Two-thirds of urate is excreted via the renal pathway and the remaining one-third via the extra-renal pathway, the latter mainly via the intestine in healthy individuals. ABCG2, a urate exporter, is expressed in various tissues including the kidney and intestine, and its dysfunction leads to hyperuricemia and gout. ABCG2 is regarded as being responsible for most of the extra-renal urate excretion. However, the extra-renal urate excretion capacity via ABCG2 remains undefined in end-stage kidney diseases. Therefore, we evaluated the capacity of extra-renal ABCG2 using 123 anuric hemodialysis patients whose urate excretion depended on only the extra-renal pathway. ABCG2 function in each participant was estimated based on ABCG2 dysfunctional variants. We computed the uric acid pool (PoolUA) from bodyweight and serum urate level (SUA) using previously reported radio-isotopic data, and we analyzed the association between ABCG2 function and the PoolUA. SUA and PoolUA increased significantly with ABCG2 dysfunction, and extra-renal ABCG2 could excrete up to approximately 60% of the daily uric acid turnover in hemodialysis patients. Our findings indicate that the extra-renal urate excretion capacity can expand with renal function decline and highlight that the extra-renal pathway is particularly important in the uric acid homeostasis for patients with renal dysfunction.

Objective Several studies have shown an increased risk of bullous pemphigoid (BP) when receiving dipeptidyl pepitidase-4 inhibitor (DPP-4i) treatment. The present study explored the associations of DPP-4i treatment with the clinical phenotypes and clinical course of BP. Methods We analyzed data of 146 patients with BP at Tokai University School of Medicine from December 1, 2009, to December 31, 2021. We obtained data by a retrospective medical record review and compared the bullous pemphigoid disease area index (BPDAI) between diabetes patients receiving DPP-4i treatment and those not receiving DPP-4i treatment. We employed multivariable linear regression models to explore the association between the DPP-4i treatment and the BPDAI scores. Results Among 53 BP patients with diabetes, 33 had developed BP during treatment with DPP-4i agents, among which vildagliptin was the most frequently used. The urticaria/erythema scores of the BPDAI were significantly lower in patients who developed BP while receiving DPP-4i treatment than among others. Of note, 69.2% of the patients who stopped DPP-4i treatment experienced complete remission, and the clinical course was more favorable in patients with lower scores for urticaria/erythema than among others. Conclusion These findings suggest that, in patients who developed BP while receiving DPP-4i treatment, a noninflammatory phenotype may indicate a high likelihood that DPP-4i treatment contributes to the development of BP. The discontinuation of DPP-4i should be carefully considered in close consultation with dermatologists.

Reduction in blood pressure (BP) contributes to the cardiovascular and renal protective effects of sodium-glucose co-transporter 2 inhibitors (SGLT-2is) and glucagon-like peptide 1 receptor agonists (GLP-1Ras). However, there has been no direct comparison in terms of BP-lowering efficacies. We compared the rates of achieving a target BP with SGLT-2i and GLP-1Ra treatments administered to Japanese patients with type 2 diabetes mellitus (T2DM). This retrospective study included 384 SGLT-2i- and 160 GLP-1Ra-treated patients with a BP > 130/80 mmHg before treatment. Inverse probability weighting methods using propensity scores were applied in this study. The integrated odds ratios (OR) for BP control rates were calculated and clinical changes were analyzed using a generalized linear model. SGLT-2i treatment resulted in significantly higher BP control rates than the GLP1Ra treatment (integrated OR = 2.09 [1.80, 2.43]). Compared with GLP-1Ra, SGLT-2i treatment determined significantly larger decreases in diastolic BP, mean arterial pressure, and body weight (-3.8 mmHg, P = 0.006; -4.1 mmHg, P = 0.01; and -1.5 kg, P = 0.008, respectively) and increased annual estimated glomerular filtration rate (eGFR; 1.5 mL/min/1.73 m2/year, P = 0.04). In T2DM patients with poorly controlled BP, compared with GLP-1Ra, SGLT-2i treatment significantly improved BP management along with increasing eGFR.