Key pathological features characterize minimal change disease-like IgA nephropathy.

AIMS: A subset of IgA nephropathy (IgAN) patients exhibiting minimal change disease (MCD) like features present with nephrotic-range proteinuria and warrants immunosuppressive therapy (IST). However, the diagnosis of MCD-like IgAN varied by reports. We aimed to identify the key pathological features of MCD-like IgAN. METHODS: In this cohort, 228 patients had biopsy-proven IgAN from 2009 to 2021, of which 44 without segmental sclerosis were enrolled. Patients were classified into segmental (< 50% glomerular capillary loop involvement) or global (> 50%) foot process effacement (FPE) groups. We further stratified them according to the usage of immunosuppressant therapy after biopsy. Clinical manifestations, treatment response, and renal outcome were compared. RESULTS: 26 cases (59.1%) were classified as segmental FPE group and 18 cases (40.9%) as global FPE group. The global FPE group had more severe proteinuria (11.48 [2.60, 15.29] vs. 0.97 [0.14, 1.67] g/g, p = 0.001) and had a higher proportion of complete remission (81.8% vs. 20%, p = 0.018). In the global FPE group, patients without IST experienced more rapid downward eGFR change than the IST-treated population (-0.38 [-1.24, 0.06] vs. 1.26 [-0.17, 3.20]mL/min/1.73 m2/month, p = 0.004). CONCLUSIONS: The absence of segmental sclerosis and the presence of global FPE are valuable pathological features that assist in identifying MCD-like IgAN.

Pentraxin 3 Predicts Arteriovenous Fistula Functional Patency Loss and Mortality in Chronic Hemodialysis Patients.

INTRODUCTION: Viable vascular access is the lifeline for hemodialysis patients. In the nondialysis population, emerging evidence suggests that circulating pentraxin 3 (PTX3), neutrophil gelatinase-associated lipocalin (NGAL), and chitinase-3-like protein 1 (CHI3L1) are associated with cardiovascular inflammation and endothelial injury. However, predictive values of these three biomarkers on arteriovenous fistula (AVF) outcomes are unknown. METHODS: This prospective observational cohort study enrolled 135 hemodialysis patients using AVF and then followed them for 3 years. Plasma levels of PTX3, NGAL, and CHI3L1 were measured. Patients were followed up prospectively for two clinical outcomes, including AVF functional patency loss and death. Cox proportional hazards regression models were used to analyze hazard ratios for the commencement of AVF functional patency loss and mortality. RESULTS: Among 135 patients, the mean age was 66.0 ± 15.7 years old and 48.1% were male. The plasma level of PTX3, NGAL, and CHI3L1 was 2.8 ± 2.3 ng/mL, 349.2 ± 111.4 ng/mL, and 185.5 ± 66.8 ng/mL, respectively. During a 3-year follow-up period, the plasma level of PTX3 was an independent predictor for AVF functional patency loss (per 1 ng/mL increase, HR 1.112 [95% CI: 1.001-1.235], p = 0.048). Besides, patients with higher plasma levels of PTX3 were more likely to suffer from cardiovascular mortality (per 1 ng/mL increase, HR 1.320 [95% CI: 1.023-1.703], p = 0.033), infectious mortality (per 1 ng/mL increase, HR 1.394 [95% CI: 1.099-1.769], p = 0.006), and all-cause mortality (per 1 ng/mL increase, HR 1.233 [95% CI: 1.031-1.476], p = 0.022). CONCLUSIONS: The plasma level of PTX3, not NGAL or CHI3L1, was associated with higher risks of AVF functional patency loss in chronic hemodialysis patients, showing its value in reflecting AVF endothelial dysfunction. Furthermore, PTX3 also predicts mortality in chronic hemodialysis patients.

Prediction of the development of acute kidney injury following cardiac surgery by machine learning.

BACKGROUND: Cardiac surgery-associated acute kidney injury (CSA-AKI) is a major complication that results in increased morbidity and mortality after cardiac surgery. Most established prediction models are limited to the analysis of nonlinear relationships and fail to fully consider intraoperative variables, which represent the acute response to surgery. Therefore, this study utilized an artificial intelligence-based machine learning approach thorough perioperative data-driven learning to predict CSA-AKI. METHODS: A total of 671 patients undergoing cardiac surgery from August 2016 to August 2018 were enrolled. AKI following cardiac surgery was defined according to criteria from Kidney Disease: Improving Global Outcomes (KDIGO). The variables used for analysis included demographic characteristics, clinical condition, preoperative biochemistry data, preoperative medication, and intraoperative variables such as time-series hemodynamic changes. The machine learning methods used included logistic regression, support vector machine (SVM), random forest (RF), extreme gradient boosting (XGboost), and ensemble (RF + XGboost). The performance of these models was evaluated using the area under the receiver operating characteristic curve (AUC). We also utilized SHapley Additive exPlanation (SHAP) values to explain the prediction model. RESULTS: Development of CSA-AKI was noted in 163 patients (24.3%) during the first postoperative week. Regarding the efficacy of the single model that most accurately predicted the outcome, RF exhibited the greatest AUC (0.839, 95% confidence interval [CI] 0.772-0.898), whereas the AUC (0.843, 95% CI 0.778-0.899) of ensemble model (RF + XGboost) was even greater than that of the RF model alone. The top 3 most influential features in the RF importance matrix plot were intraoperative urine output, units of packed red blood cells (pRBCs) transfused during surgery, and preoperative hemoglobin level. The SHAP summary plot was used to illustrate the positive or negative effects of the top 20 features attributed to the RF. We also used the SHAP dependence plot to explain how a single feature affects the output of the RF prediction model. CONCLUSIONS: In this study, machine learning methods were successfully established to predict CSA-AKI, which determines risks following cardiac surgery, enabling the optimization of postoperative treatment strategies to minimize the postoperative complications following cardiac surgeries.

Long-term Outcomes of Parathyroidectomy in Kidney Transplant Recipients with Persistent Hyperparathyroidism.

BACKGROUND/AIMS: Hyperparathyroidism (HPT) is a common complication of chronic kidney disease and contributes to hypertension and cardiovascular risks. Successful kidney transplantation corrects abnormal mineral metabolism, but persistent HPT is still observed in up to 25% of patients one year after transplantation despite renal function improvement. The purpose of this study was to examine the long-term effects of parathyroidectomy (PTX) on blood pressure (BP) and graft function in patients with persistent post-transplant HPT. METHODS: This is a retrospective study of renal allograft recipients at a single institute. Records from all the patients who received kidney transplantation at the Taipei Veterans General Hospital between 2004 and 2012 were reviewed and enrolled 19 patients who underwent PTX for persistent post-transplant HPT. Preoperative and postoperative clinical and biochemical data were compared. Matched controls (n = 19) in the corresponding time span were enrolled for graft function comparisons. RESULTS: The mean systolic BP (127.7 ± 14.3 to 119.5 ± 12.7 mmHg, p = 0.028, 1 year after PTX; 127.7 ± 14.3 to 117 ± 12.4 mmHg, p = 0.007, 2 years after PTX) and pulse pressure (PP) (51.3 ± 10.7 to 44.3 ± 11.6, p = 0.019 1 year after PTX; 51.3 ± 10.7 to 44.9 ± 12.5 mmHg, p = 0.028, 2 years after PTX) reduced significantly at 1 year and 2 years of follow-up. However, no significant change of diastolic BP was observed. The improvement of SBP, DBP and PP was not correlated with the reduction of serum calcium level 1 year after PTX. The estimated glomerular filtration rate decreased significantly from 74.0 ± 20.5 mL/min/1.73m(2) preoperatively to 68.2 ± 24.8 mL/min/1.73 m(2) 12 months after PTX but recovered at 15 months and lasted to 2 years after PTX. The all-cause hospitalization rate 1 year after PTX tended to be higher than that 1 year before PTX (105.3 versus 47.4 per 100 patient-years; RR, 2.22; 95 % CI: 0.97-5.54), but there was no significant difference between them. CONCLUSIONS: Our study demonstrated systolic BP and PP reduced 2 years after PTX and there was no significant difference between the peri-operative all-cause hospitalization rates. In addition, kidney allograft function impaired temporarily 12 months after PTX, but recovered 15 months after PTX.