Applicable Machine Learning Model for Predicting Contrast-induced Nephropathy Based on Pre-catheterization Variables.

Objective Contrast agents used for radiological examinations are an important cause of acute kidney injury (AKI). We developed and validated a machine learning and clinical scoring prediction model to stratify the risk of contrast-induced nephropathy, considering the limitations of current classical and machine learning models. Methods This retrospective study included 38,481 percutaneous coronary intervention cases from 23,703 patients in a tertiary hospital. We divided the cases into development and internal test sets (8:2). Using the development set, we trained a gradient boosting machine prediction model (complex model). We then developed a simple model using seven variables based on variable importance. We validated the performance of the models using an internal test set and tested them externally in two other hospitals. Results The complex model had the best area under the receiver operating characteristic (AUROC) curve at 0.885 [95% confidence interval (CI) 0.876-0.894] in the internal test set and 0.837 (95% CI 0.819-0.854) and 0.850 (95% CI 0.781-0.918) in two different external validation sets. The simple model showed an AUROC of 0.795 (95% CI 0.781-0.808) in the internal test set and 0.766 (95% CI 0.744-0.789) and 0.782 (95% CI 0.687-0.877) in the two different external validation sets. This was higher than the value in the well-known scoring system (Mehran criteria, AUROC=0.67). The seven precatheterization variables selected for the simple model were age, known chronic kidney disease, hematocrit, troponin I, blood urea nitrogen, base excess, and N-terminal pro-brain natriuretic peptide. The simple model is available at http://52.78.230.235:8081/Conclusions We developed an AKI prediction machine learning model with reliable performance. This can aid in bedside clinical decision making.

Antibody response in patients undergoing chronic hemodialysis post-severe acute respiratory syndrome coronavirus 2 vaccination: A prospective observational study.

Vaccination is important for patients undergoing hemodialysis (HD) to prevent coronavirus disease 2019 (COVID-19) infection since they are more vulnerable. However, they exhibit a weak response to vaccines, underscoring the importance of understanding whether antibodies are sufficiently produced and their durability post-COVID-19 vaccination. This prospective observational study assessed the antibody response of Korean patients undergoing HD for 1 year. We compared the antibody responses of patients undergoing HD to the COVID-19 vaccine with those of healthy volunteers from 2021 to 2022. The patient and control groups received 2 doses of ChAdOx1 nCoV-19 and mRNA-1273, respectively. Immunoglobulin G (IgG) and neutralizing antibody levels were measured weeks or months apart after 2 doses for 1 year using enzyme-linked immunosorbent and fluorescence-based competitive severe acute respiratory syndrome coronavirus 2 neutralizing assays, respectively. We analyzed the third dose's effect on the patient group by categorizing the group into patients who received the third dose and those who did not since it was initiated midway through the study. In the control group, we enrolled participants who had completed 3 doses of mRNA-1273 since almost all participants received the third dose. Thirty-two patients undergoing HD and 15 healthy participants who received 2 doses of ChAdOx1 nCoV-19 and 3 of mRNA-1273, respectively, were enrolled. Although antibody production was weaker in the patient group than in the control group (P < .001), patients showed an increase in IgG levels (0.408 ± 0.517 optical density (OD) pre-vaccination, 2.175 ± 1.241 OD in patients with 2 doses, and 2.134 ± 1.157 OD in patients with 3 doses 1 year after the second dose) and neutralizing antibodies (23 ± 8% pre-vaccination, 87 ± 23% in patients with 2 doses, and 89 ± 18% in patients with 3 doses 1 year after the second dose) post-vaccination (P < .001). In the patient group, 19 patients received a third dose (BNT162b2 or mRNA-1273); however, it did not increase the antibody levels (P = 1.000). Furthermore, the antibodies produced by the vaccination did not wane until 1 year. Two doses of vaccination resulted in a significant antibody response in patients undergoing HD, and antibody levels did not wane until 1 year.

Antibody response to COVID-19 vaccination in patients on chronic hemodialysis.

Purpose: Since patients on hemodialysis (HD) are known to be vulnerable to coronavirus disease 2019 (COVID-19), many studies were conducted regarding the effectiveness of the COVID-19 vaccine in HD patients in Western countries. Here, we assessed antibody response of HD patients for 6 months post-vaccination to identify the duration and effectiveness of the COVID-19 vaccine in the Asian population. Materials and Methods: We compared antibody response of the COVID-19 vaccine in HD patients with healthy volunteers. Patient and control groups had two doses of ChAdOx1 nCoV-19 and mRNA-1273, respectively. Immunoglobulin G (IgG) was measured before vaccination, 2 weeks after the first dose, 2 and 4 weeks, 3 and 6 months after the second dose. Neutralizing antibody was measured before vaccination and at 2 weeks, 3 and 6 months after second dose. Since the third dose was started in the middle of the study, we analyzed the effect of the third dose as well. Results: Although antibody production was weaker than the control group (n=22), the patient group (n=39) showed an increase in IgG and neutralizing antibody after two doses. And, 21/39 patients and 14/22 participants had a third dose (BNT162b2 or mRNA-1273 in the patient group, mRNA-1273 in the control group), and it did not affect antibody response in both group. Trend analysis showed IgG and neutralizing antibody did not decrease over time. Age, sex, and HD vintage did not affect antibody production in HD patients. Patients with higher body mass index displayed better seroresponse, while those on immunosuppressants showed poor seroresponse. Conclusion: Two doses of vaccination led to significant antibody response in HD patients, and the antibody did not wane until 6 months.

The importance of muscle mass in predicting intradialytic hypotension in patients undergoing maintenance hemodialysis.

BACKGROUND: Patients undergoing hemodialysis are susceptible to sarcopenia. As intracellular reservoirs of water, skeletal muscles are important contributors to intradialytic hypotension. This study was designed to determine the role of skeletal muscle mass in intradialytic hypotension. METHODS: In a cross-sectional study, the body composition of 177 patients was measured immediately after hemodialysis using bioelectrical impedance analysis. The parameters measured were skeletal muscle mass, intracellular and extracellular water contents, total body water, and cell-membrane functionality (in phase angle at 50 kHz). Data from laboratory tests, chest radiography, measurements of handgrip strength and mid-arm circumference, and questionnaires were collected. The main outcome was intradialytic hypotension, defined as more than two episodes of hypotension (systolic blood pressure of <90 mmHg) with intervention over the 3 months following enrollment. Logistic regression models including each parameter related to sarcopenia were compared with a clinical model. RESULTS: Patients with a low ratio of skeletal muscle mass to dry body weight (SMM/WT) had a higher rate of intradialytic hypotension (40.7%). Most low-SMM/WT patients were female, obese, diabetic, and had a lower handgrip strength compared with the other patients. In the high-SMM/WT group, the risk of intradialytic hypotension was lower, with an odds ratio of 0.08 (95% confidence interval [CI], 0.02-0.28) and adjusted odds ratio of 0.06 (95% CI, 0.01-0.29). CONCLUSION: Measurement and maintenance of skeletal muscle can help prevent intradialytic hypotension in frail patients undergoing hemodialysis.

Characterization of Medication Trends for Chronic Kidney Disease: Mineral and Bone Disorder Treatment Using Electronic Health Record-Based Common Data Model.

Chronic kidney disease-mineral bone disorder (CKD-MBD) is the most common complication in CKD patients. Although there is a consensus on treatment guidelines for CKD-MBD, it remains uncertain whether these treatment recommendations reflect actual practice. Therefore, the aim of this study was to investigate the CKD-MBD medication trend in real-world practice. This was a retrospective and observational study using a 12-year period database transformed into a common data model from three tertiary university hospitals. Study populations were subjects initially diagnosed as CKD. The date of diagnosis was designated as the index date. New patients were categorized year to year from 2008 to 2019 with a fixed observation period of 365 days to check the prescription of CKD-MBD medications including calcium-containing phosphate binder, noncalcium-containing phosphate binder, aluminium hydroxide, vitamin D receptor activator (VDRA), and cinacalcet. The numbers of CKD patients in the three hospitals were 7555, 2424, and 5351, respectively. The proportion for patients with CKD-MBD medication prescription decreased yearly regardless of hospital and CKD stage (p for trend < 0.05). The use of aluminium hydroxide disappeared steadily while the use of VDRA increased annually in all settings. Despite these changes in prescription patterns, the mean value for CKD-MBD-related serologic markers was almost within target range. The proportion of the population within the target value was not significantly changed. Irrespective of hospital and CKD stage, similar trends of prescription for CKD-MBD medications were observed in real-world practice. Further research with a distributed network study may be helpful to understand medication trends in CKD-MBD treatment.

MAGEH1 interacts with GADD45G and induces renal tubular cell apoptosis.

BACKGROUND: Melanoma-associated antigen H1 (MAGEH1) is a protein that belongs to melanoma-associated antigen (MAGE) superfamily. Growth arrest and DNA damage 45G (GADD45G) is a member of the DNA damage-inducible gene family which responds to environmental stresses. We have previously shown that GADD45G is a protein that promotes apoptosis of renal tubular cells in response to a nephrotoxic injury. In this study, we show evidence that MAGEH1 interacts with GADD45G and is involved in the induction of nephrotoxin-induced apoptosis of renal tubular cells. METHODS: Primary human renal tubular epithelial (HRE) cells and human kidney 2 (HK-2) cells were used in this study. To produce stable cell lines in which MAGEH1 expression was silenced, HRE cells were transduced with a lentiviral vector encoding a single guide RNA construct targeting the MAGEH1 gene. To knockdown GADD45G expression in HRE cells, a vector containing short hairpin RNA (shRNA) was used. We used short interfering RNAs (siRNA) to achieve transient silencing of genes in HK-2 cells. Recombinant adenoviruses were synthesized to overexpress MAGEH1 and GADD45G proteins. Human protein microarray was used to identify proteins that binds to GADD45G. Co-immunoprecipitation assays were then performed to confirm microarray results. Cell death was induced by cyclosporine A (CsA). Real-time quantitative PCR assay was used to evaluate gene expression levels. The degree of apoptosis and necrosis of cultured cells was evaluated by flow cytometry. Expression levels of caspases were examined using western blot analysis. RESULTS: We found that GADD45G bound to one protein spotted in the protein microarray, which was subsequently identified as MAGEH1. We confirmed the interaction between GADD45G and MAGEH1 protein using the co-immunoprecipitation assay. MAGEH1 gene expression was not altered by CsA-induced cytotoxic injury, whereas GADD45G gene expression was increased significantly upon CsA treatment. MAGEH1 expression was significantly downregulated in GADD45G knockdown HRE stable cells suggesting that MAGEH1 expression may be dependent on GADD45G expression. CsA-induced apoptosis was significantly reduced in MAGEH1 knockdown HRE stable cells which led to an increased survival of these cells. Similar results were observed in GADD45G knockdown HRE stable cells. Accordingly, CsA-induced apoptosis was significantly decreased in MAGEH1 siRNA and GADD45G siRNA transfected HK-2 cells. CsA-induced activation of caspase-7 and caspase-9 was inhibited in MAGEH1 knockdown HRE stable cells, and similarly in GADD45G knockdown HRE stable cells. CONCLUSIONS: To the best of our knowledge, this is the first study to show that MAGEH1 interacts with GADD45G and that MAGEH1 is involved in caspase-dependent apoptosis of renal tubular cells induced by nephrotoxic drugs.

Preexisting comorbidities are associated with the mortality rate as well as the predialysis adverse events in incident dialysis patients.

BACKGROUND: Optimal estimated glomerular filtration rate (eGFR) to start maintenance dialysis is controversial. Observational studies have reported that initiation of dialysis at high eGFRs is associated with worse postdialysis survival. METHODS: We retrospectively investigated 1,038 incident dialysis patients who started maintenance dialysis during 2010-2015. Patients were assessed for comorbidities and adverse events during the transitional period of dialysis initiation. Patients were classified as planned dialysis (PD) vs. unplanned dialysis (UD) according to indications for dialysis initiation. RESULTS: UD group comprised 352 patients (33.9%). Mean eGFR at dialysis initiation was higher in UD patients than PD patients (7.9 ± 5.1 vs. 5.9 ± 3.4 mL/min/1.73 m2, p < 0.001). Mean Davies comorbidity index in the UD group was higher (vs. PD group, 1.3 ± 1.0 vs. 0.9 ± 1.0, p < 0.001). Patients with more comorbidities experienced more ischemic heart disease (hazard ratio [HR], 4.36; 95% confidence interval [CI], 1.71-11.14) in the medium-risk group and HR of 8.84 (95% CI, 3.06-25.55) in the high-risk group (vs. low-risk group, p < 0.001)) during the predialysis period. High-risk group had increased postdialysis mortality (HR, 2.48; 95% CI, 1.46-4.20; p = 0.001). Adjusted HR of mortality was higher in the medium-risk group of UD patients (HR, 1.72; 95% CI, 1.16-2.56; p = 0.007). CONCLUSION: Patients with more comorbidities were at increased risk of predialysis ischemic heart disease and postdialysis mortality. UD patients in the medium-risk population had increased risk of postdialysis mortality. Dialysis start should be individualized by considering comorbidities.

Trabecular bone score may indicate chronic kidney disease-mineral and bone disorder (CKD-MBD) phenotypes in hemodialysis patients: a prospective observational study.

BACKGROUND: In the general population, the trabecular bone score (TBS) represents the bone microarchitecture and predicts fracture risk independent of bone mineral density (BMD). A few studies reported that TBS is significantly reduced in dialysis patients. Chronic kidney disease-mineral and bone disorder (CKD-MBD) are accompanied by increased fracture risk, cardiovascular morbidity, and mortality. We investigated whether TBS is associated with comorbidity related to CKD-MBD or frailty in hemodialysis patients. METHODS: In this prospective observational study, TBS was obtained using the TBS iNsight software program (Med-Imaps) with BMD dual energy x-ray absorptiometry (DXA) images (L1-L4) from prevalent hemodialysis patients. A Tilburg frailty indicator was used to evaluate frailty, and hand grip strength and bio-impedance (InBody) were measured. A patient-generated subjective global assessment (PG-SGA) was used for nutritional assessment. The history of cardiovascular events (CVE) and demographic, clinical, laboratory, and biomarker data were collated. We then followed up patients for the occurrence of CKD-MBD related complications. RESULTS: We enrolled 57 patients in total. The mean age was 56.8 ± 15.9 years (50.9% female). Prevalence of Diabetes mellitus (DM) was 40.4% and CVE was 36.8%. Mean TBS was 1.44 ± 0.10. TBS significantly reduced in the CVE group (1.38 ± 0.08 vs. 1.48 ± 0.10, p <  0.001). Multivariable regression analysis was conducted adjusting for age, sex, dialysis vintage, DM, CVE, albumin, intact parathyroid hormone, fibroblast growth factor 23, handgrip strength, and phosphate binder dose. Age (ß = - 0.030; p = 0.001) and CVE (ß = - 0.055; p = 0.024) were significant predictors of TBS. During the follow up period after TBS measurements (about 20 months), four deaths, seven incident fractures, and six new onset CVE were recorded. Lower TBS was associated with mortality (p = 0.049) or new onset fracture (p = 0.007, by log-rank test). CONCLUSION: Lower TBS was independently associated with increased age and CVE prevalence in hemodialysis patients. Mortality and fracture incidence were significantly higher in patients with lower TBS values. These findings suggest that TBS may indicate a phenotype of frailty and also a CKD-MBD phenotype reciprocal to CVE.

Growth arrest and DNA damage 45γ is required for caspase-dependent renal tubular cell apoptosis.

BACKGROUND: Growth Arrest and DNA Damage 45γ (GADD45γ) is a member of the DNA damage-inducible gene family which responds to environmental stresses. Apoptosis is a critical mode of renal tubular cell death in nephrotoxin-induced acute kidney injury. In this study, we investigated the role of GADD45γ in renal tubular cell apoptosis induced by nephrotoxic drugs. METHODS: Primary human renal tubular epithelial (HRE) cells were used in this study. To derive stable cell lines in which GADD45γ expression was silenced, HRE cells were transduced with a plasmid encoding GADD45γ-specific shRNA. The recombinant adenovirus containing the GADD45γ gene was synthesized to overexpress GADD45γ protein. Cell death was induced by cisplatin and cyclosporine A (CsA). To prevent apoptotic cell death, pan-caspase inhibitor ZVAD-FMK was used. To prevent non-apoptotic cell death, necrostatin-1 and ferrostatin-1 were used. The degree of apoptosis and necrosis of cultured cells were evaluated by flow cytometry. RESULTS: Expression of the GADD45γ gene was significantly upregulated in response to treatment with CsA and cisplatin. Apoptosis and necrosis induced by these drugs were significantly reduced by silencing of GADD45γ, and significantly augmented by the overexpression of GADD45γ. The activation of caspase-3 and caspase-7 as well as caspase-9 induced by cisplatin or CsA was reduced by silencing of GADD45γ, and was augmented by the overexpression of GADD45γ, indicating that caspase activation is dependent on the expression of GADD45γ. ZVAD-FMK significantly inhibited apoptosis induced by cisplatin or CsA, indicating a role of caspases in mediating apoptotic cell death. ZVAD-FMK was effective to prevent necrosis as well, indicating that the observed necrosis was a secondary event following apoptosis at least in part. CONCLUSIONS: To our knowledge, this is the first study to show that GADD45γ is required for the caspase-dependent apoptosis of renal tubular cells induced by nephrotoxic drugs.

Efficacy and safety of CKD-11101 (darbepoetin-alfa proposed biosimilar) compared with NESP in anaemic chronic kidney disease patients not on dialysis.

OBJECTIVE: To evaluate the efficacy and safety of CKD-11101 (biosimilar darbepoetin-alfa, Chong Kun Dang Pharm.) compared with NESP® in treatment of anaemia in patients with chronic kidney disease not on dialysis. CLINICAL TRIAL REGISTRATION: NCT03431623. METHOD: In this multi-centre, randomized, double-blind study, patients were treated with CKD-11101 and NESP. The efficacy evaluation period (EEP) was 24 weeks, during which patients were treated every 2 weeks. All patients who completed the EEP were treated with CKD-11101 every 2 weeks for the first 4 weeks and every 4 weeks for the safety evaluation period (SEP), which was from 24 weeks to 52 weeks. The primary efficacy endpoint was the change in mean haemoglobin (Hb) level from baseline to end of EEP and mean dose needed to achieve the target Hb. RESULTS: The mean Hb level was increased in both groups during the EEP (both p < 0.001). The difference in mean Hb level change between the two groups was 0.01 g/dL (95% CI = -0.213-0.242), indicating that CKD-11101 was equivalent to NESP. The difference in mean administration dose between groups was -1.40 mcg (95% CI = -6.859-4.059) included in the equivalent range. The incidence of AEs and ADRs was not different between the two groups, and the frequency of ADRs was favourable in both groups (1.2% in CKD-11101 vs 7.7% in the NESP to CKD-11101 conversion group). CONCLUSION: CKD-11101 has an equivalent therapeutic effect as NESP in chronic kidney disease patients with renal anaemia. CKD-11101 can be safely used for long-term treatment and in patients converted from NESP.

Can we predict when to start renal replacement therapy in patients with chronic kidney disease using 6 months of clinical data?

PURPOSE: We aimed to develop a model of chronic kidney disease (CKD) progression for predicting the probability and time to progression from various CKD stages to renal replacement therapy (RRT), using 6 months of clinical data variables routinely measured at healthcare centers. METHODS: Data were derived from the electronic medical records of Ajou University Hospital, Suwon, South Korea from October 1997 to September 2012. We included patients who were diagnosed with CKD (estimated glomerular filtration rate [eGFR] < 60 mL·min-1·1.73 m-2 for ≥ 3 months) and followed up for at least 6 months. The study population was randomly divided into training and test sets. RESULTS: We identified 4,509 patients who met reasonable diagnostic criteria. Patients were randomly divided into 2 groups, and after excluding patients with missing data, the training and test sets included 1,625 and 1,618 patients, respectively. The integral mean was the most powerful explanatory (R2 = 0.404) variable among the 8 modified values. Ten variables (age, sex, diabetes mellitus[DM], polycystic kidney disease[PKD], serum albumin, serum hemoglobin, serum phosphorus, serum potassium, eGFR (calculated by Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), and urinary protein) were included in the final risk prediction model for CKD stage 3 (R2 = 0.330). Ten variables (age, sex, DM, GN, PKD, serum hemoglobin, serum blood urea nitrogen[BUN], serum calcium, eGFR(calculated by Modification of Diet in Renal Disease[MDRD]), and urinary protein) were included in the final risk prediction model for CKD stage 4 (R2 = 0.386). Four variables (serum hemoglobin, serum BUN, eGFR(calculated by MDRD) and urinary protein) were included in the final risk prediction model for CKD stage 5 (R2 = 0.321). CONCLUSION: We created a prediction model according to CKD stages by using integral means. Based on the results of the Brier score (BS) and Harrel's C statistics, we consider that our model has significant explanatory power to predict the probability and interval time to the initiation of RRT.

Comparison of creatinine index and geriatric nutritional risk index for nutritional evaluation of patients with hemodialysis.

INTRODUCTION: Malnutrition is prevalent in hemodialysis (HD) patients, and the risk of mortality is strongly correlated with malnutrition. Current methods of nutritional evaluation are mostly subjective, time-consuming, and cumbersome. Creatinine index (CI) and geriatric nutritional risk index (GNRI) are very simple and objective methods to assess the nutritional status of HD patients. The present study compares the performance of CI and GNRI as nutritional risk assessment tools. METHODS: Eighty-eight patients with end-stage renal disease on HD were recruited from a single tertiary center. A clinical dietitian carried out individual interviews of all patients and made nutritional diagnosis. Demographic and clinical data were also used to derive GNRI and CI over 4 months. FINDINGS: Thirty-eight out of 88 patients (44%) were diagnosed with normal nutritional status. Twenty-two patients (25%) were diagnosed with severe malnutrition and 27 (31%) had moderate malnutrition. Compared with patients with severe malnutrition, the normal group and those with moderate malnutrition showed significantly higher levels of body mass index and GNRI. Even though GNRI was associated with CI, protein intake, uric acid, and normalized protein nitrogen were not significantly correlated with GNRI, whereas the markers were highly associated with CI (P = 0.000). GNRI enable the identification of the severe malnutrition group but not the normal and moderate-malnutrition groups. However, based on CI, the normal group was distinguished while those with severe and moderate malnutrition were not. DISCUSSION: Either CI or GNRI was a valid tool for longitudinal observation of nutritional status of patients on chronic HD and facilitated the screening of cases with malnutrition. Compared with GNRI, CI ranked higher in performance for the assessment and monitoring of nutritional status in HD patients.

Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial.

BACKGROUND: For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. METHODS: We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48) or a control group (n = 22). We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. RESULTS: The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0%) patients achieved the primary goal, as compared with 16 (72.7%) in the control group (P = 0.430). The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087), but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851). However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193). The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363) nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569). CONCLUSION: Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy.

Clinical analysis of single filtration plasmapheresis using continuous renal replacement therapy machines in kidney transplantation.

BACKGROUND: Plasmapheresis has become an essential element of kidney transplantation (KT). In the present study, we report clinical outcomes of filtration plasmapheresis using continuous renal replacement therapy machines with a single filter for the first time in Korea. METHODS: We retrospectively analyzed six patients who underwent filtration plasmapheresis for KT in our center; plasmapheresis was performed using the Plasmaflex (Baxter®) with a TPE 2000 filter set (Baxter®) in our hemodialysis unit. Five percent albumin was used as the replacement fluid, and intravenous immunoglobulin G was administered after each plasmapheresis session. The target preoperative ABO isoagglutinin titer was less than 1:8. RESULTS: Filtration plasmapheresis was performed in four patients for ABO-incompatible KT, one for antibody-mediated rejection after KT, and the last one for positive T cell crossmatch. Altogether, 46 sessions of plasmapheresis were performed. ABO isoagglutinin titers successfully declined to or below the target level in all patients, and all patients successfully received KT with no significant antibody titer rebound. Acute antibody-mediated rejection and positive T cell crossmatch were well treated with filtration plasmapheresis, and no patient required fresh frozen plasma infusion for coagulopathy. There were one episode of hypotension and three of hypocalcemia. No patients experienced bleeding, infection, or allergic reaction. CONCLUSION: Filtration plasmapheresis was effective and safe. Although our result is from a single center, our protocol appears to be promising.

Tumor necrosis factor α is a risk factor for infection in peritoneal dialysis patients.

BACKGROUND/AIMS: It has been shown that circulating tumor necrosis factor α (TNF-α) is elevated in end stage renal disease patients; however, the relationship between TNF-α and the development of infection in these patients is unknown. In this study, we investigated the association of plasma TNF-α and interleukin 6 (IL-6) with infection in peritoneal dialysis (PD) patients. We also evaluated the association of their plasma levels with the production by peripheral blood mononuclear cells (PBMC), and with various clinical parameters. METHODS: We enrolled 32 patients on maintenance PD and 10 healthy controls. Plasma and PBMC were isolated from blood. PBMC were stimulated with lipopolysaccharide in vitro. RESULTS: Mean follow-up duration was 775 days. Six patients developed organ infections (five pneumonia and one liver abscess), and six patients developed PD peritonitis and eight developed exit site infection. Plasma TNF-α and IL-6 levels were significantly elevated in organ infections but not in peritonitis or in exit site infection. Plasma TNF-α was the only significant risk factor for organ infections and pneumonia in multivariate regression analysis. Patients with high plasma TNF-α levels showed a significantly greater cumulative hazard rate for organ infections compared to those with low TNF-α levels. Plasma TNF-α levels correlated with TNF-α production by PBMC and showed an inverse association with Kt/V. CONCLUSIONS: This is the first study showing that plasma TNF-α is a significant risk factor for infection in PD patients.

Comparison of estimated glomerular filtration rate equations at the time of hemodialysis initiation.

BACKGROUND: Estimated glomerular filtration rate (eGFR) is one of the most important guidelines in deciding the optimal timing of dialysis initiation. In the present study, we calculated the eGFR at the time of hemodialysis (HD) initiation using 5 commonly used equations to relate them with clinical and laboratory characteristics of the patients and to evaluate which of these equations best define the eGFR at HD initiation. METHODS: We retrospectively analyzed 409 end-stage renal disease patients who were newly started on HD treatment in our institution. The eGFR was calculated using the Cockcroft-Gault equation, the Cockcroft-Gault equation corrected for body surface area, the Modification of Diet in Renal Disease (MDRD) equation, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, and the Nankivell equation. RESULTS: The mean eGFRs at HD start were significantly different across the equations. The mean eGFR was 7.8 mL/min for the corrected Cockcroft-Gault equation, 7.7 mL/min for the Cockcroft-Gault equation, 6.2 mL/min/1.73 m(2) for the MDRD equation, and 5.6 mL/min/1.73 m(2) for the CKD-EPI equation. The corrected Cockcroft-Gault, the MDRD, and the CKD-EPI equations were well correlated with all CKD-specific complications including hypertension, anemia, hyperkalemia, metabolic acidosis, hypocalcemia, hyperphosphatemia, and hyperparathyroidism. The mean eGFR calculated by the corrected Cockcroft-Gault equation showed the lowest coefficient of variation among all the equations. CONCLUSIONS: The eGFR at HD initiation are significantly different according to the used eGFR equations, and the corrected Cockcroft-Gault equation may be the best in defining the eGFR at HD initiation.

Severe but reversible acute kidney injury resulting from Amanita punctata poisoning.

Mushroom-related poisoning can cause acute kidney injury. Here we report a case of acute kidney injury after ingestion of Amanita punctata, which is considered an edible mushroom. Gastrointestinal symptoms occurred within 24 hours from the mushroom intake and were followed by an asymptomatic period, acute kidney injury, and elevation of liver and pancreatic enzymes. Kidney function recovered with supportive care. Nephrotoxic mushroom poisoning should be considered as a cause of acute kidney injury.

Comparison of hyperkalemic risk in hospitalized patients treated with different angiotensin receptor blockers: a retrospective cohort study using a Korean clinical research database.

BACKGROUND AND AIM: Clinical use of angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) is associated with hyperkalemia as an adverse drug reaction. Although it has significant clinical implications, the incidence and relative risks of hyperkalemia with various ARBs have not yet been fully evaluated. The purpose of this study was to determine the risk of hyperkalemic events in hospitalized patients treated with different ARBs and to compare the risk among them. METHODS: We constructed a retrospective cohort composed of hospitalized adult patients who took ARBs in a single tertiary teaching hospital between April 2004 and March 2010. We estimated the incidence of hyperkalemia (serum potassium level >5.5 mEq/L) with various ARBs, and then compared the risk between them using a multivariate Cox proportional hazard model based on age, sex, Charlson co-morbidity score, baseline serum potassium, underlying diseases, and concomitant drugs. RESULTS: We identified 6992 evaluable intervals from 5449 patients treated with one of the seven ARBs during hospitalization over the 71-month study period with 2521.6 patient-months. We found 381 hyperkalemic events (5.4%) during the study period and an overall event rate of 15.1/100 patient-months. Moderate to fatal hyperkalemia was relatively rare (>6.0 mEq/L, 2.1% [moderate]; >6.5 mEq/L, 0.9% [severe]; >7.0 mEq/L, 0.3% [fatal]). After adjustment for covariates, telmisartan showed a lower risk of hyperkalemia (hazard ratio 0.67; 95% confidence interval 0.51, 0.89) compared with all other ARBs. CONCLUSION: The risk of hyperkalemic events in hospitalized patients treated with different ARBs was defined. Telmisartan showed a relatively lower hyperkalemic risk profile in hospitalized patients compared with other ARBs.

GADD45γ regulates TNF-α and IL-6 synthesis in THP-1 cells.

OBJECTIVE AND DESIGN: This study investigated the link between growth arrest and DNA damage 45γ (GADD45γ) expression and tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) synthesis. METHODS: We stimulated THP-1 monocyte cells using lipopolysaccharide (LPS). We knocked-down and over-expressed GADD45γ using lentiviral vectors harboring GADD45γ short hairpin RNA and GADD45γ open reading frame, respectively. To inhibit activation of c-Jun-terminal kinase (JNK), we used a specific inhibitor, SP600125. RESULTS: LPS stimulation of THP-1 cells resulted in increased expression of GADD45γ mRNA which reached its peak 2 h after stimulation and gradually diminished thereafter. TNF-α and IL-6 were up-regulated at both the mRNA and protein levels in activated THP-1 cells. Knock-down of GADD45γ reduced TNF-α protein production by up to 75 % and IL-6 protein by up to 60 %. In contrast, over-expression of GADD45γ increased TNF-α production by six-fold and IL-6 protein by 80-fold. There was a discrepancy between TNF-α mRNA and its protein level, whereas IL-6 mRNA and its protein level were correlated. Knock-down of GADD45γ decreased the JNK activity, suggesting that JNK may play the role of a downstream mediator for the pro-inflammatory effects of GADD45γ. CONCLUSIONS: We show evidence that GADD45γ may regulate TNF-α and IL-6 expression in activated THP-1 monocyte cells.

Improved gastrointestinal symptoms and quality of life after conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in renal transplant patients receiving tacrolimus.

It is reported that a conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) relieves gastrointestinal (GI) symptom burden and improves health-related quality of life (HRQoL). However, it is unclear whether renal transplant recipients using tacrolimus receive the same benefit from the conversion. In this prospective, multi-center, open-label trial, patients were categorized into two groups by their GI symptom screening. Equimolar EC-MPS (n=175) was prescribed for patients with GI burdens; those with no complaints remained on MMF (n=83). Gastrointestinal Symptom Rating Scale (GSRS) and Gastrointestinal Quality of Life Index (GIQLI) were evaluated at baseline and after one month. Patients and physicians completed Overall Treatment Effect (OTE) at one month. EC-MPS-converted patients had worse GSRS and GIQLI scores at baseline than MMF-continued patients (all P<0.001). Significant improvements in GSRS and GIQLI scores were observed for EC-MPS-converted patients at one month, but MMF-continued patients showed worsened GSRS scores (all P<0.05). OTE scale indicated that EC-MPS patients improved in overall GI symptoms and HRQoL more than MMF patients did (P<0.001). In tacrolimus-treated renal transplant recipients with GI burdens, a conversion from MMF to EC-MPS improves GI-related symptoms and HRQoL.