Rationale & ObjectiveIn 2021, the new Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) updated the creatinine-based estimated glomerular filtration rate (eGFR) equation and removed the coefficient for race. The development and validation of this equation involved binarizing race into Black and non-Black, involving few Asian participants. This study aimed to examine the difference between the 2021 equation and the previous 2009 equation on CKD prevalence estimates in two Asian populations. Study DesignObservational study utilizing two national surveys. Setting & ParticipantsParticipants from the 2019 Korea National Health and Nutrition Survey and participants self-reported as Asian from the 2011-2020 United States (US) National Health and Nutrition Survey. ExposureeGFR using 2009 and 2021 CKD-EPI creatinine equation. OutcomesPrevalence of CKD (eGFR <60 mL/min/1.73 m2 or urine albumin-to-creatinine ratio [UACR] ≥30 mg/g) Analytical ApproachSampling-weighted prevalence estimated by the 2009 and 2021 equations as well as the percentage individuals with CKD G3+ by the 2009 equation being reclassified as not having CKD G3+ by the 2021 equation. ResultsThe prevalence of CKD estimated by the 2021 equation was 9.75% (95% confidence interval [CI] 8.80–10.80%) in Koreans and 11.60% (95% CI 10.23–13.13%) in US Asians. The prevalence of CKD estimated by the 2021 equation was slightly lower compared that by the 2009 equation in both Korean and US Asian populations, by 0.63% (95% CI 0.44–0.90%) and 0.84% (95% CI 0.52–1.34%), respectively. Further, 32.8% and 30.2% of Koreans and US Asians with CKD G3-5, respectively, by the 2009 equation were reclassified as not having CKD G3-5 when the eGFR was calculated by the 2021 equation. LimitationsMeasured GFR was not available. ConclusionsThe 2021 CKD-EPI creatinine equation led to a small decrease in CKD prevalence in both Korean and US Asian populations, and of similar magnitude, resulting in significant reclassification among those originally classified as having CKD G3+.

Rationale & ObjectiveThis study aims to compare the efficacy of a cannabis cream and a placebo in the treatment of chronic kidney disease (CKD)-associated pruritus. Study DesignA double-blind randomized controlled study. Setting & ParticipantsSixty hemodialysis patients with the Worst Itching Intensity Numerical Rating Scale (WI-NRS) ≥ 3. ExposurePatients received cannabis cream or placebo. OutcomesThe primary endpoint was the WI-NRS score at week 4. The secondary endpoints included the WI-NRS at week 2, Skindex-10 score at week 2 and 4, and the mean difference score between baseline and week 4 for WI-NRS and the Skindex-10 score Analytical ApproachWe utilized unpaired t-tests or Mann–Whitney U tests, along with Chi-square or Fisher’s exact tests as appropriate. Adjusted mean differences were determined using ANCOVA, adjusting for baseline scores. ResultsAmong 60 participants, mean age was 61.6 ± 14.4 years and mean baseline WI-NRS was 6.7 ± 1.7. The placebo and cannabis cream groups were similar at baseline, although more individuals in the placebo group had diabetes. At 4 weeks, the WI-NRS dropped to 2.6 in the cannabis group and 3.6 in the placebo group (mean difference after adjustment for baseline scores:-1.1, 95% CI: -2.1 to -0.2, p = 0.02). Skindex-10 scores at week 4 were also lower in the cannabis group, but after adjustment for baseline scores, statistical significance was not maintained. No side effects were observed in either group. LimitationsA single study with a small sample size restricts its generalizability. Variances in participants' diabetes statuses might have impacted itch outcomes. The absence of cannabinoid level assessment in blood prevents conclusive determination of potential systemic impacts. A four-week follow-up period inadequately captures long-term effect. ConclusionsIn CKD-associated pruritus, the topical cream containing cannabis significantly reduced the severity of itching symptoms compared to the placebo.

Rationale & ObjectiveDiabetic Kidney Disease (DKD) is a significant complication of diabetes mellitus, often leading to kidney failure. The absence of well-defined factors prevents distinguishing DKD from Non-Diabetic Kidney Disease (non-DKD; alternative primary diagnosis identified on kidney biopsy). Study DesignRetrospective cohort study. Setting& Participants: 1,242 patients with a history of diabetes from the Cleveland Clinic Kidney Biopsy Epidemiology Project between January 2015 and September 2021. ExposureProteinuria, retinopathy, A1c and eGFR. OutcomesNon-DKD, defined as an alternative primary diagnosis identified on kidney biopsy other than DKD. Analytical ApproachMultivariate logistic regression model with backward elimination method. ResultsAt the time of biopsy, the median (IQR) age was 63 (53-71) years, 58.8% were male, hemoglobin A1c was 6.7% (6.0-8.1), and serum creatinine was 2.5 (1.6-3.9) mg/dL. Among 1,242 patients, 462 (37.2%) had DKD alone, and 780 (62.8%) had non-DKD. Among those with non-DKD, the most common diagnoses were focal segmental glomerulosclerosis (24%), global glomerulosclerosis NOS (13%), acute tubular necrosis (9%), IgA nephropathy (8%), ANCA vasculitis (7%), and membranous nephropathy (5%). Factors associated with having non-DKD on biopsy were having no retinopathy (vs retinopathy) (adjusted odds ratio [aOR], 3.98; 95% CI, 2.69-5.90), lower A1c (<7% vs. ≥7%) (aOR, 3.08; 95%CI, 2.16-4.39), higher eGFR (≥60 vs. <60 ml/min/1.73m2) (aOR, 2.39; 95%CI 1.28-4.45), microalbuminuria (<300 vs. macroalbuminuria ≥300 [mg/g]) (aOR; 2.94; 95%CI, 1.84-4.72), and lower protein to creatinine ratio in random urine (<3 vs. ≥3mg/mg) (aOR; 1.80; 95%CI, 1.24-2.61). LimitationsSelection bias of clinically indicated biopsies, not protocol biopsies, which likely represent a ceiling (maximum) for non-DKD. ConclusionsAmong diabetic patients undergoing kidney biopsy, 63% have findings in addition to DKD on biopsy. We identified clinical parameters associated with non-DKD in the setting of diabetes. This provides valuable information for clinicians when kidney biopsy should be considered among diabetic patients to capture all etiologies of proteinuria and kidney dysfunction.

Rationale & ObjectivePostpartum renal cortical necrosis (postpartum RCN) is a severe form of obstetric acute kidney injury. This study aimed to identify clinicopathological features in Chinese postpartum RCN cases to determine how pathologic findings may contribute to the treatment and prognosis. Study DesignSingle-center, case series Setting & ParticipantsTwelve patients with postpartum RCN had kidney biopsies at Peking University First Hospital between 2014 and 2021. The diagnosis of postpartum RCN was made according to typical MRI or pathological features. Clinical, laboratory and pathological data were compared between patients with eGFR <30 (poor outcome) and ≥30 ml/min/1.73 m2 after six months. ObservationsAll postpartum RCN patients presented with stage 3 AKI attributed to a probable atypical hemolytic uremic syndrome. Pregnancy terminations occurred at a median gestational age of 35.5 weeks. Kidney biopsy was performed ranging 18 days to 4 months from delivery. Upon biopsy, hemoglobin, platelet count and LDH levels had been restored to 137 g/L, 214 ×109/L and 231.50±65.01 U/L, respectively. Four patients exhibited poor outcome, demonstrating higher schistocyte count, serum creatinine and mean arterial pressure at onset. Pathologically, glomerular segmental sclerosis was prevalent. The NOS variant was the most common type, followed by collapsing variant, cellular variant, and tip variant. Patients with poor kidney outcome had more glomerular coagulative necrosis, capillary thrombosis, extensive cortical coagulative necrosis, and pronounced arteriole/artery lesions including increased interlobular arteriole intimal edema and fibrin thrombosis, but a lower occurrence of segmental sclerosis. LimitationsLimited sample size and retrospective design. ConclusionsOur research has identified key pathological features in postpartum RCN patients with aHUS, highlighting the necessity for more effective therapeutic options. There is a clear demand for non-invasive biomarkers that can accurately track disease progression and inform treatment duration for long-term outcomes improvement.

Rationale & ObjectiveAllopurinol and febuxostat, which are xanthine oxidoreductase inhibitors, have been widely used as uric acid-lowering medications. However, evidence regarding their cardiovascular effects in hemodialysis is insufficient. This study compared the effects of allopurinol and febuxostat on mortality and cardiovascular outcomes in patients receiving hemodialysis. Study DesignRetrospective observational cohort study. Setting & ParticipantsData of 6,791 patients who had no history of topiroxostat usage and underwent maintenance hemodialysis between March 2016 and March 2019 at Yokohama Daiichi Hospital, Zenjinkai, and its affiliated dialysis clinics in Japan’s Kanagawa and Tokyo metropolitan areas were collected. ExposureAllopurinol, febuxostat, and non-treatment. OutcomesAll-cause mortality, cardiovascular disease (CVD) events, heart failure (HF), acute myocardial infarction (AMI), and stroke. Analytical ApproachFor the main analyses, marginal structural Cox proportional hazards models were used to estimate hazard ratios (HRs) adjusted for time-varying confounding and selection bias due to censoring. ResultsAllopurinol and febuxostat showed significantly better survival than non-treatment for all-cause mortality (HR: 0.40, 95% confidence interval [CI]: 0.30–0.54; HR: 0.49, 95% CI: 0.38–0.63, respectively), without significant difference between allopurinol and febuxostat. Allopurinol showed significantly better survival than non-treatment, whereas febuxostat did not for CVD events (HR: 0.89, 95% CI: 0.84–0.95; HR: 1.01, 95% CI: 0.96–1.07, respectively), HF (HR: 0.71, 95% CI: 0.56–0.90; HR: 1.03, 95% CI: 0.87–1.21, respectively), and AMI (HR: 0.48, 95% CI: 0.25–0.91; HR: 0.76, 95% CI: 0.49–1.19, respectively). No comparisons showed significant results for stroke. LimitationsThe ratio of renal or intestinal excretion of uric acid and uremic toxins could not be elucidated, and we could not investigate gene polymorphism because of the large number of cases. ConclusionsAllopurinol and febuxostat improved survival for all-cause mortality. Allopurinol, and not febuxostat, reduced the risk of CVD events, HF, and AMI.

Immunosuppressive therapy after kidney transplantation is associated with an increased risk for the development of opportunistic infections, such as pneumocystic jirovecii pneumonia. Belatacept, a selective costimulatory blocker that prevents T cell activation, was previously suggested as a potential risk factor for PJP development in kidney transplant recipients. Here we present two cases of kidney transplant patients with PJP whose diagnosis came unexpectedly to light during a diagnostic work-up for fever of unknown origin. Both patients lacked typical clinical findings such as hypoxia, ground-glass pattern on computed tomography or suggestive biochemical alterations such as high lactate dehydrogenase (LDH) levels or hypercalcemia. PJP should therefore be in the differential diagnosis when evaluating fever in kidney transplant recipients receiving belatacept, even in the absence of typical pulmonary and laboratory findings.

Paraneoplastic cast nephropathy, a rare cause of acute kidney injury, is most commonly observed in cases of multiple myeloma, and is characterized by the formation of intratubular casts composed of monoclonal light chains. Non-monoclonal paraneoplastic cast nephropathy has also been reported in patients with pancreatic acinar cell carcinoma or prolactinoma. In this case report, we present a case of polyclonal cast nephropathy in a patient with metastatic acinar cell carcinoma. We aim to emphasize the significance of recognizing this uncommon complication in patients with solid tumors and to discuss the diagnostic challenges and potential pathophysiology of this unique condition.

People with Sickle cell disease experience a high incidence of chronic kidney disease and end stage kidney disease secondary to tubular and glomerular effect of vaso-occlusion-induced hypoxia. Due to concerns of sub-optimal kidney function sickle cell donors are usually not considered for kidney donation even if rest of the parameters are acceptable for organ donation. A significant gap exists between the number of organ donors and number of candidates waiting for a kidney transplant in the United States. In order to bridge the gap, we need to consider using nontraditional donors.We report kidney transplant outcomes in six recipients from four sickle cell kidney donors. Intracranial hemorrhage and sepsis were the causes of the death in donors, no donor was in sickle cell crisis at the time of donation. None of the recipients experienced delayed graft function and all recipients achieved excellent allograft function. The earliest allograft failure was at twenty-seven months in a recipient who developed early acute rejection, while the longest follow-up was ten years with adequate kidney function. In conclusion, given the shortage of kidneys for transplantation and demonstrated good outcomes, we propose that kidneys from sickle-cell donors can be safely used.