Sang-Kyung Jo

The Mildly Elevated Serum Bilirubin Level is Negatively Associated with the Incidence of End Stage Renal Disease in Patients with IgA Nephropathy

Oxidative stress plays various roles in the development and progression of IgA nephropathy, while bilirubin is known as a potent antioxidant. We therefore hypothesized that serum bilirubin would be associated with renal prognosis in IgA nephropathy. The study subjects comprised 1,458 adult patients with primary IgA nephropathy in Korea. We grouped patients according to the following quartile levels of bilirubin: <0.4 mg/dL (Q1), 0.4-0.5 mg/dL (Q2), 0.6-0.7 mg/dL (Q3), and >0.8 mg/dL (Q4). The outcome data were obtained from the Korean Registry of end-stage renal disease (ESRD). Eighty patients (5.5%) contracted ESRD during a mean follow-up period of 44.9 months. The ESRD incidences were 10.7% in Q1, 8.2% in Q2, 2.8% in Q3, and 2.8% in Q4 (p<0.001). The relative risk of ESRD compared to that in Q1 was 0.307 (95% confidence interval [CI], 0.126-0.751) in Q3 and 0.315 (95% CI, 0.130-0.765) in Q4. The differences of ESRD incidence were greater in subgroups of males and of patients aged 35 yr or more, with serum albumin 4.0 g/dL or more, with normotension, with eGFR 60 mL/min/1.73 m2 or more, and with proteinuria less then 3+ by dipstick test. In conclusion, higher bilirubin level was negatively associated with ESRD incidence in IgA nephropathy.

Urine Neutrophil Gelatinase-Associated Lipocalin Predicts Graft Outcome up to 1 Year After Kidney Transplantation

BACKGROUND Several recent reports demonstrated the usefulness of new biomarkers in early prediction of delayed graft function (DGF) and graft recovery after kidney transplantation (KT). It is unknown, however, whether these biomarkers would predict long-term graft outcome. In this study, we examined whether the biomarkers including neutrophil gelatinase-associated lipocalin (NGAL) and liver-type fatty acid-binding protein (L-FABP) can predict 1-year graft outcome as well as short-term graft function especially in patients with early graft function (EGF). METHODS This was a single-center, prospective observational study. Urine samples at 0 hours and 2 and 6 days were obtained and the level of NGAL and L-FABP were measured. RESULTS Of the 69 KT recipients enrolled, seven developed DGF, and the remaining 62 patients were finally enrolled as EGF recipients. EGF recipients were additionally divided into immediate graft function (IGF, n = 48) and slow graft function (SGF, n = 14) groups. Urinary NGAL (u-NGAL) level on day 2, but not L-FABP nor serum creatinine, was significantly higher in SGF compared to IGF group. Higher day 2 u-NGAL level was associated with more frequent development of SGF and, in addition, with significantly lower 1-year estimated glomerular filtration rate (eGFR). In multivariate logistic regression analysis, day 2 u-NGAL was a significant, independent factor for predicting poor long-term graft function (1-year eGFR < 60 mL/min/1.73 m(2)). CONCLUSIONS This study demonstrates the possibility that u-NGAL might be useful in predicting adverse 1-year outcome as well as short-term graft function even in EGF patients.

Urine Liver-Type Fatty Acid-Binding Protein Predicts Graft Outcome up to 2 Years After Kidney Transplantation

BACKGROUND Several new biomarkers for the detection of early tubular injury have been investigated in kidney transplant recipients. We recently identified day 2 urinary neutrophil gelatinase-associated lipocalin (NGAL) as a predictor of slow graft function and adverse 1-year outcome. In the present study, we further investigated the value of urinary NGAL and liver-type fatty acid binding protein (L-FABP) for predicting long-term graft outcomes up to 2 years. METHODS This study was a single-center, prospective observational study. Serial urinary NGAL and L-FABP levels at 0 hours, 2 days, and 6 days after kidney transplantation (KT) were measured, and the clinical data were assessed during the 2-year period after KT. RESULTS During the 2-year follow-up period, 13 (18.8%), 5 (7.2%), and 4 (5.8%) patients were diagnosed with acute T-cell-mediated rejection, acute antibody-mediated rejection (AMR) and chronic AMR, respectively. In addition, 10 patients (14.3%) developed calcineurin inhibitor toxicity and 6 (8.7%) developed BK viremia. The mean estimated glomerular filtration rates (eGFR) at 1 and 2 years after KT were 65.1 ± 19.1 and 58.5 ± 22.6 mL/min/1.73 m(2), respectively, When poor long-term graft function was defined as eGFR of less than 50 mL/min/1.73 m(2) at 2 years, elderly donors, acute rejection, and high 0-hour urinary L-FABP levels were significant risk factors. Furthermore, in rejection-free patients, L-FABP was strongly associated with poor long-term graft function (P = .006). Multivariate logistic regression analysis showed that high 0-hour L-FABP (P = .015) and acute rejection (P = .006) were independent factors predicting poor long-term graft function. Receiver operating characteristic analysis showed that the area under the curve for urinary L-FABP was 0.692 (P = .036). CONCLUSIONS Our results suggest that urinary L-FABP may be a useful predictor of adverse long-term outcomes in KT patients.

Postoperative Hemolytic Uremic Syndrome with Renal Cortical Necrosis Following Laparoscopic Hemicolectomy

Non-Shiga-like toxin-producing Escherichia coli (STEC) or atypical hemolytic uremic syndrome (aHUS) is observed in 5–10% of all hemolytic uremic syndrome (HUS) cases, and usually develops secondary to infections, malignancies, drugs, transplantation, pregnancy, and autoimmune disease. However, there has been no report on adult onset HUS initiated by surgical procedures except transplantation. We report a 66-year-old woman who incurred renal impairment on the first day after laparoscopic hemicolectomy. Hemolytic anemia, thrombocytopenia, absence of Shiga toxin associated disease, normal ADAMTS13 activity, and low serum C3 (not C4) were consistent with a diagnosis of aHUS. We performed plasma exchange with fresh frozen plasma. Nevertheless, deteriorated renal function was not recovered after the treatment. Although it is an uncommon postoperative complication, aHUS needs to be considered as a possible cause of acute kidney injury combined with thrombocytopenia and anemia after surgical procedures, considering its different treatment modality and poor outcomes.

Urinary Tissue Inhibitor of Metalloproteinase and Insulin-like Growth Factor–7 as Early Biomarkers of Delayed Graft Function After Kidney Transplantation

BACKGROUND Recently, urinary tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor-7 (IGFBP-7), markers for G1 cell cycle arrest, have been identified and validated in predicting the development of acute kidney injury in critically ill patients. It is unknown, however, whether these two biomarkers could predict the development of delayed graft function (DGF) after kidney transplantation (KT). METHODS This is a single-center, prospective, observational study. We enrolled 74 patients who underwent KT between August 2013 and December 2016. Urine sample were collected immediately after the operation. The primary outcome was development of DGF as defined by need for dialysis of more than 1 session within 7 days of KT. RESULTS Twenty-three patients (31%) were diagnosed with DGF. In univariate analysis, kidneys from expanded criteria donors, higher donor serum creatinine, lower donor estimated glomerular filtration rate, antithymoglobulin exposure, neutrophil gelatinase associated lipocalin, and urinary [TIMP-2]·[IGFBP7] were significantly different between early graft function and DGF. However, in multivariate analysis adjusting other factors, deceased donor and urinary [TIMP-2]·[IGFBP7] at 0 hours post-transplantation could predict the development of DGF. The receiver operating characteristic curve for prediction of DGF showed an area under the curve of 0.867 (sensitivity 0.86, specificity 0.71) for a cutoff value of 1.39. CONCLUSIONS Our results indicate that urine [TIMP-2]·[IGFBP7] immediately after transplantation could be an early, predictive biomarker of DGF in kidney transplantation.