFR was significant (ρ=-0.554; P=0.0210) and IDO activity differed across classes of albuminuria (F=3.702; P=0.05). Moreover, IDO activity was higher in patients with history of cardiovascular disease compared to those with no such history [10.22 (8.39 to 22.92) vs 7.57 (4.76 to 8.09) %; P=0.0343] whereas tryptophan had an opposite behaviour (17.00 ± 2.06 vs 22.00 ± 3.78 µmol/l; P=0.0036).

Conclusion

We observed lower kynurenine levels in CKD patients treated with RAASis compared to untreated patients, independently of the presence of DM, and a significant association between kynurenine and markers of renal damage only in the group not receiving RAASis. We could hypothesize that kynurenine may play a role in the pathophysiology of renal damage, as already suggested, and that drugs interfering with RAAS activation may act also by reducing kynurenine levels, in addition to their already known effects at the renal level. Indeed, kynurenine synthesis results to be higher in states of inflammation and RAAS has pro-inflammatory and pro-fibrotic actions; accordingly, RAASis could reduce the enzymatic activity responsible for kynurenine increase and this could be one of the mechanisms mediating the beneficial effects of RAAS inhibition on CKD progression. This may be relevant because kynurenine has shown pro-thrombotic effects and is emerging as a potential new biomarker of CKD.

P0443ONE YEAR AFTER PROTEINURIA IN LUPUS NEPHRITIS: EURO LUPUS VS MYCOPHENOLATE, A SINGLE-CENTER EXPERIENCE

Background and Aims

Lupus nephritis (LN) develops in about 50% of patients affected by Systemic Lupus Erythematosus (SLE) and it is associated with higher morbidity and mortality risk. Approximately 10 % of LN patients is expected to reach end stage renal disease (ESRD). Proteinuria at 1 year has been demonstrated as the best predictor factor of long-term renal outcome. We compared the effects of two different induction therapies (Euro Lupus protocol [EL] vs Mycophenolate [MMF]) in terms of eGFR, proteinuria, serum albumin and complement activation in LN patients related to our centre.

Method

We retrospectively reviewed the records of 34 adult patients with LN from 2011 to 2019. Patients were divided in two groups according to therapeutic strategy chosen: EL (n=21 patients, group 1) and MMF (n=13, group 2). Data with normal distribution are expressed as average ± standard deviation, while data with non normal distribution are referred to as median and interquartile range [IQR]. Basal values of eGFR, proteinuria, albumin and complement were compared to 1 year values with Student t-test for normal variables or with Wilcoxon test for non normal variables.

Results

The mean age of the patients was 41.27±17.43 years, there was a predominance of female (85,3%) LN was diagnosed at 32±16 years old. According to LN classification, 88.2% of them was affected by III, IV, V and mixed LN class Basal values of eGFR (estimated with CKD-EPI method) were similar between groups 1 and 2 (86.12±52.86 vs 73.75±30.35, P=0.4890) as well as proteinuria (2.00 [0.48-4.57] vs 0.71 [0.28-1.39] g/24h, P=0.3284). After one year of follow up, eGFR did not show significant differences between two groups, while proteinuria was significantly lower in group 1 (2.)). 00 [0.48-4.57] vs 0.44 [0.19-0.91] g/24h, P=0.0034) than in group 2 (0.71 [0.28-1.39] vs 0.15 [0.08-0.77] g/24h, P=0.4687) (fig.1). Moreover, we recorded in group 1 higher values of albumin after one year of follow up (3.20 [2.52-3.94] vs 4.33 [3.99-4.57] g/dl, P=0.0195) (fig.2) and C3 consumption (35.00 [1.00-81.25] vs 89.00 [2.00-112.50] mg/dl, P=0.0067) (fig.3), while group 2 did not show any statistically significant differences.

Conclusion

In patients affected by LN, EL protocol demonstrated to be more effective than MMF in reducing one year after proteinuria, thus improving albumin and C3 serum titer.

P0491THE ROUTE TO INDIVIDUALIZED THERAPIES IN PRIMARY MEMBRANOUS NEPHROPATHY: BMI AND KIDNEY OUTCOMES

Background and Aims

A real progress in treating patients more than diseases, would rest on tailored medicine and go beyond the hypothesis that “one size fits all”. Glomerular diseases are not an exception to this consideration, and deserve case-by-case evaluation for choosing both the most suitable therapeutic agent and its appropriate dose, because a standardized treatment may result in worse prognosis.

We analyzed the role of body mass index (BMI) in modifying renal outcomes of patients with nephrotic syndrome due to membranous nephropathy (MN) treated with immunosuppressive drugs.

Method

We performed a retrospective analysis of 29 MN patients related to our center (M 19, F 10), checking their anti PLA2R status at kidney biopsy time and any change in proteinuria, serum creatinine (SCr) and body mass index (BMI) between diagnosis and at last follow-up visit, in search of a correlation with their response to immunosuppressive treatment. Data with non normal distribution are expressed as median and interquartile range [IQR].

Results

The median follow-up of our patients lasted 49 months [IQR 14-80]. At biopsy time, almost half of them was anti-PLA2R positive (n=14 subjects) while the other resulted to be negative and were thus screened for secondary causes of MN (n=15). Irrespective either of anti-PLA2R status or the administration of Ponticelli regimen or Rituximab, complete remission was achieved in 31% of patients, while 34.5% experienced a partial remission and 34.5% resulted non responder to at least a therapeutic protocol. Median proteinuria reduction was of 3.732g/24h [IQR 7.636-1.77 g/24h]. Median rise in SCr was 0.140 mg/dl [IQR -0.11 – 0.4 mg/dl]. Direct association between the proteinuria/BMI ratio at diagnosis and remission of proteinuria at last follow up was statistically significant (r=-0.7506; P&lt;0.0001) (Fig.1).

Conclusion

Albeit remission is not directly correlated with basal BMI, our results appear to confirm that an appropriate drug posology, not only according to patients’ renal or hepatic function but also to their body mass, may result in more effective individualized therapies in MN; nevertheless, this recorded association must be confirmed by large scale randomized clinical trials.

P1845HISTORY AND FUTURE PERSPECTIVES OF PAROXYSMAL NOCTURNAL HEMOGLOBINURIA

Background and Aims

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal disorder that affects about 1-1,5 cases per million individuals, characterized by hemolysis, peripheral blood cytopenia, bone marrow dysfunction, thrombosis, renal impairment and arterial and pulmonary hypertension.

The first case of PNH was probably described in 1793 by a surgeon, Dr Charles Stewart, in the medical commentaries “Account of a singular periodical discharge of blood from the urethra”. In the following decades several cases have been reported by the most eminent physicians and scientists of the time.

Method

In 1882 Paul Strübing was the first to identify PNH as a new disease entity. Hijmans in 1911 considered the possibility that the complement system mediated the hemolysis of PNH erythrocytes and in the same year, Italian scientists Ettore Marchiafava and Nazari scrupulously described the pathogenesis of the affection.

In the 1925 Enneking introduced for the first time the name “paroxysmal nocturnal hemoglobinuria”, to define this pathology.

Results

Despite the increased knowledge of this syndrome, therapies for PNH were still only experimental and symptomatic, with the use of antimicrobial agents, corticosteroids and blood transfusions. The natural history of PNH changed remarkably only in the 2007, with the introduction of Eculizumab complement blockade agent. The Ravulizumab, a long-acting C5 complement inhibitor approved on December 2018 by the U.S. food and drug Administration (FDA), and on July 2019 by the European Commission, represent a new promising instrument for PNH treatment.

Conclusion

Second generation of anti-complement agents are currently under investigation, representing future promising instruments for the treatment of PNH.

Chronic Kidney Disease Management in General Practice: A Focus on Inappropriate Drugs Prescriptions

Nephrotoxic drugs prescriptions are often prescribed inappropriately by general practitioners (GPs), increasing the risk of chronic kidney disease (CKD). The aim of this study was to detect inappropriate prescriptions in patients with CKD and to identify their predictive factors. A retrospective study on patients with creatinine values recorded in the period 2014-2016 followed by 10 GPs was performed. The estimated glomerular filtration rate (eGFR) was used to identify CKD patients. The demographic and clinical characteristics and drugs prescriptions were collected. A descriptive analysis was conducted to compare the characteristics and logistic regression models to estimate the predictive factors of inappropriate prescriptions. Of 4098 patients with creatinine values recorded, 21.9% had an eGFR <60 mL/min/1.73m². Further, 56.8% received inappropriate prescriptions, with a significantly lower probability in subjects with at least a nephrologist visit (Adj OR 0.54 (95% CI 0.36-0.81)) and a greater probability in patients treated with more active substances (1.10 (1.08-1.12)), affected by more comorbidities (1.14 (1.06-1.230)), or with serious CKD (G4/G5 21.28 (7.36-61.57)). Nonsteroidal anti-inflammatory drugs (NSAIDs) were the most used contraindicated drugs (48.5%), while acetylsalicylic acid was the most inappropriately prescribed (39.5%). Our results highlight the inappropriate prescriptions for CKD authorized by GPs and underline the need of strategies to improve prescribing patterns.