Stage G4 Research Articles

Breath Analysis: Identification of Potential Volatile Biomarkers for Non-Invasive Diagnosis of Chronic Kidney Disease (CKD).

Recently, volatile organic compound (VOC) determination in exhaled breath has seen growing interest due to its promising potential in early diagnosis of several pathological conditions, including chronic kidney disease (CKD). Therefore, this study aimed to identify the breath VOC pattern providing an accurate, reproducible and fast CKD diagnosis at early stages of disease. A cross-sectional observational study was carried out, enrolling a total of 30 subjects matched for age and gender. More specifically, the breath samples were collected from (a) 10 patients with end-stage kidney disease (ESKD) before undergoing hemodialysis treatment (DIAL); (b) 10 patients with mild-moderate CKD (G) including 3 patients in stage G2 with mild albuminuria, and 7 patients in stage G3 and (c) 10 healthy controls (CTRL). For each volunteer, an end-tidal exhaled breath sample and an ambient air sample (AA) were collected at the same time on two sorbent tubes by an automated sampling system and analyzed by Thermal Desorption-Gas Chromatography-Mass Spectrometry. A total of 110 VOCs were detected in breath samples but only 42 showed significatively different levels with respect to AA. Nonparametric tests, such as Wilcoxon/Kruskal-Wallis tests, allowed us to identify the most weighting variables able to discriminate between AA, DIAL, G and CTRL breath samples. A promising multivariate data mining approach incorporating only selected variables (showing p-values lower than 0.05), such as nonanal, pentane, acetophenone, pentanone, undecane, butanedione, ethyl hexanol and benzene, was developed and cross-validated, providing a prediction accuracy equal to 87% and 100% in identifying patients with both mild-moderate CKD (G) and ESKD (DIAL), respectively.

Impact of Prepared Vascular Access on Mortality and Medical Expenses in Elderly and Nonelderly Japanese Patients with CKD Stage G5: A Retrospective Cohort Study

Impact of Prepared Vascular Access on Mortality and Medical Expenses in Elderly and Nonelderly Japanese Patients with CKD Stage G5: A Retrospective Cohort Study

Polypharmacy and Potentially Inappropriate Medications among Elderly Patients with Advanced Stage G5 CKD

Polypharmacy and Potentially Inappropriate Medications among Elderly Patients with Advanced Stage G5 CKD

Bioimpedance Analysis for the Assessment of Body Composition and Relation with Muscle Strength in Patients with CKD Stage G3 to G5 and Healthy Controls

Bioimpedance Analysis for the Assessment of Body Composition and Relation with Muscle Strength in Patients with CKD Stage G3 to G5 and Healthy Controls

Chemostratigraphy and mineralogical characterization of Piacenzian sapropels cluster A (2.75–2.57 Ma) in the Gelasian GSSP type-section of Monte San Nicola (Sicily, Italy): Paleoenvironmental and paleogeographic implications

Mineralogical, geochemical and stable isotope (δ18O, δ13C) data from Marine Isotope Stages (MIS) G4 to 103 are here presented. The studied interval includes the sapropelic cluster A (A2-A5) from the Gelasian GSSP type-section, outcropping at Monte San Nicola (Sicily, Italy). The studied section exhibits a good response of the δ18O measured on the bulk carbonate to the Earth's astronomical parameters. The sapropelic red/brown layers (A2- A5) are alternated to grey marls and this cyclicity is clearly evident by the difference in colour, organic matter content, redox-sensitive elements and runoff indicators, tied to the precession/insolation cycles. Further, the obliquity signal is well evident in paleoproductivity indicators and mineralogical composition, driven by glacial-interglacial cycles. The obtained dataset has allowed the reconstruction of the paleoenvironmental conditions during marls/sapropels deposition, which appears to be influenced by the precessional forcing that induced strong changes in the marine water circulation. This scenario is also integrated by an original paleogeographic model including the presence of a high topographic structure in SE Sicily that limited water exchanges between the Ionian and Central Mediterranean Seas during sea level drawdowns, caused by glacial phases, triggered by obliquity minima.

Cost-Effectiveness of Empagliflozin in Chronic Kidney Disease with or without Albuminuria

Key Points Empagliflozin is cost-effective for the treatment of CKD in patients with an urine albumin-to-creatinine ratio of 30 mg/g or more.Empagliflozin is not cost-effective for the treatment of CKD in patients with an urine albumin-to-creatinine ratio <30 mg/g. Background The Study of Heart and Kidney Protection with Empagliflozin (EMPA-KIDNEY) expanded the CKD population that may benefit from sodium-glucose cotransporter 2 inhibitors in terms of eGFR and urine albumin-to-creatinine ratio. This enables a cost-effectiveness analysis of empagliflozin in subgroups stratified by these two parameters. Methods A cost–utility analysis using the Markov model was performed to evaluate the cost-effectiveness of adding empagliflozin to the standard treatment for CKD in Japan over 20 years of observation. Each cohort with the initial eGFR (≥45 but <60 ml/min per 1.73 m2, ≥30 but <45 ml/min per 1.73 m2, or ≥20 but <30 ml/min per 1.73 m2) and urine albumin-to-creatinine ratio (<30 mg/g, ≥30 but <300 mg/g, or ≥300 mg/g) within the defined ranges was analyzed. The changes in eGFR were determined on the basis of the EMPA-KIDNEY study. An incremental cost-effectiveness ratio of <¥5,000,000 (approximately $35,500) per quality-adjusted life-year (QALY) was considered cost-effective. One-way deterministic analyses, probabilistic sensitivity analyses, and scenario analyses were conducted to ensure the robustness of the results. Results The addition of empagliflozin to the standard treatment was associated with lower costs and higher QALYs in the macroalbuminuria or microalbuminuria cohorts while the incremental cost-effectiveness ratios in the negative albuminuria cohorts were >¥5,000,000 per QALY, regardless of the initial eGFR. The probabilities of empagliflozin being cost-effective were >84% in the macroalbuminuria or microalbuminuria cohorts but <30% in the negative albuminuria cohorts. Scenario analyses where empagliflozin suppressed the eGFR decline in the negative albuminuria cohorts showed that the drug was cost-effective in CKD stage G3b and G4 cohorts. Empagliflozin was not cost-effective in patients with CKD stage G3a and microalbuminuria with the observation period of 10 years. Conclusions In patients meeting the enrollment criteria for the EMPA-KIDNEY trial, the addition of empagliflozin to the standard treatment of CKD was judged as cost-effective for patients with albuminuria but not for those without albuminuria in the Japanese health care system.

Recipients of public assistance with advanced chronic kidney disease: insights into receiving a presentation of kidney replacement therapy options and polypharmacy from Japanese investigators with innovative network about kidney disease study.

The characteristics of patients with advanced chronic kidney disease (CKD) who are recipients of public assistance in Japan, and the adequacy of their medical care have not been reported previously. The records of patients with CKD stage G5 who visited nine facilities in Japan from April to June 2013 were retrospectively reviewed to compare the characteristics and care of recipients of public assistance with those of non-recipients. Receiving a presentation of kidney replacement therapy (KRT) options and polypharmacy were used as indicators of suboptimal medical care. Of the 592 patients included in this analysis (mean age, 69.6years; male, 59.3%), 56 (9.5%) were recipients of public assistance and 536 (90.5%) were non-recipients of public assistance. The prevalence of diabetes mellitus, unmarried status, and living alone were higher in recipients of public assistance. In multivariable logistic regression analysis, compared with non-recipients of public assistance, recipients of public assistance were less likely to receive a presentation of KRT options (adjusted odds ratio [aOR], 0.31; 95% confidence interval [CI], 0.17-0.56), and were more likely to receive ≥ 10 (aOR, 1.92; 95% CI, 1.05-3.51), and ≥ 15 (aOR, 2.78; 95% CI, 1.23-6.26) types of medication. Patients with advanced CKD receiving public assistance were less likely to receive a presentation of KRT options and more likely to receive ≥ 10 and ≥ 15 types of medication, suggesting that recipients of public assistance are more likely to receive suboptimal medical care.

Trends in fluid overload-related hospitalisations among patients with diabetes mellitus The impact of chronic kidney disease.

Fluid overload is a known complication in patients with diabetes mellitus, particularly those with cardiovascular and/or chronic kidney disease (CKD). This study investigates the impact of fluid overload on healthcare utilisation and its association with diabetes-related complications. Electronic medical records from the SingHealth Diabetes Registry (2013-2022) were analysed. Hospitalisations due to fluid overload were identified using International Classification of Diseases, 10th Revision (ICD-10) discharge codes. Trends were examined using Joinpoint regression, and associations were assessed with generalised estimating equation models. Over a period of 10 years, 259,607 individuals treated at primary care clinics and tertiary hospitals were studied. The incidence of fluid overload-related hospitalisations decreased from 2.99% (n=2778) in 2013 to 2.18% (n=2617) in 2017. However, this incidence increased from 2.42% (n=3091) in 2018 to 3.71% (n=5103) in 2022. The strongest associations for fluid overload-related hospitalisation were found with CKD stages G5 (odds ratio [OR] 6.61, 95% confidence interval [CI] 6.26-6.99), G4 (OR 5.55, 95% CI 5.26-5.86) and G3b (OR 3.18, 95% CI 3.02-3.35), as well as with ischaemic heart disease (OR 3.97, 95% CI 3.84-4.11), acute myocardial infarction (OR 3.07, 95% CI 2.97-3.18) and hypertension (OR 3.90, 95% CI 3.45-4.41). Additionally, the prevalence of stage G5 CKD among patients with fluid overload increased between 2018 and 2022. Our study revealed a significant increase in fluid overload-related hospitalisations and extended lengths of stay, likely driven by severe CKD. This underscores an urgent need for initiatives aimed at slowing CKD progression and reducing fluid overload-related hospitalisations in diabetes patients.

Interpreting pathology test result values with comparators (< , >) in Electronic Health Records research: an OpenSAFELY short data report

Background Numeric results of pathology tests are sometimes returned as a range rather than a precise value, e.g. “<10”. In health data research, test result values above or below clinical threshold values are often used to categorise patients into groups; however comparators (<, > etc) are typically stored separately to the numeric values and often ignored, but may influence interpretation. Methods With the approval of NHS England we used routine clinical data from 24 million patients in OpenSAFELY to identify pathology tests with comparators commonly attached to result values. For each test we report: the proportion returned with comparators present, split by comparator type and geographic region; the specific numeric result values returned with comparators, and the associated reference limits. Results We identified 11 common test codes where at least one in four results had comparators. Three codes related to glomerular filtration rate (GFR) tests/calculations, with 31-45% of results returned with “≥” comparators. At least 90% of tests with numeric values 60 and 90 represented ranges (≥60 and ≥90 respectively) rather than exact values. The other tests - four blood tests (Nucleated red blood cell count, Plasma C reactive protein, Tissue transglutaminase immunoglobulin A, and Rheumatoid factor), two urine tests (albumin/microalbumin) and two faecal tests (calprotectin and quantitative faecal immunochemical test) - were returned with “≤” comparators (29-86%). Conclusions Comparators appear commonly in certain pathology tests in electronic health records. For most common affected tests, we expect there to be minimal implications for researchers for most use-cases. However, care should be taken around whether results falling exactly on clinical threshold values should be considered “normal” or “abnormal”. Results from GFR tests/calculations cannot reliably distinguish between mild kidney disease (stage G2, 60-<90) versus healthy kidney function (90+). More broadly, health data researchers using numeric test result values should consider the impact of comparators.

Association of Kidney Function With Inpatient Mortality and Morbidity After Cardiac Surgery

BackgroundContemporary population-based data examining the rates of cardiac surgery and the relationship between non–dialysis-requiring chronic kidney disease (CKD) and postoperative outcomes in cardiac surgery are limited. MethodsWe identified hospital admissions for cardiac surgical procedures in adults from 2010-2019 in the United States. The primary exposure was kidney disease, categorized as CKD stage G3, CKD stages G4 or G5, and end-stage kidney disease (ESKD). The primary outcome was in-hospital mortality. We evaluated the association between CKD stage and in-hospital-mortality by using multivariable logistic regression. We calculated the annual national incidence of cardiac surgical procedures by CKD stage by incorporating data from the United States Census Bureau. ResultsWe identified an estimated 2,772,081 admissions during which patients aged 18 years or older underwent cardiac surgical procedures. The incidence of cardiac surgical procedures was 1.1, 1.0, and 13.0 per 1000 person-years among patients with normal or nearly normal kidney function, non–dialysis-requiring kidney disease, and ESKD, respectively. In-hospital mortality was 2.2%, 3.7%, 6.7%, and 8.8% among patients with normal or nearly normal kidney function, CKD stage G3, CKD stages G4 or G5, and ESKD, respectively. In adjusted analyses, patients with CKD stage G3, CKD stage G4 or G5, and ESKD experienced absolute risks of in-hospital mortality that were 0.6% (95% CI, 0.5%-0.7%), 2.2% (95% CI, 1.8%-2.6%), and 4.4% (95% CI, 4.0%-4.8%) higher, respectively, than in patients with normal or nearly normal kidney function. ConclusionsIn the United States, advanced stages of CKD are associated with an increased incidence of cardiac surgical procedures, as well as high adjusted risks of in-hospital mortality.

Estimated Proximal Tubule Fluid Phosphate Concentration and Renal Tubular Damage Biomarkers in Early Stages of Chronic Kidney Disease

IntroductionAn increase in proximal tubule fluid phosphate concentration is caused by increased serum fibroblast growth factor 23 (FGF23) levels, which resulted in renal tubular damage in a mouse model of chronic kidney disease (CKD). However, few human studies have supported this concept. This study aimed to explore the association among estimated proximal tubule fluid phosphate concentration (ePTFp), serum FGF23 levels, and renal tubular damage biomarkers in middle-aged and older populations with mild decline in renal function. MethodsThis cross-sectional study included 218 participants aged ≥45 with CKD stages G2–G4. Anthropometric measurements, blood tests, spot urine biomarkers, renal ultrasonography, cardiovascular assessment, smoking status, and medication usage were obtained in the morning in fasted states. The ePTFp was calculated using serum creatinine, urine phosphate, and creatinine concentrations. Urinary β2-microglobulin and liver-type fatty acid-binding protein (L-FABP) levels were evaluated to assess renal tubular damage.Results: ePTFp, serum FGF23, urinary β2-microglobulin, and urinary L-FABP levels increased with CKD stage progression (stages G2, G3, and G4). However, serum and urine phosphate concentrations were comparable across the CKD stages. Univariate analysis revealed a stronger correlation of ePTFp with serum FGF23, urinary β2-microglobulin, and urinary L-FABP levels than with the corresponding serum and urine phosphate concentrations. Multivariate analyses demonstrated that increased ePTFp was independently associated with elevated serum FGF23 and urinary β2-microglobulin levels, even after adjusting for potential covariates, including the estimated glomerular filtration rate and urinary albumin-to-creatinine ratio. ConclusionsOur results are consistent with the concept in mouse model and suggest that increased ePTFp are associated with increased serum FGF23 levels and renal tubular damage during the early stages of CKD.

Study of Sexual Maturation in Children With Juvenile Dermatomyositis

Objective: There is complete absence of sexual maturity data on patients afflicted with juvenile dermatomyositis (JDMS) from the Indian subcontinent. Hence, this study aimed to unfold the effect of this disease on the sexual development of JDMS children. Methods: In the Growth Laboratory/Clinic of the Department of Pediatrics, 60 (25 male and 35 female) sexual maturity-related observations were made on 35 JDMS patients, aged 10–17 years, enrolled from the Pediatric Rheumatology Clinic. Breast development stage and age of onset of menarche were recorded among female patients. In male patients, besides, determining the genitalia development stage, measurement of stretched penile length and testicular volume was done. Appearance of pubic and axillary hair among JDMS patients of both sexes was recorded. Results: Most girls with JDMS (34.28%) were in breast development stage-B2 (mean age 10.91 ± 1.08 years) and 22.86% had attained menarche. However, breast stage B5 was attained at 14.62 ± 1.06 years. JDMS girls reached stage B2 at the same age as their normal healthy counterparts. Onset of menarche was delayed by almost a year in JDMS girls. Age of attainment of genitalia stage G2 in JDMS boys (12 years) was delayed by 6 months as compared to well-off Chandigarh boys (11.5 years), whereas it was advanced by 1.5 years when contrasted with affluent Indian counterparts (13.3 years). Conclusion: Comparable pubertal attainments in JDMS males and somewhat delayed start of menarche in female JDMS patients as compared to their normal counterparts show that disease activity has a smaller effect on the sexual development of JDMS patients from north-western India.

Oral alkalinizing supplementation suppressed intrarenal reactive oxidative stress in mild-stage chronic kidney disease: a randomized cohort study.

The beneficial effects of oral supplements with alkalinizing agents in patients with chronic kidney disease (CKD) have been limited to the severe stages. We investigated whether two types of supplements, sodium bicarbonate (SB) and potassium citrate/sodium citrate (PCSC), could maintain renal function in patients with mild-stage CKD. This was a single-center, open-labeled, randomized cohort trial. Study participants with CKD stages G2, G3a, and G3b were enrolled between March 2013 and January 2019 and randomly assigned by stratification according to age, sex, estimated glomerular filtration rate (eGFR), and diabetes. They were followed up for 6months (short-term study) for the primary endpoints and extended to 2years (long-term study) for the secondary endpoints. Supplementary doses were adjusted to achieve an early morning urinary pH of 6.8-7.2. We observed renal dysfunction or new-onset cerebrovascular disease and evaluated urinary surrogate markers for renal injury. Overall, 101 participants were registered and allocated to three groups: standard (n = 32), SB (n = 34), and PCSC (n = 35). Two patients in the standard group attained the primary endpoints (renal stones and overt proteinuria) but were not statistically significant. There was one patient in the standard reduced eGFR during the long-term study (p = 0.042 by ANOVA). SB increased proteinuria (p = 0.0139, baseline vs. 6months), whereas PCSC significantly reduced proteinuria (p = 0.0061, baseline vs. 1year, or p = 0.0186, vs. 2years) and urinary excretion of 8-hydroxy-2'-deoxyguanosine (p = 0.0481, baseline vs. 6months). This study is the first to report supplementation of PCSC reduced intrarenal oxidative stress in patients with mild-stage CKD.

The interaction between estimated glomerular filtration rate and dietary magnesium intake and its effect on stroke prevalence: a cross-sectional study spanning 2003-2018.

Despite the known associations of dietary magnesium intake and estimated glomerular filtration rate (eGFR) with cardiovascular diseases, their combined effects on stroke risk remain unclear. Therefore, this study aims to explore the associations of dietary magnesium intake and eGFR with stroke risk. The National Health and Nutrition Examination Survey (NHANES) data of 37,637 adult participants (≥18 years) from 2003 to 2018 was analyzed. Dietary magnesium intake was categorized as low (≤ 254 mg/day) and normal (> 254 mg/day) based on experimental data. Multiple logistic regression analyses and interaction tests were conducted to assess the associations of dietary magnesium intake and eGFR with stroke risk, with a focus on the interaction between different chronic kidney disease (CKD) stages based on eGFR levels and dietary magnesium intake. Additional analyses included multiplicative interaction analysis, restricted cubic spline analysis, and subgroup evaluations by age, sex, and ethnicity. Dietary magnesium intake and eGFR were inversely correlated with the risk of stroke. Participants with low dietary magnesium intake had a higher stroke risk than those with normal magnesium intake (odds ratio [OR] 1.09, 95% confidence interval [CI]: 1.03-1.42). Likewise, low eGFR was associated with an elevated stroke risk compared with normal eGFR (OR 1.56, 95% CI: 1.15-2.13). Furthermore, the two factors showed a multiplicative interaction effect on stroke risk (OR 1.05, 95% CI: 1.01-1.09). We observed a significant interaction between stage G3 CKD and low dietary magnesium intake (OR 1.05, 95% CI: 1.01-1.09), suggesting a potential association with stroke risk. However, similar associations were not observed for stages G4 and G5, possibly due to the smaller number of participants with G4 and G5 CKD. The restricted cubic spline analysis revealed a non-linear relationship between dietary magnesium intake, eGFR, and stroke risk. The interaction between magnesium deficiency and low eGFR persisted in participants aged >60 years, as well as in females, non-Hispanic Black people, and people of other races. Dietary magnesium intake and eGFR correlate negatively with stroke prevalence. Moreover, there was an interaction between dietary magnesium intake and stroke prevalence across different CKD stages. Further large-scale prospective studies are needed to analyze the potential relationship between dietary magnesium intake, eGFR, and stroke.

Changes of Dissociative Properties of Hemoglobin in Patients with Chronic Kidney Disease.

Background: The ability of hemoglobin to bind and dissociate oxygen is crucial in delivering oxygen to tissues and is influenced by a range of physiological states, compensatory mechanisms, and pathological conditions. This may be illustrated by the oxyhemoglobin dissociation curve (ODC). The key parameter for evaluating the oxygen affinity to hemoglobin is p50. The aim of this study was to evaluate the impact of hemodialysis on p50 in a group of patients with chronic kidney disease (CKD). An additional goal was to assess the correlation between p50 and the parameters of erythropoiesis, point-of-care testing (POCT), and other laboratory parameters. Methods: One hundred and eighty patients (106 male, 74 female), mean age 62.5 ± 17 years, with CKD stage G4 and G5 were enrolled in this cross-sectional study. Patients were divided into two groups, including 65 hemodialysis (HD) patients and 115 patients not receiving dialysis (non-HD). During the standard procedure of arteriovenous fistula creation, blood samples from the artery (A) and the vein (V) were taken for POCT. The causes of CKD, as well as demographic and comorbidity data, were obtained from medical records and direct interviews. Results: The weekly dose of erythropoietin was higher in HD patients than in non-HD patients (4914 ± 2253 UI vs. 403 ± 798 UI, p < 0.01), but hemoglobin levels did not differ between these groups. In the group of non-HD patients, more advanced metabolic acidosis (MA) was found, compared to the group with HD. In arterial and venosus blood samples, the non-HD group had significantly lower pH, pCO2 and HCO3-. This group had a higher proportion of individuals with MA with HCO3- < 22 mmol/L (42% vs. 24%, p < 0.01). The absolute difference of p50 in arterial and venous blood was determined using the formula Δp50 = (p50-A) - (p50-V). Δp50 was significantly higher in the HD group in comparison to non-HD (0.08 ± 2.05 mmHg vs. -0.66 ± 1.93 mmHg, p = 0,02). There was a negative correlation between pH and the p50 value in arterial (pH-A vs. p50-A, r = -0.56, p < 0.01) and venous blood (pH-V vs. p50-V, r = -0.45, p < 0.01). In non-HD patients, hemoglobin levels correlated negatively with p50 (r = -0.29, p < 0.01), whereas no significant relation was found in HD patients. Conclusions: The ODC in pre-dialysis CKD (non-HD) patients is shifted to the right due to MA, and this is an additional factor influencing erythropoiesis. Hemodialysis restores the natural differences in hemoglobin's dissociation characteristics in the arterial and venous circulation.

#1694 The Cl-/HCO3-ratio as a predictor of decompensated metabolic acidosis in CKD stages G4 and G5

Abstract Background and Aims Metabolic acidosis (MA) is a common disorder in patients with chronic kidney disease (CKD) and is associated with both a normal anion gap (AGMA) and a high anion gap (HAGMA). AGMA is typically detected early in the course of CKD, whereas HAGMA appears later in the course of CKD due to the accumulation of non-chloride anions such as phosphate, sulphate, and an array of organic acids. The anion gap (AG) is usually calculated as the difference between serum concentration of cations and anions using the formula AG=Na+-(Cl−+HCO3−). The most important anions in serum are chlorides (Cl−) and bicarbonates (HCO3−). The more advanced the CKD, the higher the AG. As eGFR decreases, a reciprocal decrease in HCO3− and an increase in chloride concentration is observed to correct the AG. The aim of this study is to determine whether the Cl−/HCO3− ratio can be used to predict decompensated metabolic acidosis with pH decline in CKD stages G4 and G5. Method A total of 115 patients (median age 63 ± 17 years), with CKD stage G4 or G5 were enrolled in this cross-sectional study. Demographic and comorbidity data was obtained from medical records, and the Charlson Comorbid Index (CCI) was calculated. A two-year clinical follow-up was conducted to assess the clinical status of each patient. The number of patients, the time dialysis was started, and deaths were all recorded. All patients were qualified for arteriovenous fistula creation in predialysis period. The arterial (A) and venous (V) blood samples were taken during surgery, directly after vessel dissection, and evaluated in a point of care testing analyzer (POCT). The ratio of arterial Cl− and HCO3− concentration were calculated. According to mean arterial pH (pH-A) the group was divided into Group A pH-A&amp;lt;7.33 and Group B pH-A≥7.33 (Table 1). Results In Group A was significantly lower pH-A, pH-V, HCO3−-A, HCO3−-V, pCO2-A, pCO2-V, and significantly higher both arterial and venous Cl− and the Cl−/HCO3− ratios compared to Group B. No such differences were observed in the case of AG. Cl−/HCO3−-A ratio negatively correlated with pH (r = −0.77, p &amp;lt; 0.01) (Fig. 1A). The discriminative power of Cl−/HCO3−-A ratio for predicting pH-A≤7.33 was 0.917 (95% confidence interval [CI] = 0.87–0.97; p &amp;lt; 0.01) which provided 87% sensitivity and 84% specificity (Fig. 1B). The best cut-off was 6.22 (mmol/l)/(mmol/l). Conclusion The Cl−/HCO3− ratio lower than 6.22 (mmol/l)/(mmol/l) may be used as predictor of decompensated metabolic acidosis.

#2904 Chronic kidney disease staging in the very old: the role of cystatin C

Abstract Background and Aims Over the past decade, an unanswered question has emerged: which is the best equation for estimating glomerular filtration rate (eGFR) in older patients with chronic kidney disease (CKD)? Despite the lack of consensus, cystatin C appears to hold promise, as it is not influenced by factors often affected in the very elderly, such as muscle mass or protein intake, offsetting the limitations of creatinine-dependent formulas. This may have implications for correctly classifying patients across the different stages of CKD. The aim of this study is to analyze the concordance between different eGFR formulas and the Chronic Kidney Disease Epidemiology Collaboration formula combining the use of creatinine and cystatin C (CKD-EPIcr-cys), which is recommended by the European Renal Best Practice Group. Method A cross-sectional observational study was conducted with patients ≥85 years old with CKD admitted to an Acute Geriatric Unit due to acute illness over a period of four months. Variables included age, sex, previous Barthel Index (BI), dementia (defined by Reisberg's GDS≥4), frailty (FRAIL scale ≥3), polypharmacy (≥5 drugs), comorbidities (degree of CKD according to CKD-EPI, hypertension, diabetes mellitus, dyslipidemia, chronic heart failure (CHF), Charlson Comorbidity Index (CCI)), nutritional and laboratory parameters (Mini Nutritional Assessment-Short Form (MNA-SF), body mass index (BMI), serum cholesterol and albumin, glucose, glycated hemoglobin), and estimated glomerular filtration rate at admission by CKD-EPIcr-cys, CKD-EPIcys, CKD-EPI, MDRD and Cockcroft-Gault. The intra-class correlation coefficient (ICC) and the Kappa index were used to analyze concordance. Results A total of 407 patients were recruited, with a mean age of 90.7±4.1 years, 68.1% female. The previous BI was 59.1±32.3. Dementia was present in 28.3%. Frailty was noted in 66.6%, and polypharmacy in 90.9%. CKD stage: G3a (37.6%), G3b (44.2%), G4 (17.7%), G5 (0.5%). Comorbidities included hypertension (90.7%), CHF (68.3%), dyslipidemia (53.8%), and diabetes mellitus (37.8). The CCI was 2.9±1.8. MNA-SF score was 9.5±2.4 (18.4% malnutrition), and average BMI was 28±5.5 kg/m2 (29% obesity). The mean values for cholesterol, albumin, glucose, and glycated hemoglobin were 156.3±47.7 mg/dL, 35.5±4.6 g/L, 126.1±91.3 mg/dL, and 5.9±2%, respectively. The eGFR at admission according to CKD-EPIcr-cys was 31.9±12.2 mL/min/1.73 m2, while using CKD-EPI, CKD-EPIcys, MDRD, and Cockcroft-Gault were 37.5±14.5 mL/min/1.73 m2, 28.2±12.1 mL/min/1.73 m2, 42.8±16 mL/min/1.73 m2, and 30.4±11.7 mL/min/1.73 m2, respectively. The formulas showed high concordance with CKD-EPIcr-cys: CKD-EPI (ICC=0.90 [0.52 to 0.96; p &amp;lt; 0.001]), CKD-EPIcys (ICC=0.94 [0.79 to 0.97; p &amp;lt; 0.001]), MDRD (ICC=0.80 [-0.14 to 0.94; p &amp;lt; 0.001]), Cockcroft-Gault (ICC=0.86 [0.82 to 0.88; p &amp;lt; 0.001]). However, when comparing stratification into different stages of CKD, the concordance with the various formulas was lower: CKD-EPI (k=0.4; p &amp;lt; 0.001), CKD-EPIcys (k=0.59; p &amp;lt; 0.001), MDRD (k=0.12; p &amp;lt; 0.001), Cockcroft-Gault (k=0.4; p &amp;lt; 0.001). When referencing CKD-EPIcr-cys, it is notable that only 34.3% of patients were correctly classified using MDRD, followed by CKD-EPI (57.1%), Cockcroft-Gault (59.8%), and CKD-EPIcys (73%). Specifically, of the patients classified as stage G4 according to CKD-EPIcr-cys, there was a reclassification to stage G3b in 2.1% (CKD-EPIcys), 18.1% (Cockcroft-Gault), 33.3% (CKD-EPI), and 52.1% (MDRD). Conclusion

#2994 Nephrotoxicity post injection of iodized PDC in patients with renal failure in the emergency room

Abstract Background and Aims Nephropathy following injection of iodinated contrast media (PDC) is the leading cause of iatrogenic acute renal failure. Several associated factors have been identified, including renal function before the procedure. Objective To study the incidence of nephrotoxicity post venous-injection of iodinated PDC in patients with impaired renal function. Method This was a prospective, descriptive, single-center study over a six-month period. Patients aged over 14 years and having undergone an injection of iodinated contrast products for diagnostic or therapeutic purposes were included. We excluded patients with stage IV renal insufficiency (Cl ≤ 29 ml/min) with or without indication for extra-renal purification. Nephropathy in this context was defined by an elevation in baseline plasma creatinine of more than 25% in the 48 to 72 hours following injection. Results During the study period, 135 patients were collected with a mean age of 46 ± 18 years and range of 16 to 97 years. The gender ratio was 3.2 with a male predominance. Thirty-two patients had impaired renal function on admission, of which seven patients (5.2%) were known to have chronic renal failure and twenty-five patients (18.5%) had impaired renal function discovered on admission. The mean renal clearance was 90.9 ± 36.3 ml/min with extremes ranging from 30 ml/min to 176 ml/min. More than half of the patients had normal renal function (Stage G1 according to the KDIGO 2022 classification) (n = 79, 58.5%). The incidence of nephropathy post venous-injection of iodized PDCs was 15.6%. 111 patients (82.8%) benefited from per-procedure hydration protocol. In univariate analysis, chronic renal failure or discovered on admission was associated with the risk of worsening renal function with a statistically significant difference, p respectively at 0.007 and 0.009. Furthermore, the correlation between the worsening of renal function as a function of initial plasma creatinine showed that initial plasma creatinine was higher in patients who developed iodinated contrast nephropathy with a statistically significant difference, p = 0.005, a sensitivity of 57% and a specificity of 78%. ROC curve analysis showed an AUC of 0.691; 95% CI [0.567-0.815], with a discriminant Cut off of plasma creatinine at 90.5 µmol/l. Conclusion The incidence of post-iodized PDC injection nephropathy was high in emergency room. Among the independent associated factors identified, chronic renal insufficiency or discovered on admission which requires special precautions, especially through optimal hydration.

#3104 Adequacy of nephroprotective prescription in an elderly diabetic population in a primary care setting

Abstract Background and Aims The prevalence of chronic kidney disease (CKD) has been increasing and one of the main risk factors is diabetes mellitus (DM). The addition of sodium-glucose cotransporter 2 inhibitors (SGLT2i) to the renin-angiotensin inhibitors (RASi) is recommended in patients with DM and CKD due to the benefits in metabolic control, decrease in proteinuria, and in delaying glomerular filtration decline. Method A retrospective cohort was performed and included a sample of patients with diabetes registered and monitored in a primary care facility. A random sample was selected, calculated for an expected prevalence of 40%, error of 4%, and alpha of 0.05. The primary outcome was to assess the adequacy of nephroprotective prescription. Secondary outcomes were to determine the prevalence of CKD (and associated factors) in the sample, and to assess the percentage of patients with correct CKD diagnosis. Demographic and analytical data of patients (glomerular filtration rates and values of albuminuria) were collected from their electronic health records. Statistical analysis was performed using SPSS v28.0. A p-value &amp;lt; 0.05 was considered statistically significant. The study protocol was approved by the Ethics Committee. Results 338 patients were included, 58% were men, and with a mean age of 71.4 years. 22.2% [95% CI 16.2-29.7%] of patients had the pathology properly coded in the problem list. The prevalence of CKD found was 42.6% [95% CI 37.4-48.0%]. Most patients were in stages G2 (33.3%), G3a (30.6%) and G3b (14.6%). Concerning albuminuria, most were in stage A2 (68.8%). Of the patients with CKD, 77.1% [95% CI 69.6%-83.2%], 60.4% [95% CI 52.3%-68.0%] and 43.1 [95% CI 35.3–51.2%] were medicated with RASi, SGLT2i and both, respectively. Conclusion In this primary setting study, the majority of this elderly population was under nephroprotective therapies (RASi and/or SGLT2i). The relatively low coding suggests underdiagnosis. Further optimization of nephroprotective therapies can be made in order to avoid renal failure, as long as the pathology is properly recognized.

#2811 Factor B inhibition with iptacopan in C3 glomerulopathy recurrence after transplantation: a case presentation

Abstract Background and Aims C3 glomerulopathy (C3G) is a clinical-pathological entity resulting from dysregulation of the alternative pathway of the complement system (APC) in the fluid phase. The recurrence risk of C3G after kidney transplantation is about 70% with high risk of graft loss. Standard treatment relies on nephroprotection and unspecific immunosuppression but there are currently new molecules that target specifically APC under development. A novel factor B inhibitor, iptacopan, has shown promising results both in native kidney and transplant recurrence cases in a phase II trial. Method We present a real-world clinical case of early C3G recurrence after kidney transplantation treated with iptacopan (Novartis MAPs program). Patient was vaccinated for encapsulated bacteria. Iptacopan was initiated 200 mg BID. We also present histological response. Results 38-year-old male with chronic kidney disease secondary to C3G initially presented with nephrotic syndrome and hematuria at the age of 31y following a respiratory infection. Blood test showed low serum C3 levels and the presence of C3 nephritic factor without pathological genetic alterations. Kidney biopsy confirmed membranoproliferative glomerulonephritis (MPGN) with predominant C3 deposition. He progressed to CKD stage G5 requiring hemodialysis instead of nephroprotection and immunosuppression with corticosteroids and mycophenolate; and addition with cyclophosphamide and rituximab after 19 months from onset. Five years later, the patient was admitted as first kidney transplant recipient from deceases donor Maastricht-III. Induction therapy included thymoglobulin, and tacrolimus, mycophenolate, and corticosteroids. He experienced delayed graft function requiring hemodialysis. An early biopsy proved C3G recurrence with endocapillary proliferation without C4d deposit and absence of donor specific antibodies. Despite conventional immunosuppression and addition of rituximab and plasma exchange; hemodialysis requirement still be present. So, because C3G pathophysiological base, iptacopan was begun with successful clinical response as he reached hemodialysis discontinuation; and kidney function stabilized after one year of treatment with an estimated glomerular filtration rate about 30 mL/min/1.73 m2. In the follow-up biopsy 5 months later, deposit of C3 in the glomerulus disappeared compared to the post-transplant recurrence but with persistence of endocapillary and mesangial proliferation (see Fig. 1). However, interestingly, he experienced a clinical recurrence with acute kidney injury and hematuria after unintentional iptacopan discontinuation, which was resolver after reinitiating and recovering its previous graft function. No infectious complications were observed after one year of treatment with factor B inhibitor. Conclusion New molecules under development that specifically target APC (fluid phase) may change the treatment scenario of C3G and its recurrence in kidney transplantation. We expose a real-practice early C3G recurrence after kidney transplantation successfully treated with iptacopan. The patient reached kidney function stabilization and disappearance of C3 deposits on immunofluorescence of the follow-up biopsy, identical results as the phase II clinical trial of iptacopan in C3G. So, we might conclude that iptacopan is an effective and safe option for C3G recurrence after kidney transplantation. But, data from randomized studies are needed in order to confirm the efficacy and safety of new inhibitors of the APC as iptacopan.