이지하, 한승우, 허현, 오주환, 선인오

195

￭♣

￭

Urinary exosomal microRNA-21 as a marker of scrub typhus associated acute kidney injury

예수병원 내과

*

이지하, 한승우, 허현, 오주환, 선인오

Background/Aims: Extracellular vesicles contain various molecules including DNA, mRNA, and microRNA (miRNA), and are involved in cell-to-cell communication. MiRNA-21 is reported to be a biomarker for detection of acute kidney injury (AKI). The aim of this study is to investigate the clinical sig- nificance of urinary exosomal miRNA-21 for AKI in patients with scrub typhus. Methods: In a cross-sectional study, we collected 138 urine samples at the time of admission from 145 patients with scrub typhus. For 25 patients with scrub typhus-associated AKI and 25 age, sex-matched patient without AKI, we measured miRNA-21 in urinary exosomal fraction. Then, we investigated correation between urinary exosomal miRNA-21 and clinical parameters.

Results: Compared with patients in the non-AKI group, patients in the AKI group had worse renal function (30 ± 13 vs. 56 ± 20 mL/min/1.73m², p<0.01) at admission and higher total leukocyte counts (10.4 × 103/ mL vs. 5.2 × 103/mL, p<0.01). Serum NGAL (404 ± 269 vs. 104 ± 51 ng/mL, p<0.01) and urine NGAL/creatinine values (371± 672 vs. 37± 57 ng/mg, p<0.01) were higher in the AKI group than in the non-AKI group. The levels of urinary exosomal miRNA-21 (17.8 ± 1.8 vs. 20.1 ± 1.2 ∆Ct value of miRNA-21, p<0.01) were higher in the AKI group than in the non-AKI group, while those levels in uri- nary supernatant were not different between two groups. Urinary exosomal miRNA-21 levels correlated directly with total leukocyte counts and serum NGAL values and inversely with estimated glomerular filtration rate. The reciver operator characteristics curve analysis for urinary exosomal miRNA-21 showed good discriminative power for detecting scrub typhus-associated AKI, with area under the curved value of 0.887. Conclusions: Urinary exosomal miRNA-21 could be a surrogate markers for the diagnosis of scrub typhus–associated AKI.

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Fecal calprotectin correlates with serum albumin level in patients with chronic kidney disease

1가톨릭대학교 의과대학 내과학교실, ²가톨릭대학교여의도성모병원 내과

*

최경석

, 손종호

, 고은실

, 정성진

Background/Aims: Persistent inflammation, a characteristic feature in chronic kidney disease, contributes to decreased serum albumin levels and plays a central role in the Malnutrition, Inflammation and Atherosclerosis (MIA) syndrome, which is associated with poor clinical outcomes. Altered bowel habit is also a highly frequent status among patients with chronic kidney disease potentially due to their low fiber and fluid intake, medications, multiple comorbid- ities and dysbiosis of the gut microbiota. In this study, we have explored whether measurement of fecal calprotectin, a commonly used marker for increased neutrophil migration and local inflammation in gastrointestinal diseases, could reflect a state of low serum albumin in patients with chronic kidney disease.

Methods: Clinical and biochemical data including stool samples for calprotectin were collected from 129 chronic kidney disease patients with no history of inflammatory bowel disease. Results: Fecal calprotectin was not different according to estimated glomerular filtration rate, degree of proteinuria and medication of polystyrene sulfonate and ferrous sulfate. However, it was significantly and negatively correlated with serum albumin and total protein con- centrations in patients with chronic kidney disease (r=-0.260, p=0.003 and r=-0.250, p=0.004, respectively). Patients with higher tertile of fecal calprotectin were older and likely to have lower hematocrit and serum total protein levels. Multivariable linear regression analysis showed that fecal calprotectin was significantly correlated with serum albumin (β=-0.268, p=0.012). In adjusted multivariable linear regression, serum albumin and total protein levels were independently correlated with fecal calprotectin (β=-0.229, p=0.012 and β=-0.227, p=0.025, respectively). Conclusions: These observations that serum al- bumin and total protein were significantly correlated with fecal calprotectin in patients with chronic kidney disease, suggest that the bowel inflammatory re- sponse may be another contributing factor.

195

￭♣

￭

Urinary exosomal microRNA-21 as a marker of scrub typhus associated acute kidney injury

예수병원 내과

*

이지하, 한승우, 허현, 오주환, 선인오

Background/Aims: Extracellular vesicles contain various molecules including DNA, mRNA, and microRNA (miRNA), and are involved in cell-to-cell communication. MiRNA-21 is reported to be a biomarker for detection of acute kidney injury (AKI). The aim of this study is to investigate the clinical sig- nificance of urinary exosomal miRNA-21 for AKI in patients with scrub typhus. Methods: In a cross-sectional study, we collected 138 urine samples at the time of admission from 145 patients with scrub typhus. For 25 patients with scrub typhus-associated AKI and 25 age, sex-matched patient without AKI, we measured miRNA-21 in urinary exosomal fraction. Then, we investigated correation between urinary exosomal miRNA-21 and clinical parameters.

Results: Compared with patients in the non-AKI group, patients in the AKI group had worse renal function (30 ± 13 vs. 56 ± 20 mL/min/1.73m², p<0.01) at admission and higher total leukocyte counts (10.4 × 103/ mL vs. 5.2 × 103/mL, p<0.01). Serum NGAL (404 ± 269 vs. 104 ± 51 ng/mL, p<0.01) and urine NGAL/creatinine values (371± 672 vs. 37± 57 ng/mg, p<0.01) were higher in the AKI group than in the non-AKI group. The levels of urinary exosomal miRNA-21 (17.8 ± 1.8 vs. 20.1 ± 1.2 ∆Ct value of miRNA-21, p<0.01) were higher in the AKI group than in the non-AKI group, while those levels in uri- nary supernatant were not different between two groups. Urinary exosomal miRNA-21 levels correlated directly with total leukocyte counts and serum NGAL values and inversely with estimated glomerular filtration rate. The reciver operator characteristics curve analysis for urinary exosomal miRNA-21 showed good discriminative power for detecting scrub typhus-associated AKI, with area under the curved value of 0.887. Conclusions: Urinary exosomal miRNA-21 could be a surrogate markers for the diagnosis of scrub typhus–associated AKI.

￭♣

￭

Fecal calprotectin correlates with serum albumin level in patients with chronic kidney disease

1가톨릭대학교 의과대학 내과학교실, ²가톨릭대학교여의도성모병원 내과

*

최경석

, 손종호

, 고은실

, 정성진

Background/Aims: Persistent inflammation, a characteristic feature in chronic kidney disease, contributes to decreased serum albumin levels and plays a central role in the Malnutrition, Inflammation and Atherosclerosis (MIA) syndrome, which is associated with poor clinical outcomes. Altered bowel habit is also a highly frequent status among patients with chronic kidney disease potentially due to their low fiber and fluid intake, medications, multiple comorbid- ities and dysbiosis of the gut microbiota. In this study, we have explored whether measurement of fecal calprotectin, a commonly used marker for increased neutrophil migration and local inflammation in gastrointestinal diseases, could reflect a state of low serum albumin in patients with chronic kidney disease.

Methods: Clinical and biochemical data including stool samples for calprotectin were collected from 129 chronic kidney disease patients with no history of inflammatory bowel disease. Results: Fecal calprotectin was not different according to estimated glomerular filtration rate, degree of proteinuria and medication of polystyrene sulfonate and ferrous sulfate. However, it was significantly and negatively correlated with serum albumin and total protein con- centrations in patients with chronic kidney disease (r=-0.260, p=0.003 and r=-0.250, p=0.004, respectively). Patients with higher tertile of fecal calprotectin were older and likely to have lower hematocrit and serum total protein levels. Multivariable linear regression analysis showed that fecal calprotectin was significantly correlated with serum albumin (β=-0.268, p=0.012). In adjusted multivariable linear regression, serum albumin and total protein levels were independently correlated with fecal calprotectin (β=-0.229, p=0.012 and β=-0.227, p=0.025, respectively). Conclusions: These observations that serum al- bumin and total protein were significantly correlated with fecal calprotectin in patients with chronic kidney disease, suggest that the bowel inflammatory re- sponse may be another contributing factor.