Association between albuminuria and retinal microvascular parameters measured with swept-source optical coherence tomography angiography in patients with diabetic retinopathy

PURPOSE

To evaluate the relationship between urine albumin excretion (UAE) and retinal microvascular parameters assessed using swept-source optical coherence tomography angiography (SS-OCTA) in patients with diabetic retinopathy (DR).

METHODS

This retrospective cross-sectional study included 180 patients with diabetes and 50 age-matched controls. Patients with diabetes were grouped according to the five-stage DR severity, combined with the presence of albuminuria. All subjects underwent 12×12mm2 field SS-OCTA. The foveal avascular zone metrics, vessel density, and capillary nonperfusion area (NPA) were quantified using a semi-automatic software algorithm on three different rectangular fields (3×3 mm2, 6×6 mm2, and 10×10 mm2). The correlations between albuminuria and the four OCTA parameters were analyzed.

RESULTS

A total of 105 subjects had normal UAE, and 75 subjects had albuminuria. Of the 102 subjects whose DR severity was higher than mild non-proliferative DR (NPDR), capillary NPA on the 3×3 mm2, 6×6 mm2, and 10×10 mm2 fields was significantly larger in the albuminuria group. None of the OCTA parameters were significantly different between the two groups in subjects with mild NPDR or without DR. Multiple logistic regression analysis showed that an increase in NPA in the 6×6 mm2 and 10×10 mm2 fields was a significant risk factor for the presence of albuminuria (odds ratio = 1.92 and 1.35).

CONCLUSION

An increase in capillary NPA was independently associated with albuminuria in patients with clinically significant DR levels. SS-OCTA imaging can be a useful marker for the early detection of diabetic nephropathy.

Circulatory endostatin level and risk of cardiovascular events in patients with end-stage renal disease on hemodialysis

BACKGROUND

Endostatin is released during extracellular matrix remodeling and is involved in the development of vascular pathology and cardiovascular (CV) disease. However, the role of circulating endostatin as a biomarker of vascular calcification and CV events in patients undergoing hemodialysis (HD) remains unclear.

METHODS

A total of 372 patients undergoing HD were prospectively recruited. Plasma endostatin levels were measured at baseline, and their associations with circulating mineral bone disease (MBD) biomarkers and abdominal aortic vascular calcification scores were analyzed. The primary endpoint was defined as a composite of CV and cardiac events.

RESULTS

Plasma levels of patients in endostatin tertile 3 were significantly associated with low-density lipoprotein cholesterol levels and predialysis systolic blood pressure in multivariate analysis. However, endostatin levels did not correlate with circulating MBD biomarkers or vascular calcification scores. Patients in endostatin tertile 3 had a significantly higher cumulative event rate for the composite of CV events (p = 0.006). Endostatin tertile 3 was also associated with an increased cumulative rate of cardiac events (p = 0.04). In multivariate Cox regression analyses, endostatin tertile 3 was associated with a 4.37-fold risk for composite CV events and a 3.88-fold risk for cardiac events after adjusting for multiple variables.

CONCLUSION

Higher circulating endostatin levels were independently associated with atherosclerotic risk factors but did not correlate with MBD markers or vascular calcification. Higher circulating endostatin levels were associated with a greater risk of composite CV events in patients undergoing HD, and endostatin is a biomarker that helps to determine the high risk of CV events.

Target blood pressure in Korean hemodialysis patients for optimal survival

Background

Hypertension is a major cardiovascular risk factor in hemodialysis patients. This study identified the optimal blood pressure (BP) target for Korean hemodialysis patients using the Korean Renal Dialysis System (KORDS) dataset from the Korean Society of Nephrology and a pooled analysis for previous studies.

Methods

Hemodialysis patients were classified according to their systolic (SBP) and diastolic BP (DBP) at intervals of 20 and 10 mmHg, respectively. As a primary and secondary outcome, all-cause mortality and cardiovascular mortality were evaluated. Subsequently, pooled analysis with previous literatures was performed.

Results

Among 70,607 patients, 13,708 (19.4%) died in 2,426 days (interquartile range, 1,256-4,075 days). Mean SBP and DBP were 143.0 ± 19.6 and 78.5 ± 12.0 mmHg. In multivariable Cox regression, the patients with SBP of <120 and ≥180 mmHg showed 1.10- and 1.12-times increased risk of all-cause mortality compared to SBP of 120-140 mmHg. Meanwhile, DBP showed no significant association. In subgroup analysis, patients aged <70 years and without diabetes had a U-shaped SBP-mortality association. Cardiovascular mortality was increased in SBP of ≥160 mmHg compared to 120-140 mmHg, but it was not in <120 mmHg. Pooled analysis with previous studies mostly showed elevated risk in SBP of <120 mmHg, but the risks in 140-160 and 160-180 mmHg were not consistent.

Conclusion

Extremely lowering BP (<120 mmHg) or uncontrolled hypertension (≥160 mmHg) should be avoided to optimize survival in Korean hemodialysis patients. Detailed analysis for patients with SBP of 120-160 mmHg should be studied further under uniform BP measurement, along with consideration of risk of intradialytic hypotension. Tailored recommendations regarding patient risk factors also should be considered.

Clinical significance of the living kidney donor profile index for predicting long-term posttransplant outcomes: results from the Korean Organ Transplantation Registry

Background

The usefulness of the living kidney donor profile index (LKDPI) has not been widely demonstrated; therefore, it requires verification before clinical application. We analyzed the LKDPI using data from the Korean Organ Transplantation Registry (KOTRY) to confirm whether the LKDPI can be used to predict the survival of allografts in living donor kidney transplantation (LDKT) patients in Korea.

Methods

The study population was obtained from the KOTRY database. A total of 2,598 kidney recipients registered in the KOTRY database were enrolled between May 2014 and December 2020. Donor and recipient information was observed, and the LKDPI was measured.

Results

Median LKDPI score was 15.5 with a follow-up duration of 33.7 ± 16.1 months. According to LKDPI scores (group 1, <0; group 2, 0-20; group 3, 20-40; and group 4, >40), LKDPI group 4 had significantly higher death-censored graft loss than LKDPI group 1 (hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.06- 3.40; p = 0.03). When divided based on the cutoff value (LKDPI, 36.6), the high LKDPI group had higher graft loss than the low LKDPI group (HR, 2.14; 95% CI, 1.37-3.34; p < 0.001). When follow-up was repeated after transplantation, it was confirmed that the higher the LKDPI value was, the lower the average estimated glomerular filtration rate (p < 0.001).

Conclusion

This study confirmed that LKDPI can serve as an independent predictor for assessing the risk of allograft failure and transplant outcomes in Korean LDKT patients.

How obesity and metabolic syndrome affect cardiovascular events, progression to kidney failure and all-cause mortality in chronic kidney disease

BACKGROUND

Obesity and metabolic syndrome (MetS) are prevalent among chronic kidney disease (CKD) patients. However, it is unclear whether obesity without MetS is associated with a higher risk of adverse clinical outcomes in CKD patients.

METHODS

We searched the National Health Insurance Service database of Korea for patients who underwent national health screenings in 2009-2011 and identified 59 725 CKD patients. Obesity was defined as a body mass index ≥25 kg/m2. MetS was defined as the presence of ≥3 metabolic risks.

RESULTS

The cumulative event rate of cardiovascular events, progression to end-stage kidney disease (ESKD), and all-cause mortality was the lowest among obese patients without MetS (all P < 0.001). In multivariable analysis, obese (versus non-obese) patients without MetS were not at increased risks of cardiovascular events (adjusted hazard ratio [HR] 1.02; 95% confidence interval 0.94-1.11) or progression to ESKD (0.92; 0.77-1.09). Their risk of all-cause mortality was significantly decreased (0.82; 0.75-0.90). These findings were consistently observed in overweight, obese, and morbidly obese patients without MetS. Moreover, despite a linear increase in HR for each additional metabolic abnormality in both obese and non-obese patients, the slope of HR increase for cardiovascular events was significantly slower in obese patients (P for interaction = 0.038).

CONCLUSIONS

Obesity without MetS did not increase the risk of cardiovascular complications or progression to ESKD. The healthy effect of obesity on all-cause mortality risk and its weakening effect on the association between metabolic hazards and cardiovascular risk should be considered in CKD patients.

A questionnaire survey on the diagnosis and treatment of Fabry nephropathy in clinical practice

BACKGROUND

Fabry nephropathy is characterized by a deficiency of lysosomal alpha-galactosidase A, which results in proteinuria and kidney disease. The ineffectiveness of enzyme replacement therapy (ERT) for severe kidney failure highlights the need for early detection and meaningful markers. However, because the diagnosis and treatment of Fabry disease can vary according to the expertise of physicians, we evaluated the opinions of Korean specialists.

METHODS

A questionnaire regarding the management of Fabry nephropathy was emailed to healthcare providers with the experience or ability to treat individuals with Fabry nephropathy.

RESULTS

Of the 70 experts who responded to the survey, 43 were nephrologists, and 64.3% of the respondents reported having treated patients with Fabry disease. Pediatricians are treating primarily patients with classic types of the disease, while nephrologists and cardiologists are treating more patients with variant types. Only 40.7% of non-nephrologists agreed that a kidney biopsy was required at the time of diagnosis, compared with 81.4% of nephrologists. Thirty-eight of 70 respondents (54.3%) reported measuring globotriaosylsphingosine (lyso-Gb3) as a biomarker. The most common period to measure lyso-Gb3 was at the time of diagnosis, followed by after ERT, before ERT, and at screening. For the stage at which ERT should begin, microalbuminuria and proteinuria were chosen by 51.8% and 28.6% of respondents, respectively.

CONCLUSION

Nephrologists are more likely to treat variant Fabry disease rather than classic cases, and they agree that ERT should be initiated early in Fabry nephropathy, using lyso-Gb3 as a biomarker.

Novel Genetic Variants Associated with Chronic Kidney Disease Progression

SIGNIFICANCE STATEMENT

eGFR slope has been used as a surrogate outcome for progression of CKD. However, genetic markers associated with eGFR slope among patients with CKD were unknown. We aimed to identify genetic susceptibility loci associated with eGFR slope. A two-phase genome-wide association study identified single nucleotide polymorphisms (SNPs) in TPPP and FAT1-LINC02374 , and 22 of them were used to derive polygenic risk scores that mark the decline of eGFR by disrupting binding of nearby transcription factors. This work is the first to identify the impact of TPPP and FAT1-LINC02374 on CKD progression, providing predictive markers for the decline of eGFR in patients with CKD.

BACKGROUND

The incidence of CKD is associated with genetic factors. However, genetic markers associated with the progression of CKD have not been fully elucidated.

METHODS

We conducted a genome-wide association study among 1738 patients with CKD, mainly from the KoreaN cohort study for Outcomes in patients With CKD. The outcome was eGFR slope. We performed a replication study for discovered single nucleotide polymorphisms (SNPs) with P <10 -6 in 2498 patients with CKD from the Chronic Renal Insufficiency Cohort study. Several expression quantitative trait loci (eQTL) studies, pathway enrichment analyses, exploration of epigenetic architecture, and predicting disruption of transcription factor (TF) binding sites explored potential biological implications of the loci. We developed and evaluated the effect of polygenic risk scores (PRS) on incident CKD outcomes.

RESULTS

SNPs in two novel loci, TPPP and FAT1-LINC02374 , were replicated (rs59402340 in TPPP , Pdiscovery =7.11×10 -7 , PCRIC =8.13×10 -4 , Pmeta =7.23×10 -8 ; rs28629773 in FAT1-LINC02374 , Pdiscovery =6.08×10 -7 , PCRIC =4.33×10 -2 , Pmeta =1.87×10 -7 ). The eQTL studies revealed that the replicated SNPs regulated the expression level of nearby genes associated with kidney function. Furthermore, these SNPs were near gene enhancer regions and predicted to disrupt the binding of TFs. PRS based on the independently significant top 22 SNPs were significantly associated with CKD outcomes.

CONCLUSIONS

This study demonstrates that SNP markers in the TPPP and FAT1-LINC02374 loci could be predictive markers for the decline of eGFR in patients with CKD.

Clinical implications of circulating follistatin-like protein-1 in hemodialysis patients

Follistatin-like protein-1 (FSTL-1) is secreted glycoprotein, which regulates cardiovascular, immune and skeletal system. However, the clinical significance of circulating FSTL-1 levels remains unclear in hemodialysis patients. A total 376 hemodialysis patients were enrolled from June 2016 to March 2020. Plasma FSTL-1 level, inflammatory biomarkers, physical performance, and echocardiographic findings at baseline were examined. Plasma FSTL-1 levels were positively correlated with TNF-α and MCP-1. Handgrip strength showed weak positive correlation in male patients only, and gait speed showed no correlation with FSTL-1 levels. In multivariate linear regression analysis, FSTL-1 level was negatively associated with left ventricular ejection fraction (β =  - 0.36; p = 0.011). The cumulative event rate of the composite of CV event and death, and cumulative event rate of CV events was significantly greater in FSTL-1 tertile 3. In multivariate Cox-regression analysis, FSTL-1 tertile 3 was associated with a 1.80-fold risk for the composite of CV events and death(95% confidence interval (CI) 1.06-3.08), and a 2.28-fold risk for CV events (95% CI 1.15-4.51) after adjustment for multiple variables. In conclusion, high circulating FSTL-1 levels independently predict the composite of CV events and death, and FSTL-1 level was independently associated with left ventricular systolic dysfunction.

Impact of donor hypertension on graft survival and function in living and deceased donor kidney transplantation: a nationwide prospective cohort study

OBJECTIVES

Hypertensive living donors are potential candidates to expand the kidney donor pool. However, the impact of donor hypertension on graft survival and function remains to be clarified.

METHODS

We analyzed 3907 kidney transplant recipients registered in a nationwide prospective cohort from 2014 to 2018. Patients were divided by donor types and the presence of donor hypertension. The primary and secondary outcome was the occurrence of death-censored graft failure and renal allograft function, respectively.

RESULTS

The prevalence of hypertension was 9.4% (258/2740) and 19.9% (232/1167) in living and deceased donors, respectively. During a median follow-up of 21.8 months, death-censored graft survival rate was significantly worse in recipients of hypertensive living donors than in those of normotensive living donors ( P  = 0.008). In multivariable analysis, recipients of hypertensive living donors had a significantly increased risk of graft loss (adjusted hazard ratio 2.91; P  = 0.009). The risk of allograft loss was not different between recipients of hypertensive living and normotensive deceased donors. Propensity score-matched analyses had consistent worse graft survival rate in recipients of hypertensive living donors compared to those of normotensive living donors ( P  = 0.027), while it was not different between recipients of hypertensive living and normotensive deceased donors. Hypertension in living donors had a significant negative impact on one-year graft function (adjusted unstandardized β -3.64; P  = 0.011).

CONCLUSIONS

Hypertensive living donor recipients have significantly higher risks of renal allograft loss than normotensive living donor recipients, and showed similar outcomes compared to recipients of normotensive deceased donors.

Glycated hemoglobin levels and risk of all-cause and cause-specific mortality in hemodialysis patients with diabetes

AIM

Adequate glycemic control is fundamental for improving clinical outcomes in hemodialysis patients with diabetes. However, the target for glycated hemoglobin (HbA1c) level and whether cause-specific mortality differs based on HbA1c levels remain unclear.

METHODS

A total of 24,243 HD patients with diabetes were enrolled from a multicenter, nationwide registry. We examined the association between HbA1c levels and the risk of all-cause and cause-specific mortality.

RESULTS

Compared to patients with HbA1c 6.5%-7.5%, patients with HbA_1c 8.5-9.5% and ≥9.5% were associated with a 1.26-fold (95% CI, 1.12-1.42) and 1.56-fold (95% CI, 1.37-1.77) risk for all-cause mortality. The risk of all-cause mortality did not increase in patients with HbA1c < 5.5%. In cause-specific mortality, the risk of cardiovascular deaths significantly increased from small increase of HbA1c levels. However, the risk of other causes of death increased only in patients with HbA1c > 9.5%. The slope of HR increase with increasing HbA1c levels was significantly faster for cardiovascular causes than for other causes.

CONCLUSIONS

There was a linear relationship between HbA1c levels and risk of all-cause mortality in hemodialysis patients, and the risk of cardiovascular death increased earlier and more rapidly, with increasing HbA1c levels, compared with other causes of death.

Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Response After Heterologous Immunizations With ChAdOx1/BNT162b2 in End-Stage Renal Disease Patients on Hemodialysis

The Korean government decided to schedule heterologous vaccinations on dialysis patients for early achievement of immunization against Coronavirus disease 2019(COVID-19). However, the effects of heterologous immunizations in hemodialysis (HD) patients are unclear. One hundred (HD) patients from Gangdong Kyung Hee University Hospital and Kyung Hee Medical Center and 100 hospital workers from Gangdong Kyung Hee University Hospital were enrolled in this study. The HD patients received the mixing schedule of ChAdOx1/BNT162b2 vaccinations at 10-week intervals, while hospital workers received two doses of ChAdOx1 vaccines at 12-week intervals. Serum IgG to a receptor-binding domain (RBD) of the S1 subunit of the spike protein of SARS-CoV-2 was measured 1 month after the first dose, 2 months and 4 months after the second dose. The median [interquartile range] anti-RBD IgG was 82.1[34.5, 176.6] AU/ml in HD patients and 197.1[124.0, 346.0] AU/ml in hospital workers (P < 0.001) after the first dose. The percentage of positive responses (IgG > 50 AU/ml) was 65.0% and 96.0% among the both group, respectively (P < 0.001). The anti-RBD IgG levels increased significantly by 2528.8 [1327.6, 5795.1] AU/ml with a 100.0% positive response rate in HD patients 2 months after the second dose, which was higher than those in hospital workers 981.4[581.5, 1891.4] AU/ml (P < 0.001). Moreover, anti-RBD IgG remains constantly high, and positive response remains 100% in HD patients 4 months after the second dose. This study suggests that heterologous vaccinations with ChAdOx1/BNT162b2 can be an alternative solution on HD patients for early and strong induction of humoral response.

Hydrophilic Versus Lipophilic Statin Treatments in Patients With Renal Impairment After Acute Myocardial Infarction

Background Hydrophilic and lipophilic statins have similar efficacies in treating coronary artery disease. However, specific factors relevant to renal impairment and different arterial pathogeneses could modify the clinical effects of statin lipophilicity, and create differences in protective effects between statin types in patients with renal impairment. Methods and Results A total of 2062 patients with acute myocardial infarction with an estimated glomerular filtration rate <60 mL/min per 1.73 m² were enrolled from the Korea Acute Myocardial Infarction Registry between November 2011 and December 2015. The primary end point was a composite of 2-year major adverse cardiac and cerebrovascular events (MACEs) after acute myocardial infarction occurrence. MACEs were defined as all-cause death, recurrent myocardial infarction, revascularization, and stroke. Propensity-score matching and Cox proportional hazards regression were performed. A total of 529 patients treated with hydrophilic statins were matched to 529 patients treated with lipophilic statins. There was no difference in the statin equivalent dose between the 2 statin groups. The cumulative event rate of MACEs, all-cause mortality, and recurrent myocardial infarction were significantly lower in patients treated with hydrophilic statins in the propensity-score matched population (all P<0.05). In the multivariable Cox regression analysis, patients treated with hydrophilic statins had a lower risk for composite MACEs (hazard ratio [HR], 0.70 [95% CI, 0.55-0.90]), all-cause mortality (HR, 0.67 [95% CI, 0.49-0.93]), and recurrent myocardial infarction (HR, 0.40 [95% CI, 0.21-0.73]), but not for revascularization and ischemic stroke. Conclusions Hydrophilic statin treatment was associated with lower risk of MACEs and all-cause mortality than lipophilic statin in a propensity-score matched observational cohort of patients with renal impairment following acute myocardial infarction.

Galactose-Deficient IgA1 as a Candidate Urinary Marker of IgA Nephropathy

In patients with IgA nephropathy (IgAN), circulatory IgA1 and IgA1 in the mesangial deposits contain galactose-deficient IgA1 (Gd-IgA1). Some of the Gd-IgA1 from the glomerular deposits is excreted in the urine and thus urinary Gd-IgA1 may represent a disease-specific marker. We recruited 338 Japanese biopsy-proven IgAN patients and 120 patients with other renal diseases (disease controls). Urine samples collected at the time of renal biopsy were used to measure Gd-IgA1 levels using a specific monoclonal antibody (KM55 mAb). Urinary Gd-IgA1 levels were significantly higher in patients with IgAN than in disease controls. Moreover, urinary Gd-IgA1 was significantly correlated with the severity of the histopathological parameters in IgAN patients. Next, we validated the use of urinary Gd-IgA1 levels in the other Asian cohorts. In the Korean cohort, urinary Gd-IgA1 levels were also higher in patients with IgAN than in disease controls. Even in Japanese patients with IgAN and trace proteinuria (less than 0.3 g/gCr), urinary Gd-IgA1 was detected. Thus, urinary Gd-IgA1 may be an early disease-specific biomarker useful for determining the disease activity of IgAN.

Corrigendum: Non-Invasive Diagnosis for Acute Rejection Using Urinary mRNA Signature Reflecting Allograft Status in Kidney Transplantation

[This corrects the article DOI: 10.3389/fimmu.2021.656632.].

Renal Function Effect on the Association Between Body Mass Index and Mortality Risk After Acute Myocardial Infarction

Background: Body mass index (BMI) is a critical determinant of mortality after acute myocardial infarction (AMI), and higher BMI is associated with survival benefit in patients with renal impairment. However, there are no studies investigating the interactive effects of BMI and renal function on mortality risk after AMI occurrence. Methods: We enrolled 12,647 AMI patients from Korea Acute Myocardial Infarction Registry between November 2011 and December 2015. Patients were categorized based on estimated Glomerular Filtration Rate (eGFR) and BMI. The primary endpoint was all-cause mortality after AMI treatment. Results: Within each renal function category, the absolute mortality rate was decreased in patients with higher BMI. However, the adjusted hazard ratio (HR) of all-cause mortality for higher BMI was decreased as renal function worsened [adjusted HR (95% confidence interval) at BMI ≥ 25 kg/m²: 0.63 (0.41-0.99), 0.76 (0.59-0.97), and 0.84 (0.65-1.08) for patients with eGFR ≥ 90, 90-45, and <45 mL/min/1.73 m², respectively]. There was a significant interaction between BMI and renal function (P for interaction = 0.010). The protective effect of higher BMI was preserved against non-cardiac death and it was also decreased with lowering eGFR in competing risks models [adjusted HR at BMI ≥25 kg/m²: 0.38 (0.18-0.83), 0.76 (0.59-0.97), and 0.84 (0.65-1.08) for patients with eGFR ≥ 90, 90-45, and <45 mL/min/1.73 m², respectively; P for interaction = 0.03]. However, renal function did not significantly affect the association between BMI and risk of cardiac death (P for interaction = 0.20). Conclusions: The effect of BMI on the mortality risk after AMI was dependent on renal function. The association between greater BMI and survival benefit was weakened as renal function was decreased. In addition, the negative effect of renal function on the BMI - mortality association was pronounced in the non-cardiac death.

Risk Due to ABO Incompatibility and Donor-Recipient Weight Mismatch in Living Donor Kidney Transplantation: A National Cohort Study

The effect of donor-recipient weight mismatch is not well established in ABO-incompatible living donor kidney transplantation (LDKT). A total of 2584 LDKT patients in the Korean Organ Transplantation Registry were classified into four groups according to the presence or absence of ABO incompatibility and donor-recipient weight mismatch (donor-to-recipient weight ratio (DRWR) < 0.8). In a multivariable Cox analysis, the combination of ABO incompatibility and DRWR incompatibility (n = 124) was an independent risk factor for graft survival (HR = 2.73, 95% CI = 1.11-6.70) and patient survival (HR = 3.55, 95% CI = 1.39-9.04), whereas neither factor alone was a significant risk factor for either outcome. The combination of ABO incompatibility and DRWR incompatibility was not an independent risk factor for biopsy-proven graft rejection (HR = 1.27, 95% CI = 0.88-1.82); however, it was an independent risk factor for pneumonia (HR = 2.94, 95% CI = 1.64-5.57). The mortality rate due to infection was higher among patients with both ABO incompatibility and DRWR incompatibility than among patients with neither factor or with either factor alone. The combination of ABO incompatibility and DRWR incompatibility was an independent risk factor for graft and patient survival after LDKT, whereas neither factor alone significantly affected graft or patient survival. Thus, donor-recipient weight matching should be cautiously considered in LDKT with ABO incompatibility.

Circulating Vascular Adhesion Protein-1 Level Predicts the Risk of Cardiovascular Events and Mortality in Hemodialysis Patients

Background: Vascular adhesion protein-1 (VAP-1) is an oxidative enzyme of primary amines that facilitates the transmigration of inflammatory cells. Its oxidative and inflammatory effects are prominently increased in pathological conditions, such as metabolic, atherosclerotic, and cardiac diseases. However, the clinical significance of circulating VAP-1 levels in hemodialysis (HD) patients is unclear.

Methods: A total of 434 HD patients were enrolled in a prospective multicenter cohort study between June 2016 and April 2019. Plasma VAP-1 levels were measured at the time of data entry, and the primary endpoint was defined as a composite of cardiovascular (CV) and cardiac events.

Results: Circulating VAP-1 levels were positively correlated with plasma levels of cardiac remodeling markers, including brain natriuretic peptide, galectin-3, and matrix metalloproteinase-2. Multivariable logistic regression analysis revealed that patients with higher circulating VAP-1 levels were more likely to have left ventricular diastolic dysfunction [odds ratio, 1.40; 95% confidence interval [CI], 1.04–1.88]. The cumulative event rate of the composite of CV events was significantly greater in VAP-1 tertile 3 than in VAP-1 tertiles 1 and 2 (P = 0.009). Patients in tertile 3 were also associated with an increased cumulative event rate of cardiac events (P = 0.015), with a 2.06-fold higher risk each for CV (95% CI, 1.10–3.85) and cardiac (95% CI, 1.03–4.12) events after adjusting for multiple variables.

Conclusions: Plasma VAP-1 levels were positively associated with left ventricular diastolic dysfunction and the risk of incident CV and cardiac events in HD patients. Our results indicate that VAP-1 may aid clinicians in identifying HD patients at a high risk of CV events.

COVID-19 and Sirolimus Treatment in a Kidney Transplant Recipient

One year after COVID-19 was declared a pandemic, the management of the disease in kidney transplant patients remains uncertain. The interruption of immunosuppressive therapy is frequently suggested in kidney transplant recipients with COVID-19; however, such an interruption potentially increases the risk of allograft rejection and hyperimmune response. We here report the successful treatment of COVID-19 pneumonia in a kidney transplant recipient who received a sirolimus-based regimen. The course of COVID-19 management was favorable for maintaining sirolimus treatment. Nevertheless, the patient showed signs of extreme overexposure to sirolimus because of drug interaction with antiviral treatment. This case illustrates the advantages and related adverse events of sirolimus-based immunosuppression in the management of COVID-19 in kidney transplant recipients.

Renal Aging Resembles a Continuum Between Normal and Diseased Kidneys That Potentiates Inflammatory Response to Injury

Renal aging is a natural process that can lead to structural changes and functional decline in the kidneys. These age-related changes are considered irreversible physiological processes, but resemble diseased kidneys. To enhance understanding of the molecular nature of renal aging, we first compared whole-kidney RNA sequencing between naturally aging mice (24-month-old) and adenine-induced nephropathy in young mice (2-month-old). Young mice (2-month-old) without intervention were used as the control group to investigate transcription alteration with aging or by adenine-enriched diet. Next, we compared the functional and structural renal consequences of aging and adenine-induced nephropathy between young (2-month-old) and old mice (18- to 22-month-old). C57BL/6 male mice were used in all experimental studies. Both aging kidneys and adenine-induced nephropathy showed similar transcriptional profiles characterized by upregulation in innate and adaptive immune system activation and inflammation, although these alterations were generally less significant in the aging kidneys. In contrast to aging kidneys, adenine-induced nephropathy showed prominent expression of the genes related to cytokines, T-cell activation, and fibrosis and decreased expression of the genes implicated in transporter activity and metabolism. The subclinical immunological micromilieu in aging kidneys potentially causes augmented kidney damage in response to injurious stimulus. When mice were fed with adenine-enriched diet, aging kidneys showed more extensive tubular injury and fibrosis with stronger inflammatory response than young kidneys. Taken together, our results suggest that renal aging may lie on a continuum between normal kidneys and diseased kidneys in the context of immune system upregulation that can worsen kidney damage upon injury.

Circulating Neprilysin Level Predicts the Risk of Cardiovascular Events in Hemodialysis Patients

Background: Neprilysin inhibition has demonstrated impressive benefits in heart failure treatment, and is the current focus of interest in cardiovascular (CV) and kidney diseases. However, the role of circulating neprilysin as a biomarker for CV events is unclear in hemodialysis (HD) patients.

Methods: A total of 439 HD patients from the K-cohort were enrolled from June 2016 to April 2019. The plasma neprilysin level and echocardiographic findings at baseline were examined. The patients were prospectively followed up to assess the primary endpoint (composite of CV events and cardiac events).

Results: Plasma neprilysin level was positively correlated with left ventricular (LV) mass index, LV end-systolic volume, and LV end-diastolic volume. Multivariate linear regression analysis revealed that neprilysin level was negatively correlated with LV ejection fraction (β = −2.14; p = 0.013). The cumulative event rate of the composite of CV events was significantly greater in neprilysin tertile 3 (p = 0.049). Neprilysin tertile 3 was also associated with an increased cumulative event rate of cardiac events (p = 0.016). In Cox regression analysis, neprilysin tertile 3 was associated with a 2.61-fold risk for the composite of CV events [95% confidence interval (CI), 1.37–4.97] and a 2.72-fold risk for cardiac events (95% CI, 1.33–5.56) after adjustment for multiple variables.

Conclusions: Higher circulating neprilysin levels independently predicted the composite of CV events and cardiac events in HD patients. The results of this study suggest the importance of future studies on the effect of neprilysin inhibition in reducing CV events.

Non-Invasive Diagnosis for Acute Rejection Using Urinary mRNA Signature Reflecting Allograft Status in Kidney Transplantation

Urine has been regarded as a good resource based on the assumption that urine can directly reflect the state of the allograft or ongoing injury in kidney transplantation. Previous studies, suggesting the usefulness of urinary mRNA as a biomarker of acute rejection, imply that urinary mRNA mirrors the transcriptional activity of the kidneys. We selected 14 data-driven candidate genes through a meta-analysis and measured the candidate genes using quantitative PCR without pre-amplification in the cross-sectional specimens from Korean kidney transplant patients. Expression of 9/14 genes (CXCL9, CD3ϵ, IP-10, LCK, C1QB, PSMB9, Tim-3, Foxp3, and FAM26F) was significantly different between acute rejection and stable graft function with normal pathology and long-term graft survival in 103 training samples. CXCL9 was also distinctly expressed in allografts with acute rejection in in situ hybridization analysis. This result, consistent with the qPCR result, implies that urinary mRNA could reflect the magnitude of allograft injury. We developed an AR prediction model with the urinary mRNAs by a binary logistic regression and the AUC of the model was 0.89 in the training set. The model was validated in 391 independent samples, and the AUC value yielded 0.84 with a fixed manner. In addition, the decision curve analysis indicated a range of reasonable threshold probabilities for biopsy. Therefore, we suggest the urine mRNA signature could be used as a non-invasive monitoring tool of acute rejection for clinical application and could help determine whether to perform a biopsy in a recipient with increased creatinine.

Serum interferon-γ and urinary monocyte chemoattractant peptide-1 are important factors in the pathogenesis of immunoglobulin A nephropathy

Background

Imbalance of T helper (Th) 1/2 cells has been shown to contribute to the development of immunoglobulin A nephropathy (IgAN). To address the inconsistent results on the role of Th1/Th2 polarization, we evaluated the levels of Th1/Th2 cytokines in various samples from patients with IgAN.

Methods

Thirty-one patients with biopsy-proven IgAN (age, 34.48 ± 12.10 years) and 25 healthy controls (age, 44.84 ± 13.72 years) were enrolled. We evaluated the relationship between the levels of Th1/Th2 cytokines and the response to glucocorticoid treatment.

Results

The levels of serum interferon-gamma (IFNγ) and urinary monocyte chemoattractant peptide (MCP)-1 were higher in the IgAN group than in the control group. The levels of MCP-1 in urine and secreted by peripheral blood mononuclear cells (PBMCs) were significantly different among three groups categorized based on daily proteinuria. The level of urinary MCP-1 was significantly correlated with proteinuria. The levels of urinary MCP-1, serum interleukin (IL)-4, IFNγ, and IL-2 secreted by PBMCs and intrarenal IL-1 messenger RNA (mRNA) were significantly correlated with the ratio of proteinuria at 6 months to baseline proteinuria in patients undergoing glucocorticoid treatment. MCP-1 mRNA and protein levels were significantly upregulated in mesangial cells stimulated with IFNγ among representative Th1/Th2 cytokines.

Conclusion

IFNγ was shown to be a key cytokine in the pathogenic processes underlying IgAN, and its upregulation induced an increase in urinary MCP-1 production. These findings suggest that Th1 cytokines may play an important role in the development of IgAN.

Comparison of Different Types of Oral Adsorbent Therapy in Patients with Chronic Kidney Disease: A Multicenter, Randomized, Phase IV Clinical Trial

PURPOSE

Oral adsorbents delay disease progression and improve uremic symptoms in patients with chronic kidney disease (CKD). DW-7202 is a newly developed oral adsorbent with high adsorptive selectivity for uremic toxins. We evaluated patient preference for and adherence to DW-7202 versus AST-120 therapy and compared treatment efficacy and safety in patients with pre-dialysis CKD.

MATERIALS AND METHODS

A seven-center, randomized, open-label, two-way crossover, active-controlled, phase IV clinical trial was conducted. Patients with stable CKD were randomly assigned to receive DW-7202 (capsule type) or AST-120 (granule type) for 12 weeks. The groups then switched to the other adsorbent and took it for the next 12 weeks. Patient preference was the primary outcome. Secondary outcomes included changes in estimated glomerular filtration rate (eGFR) and serum creatinine, cystatin C, and indoxyl sulfate (IS) levels.

RESULTS

Significantly more patients preferred DW-7202 than AST-120 (p<0.001). Patient adherence improved after switching from AST-120 to DW-7202; there was no apparent change in adherence after switching from DW-7202 to AST-120. Changes in eGFR and serum creatinine, cystatin C, and IS levels were not significantly different according to adsorbent type. There was also no significant difference in the incidences of adverse events during treatment with DW-7202 and AST-120.

CONCLUSION

DW-7202 can be considered as an alternative to AST-120 in patients who cannot tolerate or show poor adherence to granule type adsorbents. Further studies to evaluate factors affecting patient preferences and improved adherence are warranted (Clinical trial registration No. NCT02681952).

Plasma Endocan as a Predictor of Cardiovascular Event in Patients with End-Stage Renal Disease on Hemodialysis

Endocan, a potential biomarker of endothelial dysfunction, is associated with increased cardiovascular risk. We investigated the utility of plasma endocan for predicting cardiovascular risk in end-stage renal disease (ESRD) patients undergoing hemodialysis. Of the 452 patients in the K-cohort, 354 with available plasma endocan levels were enrolled. The correlation between plasma endocan levels and the clinical characteristics of a study population were analyzed. We divided patients into two groups, according to plasma endocan levels, and investigated the predictive value of endocan for the occurrence of cardiovascular events. In a multiple linear regression analysis, plasma endocan levels were positively correlated with previous cardiovascular events and negatively correlated with body mass index, albumin, and triglyceride. Patients with higher plasma endocan levels experienced more frequent cardiovascular events than those with lower plasma endocan levels (12.9% in the lower group vs. 22.7% in the higher group, p = 0.016). Cox proportional hazard models showed that higher plasma endocan levels were an independent predictor of cardiovascular events in ESRD patients on hemodialysis ((hazard ration) HR 1.949, 95% (confidence interval) CI 1.144–3.319, p = 0.014). Our results suggest that plasma endocan level might be a useful biomarker for predicting cardiovascular events in ESRD patients on hemodialysis.

Epidemiology, risk factors, and clinical impact of early post-transplant infection in older kidney transplant recipients: the Korean organ transplantation registry study

Background

As in younger recipients, post-transplant infection is a frequent and devastating complication after kidney transplantation (KT) in older recipients. However, few studies have analyzed characteristics of post-transplant infection in older kidney recipients. In this study of a nation-wide cohort of older kidney recipients, we investigated the current epidemiology, risk factors, and clinical impacts of early post-transplant infection, which was defined as infectious complications requiring hospitalization within the first 6 months after KT.

Methods

Three thousand seven hundred thirty-eight kidney recipients registered in the Korean Organ Transplantation Registry between 2014 and 2017 were enrolled. Recipients were divided into two groups, younger (n = 3081) and older (n = 657), with a cutoff age of 60 years. We observed characteristics of early post-transplant infection, and investigated risk factors for the development of infection. We also analyzed the association of early post-transplant infection with clinical outcomes including cardiac events, rejection, graft loss, and all-cause mortality.

Results

The incidence of early post-transplant infection was more frequent in older recipients (16.9% in younger group and 22.7% in older group). Bacteria were the most common causative pathogens of early post-transplant infection, and the most frequent site of infection was the urinary tract in both older and younger recipients. Older recipients experienced more mycobacterial infections, co-infections, and multiple site infections compared with younger recipients. In older recipients, female sex (HR 1.398, 95% CI 1.199–1.631), older donor age (HR 1.010, 95% CI 1.004–1.016), longer hospitalization after KT (HR 1.010, 95% CI 1.006–1.014), and experience of acute rejection (HR 2.907, 95% CI 2.471–3.419) were independent risk factors for the development of early post-transplant infection. Experiencing infection significantly increases the incidence of rejection, graft loss, and all-cause mortality.

Conclusion

Our results illustrate current trends, risk factors, and clinical impacts of early post-transplant infection after KT in older recipients. Considering the poor outcomes associated with early post-transplant infection, careful screening of recipients at high risk for infection and monitoring of recipients who experience infection are advised. In addition, since older recipients exhibit different clinical characteristics than younger recipients, further studies are needed to establish effective strategies for treating older recipients.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12877-020-01859-3.

Rhabdomyolysis-Induced AKI Was Ameliorated in NLRP3 KO Mice via Alleviation of Mitochondrial Lipid Peroxidation in Renal Tubular Cells

Introduction: A recent study showed that early renal tubular injury is ameliorated in Nod-like receptor pyrin domain-containing protein 3 (NLRP3) KO mice with rhabdomyolysis-induced acute kidney injury (RIAKI). However, the precise mechanism has not been determined. Therefore, we investigated the role of NLRP3 in renal tubular cells in RIAKI. Methods: Glycerol-mediated RIAKI was induced in NLRP3 KO and wild-type (WT) mice. The mice were euthanized 24 h after glycerol injection, and both kidneys and plasma were collected. HKC-8 cells were treated with ferrous myoglobin to mimic a rhabdomyolytic environment. Results: Glycerol injection led to increase serum creatinine, aspartate aminotransferase (AST), and renal kidney injury molecule-1 (KIM-1) level; renal tubular necrosis; and apoptosis. Renal injury was attenuated in NLRP3 KO mice, while muscle damage and renal neutrophil recruitment did not differ between NLRP3 KO mice and WT mice. Following glycerin injection, increases in cleaved caspase-3, poly (ADP-ribose) polymerase (PARP), and a decrease in the glutathione peroxidase 4 (GPX-4) level were observed in the kidneys of mice with RIAKI, and these changes were alleviated in the kidneys of NLRP3 KO mice. NLRP3 was upregulated, and cell viability was suppressed in HKC-8 cells treated with ferrous myoglobin. Myoglobin-induced apoptosis and lipid peroxidation were significantly decreased in siNLRP3-treated HKC-8 cells compared to ferrous myoglobin-treated HKC-8 cells. Myoglobin reduced the mitochondrial membrane potential and increased mitochondrial fission and reactive oxygen species (ROS) and lipid peroxidation levels, which were restored to normal levels in NLRP3-depleted HKC-8 cells. Conclusions: NLRP3 depletion ameliorated renal tubular injury in a murine glycerol-induced acute kidney injury (AKI) model. A lack of NLRP3 improved tubular cell viability via attenuation of myoglobin-induced mitochondrial injury and lipid peroxidation, which might be the critical factor in protecting the kidney.

Renal dysfunction is associated with decline of cognitive function in community-dwelling older adults: Korean frailty and aging cohort study

Background

Cognitive decline is common in older adults. Similarly, the prevalence of renal dysfunction is also increased in the elderly population. We conducted this study to clarify the relationship between renal dysfunction and decline of cognitive function in community-dwelling elderly population.

Methods

A cross-sectional analysis was performed using data from the Korean Frailty and Aging Cohort Study, a nationwide cohort study. Total 2847 (1333 men, 1514 women) eligible participants were enrolled for this study. The estimated glomerular filtration rate (eGFR, mL/min/1.73m²) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Global cognitive function was assessed with the Mini-mental State Examination-Korean version. Other domains of cognitive function were tested with the Consortium to Establish a Registry for Alzheimer’s disease and the Frontal Assessment Battery.

Results

The mean age of all participants was 76.0 ± 3.9 years and eGFR (all in mL/min/1.73 m²) was 77.5 ± 14.3. And the mean eGFR was 91.7 ± 3.2 in quartile 1, 84.9 ± 1.8 in quartile 2, 76.1 ± 3.7 in quartile 3, and 57.2 ± 10.8 in quartile 4. In baseline characteristics, participants with lower eGFR tend to have lower cognitive function scores than participant with higher eGFR. In linear regression analysis, eGFR was correlated with the word list memory (β = 0.53, P = 0.005), word list recall (β = 0.86, P < 0.001), and word list recognition (β = 0.43, P = 0.030) after adjustment of confounding variables. Moreover, after multivariate adjustment the association with cognitive impairment in quartile 2 was stronger (adjusted OR: 1.535, 95% CI: 1.111–2.120, P = 0.009), and the ORs of cognitive impairment were 1.501 (95% CI: 1.084–2.079, P = 0.014) in quartile 3 and 1.423 (95% CI: 1.022–1.983, P = 0.037) in quartile 4.

Conclusion

In older adults, the immediate, recent memory, and recognition domains were significantly related to renal function. Also, the mild renal dysfunction was independently associated with impairment of global cognitive function. These results suggest that the early stages of renal dysfunction could be an effective target to prevent worsening of cognitive impairment. Therefore, regular monitoring and early detection of mild renal dysfunction in elderly population might be needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-020-01862-8.

Associations between Cell-Free Mitochondrial DNA and Inflammation, and Their Clinical Implications for Patients on Hemodialysis: A Prospective Multicenter Cohort Study

BACKGROUND

Cell-free mitochondrial DNA (cf-mtDNA) has recently been in the spotlight as an endogenously produced danger molecule that can potentially elicit inflammation. However, its clinical and prognostic implications are uncertain in patients undergoing hemodialysis.

METHODS

We examined the association of baseline cf-mtDNA categorized as tertiles with health-related quality of life (HRQOL), inflammatory cytokines, and mortality in a multicenter prospective cohort of 334 patients on hemodialysis. To better understand cf-mtDNA-mediated inflammation, we measured cytokine production after in vitro stimulation of bone marrow-derived macrophages (BMDMs) with mtDNA.

RESULTS

The higher cf-mtDNA tertile had a longer dialysis vintage, a greater comorbidity burden, and increased levels of inflammatory markers, including high-sensitivity-C-reactive protein, tumor necrosis factor-alpha, CXCL16, and osteoprotegerin. In particular, mtDNA augmented inflammatory cytokine release from BMDMs by lipopolysaccharide, the levels of which are reported to be increased in hemodialysis patients. Although the patients with higher levels of cf-mtDNA generally had lower (poorer) scores for HRQOL, cf-mtDNA was not associated with all-cause mortality in hemodialysis patients.

CONCLUSION

cf-mtDNA was correlated with poor clinical status and modestly associated with impaired quality of life in patients on hemodialysis. In proinflammatory milieu in end-stage renal disease, these associations may be attributed to the boosting effects of cf-mtDNA on inflammation.

Association between epidermal growth factor (EGF) and EGF receptor gene polymorphisms and end-stage renal disease and acute renal allograft rejection in a Korean population

Purpose

Epidermal growth factor (EGF) has been found to be associated with the development and repair mechanisms of several renal diseases. In this study, we hypothesized that single nucleotide polymorphisms (SNPs) in EGF or its receptor genes might have an association with end-stage renal disease (ESRD) or acute renal allograft rejection (AR) in a Korean population.

Methods

Three-hundred and forty seven recipients of the first renal transplants for ESRD, including 63 AR patients along with 289 healthy adults were included in the study. Five EGF gene SNPs (rs11568835, rs11568943, rs2237051, rs11569017, and rs3756261) and four EGFR gene SNPs (rs1140475, rs2293347, rs1050171, and rs6965469) were analyzed. The genotypes of these SNPs were analyzed using the AxiomTM genome-wide human assay. Statistical analysis was performed using SNPStats and Haploview version 4.2 software. Multiple logistic regression models (codominant, dominant, recessive, and Log-additive) were used to estimate the odds ratio (OR), 95% confidence interval (CI), and P value.

Results

One SNP (rs11569017) in the EGF gene showed significant association with ESRD but not with AR. Another SNP (rs11568835) in the EGF gene showed significant association with susceptibility to AR but not with ESRD. One SNP (rs1050171) in the EGFR gene showed significant association with susceptibility to AR but not with ESRD.

Conclusion

Our findings suggest that SNPs in the EGF and EGFR gene may be associated with the risk of ESRD and AR development in the Korean population.

P0912AKIDNEY AGING CONSTITUTES INFLAMMATORY PROCESS THAT CONTRIBUTES TO EXACERBATION OF KIDNEY INJURY

Background and Aims

Aging is a natural process accompanied by decline of regenerative potential. Some argue that aging process is just an irreversible physiologic process, whereas some advocate that it should be viewed as disease.

Method

To determine the nature of kidney aging and kidney disease at transcriptional level, whole kidney RNA sequencing was performed on young (2-month-old), middle-aged (12-month-old), and old (24-month-old) mice and young mice with adenine-induced nephropathy. In addition, young and old mice were fed with either standard or adenine-enriched diet for 4 weeks, and then the degree of renal injury was compared.

Results

The transcript profile of the old kidneys was mostly involved in inflammation and activation of innate and adaptive immune system and almost same to the transcript alterations of adenine-induced nephropathy. The genes implicated in fibrosis were downregulated until middle-age period, and then upregulated with the advance of age. The old kidneys showed augmented inflammatory response in a model of adenine-induced nephropathy compared with young kidneys, leading to more widespread fibrosis.

Conclusion

These findings showed that the pathophysiologic process of kidney aging and adenine-induced kidney injury shows similar natures in the context of inflammation and immune response. When kidney injury is superimposed on the aged kidneys, age-related inflammation potentiates inflammatory response and results in increased renal damage.

P1605THE EARLY RISE OF URINARY EXOSOMAL BK VIRUS MICRORNA AS A PREDICTIVE MARKER FOR BK VIRUS NEPHROPATHY IN A PROSPECTIVE KIDNEY TRANSPLANTATION COHORT

Background and Aims

BK virus nephropathy (BKVN) is one of the significant contributors to allograft dysfunction in kidney transplantation. Because of the lack of effective anti-viral medication, early detection of BKV replication and preemptive management is vital to preserving allograft function. Herein, we investigated the predictive value of urinary exosomal BKV-microRNA for BKVN in the kidney transplantation cohort.

Method

ARTKT (assessment of immunologic risk and tolerance in kidney transplantation) is a prospective observational cohort in which a total of 420 kidney transplant recipients were enrolled from 7 teaching hospitals in South Korea since 2015. Urine samples were collected at 0.5, 3, 6, 12, and 24 months after kidney transplantation in this cohort. All enrolled patients were reviewed to identify the patients diagnosed with BKVN histologically (biopsy-proven BKVN) and those experienced BK viremia defined as plasma BKV DNA load &gt; 4 log10 copies per mL (presumptive BKVN). Urinary exosomal miR was quantified using real-time reverse transcription PCR.

Results

10 patients and 14 patients developed biopsy-proven BKVN and presumptive BKVN, respectively. Because of unavailable urine samples, urinary exosomal BKV-microRNA was investigated in 8 patients with biopsy-proven BKVN and 13 patients with presumptive BKVN. 61 patients with no evidence of BKVN were selected as a negative control. Most of BKVN was developed in a median time of 3.4 months after transplantation. In line with this pattern, urinary exosomal BKV-microRNA peaked at 3 months after transplantation and decreased thereafter in biopsy-proven BKVN and presumptive BKVN, keeping higher value in biopsy-proven BKVN compared to presumptive BKVN after 3 months. At 2 weeks after transplantation, half of the patients with biopsy-proven BKVN showed an early rise of urinary exosomal BKV-microRNA, whereas patients with presumptive BKVN and no evidence of BKVN did not. However, plasma BK virus DNA was not detected in all groups at 2 weeks after transplantation. In multivariate cox proportional hazards model, urinary exosomal BKV-microRNA was significantly associated with biopsy-proven BKVN.

Conclusion

A urinary exosomal BKV-microRNA increase as early as 2 weeks after kidney transplantation predicts future BKVN development, enabling early intervention.

SO085CIRCULATING PCSK9 LEVEL PREDICTS RISK OF CARDIOVASCULAR EVENTS AND DEATH IN HEMODIALYSIS PATIENTS

Background and Aims

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a promising new target for prevention of cardiovascular (CV) events. However, the clinical significance of circulating PCSK9 is unclear in hemodialysis (HD) patients.

Method

A total of 353 HD patients were prospectively enrolled from June 2016 to May 2018 in a K-cohort. Plasma PCSK9 level was measured at the time of study enrollment. Patients were classified into three groups based on PCSK9 tertile. The primary endpoint was defined as composite of CV event and death from any cause.

Results

Plasma PCSK9 level was positively correlated with total cholesterol level in patients with statin treatment. However, PCSK9 was not related to plasma inflammatory (high-sensitivity C-reactive peptide, monocyte chemoattractant protein-1, interleukin-6) or calcification-related markers (osteoprotegerin and receptor activator of nuclear factor kappa-Β ligand). Multivariate linear regression analysis revealed that baseline statin treatment and serum glucose, albumin, and total cholesterol were independent determinants of circulating PCSK9 levels. In Cox-regression analysis, PCSK9 tertile 3 was associated with a 1.99-fold risk for composite events (95% CI, 1.08–3.66), and it was associated with a 2.26-fold risk for CV events (95% CI, 1.11–4.62) after adjustment for multiple variables. PCSK9 tertile 3 provides additional prognostic power to predict composite events in subgroups with higher levels of high-sensitivity C-reactive peptide and LDL.

Conclusion

In conclusion, higher circulating PCSK9 level independently predicted CV events and death in HD patients. These results suggest the importance of future studies regarding the effect of PCSK9 inhibition on reduction of CV events.

P1490AGAIT SPEED AND HANDGRIP STRENGTH AS PREDICTORS OF ALL-CAUSE MORTALITY AND CARDIOVASCULAR EVENTS IN HEMODIALYSIS PATIENTS

Background and Aims

Low physical performance in patients undergoing maintenance hemodialysis is associated with a high mortality rate. We investigated the clinical relevance of gait speed and handgrip strength, the two most commonly used methods to assess physical performance.

Method

We obtained data regarding gait speed and handgrip strength from 277 hemodialysis patients and evaluated their relationship with baseline parameters, mental health, plasma inflammatory markers, and major adverse clinical outcomes. Low physical performance was defined by the recommendations suggested by the Asian Working Group on Sarcopenia.

Results

The prevalence of low gait speed and handgrip strength were 28.2% and 44.8%, respectively. Old age, low serum albumin levels, high comorbidity index, and impaired cognitive functions were associated with low physical performance. Patients with isolated low gait speed exhibited a general trend for worse quality of life than those with isolated low handgrip strength. Gait speed and handgrip strength showed very weak correlations with had different determinant factors (older age, the presence of diabetes, and lower serum albumin for low gait speed, and lower body mass index, and the presence of previous cardiovascular events for low handgrip strength). Patients with low gait speed and handgrip strength had elevated levels of plasma endocan and matrix metalloproteinase-7 and the highest risk of all-cause mortality and cardiovascular events among the groups (adjusted hazard ratio of 2.72, p = 0.024).

Conclusion

Gait speed and handgrip strength reflected distinctive aspects of patient characteristics and that their combination improved the prediction of adverse clinical outcomes in hemodialysis patients. Gait speed seems to be a better indicator for poor patient outcomes compared with handgrip strength.

P0798ASSOCIATION BETWEEN RENAL DYSFUNCTION AND GENERAL COGNITIVE FUNCTION IN COMMUNITY DWELLING OLDER ADULTS: KOREAN FRAILTY AND AGING COHORT STUDY

Background and Aims

Cognitive impairment is common in older adults. Similarly, the prevalence of renal dysfunction is also increased in the elderly. We conducted this study to clarify the relationship between the renal function and cognitive impairment in community dwelling older adults in Korea.

Method

A cross-sectional analysis was performed on the data of the Korean Frailty and Aging Cohort Study (KFACS), a nationwide cohort study that began in 2016. Of the 3014 participants assessed in the first and second year, 2847 participants (1333 men, 1514 women) who completed baseline assessments were enrolled. The estimated glomerular filtration rate (eGFR, mL/min/1.73m2) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Renal function of the participants was classified into four groups by eGFR quartile. General cognitive function was accessed with mini-mental state exam in the Korean version (MMSE-KC). Participants who had MMSE-KC score less than 1.5 standard deviation by age, gender, and education level were regarded as the cognitive impairment. Multivariate logistic regression model was used to examine the relationship between renal function and cognitive impairment. In addition, we investigated to find the point of eGFR interval at which the odds ratio begins to increase.

Results

The mean eGFR in quartile 1 was 91.7 ± 3.22 ml/min/1.73m2, and 84.9 ± 1.81 in quartile 2, 76.1 ± 3.66 in quartile 3, and 57.2 ± 10.75 in quartile 4. In baseline characteristics, participants with lower eGFR had lower MMSE-KC scores. And the prevalence of cognitive impairment was 10.8% in quartile 1, 15.9% in quartile 2, 15.2% in quartile 3, 14.9% in quartile 4. After multivariate adjustment, the odds ratio (OR) of cognitive impairment in quartile 2 [adjusted OR: 1.569, 95% confidence intervals (CI): 1.141 - 2.158, p = 0.006] compared with quartile 1. And the odd ratios of cognitive impairment were 1.539 (95% CI: 1.113 - 2.127, p = 0.009) in quartile 3, 1.475 (95% CI: 1.062 - 2.049, p = 0.020) in quartile 4 compared with quartile 1, respectively. Among the participants with eGFR above 60 ml/min/1.73m2, the renal function was grouped by 5 ml/min/1.73m2 interval. The risk of cognitive impairment started to increase from eGFR between 80 and 85 ml/min/1.73m2 (adjusted OR: 1.667, 95% CI: 1.128 - 2.463, p = 0.010).

Conclusion

Renal dysfunction was associated with lower global cognitive function in older adults. And the risk of cognitive impairment increased from quartile 2, especially, eGFR between 80 and 85 ml/min/1.73m2 in this population. These results suggest that mild decline of kidney function is also a risk factor of cognitive decline in the elderly.

P0826OBESITY AND RISK FOR CHRONIC KIDNEY DISEASE IN THE HEALTHY MIDDLE-AGED KOREAN POPULATION

Background and Aims

Although obesity is a well-known risk factor for chronic kidney disease (CKD), previous epidemiologic studies have produced mixed results. This study was purposed to investigate the relationship between obesity and CKD occurrence in the healthy middle-aged Korean population.

Method

We used a prospective, longitudinal data from the Korean Genome and Epidemiology Study (KoGES), a population-based, epidemiology study in South Korea (2001-2014). A total of 6,678 participants aged 40-69 who were free of diabetes, hypertension, and CKD at baseline were followed-up biennially. CKD was defined as at least two-time occurrence of estimated glomerular filtration rate &lt; 60 mL/min/1.73m2 using CKD-EPI equation during the follow-up period.

Results

A total of 433 participants (6.5%) developed CKD. We divided the participants into 5 groups by BMI: underweight (BMI &lt; 18.5), normal-weight (BMI 18.5-22.0), overweight 1 (BMI 23.0-24.9), overweight 2 (BMD 25-29.9), and obesity (BMI &gt;30). Compared to the normal-weight group, hazard ratio of CKD occurrence was elevated in overweight 2 (HR=1.43, p=0.01) and obesity (HR=1.73, p=0.03) in multivariate-adjusted regression analysis (variates: age, newly developed hypertension, newly developed diabetes, fasting glucose &gt; 126mg/dL, 2hours glucose &gt; 200mg/dL, systolic blood pressure &gt; 140mmHg, physical activity, alcohol consumption, smoking). When dividing the participants into three age groups: the 40s, 50s, and 60s, only the 60s group showed a significant correlation of BMI with CKD occurrence (overweight 2: HR=1.93, p=0.05, obesity: HR=3.94, p=0.03).

Conclusion

The risk of CKD was significantly high for those in their 60s who were overweight or obese despite free of underlying diseases in the Korean population.

P0151SEXUAL DIMORPHISM IN HYPERTENSION ACCORDING TO THE CHANGE OF URINE SODIUM AND VOLUME EXCRETION BY SEX OR MENOPAUSE

Background and Aims

A recent study demonstrated female rats more rapidly excreted urine sodium and water under saline bolus infusion than male rats, and suggested sexual dimorphisms in renal transporters. However, the sexual differences in renal salt and water excretion was not yet investigated with human data. We purposed to clarify whether the sexual difference of natriuretic and diuretic ability exists, and it contributes to decreasing blood pressure (BP) in nondiabetic chronic kidney disease (CKD) patients.

Method

This is a secondary analysis of an open-label, randomized, controlled study determining the effect of intensive low-salt diet education on BP and albuminuria in nondiabetic CKD patients. A total of 235 patients had stopped all renin-angiotensin blocking agents or diuretics during a run-in period for eight weeks (0w). After the run-in period, they received olmesartan (40mg daily) for eight weeks (8w), and then maintained the same medicine with low-salt diet education for an additional eight weeks (16w).

Results

Mean age of premenopausal women (n=50), same-aged young men (n=76), postmenopausal women (n=68), and same-aged older men (n=41) was 40.7, 40.2, 59.0, and 69.9 years old, respectively. Their MDRD eGFR was 76.2, 71.6, 59.8, and 58.8 mL/min/1.73m2, respectively. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) was lower in premenopausal women (129/79 mmHg) than in young men (134/83 mmHg). Daily salt intake decreased in 16w in premenopausal women (1839 → 1288mg, p=0.008) and young men (2494 → 1552mg, p=0.001) compared with them in 0w, while there was no significant change in postmenopausal women (2443 → 2171mg, p=0.610) and older men (2870 → 2366mg, p=0.458). Except for the premenopausal women (136 (0w) → 133 (16w) mEq/day, p=0.749), urine sodium excretion for 24 hours significantly decreased in 16w compared with that in 0w or 8w (young men: 154 (8w) → 137 (16w)mEq/day p=0.042, postmenopausal women: 152 (0w) → 128m (16w)Eq/day p=0.016, older men: 181 (0w) → 145 (16w)mEq/day p=0.019). Also, urine volume was significantly larger in the premenopausal women than in young men in 8w and 16w (8w: 1009 vs. 980mL p=0.002, 16w: 1004 vs. 978mL, p=0.006), while it was not different between postmenopausal women and older men (8w: 1002 vs. 990 p=0.347, 16w: 1003 vs. 1001 p=0.895). The urine volume was positively correlated with BP in the premenopausal women, while it was negatively associated with BP in young men in 16w.

Conclusion

Although sodium intake was similarly decreased in premenopausal women and young men, urine sodium excretion did not fall, and urine volume increased in premenopausal women. This phenomenon disappeared in postmenopausal women. Augmented natriuretic and diuretic potency might contribute to lower BP in premenopausal women with nondiabetic CKD.

Effects of online hemodiafiltration on anemia and nutritional status in chronic hemodialysis patients

Background

Online hemodiafiltration (OL-HDF) offers considerable advantages in clearance of molecules of various sizes. However, evidence of clinical effects of OL-HDF is scarce in Korea. In this study, we investigated changes in laboratory values over more than 12 months after switching to OL-HDF.

Methods

Adult patients with end-stage renal disease undergoing hemodialysis (HD) were prospectively enrolled in a K-cohort (CRIS no. KCT0003281) from 6 tertiary hospitals in South Korea. We recruited 435 patients, 339 of whom were on HD at enrollment. One hundred eighty-two patients were followed for more than 24 months. Among them, 44 were switched to OL-HDF for more than 12 months without conversion to HD. We used a paired t test to compare baseline and 24-month follow-up results.

Results

The mean age of the subjects was 61.2 ± 12.2 years, and 62.6% were male. The baseline hemoglobin level was not significantly different between HD and OL-HDF group (10.61 ± 1.15 vs. 10.46 ± 1.03 g/dL, P = 0.437). However, the baseline serum protein and albumin levels were significantly lower in the OL-HDF group (6.82 ± 0.49 vs. 6.59 ± 0.48 g/dL, P = 0.006; 3.93 ± 0.28 vs. 3.73 ± 0.29 g/dL, P < 0.001). In patients switched to OL-HDF, levels of hemoglobin and serum albumin significantly increased (10.46 ± 1.03 vs. 11.08 ± 0.82 g/dL, P = 0.001; 3.73 ± 0.29 vs. 3.87 ± 0.30 g/dL, P = 0.001). The normalized protein catabolic rate decreased after 24 months, but the change was not significant (1.07 ± 0.25 vs. 1.03 ± 0.21 g/kg/day, P = 0.433). Although the dose of erythropoiesis-stimulating agent was lower in patients who converted to HDF, it was not significantly different (-115.7 ± 189.7 vs. -170.5 ± 257.1 P = 0.206).

Conclusion

OL-HDF treatment over more than 12 months was associated with no harmful effects on anemia and nutritional status.

Platelet activity with hemoglobin level in patients with hemodialysis: Prospective study

BACKGROUND

VerifyNow (VN; Accumetrics, San Diego, CA) P2Y12 reaction unit (PRU) has an inverse relation with hemoglobin level (Hb). Chronic kidney disease (CKD) is associated with low response to clopidogrel and low Hb. Our aim is to investigate the relation between PRU and Hb, and to assess whether Hb directly affects PRU or not in patients with CKD undergoing hemodialysis (HD).

METHODS

We analyzed the relation between PRU and Hb in 43 HD patients and compared it with a control group of 127 patients with normal renal function. Both groups underwent percutaneous coronary intervention for stable coronary artery disease. We also compared PRU between the 2 groups considering Hb as a confounding factor.

RESULTS

In the control group, Hb and PRU showed a significant inverse correlation (correlation coefficient r = -0.340; P < .001), but not in the HD group (correlation coefficient r = -0.099; P = .53). PRU was higher in the HD group than the control group after adjusting for the influence of Hb (299.2 [95% confidence interval: 278.4-316.7] vs 248.7 [95% confidence interval: 227.7-269.0]; P < .001), even after propensity score matching (299.2 [95% confidence interval: 278.4-316.7] vs 241.7 [95% confidence interval: 221.8-262.2]; P < .001).

CONCLUSIONS

PRU was higher regardless of lower Hb in CKD on HD patients than normal renal function patients. Therefore, Hb was not crucial factor to decide PRU in CKD on HD patients in this study.

Circulating PCSK9 Level and Risk of Cardiovascular Events and Death in Hemodialysis Patients

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a promising new target for the prevention of cardiovascular (CV) events. However, the clinical significance of circulating PCSK9 is unclear in hemodialysis (HD) patients. A total of 353 HD patients were prospectively enrolled from June 2016 to August 2019 in a K-cohort. Plasma PCSK9 level was measured at the time of study enrollment. The primary endpoint was defined as a composite of CV event and death. Plasma PCSK9 level was positively correlated with total cholesterol level in patients with statin treatment. Multivariate linear regression analysis revealed that baseline serum glucose, albumin, total cholesterol, and statin treatment were independent determinants of circulating PCSK9 levels. Cumulative rates of composite and CV events were significantly higher in patients with tertile 3 PCSK9 (p = 0.017 and p = 0.010, respectively). In multivariate Cox-regression analysis, PCSK9 tertile 3 was associated with a 1.97-fold risk of composite events (95% CI, 1.13–3.45), and it was associated with a 2.31-fold risk of CV events (95% CI, 1.17–4.59). In conclusion, a higher circulating PCSK9 level was independently associated with incident CV events and death in HD patients. These results suggest the importance of future studies regarding the effect of PCSK9 inhibition.

Baseline High Blood Pressure is Associated with Clinico-Pathologic Findings and Later Renal Progression in Chronic Glomerulonephritis

Background

Several factors had been suggested to contribute to the development of hypertension in chronic glomerulonephritis (GN). This study was conducted to find the association of baseline blood pressure (BP) with pathophysiologic findings and later renal progression in chronic GN.

Methods

Clinico-pathological findings including serum creatinine (Cr), proteinuria, pathological findings, and urinary Na excretion were analyzed in a total of 233 patients with IgA nephropathy from The Kyung-Hee Cohort of GN. Glomerular surface area (GSA) was measured by imaging analysis and urine angiotensinogen (AGT) concentrations by human ELISA kits.

Results

Systolic BP was ≥130mmHg in 124 patients (53%). Systolic BP was negatively correlated with follow-up eGFR (r=−0.32, p<0.0001) and positively serum uric acid concentrations, while it had no significant relationships with initial serum Cr and eGFR. As compared with patients with systolic BP<130 mmHg, those with ≥130 mmHg were older and showed higher serum Cr, proteinuria, 24 hr urinary Na excretion, mean GSA, and T-I fibrosis, lower follow-up eGFR, and steeper decline in slope of eGFR. The results in patients with normal serum Cr concentrations were comparable to those in whole group. Systolic BP was positively correlated with age, baseline and follow-up proteinuria, serum uric acid concentrations and IgM deposit and negatively with follow-up eGFR. In subgroup analysis, systolic BP was also positively correlated with mean GSA and urinary AGT concentrations.

Conclusion

This study showed that baseline systolic BP is related to urinary Na excretion, glomerulomegaly, T-I fibrosis and later renal progression in patients with IgA nephropathy.

Genome-wide association study identifies new susceptible loci of IgA nephropathy in Koreans

Background

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Recent evidence suggests that genetic factors are related to the pathogenesis of IgAN. We conducted a genome-wide association study (GWAS) to identify novel genetic susceptibility loci for IgAN in a Korean population.

Methods

We enrolled 188 biopsy-confirmed IgAN cases and 455 healthy controls for the discovery stage and explored associations between IgAN and single nucleotide polymorphisms (SNPs) using a customized DNA chip. The significant SNPs from the discovery samples were then selected for replication in an independent cohort with 310 biopsy-confirmed IgAN cases and 438 healthy controls.

Results

In the first stage, two SNPs (rs10172700 in LOC105373592 and rs2296136 in ANKRD16) were selected for further association analysis in the next stage. In the replication cohort, rs2296136 in ANKRD16 was significantly associated with IgAN (odds ratio [OR] = 1.40, 95% confidence interval [CI] 0.99–1.98, p = 0.05 in log-additive model, OR = 1.55, 95% CI = 1.06–−2.27, p = 0.02 in dominant model, and OR = 0.70, 95% CI = 0.17–−2.84, p = 0.62 in recessive model). rs2296136 in ANKRD16 also showed a significant association with IgAN in the entire study population combining GWAS and replication study (p = 0.0045 in log-additive model, p = 0.0027 in dominant model, and p = 0.76 in recessive model).

Conclusions

The SNPs identified in the present study could be good candidate markers for predicting IgAN in Koreans, although further experimental validation is needed.

Sex-related differences in the intratubular renin-angiotensin system in two-kidney, one-clip hypertensive rats

The intratubular renin-angiotensin system (RAS) is thought to play an essential role in hypertensive renal disease, but information regarding sex-related differences in this system is limited. The present study investigated sex differences in the intratubular RAS in two-kidney, one-clip (2K1C) rats. A 2.5-mm clip was placed on the left renal artery of Sprague-Dawley rats, and rats were euthanized 3 or 5 wk after the operation. Systolic blood pressure increased in 2K1C rats in both sexes but was significantly higher in male rats than in female rats, and an antihypertensive effect was not observed in 2K1C ovariectomized (OVX) female rats. Compared with male 2K1C rats, intratubular angiotensin-converting enzyme (ACE) and ANG II were repressed, and intratubular ACE2, angiotensin (1-7), and Mas receptor were increased in both kidneys in female 2K1C rats 5 wk after surgery. Comparison with male and female rats and intratubular mRNA levels of ACE and ANG II type 1 receptor were augmented in OVX female rats, regardless of the clipping surgery 3 wk postoperation. ANG II type 2 receptor was upregulated in female rats with or without OVX; thus, the ANG II type 1-to-type 2 receptor ratio was higher in male rats than in female rats. In conclusion, female rats were protected from hypertensive renal and cardiac injury after renal artery clipping. An increase in the intratubular nonclassic RAS [ACE2/angiotensin (1-7)/Mas receptor] and a decrease in the ANG II type 1-to-type 2 receptor ratio could limit the adverse effects of the classic RAS during renovascular hypertension in female rats, and estrogen is suggested to play a primary role in the regulation of intratubular RAS components.

Association between Plasma Levels of Growth Differentiation Factor-15 and Renal Function in the Elderly: Korean Frailty and Aging Cohort Study

BACKGROUND/AIMS

Growth differentiation factor-15 (GDF-15) expression has been reported to increase in response to tissue damage and has recently emerged as a useful biomarker for various diseases. Although emerging evidence supports the clinicopathological value of GDF-15 in renal impairment, few studies have analyzed it in the elderly. Thus, we conducted a cross-sectional study to investigate the association of plasma GDF-15 with renal function and the presence of chronic kidney disease (CKD) in community-dwelling elderly.

MATERIALS

The present study was based on the baseline data of the Korean Frailty and Aging Cohort Study (KFACS), a nationwide cohort study that began in 2016. Of the 1,559 participants assessed in the first year, 443 with available plasma GDF-15 data were enrolled in this study. We investigated the association of plasma GDF-15 levels with clinical and biochemical parameters. The study population was divided into two groups according to renal function (CKD and non-CKD groups) to investigate whether GDF-15 can determine the presence of renal dysfunction in the elderly. Plasma GDF-15 was measured by enzyme-linked immunosorbent assay (ELISA) kit.

RESULTS

In a simple regression analysis, the levels of plasma GDF-15 were negatively correlated with estimated glomerular filtration rate (eGFR; r = -0.383, p < 0.001). In multiple linear regression analysis, GDF-15 levels were still significantly correlated with eGFR, even after adjusting for other parameters (r = -0.259, p < 0.001). Plasma GDF-15 levels were significantly higher in the elderly with CKD than in those without CKD (2,364.025 ± 1,052.23 ng/L and 1,451.23 ± 835.79 ng/L, respectively; p < 0.001). The optimal cut-off value of plasma GDF-15 for detecting the presence of CKD was 1,699.4 ng/L (76.5% sensitivity and 76.0% specificity), as determined by the receiver operating characteristic curve. The area under the curve was 0.793 ± 0.033 (95% CI 0.729-0.857, p < 0.001).

CONCLUSION

Plasma GDF-15 levels were negatively associated with eGFR and were significantly increased in the elderly with CKD. Our results suggested that plasma GDF-15 might be a useful marker for discriminating renal impairment in the elderly. Further large and prospective outcome studies of extended duration are needed.

Conversion from acetate dialysate to citrate dialysate in a central delivery system for maintenance hemodialysis patients

Background

The objective of this study was to compare the impact of citrate dialysate (CD) and standard acetate dialysate (AD) in hemodialysis by central delivery system (CDS) on heparin demand, and clinical parameters.

Methods

We retrospectively evaluated 75 patients on maintenance hemodialysis with CDS. Patients underwent hemodialysis with AD over a six-month period (AD period), followed by another six-month period using CD (CD period). Various parameters including mean heparin dosage, high sensitivity C-reactive protein (hsCRP), calcium-phosphate product (CaxP), intact parathyroid hormone (iPTH), and urea reduction ratio (URR) were collated at the end of each period.

Results

Patients were 60.5 ± 14.7 years old, of whom 62.7% were male. Patients required less heparin when receiving CD (AD period: 1,129 ± 1,033 IU/session vs. CD period: 787 ± 755 IU/session, P < 0.001). After the CD period (Δ_CD), pre-dialysis total CO₂ increased to 1.21 ± 2.80 mmol/L, compared to -2.44 ± 2.96 mmol/L (P < 0.001) after the AD period (Δ_AD). After the CD period, concentrations of iPTH (Δ_AD: 73.04 ± 216.34 pg/mL vs. Δ_CD: -106.66 ± 251.79 pg/mL, P < 0.001) and CaxP (Δ_AD: 4.32 ± 16.63 mg²/dL² vs. Δ_CD: -4.67 ± 15.27 mg²/dL², P = 0.015) decreased. While hsCRP levels decreased after the CD period (Δ_AD: 0.07 ± 4.09 mg/L vs. Δ_CD: -0.75 ± 4.56 mg/L, P = 0.705), the change was statistically insignificant. URR remained above clinical guideline of 65% after both periods (Δ_AD: 72.33 ± 6.92% vs. Δ_CD period: 69.20 ± 4.49%, P = 0.046).

Conclusion

Our study confirmed that the use of CD in CDS required lower heparin doses compared to the use of AD. The use of CD also provided a more stable acid-base status.