Hypoimmunogenic human iPSCs expressing HLA-G, PD-L1, and PD-L2 evade innate and adaptive immunity.

BACKGROUND: The human induced pluripotent stem cells (hiPSCs) can generate all the cells composing the human body, theoretically. Therefore, hiPSCs are thought to be a candidate source of stem cells for regenerative medicine. The major challenge of allogeneic hiPSC-derived cell products is their immunogenicity. The hypoimmunogenic cell strategy is allogenic cell therapy without using immune suppressants. Advances in gene engineering technology now permit the generation of hypoimmunogenic cells to avoid allogeneic immune rejection. In this study, we generated a hypoimmunogenic hiPSC (HyPSC) clone that had diminished expression of human leukocyte antigen (HLA) class Ia and class II and expressed immune checkpoint molecules and a safety switch. METHODS: First, we generated HLA class Ia and class II double knockout (HLA class Ia/II DKO) hiPSCs. Then, a HyPSC clone was generated by introducing exogenous ß-2-microglobulin (B2M), HLA-G, PD-L1, and PD-L2 genes, and the Rapamycin-activated Caspase 9 (RapaCasp9)-based suicide gene as a safety switch into the HLA class Ia/II DKO hiPSCs. The characteristics and immunogenicity of the HyPSCs and their derivatives were analyzed. RESULTS: We found that the expression of HLA-G on the cell surface can be enhanced by introducing the exogenous HLA-G gene along with B2M gene into HLA class Ia/II DKO hiPSCs. The HyPSCs retained a normal karyotype and had the characteristics of pluripotent stem cells. Moreover, the HyPSCs could differentiate into cells of all three germ layer lineages including CD45+ hematopoietic progenitor cells (HPCs), functional endothelial cells, and hepatocytes. The HyPSCs-derived HPCs exhibited the ability to evade innate and adaptive immunity. Further, we demonstrated that RapaCasp9 could be used as a safety switch in vitro and in vivo. CONCLUSION: The HLA class Ia/II DKO hiPSCs armed with HLA-G, PD-L1, PD-L2, and RapaCasp9 molecules are a potential source of stem cells for allogeneic transplantation.

Favorable changes in the eGFR slope after dapagliflozin treatment and its association with the initial dip.

BACKGROUND: Renoprotective effects of sodium glucose transporter 2 (SGLT2) inhibitors, including dapagliflozin, were observed in randomized controlled trials (RCTs). The suspected underlying mechanism is a correction of hyperfiltration, observed as an "initial dip". Whether SGLT2 inhibitors can attenuate the rate of decline in the estimated glomerular filtration rate (eGFR) in clinical settings, even when considering the pre-treatment decline rate, is unknown. Although several RCTs identified an association between the initial dip and long-term renal prognoses, a conclusion has not been reached. METHODS: We collected the eGFR data of patients for whom dapagliflozin was initiated in our hospital and then calculated their eGFR slopes before and after the start of the treatment. We investigated the changes in the eGFR slopes (ΔeGFR slope) and the association between the ΔeGFR slope and the initial dip. Risks for rapid eGFR decliners (eGFR slope < - 3 mL/min/1.73 m2/year) were also examined. RESULTS: The eGFR slope was significantly milder after dapagliflozin treatment (p < 0.01). A deeper initial dip was associated with a milder rate of eGFR decline (adjusted beta: - 0.29, p < 0.001). Dapagliflozin treatment reduced the proportion of rapid eGFR decliners from 52.9 to 14.7%, and a smaller initial dip was identified as a significant risk for post-treatment rapid eGFR decline (adjusted odds ratio: 1.73, p < 0.05). CONCLUSIONS: Compared to before the administration of dapagliflozin, the rate of eGFR decline was significantly milder after its administration. The initial dip was significantly associated with long-term renoprotective effects and may be a useful predictor of treatment response.

A case of Fanconi syndrome that developed following a year of consumption of a red yeast rice supplement.

Although some dietary supplements have been reported to cause renal dysfunction, there have been few reports of supplement-induced Fanconi syndrome. We present the case of a 56-year-old woman with Fanconi syndrome that developed after she consumed a red yeast rice supplement. She was referred to our hospital because of renal dysfunction, and was found to have electrolyte abnormalities, including hypophosphatemia and hypouricemia, renal diabetes, and hyperchloremic metabolic acidosis, and was, therefore, diagnosed with Fanconi syndrome. Renal biopsy revealed proximal tubular injury characterized by severely degenerated tubular epithelial cells as well as mild hypocellular fibrosis. We speculated that the red yeast rice supplement, which the patient had been consuming for approximately 1 year, might be a cause of her syndrome, because reports of renal dysfunction associated with the consumption of red yeast rice supplements have emerged in Japan since 2024. After the supplement was discontinued and oral prednisolone treatment was initiated, the patient's renal function improved and her electrolyte abnormalities were ameliorated. Furthermore, even after tapering off and discontinuing the prednisolone over approximately 12 weeks, her renal function remained. Because Fanconi syndrome may be caused by various exogenous substances, the taking of a thorough medical history is crucial, including with respect to the use not only of prescription medications, but also other substances, including supplements.

Effect of preceding drug therapy on the renal and cardiovascular outcomes of combined sodium-glucose cotransporter-2 inhibitor and glucagon-like peptide-1 receptor agonist treatment in patients with type 2 diabetes and chronic kidney disease.

AIM: To conduct a post hoc subgroup analysis of patients with type 2 diabetes (T2D) from the RECAP study, who were treated with sodium-glucose cotransporter-2 (SGLT2) inhibitor and glucagon-like peptide 1 receptor agonist (GLP-1RA) combination therapy, focusing only on those patients who had chronic kidney disease (CKD), to examine whether the composite renal outcome differed between those who received SGLT2 inhibitor treatment first and those who received a GLP-1RA first. METHODS: We included 438 patients with CKD (GLP-1RA-first group, n = 223; SGLT2 inhibitor-first group, n = 215) from the 643 T2D patients in the RECAP study. The incidence of the composite renal outcome, defined as progression to macroalbuminuria and/or a ≥50% decrease in estimated glomerular filtration rate (eGFR), was analysed using a propensity score (PS)-matched model. Furthermore, we calculated the win ratio for these composite renal outcomes, which were weighted in the following order: (1) both a ≥50% decrease in eGFR and progression to macroalbuminuria; (2) a decrease in eGFR of ≥50% only; and (3) progression to macroalbuminuria only. RESULTS: Using the PS-matched model, 132 patients from each group were paired. The incidence of renal composite outcomes did not differ between the two groups (GLP-1RA-first group, 10%; SGLT2 inhibitor-first group, 17%; odds ratio 1.80; 95% confidence interval [CI] 0.85 to 4.26; p = 0.12). The win ratio of the GLP-1RA-first group versus the SGLT2 inhibitor-first group was 1.83 (95% CI 1.71 to 1.95; p < 0.001). CONCLUSION: Although the renal composite outcome did not differ between the two groups, the win ratio of the GLP-1RA-first group versus the SGLT2 inhibitor-first group was significant. These results suggest that, in GLP-1RA and SGLT2 inhibitor combination therapy, the addition of an SGLT2 inhibitor to baseline GLP-1RA treatment may lead to more favourable renal outcomes.

Factors affecting the sodium-glucose cotransporter 2 inhibitors-related initial decline in glomerular filtration rate and its possible effect on kidney outcome in chronic kidney disease with type 2 diabetes: The Japan Chronic Kidney Disease Database.

AIM: Sodium-glucose cotransporter 2 (SGLT2) inhibitors often cause a transient decrease in glomerular filtration rate (GFR) shortly after the initiation, referred to as the 'initial drop'. However, the clinical significance of this initial drop in real-world practice remains unclear. MATERIALS AND METHODS: Using the nationwide Japan Chronic Kidney Disease Database, we examined factors that affected the initial drop, in patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). We also evaluated the effects of the initial drop on a composite kidney outcome (a decline in GFR of ≥50% or progression to end-stage kidney disease). RESULTS: Data from 2053 patients with CKD and T2DM newly prescribed an SGLT2 inhibitor were analysed. The follow-up period after SGLT2 inhibitor administration was 1015 days (interquartile range: 532, 1678). Multivariate linear regression models revealed that the concomitant use of the renin-angiotensin system inhibitors and diuretics, urinary protein levels ≥2+, and changes in GFR before the initiation of the SGLT2 inhibitor were associated with a larger initial GFR decline (ß = -0.609, p = .039; ß = -2.298, p < .001; ß = -0.936, p = .048; ß = -0.079, p < .001, respectively). Patients in the quartile with the largest initial GFR decline experienced a higher incidence of the subsequent composite kidney outcome than those in the other quartiles (p < .001). CONCLUSIONS: The concomitant use of renin-angiotensin system inhibitors and diuretics, higher urine protein levels and pre-treatment GFR changes were associated with a larger initial GFR decline. Of these factors, the use of a diuretic had the largest effect. Furthermore, patients with CKD and T2DM experiencing an excessive initial GFR drop might be at a higher risk of adverse kidney outcomes.

Evaluating the associations between compliance with CKD guideline component metrics and renal outcomes.

Understanding the association between compliance to the Chronic Kidney Disease (CKD) guidelines in real-world clinical settings and renal outcomes remains a critical gap in knowledge. A comprehensive analysis was conducted using data from a national, multicenter CKD registry. This study included 4,455 patients with an estimated glomerular filtration rate (eGFR) measurement on the index date and eight additional metrics recorded within six months. These metrics comprised serum electrolyte levels, low-density lipoprotein cholesterol, hemoglobin, and the use of renin-angiotensin system inhibitors. The primary outcome was a composite of renal events, defined by a decline in eGFR to < 15 mL/min/1.73 m2 or a reduction of ≥ 30% in eGFR, confirmed by follow-up tests. Over a median follow-up of 513 days, 838 renal events were observed. High serum potassium levels (> 5.4 mmol/L) were associated with increased event rates compared to lower levels. Similarly, low serum sodium-chloride levels (< 33) correlated with higher event rates. Usage of renin-angiotensin system inhibitors, low serum calcium (< 8.4 mg/dL), and high uric acid levels (> 7.0 mg/dL) were also linked to increased events. Conversely, higher hemoglobin levels (≥ 13 g/dL) were associated with lower event rates. Compliance to guidelines, categorized into quartiles based on the number of met metrics, revealed a significantly reduced risk of events in the highest compliance group (meeting 8 metrics) compared to the lowest (0-5 metrics). Compliance to CKD guidelines in clinical practice is significantly associated with improved renal outcomes, emphasizing the need for guideline-concordant care in the management of CKD.

Impact of compliance with salt management guidelines before dialysis introduction on peritoneal dialysis technique survival: The importance of pre-dialysis care and education.

INTRODUCTION: Peritoneal dialysis (PD) is a mode of therapy in which the patients themselves actively participate in the care of their own disease. We examined a possible association of salt reduction before starting dialysis with PD technique survival. METHODS: This retrospective cohort study included 42 patients who started PD between April 2014 and March 2018. Participants were allocated to two groups based on their estimated daily salt intake before the initiation of dialysis: patients with an estimated daily salt intake <6 g/day were allocated to the appropriate salt intake group (AS group), while the rest were assigned to the high salt intake group (HS group). RESULTS: During a median follow-up of 47 months, PD technique survival, defined by death or transition to hemodialysis, was significantly lower in the HS group compared to the AS group. CONCLUSION: Successful salt reduction before dialysis introduction is associated with better PD technique survival.

Kidney outcomes of SGLT2 inhibitors among older patients with diabetic kidney disease in real-world clinical practice: the Japan Chronic Kidney Disease Database Ex.

INTRODUCTION: We compared the kidney outcomes between patients with diabetic kidney disease (DKD) aged ≥75 years initiating sodium-glucose cotransporter 2 (SGLT2) inhibitors versus other glucose-lowering drugs, additionally presenting with or without proteinuria. RESEARCH DESIGN AND METHODS: Using the Japan Chronic Kidney Disease Database, we developed propensity scores, implementing a 1:1 matching protocol. The primary outcome included the decline rate in estimated glomerular filtration rate (eGFR), and secondary outcomes incorporated a composite of a 40% reduction in eGFR or progression to end-stage kidney disease. RESULTS: At baseline, the mean age at initiation of SGLT2 inhibitors (n=348) or other glucose-lowering medications (n=348) was 77.7 years. The mean eGFR was 59.3 mL/min/1.73m2 and proteinuria was 230 (33.0%) patients. Throughout the follow-up period, the mean annual rate of eGFR change was -0.80 mL/min/1.73 m2/year (95% CI -1.05 to -0.54) among SGLT2 inhibitors group and -1.78 mL/min/1.73 m2/year (95% CI -2.08 to -1.49) in other glucose-lowering drugs group (difference in the rate of eGFR decline between the groups was 0.99 mL/min/1.73 m2/year (95% CI 0.5 to 1.38)), favoring SGLT2 inhibitors (p<0.001). Composite renal outcomes were observed 38 in the SGLT2 inhibitors group and 57 in the other glucose-lowering medications group (HR 0.64, 95% CI 0.42 to 0.97). There was no evidence of an interaction between SGLT2 inhibitors initiation and proteinuria. CONCLUSIONS: The benefits of SGLT2 inhibitors on renal outcomes are also applicable to older patients with DKD aged≥75 years.

Relationship between 2nd-generation angiotensin receptor blockers and the risk of hypotension in COVID-19 patients admitted to hospital.

It has not yet been established whether angiotensin II receptor blockers (ARB), statins, and multiple drugs affect the severity of COVID-19. Therefore, we herein performed an observational study on the effects of 1st- and 2nd-generation ARB, statins, and multiple drugs, on COVID-19 in patients admitted to 15 Japanese medical facilities. The results obtained showed that ARB, statins, and multiple drugs were not associated with the primary outcome (odds ratio: 1.040, 95% confidence interval: 0.688-0.571; 0.696, 0.439-1.103; 1.056, 0.941-1.185, respectively), each component of the primary outcome (in-hospital death, ventilator support, extracorporeal membrane oxygenation support, and admission to the intensive care unit), or the secondary outcomes (oxygen administration, disturbed consciousness, and hypotension, defined as systolic blood pressure ≤90 mmHg). ARB were divided into 1st- and 2nd-generations based on their approval for use (before 2000 and after 2001), with the former consisting of losartan, candesartan, and valsartan, and the latter of telmisartan, olmesartan, irbesartan, and azilsartan. The difference of ARB generation was not associated with the primary outcome (odds ratio with 2nd-generation ARB relative to 1st-generation ARB: 1.257, 95% confidence interval: 0.613-2.574). The odd ratio for a hypotension as one of the secondary outcomes with 2nd-generation ARB was 1.754 (95% confidence interval: 1.745-1.763) relative to 1st-generation ARB. These results suggest that patients taking 2nd-generation ARB may be at a higher risk of hypotension than those taking 1st-generation ARB and also that careful observations are needed. Further studies are continuously needed to support decisions to adjust medications for co-morbidities.

Effectiveness of DialBetesPlus, a self-management support system for diabetic kidney disease: Randomized controlled trial.

We evaluated the effectiveness of a mobile health (mHealth) intervention for diabetic kidney disease patients by conducting a 12-month randomized controlled trial among 126 type 2 diabetes mellitus patients with moderately increased albuminuria (urinary albumin-to-creatinine ratio (UACR): 30-299 mg/g creatinine) recruited from eight clinical sites in Japan. Using a Theory of Planned Behavior (TPB) behavior change theory framework, the intervention provides patients detailed information in order to improve patient control over exercise and dietary behaviors. In addition to standard care, the intervention group received DialBetesPlus, a self-management support system allowing patients to monitor exercise, blood glucose, diet, blood pressure, and body weight via a smartphone application. The primary outcome, change in UACR after 12 months (used as a surrogate measure of renal function), was 28.8% better than the control group's change (P = 0.029). Secondary outcomes also improved in the intervention group, including a 0.32-point better change in HbA1c percentage (P = 0.041). These improvements persisted when models were adjusted to account for the impacts of coadministration of drugs targeting albuminuria (GLP-1 receptor agonists, SGLT-2 inhibitors, ACE inhibitors, and ARBs) (UACR: -32.3% [95% CI: -49.2%, -9.8%] between-group difference in change, P = 0.008). Exploratory multivariate regression analysis suggests that the improvements were primarily due to levels of exercise. This is the first trial to show that a lifestyle intervention via mHealth achieved a clinically-significant improvement in moderately increased albuminuria.

Lipoprotein Apheresis Alleviates Treatment-Resistant Peripheral Artery Disease Despite the Normal Range of Atherogenic Lipoproteins: The LETS-PAD Study.

AIM: Peripheral artery disease (PAD) severely impairs patient prognosis and quality of life (QOL). Although lipoprotein apheresis (LA) has been applied to patients with PAD and elevated serum atherogenic lipoproteins, we hypothesized that LA can be effective for treating PAD even in patients with controlled serum lipoproteins through pleiotropic anti-atherosclerotic effects beyond lipoprotein removal. This study aimed to evaluate the efficacy of LA in patients with treatment-resistant PAD and controlled serum lipoproteins focusing on QOL. METHODS: In a single-arm prospective study, 30 patients with refractory PAD who had controlled serum lipoproteins underwent sequential LA sessions using dextran sulfate adsorption columns, aiming to complete 10 sessions. The ankle-brachial pressure index (ABI) and vascular QOL (VascuQOL) score were evaluated as the primary outcomes. Secondary outcomes included reactive hyperemia index (RHI) and biological antioxidant potential (BAP) as an endothelial function test and serum antioxidative-capacity evaluation, respectively. RESULTS: ABI significantly increased after LA sessions (pre-treatment 0.60±0.09 vs. post-treatment 0.65±0.13, p=0.023). Total VascuQOL score (3.7±1.1 vs 4.6±1.1, p＜0.001) and RHI (1.70±0.74 vs 2.34±1.76, p=0.023) significantly improved after the LA sessions. BAP tended to increase after the LA sessions, and the change reached statistical significance 3 months after treatment. CONCLUSION: ABI and QOL improved after a series of LA sessions in conventional treatment-resistant PAD patients with controlled serum lipoprotein levels. Increased antioxidative capacity and ameliorated endothelial function were observed after the LA treatment.

Influence of the combination of SGLT2 inhibitors and GLP-1 receptor agonists on eGFR decline in type 2 diabetes: post-hoc analysis of RECAP study.

Accumulating evidence has demonstrated that both SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1Ra) have protective effects in patients with diabetic kidney disease. Combination therapy with SGLT2i and GLP1Ra is commonly used in patients with type 2 diabetes (T2D). We previously reported that in combination therapy of SGLT2i and GLP1Ra, the effect on the renal composite outcome did not differ according to the preceding drug. However, it remains unclear how the initiation of combination therapy is associated with the renal function depending on the preceding drug. In this post hoc analysis, we analyzed a total of 643 T2D patients (GLP1Ra-preceding group, n = 331; SGLT2i-preceding group, n = 312) and investigated the differences in annual eGFR decline. Multiple imputation and propensity score matching were performed to compare the annual eGFR decline. The reduction in annual eGFR decline in the SGLT2i-preceding group (pre: -3.5 ± 9.4 mL/min/1.73 m2/year, post: -0.4 ± 6.3 mL/min/1.73 m2/year, p < 0.001), was significantly smaller after the initiation of GLP1Ra, whereas the GLP1Ra-preceding group tended to slow the eGFR decline but not to a statistically significant extent (pre: -2.0 ± 10.9 mL/min/1.73 m2/year, post: -1.8 ± 5.4 mL/min/1.73 m2/year, p = 0.83) after the initiation of SGLT2i. After the addition of GLP1Ra to SGLT2i-treated patients, slower annual eGFR decline was observed. Our data raise the possibility that the renal benefits-especially annual eGFR decline-of combination therapy with SGLT2i and GLP1Ra may be affected by the preceding drug.

Association of serum magnesium levels with renal prognosis in patients with chronic kidney disease.

BACKGROUND: Magnesium deficiency is associated with various health conditions, but its impact on the progression of chronic kidney disease (CKD) remains unclear. This study aimed to investigate the association between serum magnesium levels and prognosis of renal function in CKD patients. METHODS: This is an analysis of the Japan Chronic Kidney Disease Database Ex　(J-CKD-DB-Ex), which is a multicenter prospective cohort including CKD patients enrolled from January 1, 2014 to December 31, 2020. We included adult outpatients with CKD stage G3 and G4 at the time of initial magnesium measurement. Patients were classified by magnesium levels as low (<1.7 mg/dl), normal (1.7-2.6 mg/dl), or high (>2.6 mg/dl). The primary outcomes were the composite of an eGFR < 15 ml/min/1.73 m2 or a ≥30% reduction in eGFR from the initial measurement, which was defined as CKD progression. We applied the Kaplan-Meier analysis and Cox regression hazard model to examine the association between magnesium levels and CKD progression. RESULTS: The analysis included 9868 outpatients during the follow-up period. The low magnesium group was significantly more likely to reach CKD progression. Cox regression, adjusting for covariates and using the normal magnesium group as the reference, showed that the hazard ratio for the low magnesium group was 1.20 (1.08-1.34). High magnesium was not significantly associated with poor renal outcomes compared with normal magnesium. CONCLUSION: Based on large real-world data, this study demonstrated that low magnesium levels are associated with poorer renal outcomes.

ATP2B1 gene polymorphisms associated with resistant hypertension in the Japanese population.

Single-nucleotide polymorphisms (SNP) of ATP2B1 gene are associated with essential hypertension but their association with resistant hypertension (RHT) remains unexplored. The authors examined the relationship between ATP2B1 SNPs and RHT by genotyping 12 SNPs in ATP2B1 gene of 1124 Japanese individuals with lifestyle-related diseases. Patients with RHT had inadequate blood pressure (BP) control using three antihypertensive drugs or used ≥4 antihypertensive drugs. Patients with controlled hypertension had BP controlled using ≤3 antihypertensive drugs. The association between each SNP and RHT was analyzed by logistic regression. The final cohort had 888 (79.0%) and 43 (3.8%) patients with controlled hypertension and RHT, respectively. Compared with patients homozygous for the minor allele of each SNP in ATP2B1, a significantly higher number of patients carrying the major allele at 10 SNPs exhibited RHT (most significant at rs1401982: 5.8% vs. 0.8%, p = .014; least significant at rs11105378: 5.7% vs. 0.9%, p = .035; most nonsignificant at rs12817819: 5.1% vs. 10%, p = .413). After multivariate adjustment for age, sex, systolic BP, and other confounders, the association remained significant for rs2681472 and rs1401982 (OR: 7.60, p < .05 and OR: 7.62, p = .049, respectively). Additionally, rs2681472 and rs1401982 were in linkage disequilibrium with rs11105378. This study identified two ATP2B1 SNPs associated with RHT in the Japanese population. rs1401982 was most closely associated with RHT, and major allele carriers of rs1401982 required significantly more antihypertensive medications. Analysis of ATP2B1 SNPs in patients with hypertension can help in early prediction of RHT and identification of high-risk patients who are more likely to require more antihypertensive medications.

Two acute kidney injury episodes after ICI therapy: a case report.

A 74-year-old Japanese male with lung squamous cell carcinoma received his first dose of immune checkpoint inhibitors (ICIs): ipilimumab and nivolumab. He developed acute kidney injury (AKI) and was admitted to our department. We diagnosed kidney immune-related adverse effects (irAE), and a kidney biopsy revealed acute tubulointerstitial nephritis. We started oral prednisolone (PSL) and his AKI immediately improved. The patient maintained stable findings after PSL was tapered off. However, seven months after the ICI administration, he developed rapid progressive glomerular nephritis and was admitted to our department again. The second kidney biopsy showed findings consistent with anti-glomerular basement membrane glomerulonephritis. Although the patient was treated with pulse methylprednisolone followed by oral PSL and plasma exchange, he became dependent on maintenance hemodialysis. To our knowledge, no case report has described two different types of biopsy-proven nephritis. In cases of suspected relapsing kidney irAEs, both a relapse of previous nephritis and the development of another type of nephritis should be considered.

Elevated Leukocyte Count and Platelet-Derived Thrombogenicity Measured Using the Total Thrombus-Formation Analysis System in Patients with ST-Segment Elevation Myocardial Infarction.

AIMS: High platelet-derived thrombogenicity during the acute phase of ST-segment elevation myocardial infarction (STEMI) is associated with poor outcomes; however, the associated factors remain unclear. This study aimed to examine whether acute inflammatory response after STEMI affects platelet-derived thrombogenicity. METHODS: This retrospective observational single-center study included 150 patients with STEMI who were assessed for platelet-derived thrombogenicity during the acute phase. Platelet-derived thrombogenicity was assessed using the area under the flow-pressure curve for platelet chip (PL-AUC), which was measured using the total thrombus-formation analysis system (T-TAS). The peak leukocyte count was evaluated as an acute inflammatory response after STEMI. The patients were divided into two groups: the highest quartile of the peak leukocyte count and the other three quartiles combined. RESULTS: Patients with a high peak leukocyte count (＞15,222/mm3; n=37) had a higher PL-AUC upon admission (420 [386-457] vs. 385 [292-428], p=0.0018), higher PL-AUC during primary percutaneous coronary intervention (PPCI) (155 [76-229] vs. 96 [29-170], p=0.0065), a higher peak creatine kinase level (4200±2486 vs. 2373±1997, p＜0.0001), and higher PL-AUC 2 weeks after STEMI (119 [61-197] vs. 88 [46-122], p=0.048) than those with a low peak leukocyte count (≤ 15,222/mm3; n=113). The peak leukocyte count after STEMI positively correlated with PL-AUC during primary PPCI (r=0.37, p＜0.0001). A multivariable regression analysis showed the peak leukocyte count to be an independent factor for PL-AUC during PPCI (ß=0.26, p=0.0065). CONCLUSIONS: An elevated leukocyte count is associated with high T-TAS-based platelet-derived thrombogenicity during the acute phase of STEMI.