Purpose: Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction. Materials and Methods: This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images. Results: Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012). Conclusion While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.

Purpose: Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction. Materials and Methods: This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images. Results: Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012). Conclusion While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.

Purpose: Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction. Materials and Methods: This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images. Results: Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012). Conclusion While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.

Sodium glucose cotransporter 2 (SGLT2) inhibitors were initially developed to enhance glycemic control in diabetic patients, but they have emerged as a promising treatment for individuals with chronic kidney disease (CKD) regardless of diabetic status. A collaborative meta-analysis of large-scale SGLT2 inhibitor trials has provided compelling evidence supporting recommendations for the use of these agents in CKD patients, regardless of their primary kidney disease diagnosis or whether they have diabetes. Notably, the kidney-protective benefits of SGLT2 inhibitors have been observed across various stages of CKD, including advanced stage 4 CKD, and across all levels of albuminuria. Given the robust evidence highlighting the benefits of SGLT2 inhibitors across a broad spectrum of CKD patients, these agents should be considered foundational therapy for CKD, in order to mitigate the progression to kidney failure and its associated complications. Although the beneficial effects of SGLT2 inhibitors may not be immediately apparent, they are expected to grow over time, potentially altering the prognosis for numerous CKD patients.

Acute kidney injury (AKI) is characterized by an abrupt decline of excretory kidney function. The incidence of AKI has increased in the past decades. Patients diagnosed with AKI often undergo diverse clinical trajectories, such as early or late recovery, relapses, and even a potential transition from AKI to chronic kidney disease (CKD). Although recent clinical studies have demonstrated a strong association between AKI and progression of CKD, our understanding of the complex relationship between AKI and CKD is still evolving. No cohort study has succeeded in painting a comprehensive picture of these multi-faceted pathways. To address this lack of understanding, the idea of acute kidney disease (AKD) has recently been proposed. This presents a new perspective to pinpoint a period of heightened vulnerability following AKI, during which a patient could witness a substantial decline in glomerular filtration rate, ultimately leading to CKD transition. Although AKI is included in a range of kidney conditions collectively known as AKD, spanning from mild and self-limiting to severe and persistent, AKD can also occur without a rapid onset usually seen in AKI, such as when kidney dysfunction slowly evolves. In the present review, we summarize the most recent findings about AKD, explore the current state of biomarker discovery related to AKD, discuss the latest insights into pathophysiological underpinnings of AKI to CKD transition, and reflect on therapeutic challenges and opportunities that lie ahead.

When sodium-glucose cotransporter-2 (SGLT2) inhibitors were first introduced a decade ago, no one expected them to have substantial effects beyond their known glucose-lowering effects, until the emergence of evidence of their robust renal and cardiovascular benefits showing that they could attenuate progression of kidney disease, irrespective of diabetes, as well as prevent the development of acute kidney injury. Still, the precise and elaborate mechanisms underlying the major organ protection of SGLT2 inhibitors remain unclear. SGLT2 inhibitors inhibit the reabsorption of sodium and glucose in the proximal tubule of the kidney and then recovers tubuloglomerular feedback, whereby SGLT2 inhibitors reduce glomerular hyperfiltration. This simple demonstration of their beneficial effects has perplexed experts in seeking more plausible and as yet undisclosed explanations for the whole effects of SGLT2 inhibitors, including metabolism reprogramming and the modulation of hypoxia, inflammation, and oxidative stress. Given that the renal benefits of SGLT2 inhibitors in patients with kidney disease but without diabetes were comparable to those seen in patients with diabetes, it may be reasonable to keep the emphasis on their hemodynamic actions. In this context, the aim of the present review is to provide a comprehensive overview of renal hemodynamics in individuals with diabetes who are treated with SGLT2 inhibitors, with a focus on natriuresis associated with the regulation of tubuloglomerular feedback and potential aquaresis. Throughout the discussion of alterations in renal sodium and water transports, particular attention will be given to the potential enhancement of adenosine and its receptors following SGLT2 inhibition.

Evidence of the ethical appropriateness and clinical benefits of shared decision-making (SDM) are accumulating. This study aimed to not only identify physicians’ perspectives on SDM, and practices related to end-of-life care in particular, but also to gauge the effect of SDM education on physicians in Korea. Methods: A 14-item questionnaire survey using a modified Delphi process was delivered to nephrologists and internal medicine trainees at 17 university hospitals. Results: A total of 309 physicians completed the survey. Although respondents reported that 69.9% of their practical decisions were made using SDM, 59.9% reported that it is not being applied appropriately. Only 12.3% of respondents had received education on SDM as part of their training. The main obstacles to appropriate SDM were identified as lack of time (46.0%), educational materials and tools (29.4%), and education on SDM (24.3%). Although only a few respondents had received training on SDM, the proportion of those who thought they were using SDM appropriately in actual practice was high; the proportion of those who chose lack of time and education as factors that hindered the proper application of SDM was low. Conclusion: The majority of respondents believed that SDM was not being implemented properly in Korea, despite its use in actual practice. To improve the effectiveness of SDM in the Korean medical system, appropriate training programs and supplemental policies that guarantee sufficient application time are required.

Urate is produced in the liver by the degradation of purines from the diet and nucleotide turnover and excreted by the kidney and gut. The kidney is the major route of urate removal and has a pivotal role in the regulation of urate homeostasis. Approximately 10% of the glomerular filtered urate is excreted in the urine, and the remainder is reabsorbed by the proximal tubule. However, the transport of urate in the proximal tubule is bidirectional: reabsorption and secretion. Thus, an increase in reabsorption or a decrease in secretion may induce hyperuricemia.In contrast, a decrease in reabsorption or an increase in secretion may result in hyperuricosuria. In the proximal tubule, urate reabsorption is mainly mediated by apical URAT1 (SLC22A12) and basolateral GLUT9 (SLC2A9) transporter. OAT4 (SLC22A11) also acts in urate reabsorption in the apical membrane, and its polymorphism is associated with the risk of hyperuricemia. Renal hypouricemia is caused by SLC22A12 or SLC2A9 loss-of-function mutations, and it may be complicated by exercise-induced acute kidney injury. URAT1 and GLUT9 are also drug targets for uricosuric agents. Sodium-glucose cotransporter inhibitors may induce hyperuricosuria by inhibiting GLUT9b located in the apical plasma membrane. Urate secretion is mediated by basolateral OAT1 (SLC22A6) and OAT3 (SLC22A8) and apical ATP-binding cassette super-family G member 2 (>ABCG2), NPT1 (SLC17A1), and NPT4 (SLC17A3) transporter in the proximal tubule. NPT1 and NPT4 may be key players in renal urate secretion in humans, and deletion of SLC22A6 and SLC22A8 in mice leads to decreased urate excretion. Dysfunctional variants of >ABCG2 inhibit urate secretion from the gut and kidney and may cause gout. In summary, the net result of urate transport in the proximal tubule is determined by the dominance of transporters between reabsorption (URAT1, OAT4, and GLUT9) and secretion (ABCG2, NPT1, NPT4, OAT1, and OAT3).

Background: Fabry disease is a rare X-linked genetic lysosomal disorder caused by mutations in the GLA gene encoding alpha-galactosidase A. Despite some data showing that profibrotic and proinflammatory cytokines and oxidative stress could be involved in Fabry disease-related renal injury, the pathogenic link between metabolic derangement within cells and renal injury remains unclear. Methods: Renal fibrosis was triggered by unilateral ureteral obstruction (UUO) in mice with Fabry disease to investigate the pathogenic mechanism leading to fibrosis in diseased kidneys. Results: Compared to kidneys of wild-type mice, lamellar inclusion bodies were recognized in proximal tubules of mice with Fabry disease. Sirius red and trichrome staining revealed significantly increased fibrosis in all UUO kidneys, though it was more prominent in obstructed Fabry kidneys. Renal messenger RNA levels of inflammatory cytokines and profibrotic factors were increased in all UUO kidneys compared to sham-operated kidneys but were not significantly different between UUO control and UUO Fabry mice. Protein levels of Nox2, Nox4, NQO1, catalase, SOD1, SOD2, and Nrf2 were not significantly different between UUO control and UUO Fabry kidneys, while the protein contents of LC3-II and LC3-I and expression of Beclin1 were significantly decreased in UUO kidneys of Fabry disease mouse models compared with wild-type mice. Notably, TUNEL-positive cells were elevated in obstructed kidneys of Fabry disease mice compared to wild-type control and UUO mice. Conclusion These findings suggest that impaired autophagy and enhanced apoptosis are probable mechanisms involved in enhanced renal fibrosis under the stimulus of UUO in Fabry disease.