Jin Sug Kim

The predictive role of serum triglyceride to high-density lipoprotein cholesterol ratio according to renal function in patients with acute myocardial infarction

Objective A high serum triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio has been reported as an independent predictor for cardiovascular events in the general population. However, the prognostic value of this ratio in patients with renal dysfunction is unclear. We examined the association of the TG/HDL-C ratio with major adverse cardiovascular events (MACEs) according to renal function in patients with acute myocardial infarction (AMI). Method This study was based on the Korea Acute Myocardial Infarction Registry database. Of 13,897 patients who were diagnosed with AMI, the study population included the 7,016 patients with available TG/HDL-C ratio data. Patients were stratified into three groups according to their estimated glomerular filtration rate (eGFR), and the TG/HDL-C ratio was categorized into tertiles. We investigated 12-month MACEs, which included cardiac death, myocardial infarction, and repeated percutaneous coronary intervention or coronary artery bypass grafting. Results During the 12-month follow up period, 593 patients experienced MACEs. There was a significant association between the TG/HDL-C ratio and MACEs (p<0.001) in the entire study cohort. Having a TG/HDL-C ratio value in the highest tertile of TG/HDL-C ratio was an independent factor associated with increased risk of MACEs (hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.26–1.93; p<0.001). Then we performed subgroup analyses according to renal function. In patients with normal renal function (eGFR ≥ 90 ml/min/1.73m2) and mild renal dysfunction (eGFR ≥ 60 to < 90ml/min/1.73m2), a higher TG/HDL-C ratio was significantly associated with increased risk of MACEs (HR, 1.64; 95% CI, 1.04–2.60; p = 0.035; and HR, 1.56; 95% CI, 1.14–2.12; p = 0.005, respectively). However, in patients with moderate renal dysfunction (eGFR < 60 ml/min/1.73m2), TG/HDL-C ratio lost its predictive value on the risk of MACEs (HR, 1.23; 95% CI, 0.82–1.83; p = 0.317). Conclusions In patients with AMI, TG/HDL-C ratio is a useful independent predictor of 12-month MACEs. However, this ratio does not have predictive power in patients with moderate renal dysfunction.

Urinary exosomal viral microRNA as a marker of BK virus nephropathy in kidney transplant recipients

Objective Bkv-miR-B1-5p, one of the microRNAs encoded by BK virus, was recently reported to be elevated in the blood among the patients with BK virus nephropathy (BKVN). Urinary exosome was suggested to be a possible source of biomarker for kidney diseases, but it was unknown whether it could contain viral microRNA as well as human microRNAs. The aim of this study was to evaluate whether urinary exosomal BK viral microRNA were expressed during replication and could be used to diagnose BKVN in kidney transplant recipients. Materials and methods In a cross-sectional multicenter study, we collected and analyzed 458 graft biopsies from 385 kidney transplant recipients. Urine samples were collected at the time of graft biopsy, and microRNAs in urinary exosome were measured once. For 13 patients with BKVN and 67 age, sex-matched kidney transplant recipients, we measured BK viral microRNA B1-5p, 3p and human microRNA-16 in urinary exosomal fraction and compared the diagnostic value with BK viral load in plasma and urine. Results Pathology proven BKVN was diagnosed in 13 patients (2.8%). High levels of bkv-miR-B1-5p and bkv-miR-B1-3p were shown in all patients with BKVN. Meanwhile, plasma BK viral load assay (cut-off value of ≥ 4.0 log10 copies/mL) showed false negative in 3 cases and urinary BK viral load assay (cut-off value of ≥ 7.0 log10 copies/mL) showed false negative in 1 case among these 13 patients. The receiver operator characteristics curve analysis for bkv-miR-B1-5p and bkv-miR-B1-5p/miR-16 showed excellent discriminative power for the diagnosis of BKVN, with area under the curve values of 0.989 and 0.985, respectively. Conclusions This study suggests that urinary exosomal bkv-miR-B1-5p and bkv-miR-B1-5p/miR-16 could be surrogate markers for the diagnosis of BKVN.

Clinicopathological features of diabetic and nondiabetic renal diseases in type 2 diabetic patients with nephrotic-range proteinuria

Abstract Heavy proteinuria with or without features of nephrotic syndrome is associated with many primary and systemic diseases. For diabetic patients, distinguishing nondiabetic renal disease (NDRD) from diabetic nephropathy (DN) is important in choosing treatment modalities and determining renal prognosis. However, clinical relevance of heavy proteinuria is inconsistent with clinical DN assessments. This study investigated the clinicopathological features and renal outcomes of DN and NDRD in type 2 diabetic patients with nephrotic-range proteinuria. We enrolled 220 cases of type 2 diabetic patients who underwent renal biopsy. They were grouped according to the presence of nephritic-range proteinuria and pathological features. Baseline characteristics, laboratory findings, types of pathological diagnosis, and renal outcomes were analyzed in patients with heavy proteinuria. Upon kidney biopsy, 129 patients (58.6%) showed nephritic-range proteinuria. Patients with heavy proteinuria (an average urine protein-to-creatinine ratio of 10,008 ± 7307 mg/gCr) showed lower serum albumin levels and higher total cholesterol levels, but did not show any difference in age, duration of diabetes, renal function, or the presence of retinopathy compared with those with mild-to-moderate proteinuria (an average urine protein-to-creatinine ratio of 1581 ± 979 mg/gCr). Renal biopsy revealed that the prevalence of NDRD was 37.2% in patients with heavy proteinuria, which was significantly lower than that in patients with mild-to-moderate proteinuria (63.7%). The most common pathological types of NDRD were membranous nephropathy (41.7%), IgA nephropathy (14.6%), and minimal change disease (10.4%). NDRD patients showed lower prevalence of diabetic retinopathy and better kidney function irrespective of proteinuria. Immunosuppressive treatment was administered more frequently in patients with heavy proteinuria (56.3%) compared with patients with mild-to-moderate proteinuria (20%) because of the pathological differences according to the amount of proteinuria. Renal outcomes were significantly worse in patients with DN than in patients with NDRD. DN patients with heavy proteinuria exhibited different prevalence of NDRD and worse prognosis. Renal biopsy in type 2 diabetic patients should be more extensively considered to accurately diagnose NDRD, guide further management, and predict renal outcomes, especially in patients with nephrotic-range proteinuria.

Ameliorating Effect of Gemigliptin on Renal Injury in Murine Adriamycin-Induced Nephropathy

Background. Previous studies have shown the antiapoptotic and anti-inflammatory potential of DPP-IV inhibitor in experimental models of renal injury. We tested whether DPP-IV inhibitor (gemigliptin) ameliorates renal injury by suppressing apoptosis, inflammation, and oxidative stress in mice with adriamycin nephropathy. Methods. Mice were treated with normal saline (control), gemigliptin (GM), adriamycin (ADR), or adriamycin combined with gemigliptin (ADR+GM). Apoptosis, inflammation, and oxidative stress were analyzed via western blotting, real-time PCR, light microscopy, and immunofluorescence. Results. In the ADR+GM group, urine albumin creatinine ratio decreased significantly compared with that in the ADR group on day 15. Glomerulosclerosis index and tubulointerstitial injury index in mice with adriamycin-induced nephropathy decreased after gemigliptin treatment. ADR group showed higher levels of apoptosis, inflammation, and oxidative stress-related molecules compared with the control group. The upregulation of these molecules was significantly reduced by gemigliptin. In the ADR group, the staining intensities of WT-1 and nephrin reduced, but these changes were ameliorated in the ADR+GM group. Conclusion. We demonstrated that gemigliptin ameliorates nephropathy by suppressing apoptosis, inflammation, and oxidative stress in mice administered adriamycin. Our data demonstrate that gemigliptin has renoprotective effects on adriamycin-induced nephropathy.

Plasma endocan level and prognosis of immunoglobulin A nephropathy

Background Endocan, previously called endothelial cell–specific molecule-1, is a soluble proteoglycan that is secreted from vascular endothelial cells. Elevated plasma endocan levels were shown to be associated with poor cardiovascular outcomes in patients with chronic kidney disease (CKD). We investigated the clinical relevance of plasma and urine endocan levels in patients with immunoglobulin A nephropathy (IgAN). Methods Sixty-four patients with IgAN and 20 healthy controls were enrolled in this study. Plasma and urine endocan levels were measured. Clinical parameters, pathologic grades, and renal outcomes were compared among subgroups with different plasma and urine endocan levels. Results Both plasma and urine endocan levels were significantly higher in patients with IgAN than in controls. Elevated serum phosphorus and C-reactive protein were independent determinants for plasma endocan, and elevated C-reactive protein was also an independent determinant for urine endocan levels in multivariate analysis. Plasma endocan level was not significantly different across CKD stages, but patients with higher plasma endocan levels showed adverse renal outcome. Urine endocan levels were also elevated in patients with poor renal function. Cox proportional hazard models showed that high plasma endocan was an independent risk factor for CKD progression after adjusting for the well-known predictors of outcome in patients with IgAN. Conclusion This study suggested that plasma endocan might be useful as a prognostic factor in patients with IgAN.

CAPD Peritonitis Caused by Co-Infection with Cellulosimicrobium cellulans (Oerskovia xanthineolytica) and Enterobacter cloacae: A Case Report and Literature Review

A 50-year-old woman with end-stage renal disease on continuous ambulatory peritoneal dialysis was admitted with abdominal pain, fever and cloudy peritoneal fluid. The diagnosis was peritonitis, and the causative bacteria were Cellulosimicrobium cellulans and Enterobacter cloacae. She was subsequently treated with the administration of intraperitoneal antibiotics and removal of the infected indwelling catheter. We herein report a case of Cellulosimicrobium cellulans and Enterobacter cloacae co-infection in a patient with peritonitis and review the relevant literature.

Syndrome of inappropriate antidiuretic hormone secretion associated with seronegative neuromyelitis optica spectrum disorder

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a potential cause of hyponatremia of the central nervous system (CNS). Although SIADH has been reported to be associated with many other central nervous disorders, its association with neuromyelitis optica (NMO) or NMO spectrum disorders are rare. NMO is a demyelinating disorder characterized by optic neuritis and transverse myelitis. Aquaporin-4 (AQP4), which is the target antigen for a NMO autoantibody, is the predominant CNS water channel. However, some NMO patients show seronegative AQP4 antibody results. The spectrum of NMO has been changed, and new findings about the disease have been reported. Here, we report a case of seronegative NMO spectrum disorder associated with SIADH.

Significant Association between Toll-Like Receptor Gene Polymorphisms and Posttransplantation Diabetes Mellitus

Background: Posttransplantation diabetes mellitus (PTDM) is an important metabolic complication after renal transplantation. Activation of the innate immune system via toll-like receptors (TLRs) is implicated in the pathogenesis of insulin resistance and deficiency. Although links between diabetes, dysregulated innate immune responses, and the TLR signaling pathway have been reported, no study so far has investigated their associations with PTDM. In this study, we ascertained whether single nucleotide polymorphisms (SNPs) in TLRs are associated with PTDM in the Korea population. Methods: A total of 305 patients who received renal transplants without previously diagnosed diabetes were included. We analyzed the association between PTDM development and 6 SNPs within 2 genes of TLR2, 1 gene of TLR4, and 3 genes of TRL6. Results: Of 305 patients, PTDM developed in 51 patients (16.6%). Patients in the PTDM group were older than those in the non-PTDM group (45.56 ± 1.28 vs. 38.28 ± 0.71 years). Patients with PTDM had significantly higher allele frequency compared to those without PTDM for the TLR4 rs1927914*T, TLR6 rs3775073*A, TLR6 rs3821985*C, and TLR6 rs1039559*C alleles. Of the 6 SNPs, rs1927914 in the TLR4 gene and rs1039559 in the TLR6 gene were significantly associated with the development of PTDM after adjustment for age, gender, and tacrolimus usage. Conclusions: Our study demonstrates a significant association between SNPs rs1927914 in TLR4 and rs1039559 in TLR6 and PTDM in the renal transplantation recipient group. These data suggest that the activation of the innate immune system and inflammation via TLR activation might have an essential role in the pathogenesis of PTDM in renal transplantation.

A Case Report of Familial Renal Hypouricemia Confirmed by Genotyping of SLC22A12, and a Literature Review

A 24-year-old male visited our hospital because of pain in both flanks. His biochemistry profile showed an elevated serum creatinine level and low serum uric acid level. History taking revealed that he had undertaken exercise prior to the acute kidney injury (AKI) event, and he stated that family members had a history of urolithiasis. His renal profile improved after hydration and supportive care during hospitalization. Although the patient was subsequently admitted again due to AKI, his status recovered with similar treatment. Since the diagnosis of the patient was familial renal hypouricemia with exercise-induced AKI, we performed genotyping of SLC22A12, which encodes human urate transporter 1. The diagnosis was confirmed by the detection of a homozygous mutation of W258X. We herein, report a case of familial renal hypouricemia confirmed by genotyping of SLC22A12, and review the relevant literature.

Genetic Variations of Tyrosine Hydroxylase in the Pathogenesis of Hypertension

One of the major pathophysiological features of primary hypertension is an inappropriate activation of the sympathetic nervous system, which is mediated by excessive synthesis and secretion of catecholamine into the blood. Tyrosine hydroxylase (TH), a rate-limiting enzyme in the synthesis of catecholamine, has been highlighted because genetic variations of TH could alter the activity of the sympathetic nervous system activity and subsequently contribute to the pathogenesis of hypertension. Here, we discuss the role of TH as a regulator of sympathetic activity and review several studies that investigated the relationship between genetic variations of TH and hypertension.