• The Korean Journal of Nuclear Medicine
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• v.14 no.2
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• pp.10-17
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• 1980

Gentamicin is useful to the Gram negative bacterial infection, but its nephrotoxicity is a serious problem and the incidence is probably increasing. The toxicity of gentamicin to the kidney is site-specific to the proximal tubule. In this study, we measured daily peak and trough level of gentamicin, serum creatinine, serum $Beta_2$-microglobulin and 24-hr urine $Beta_2$-microglobulin in 10 gentamicin treated patients. All the patients had their peak levels of gentamicin in the safe therapeutic range, and their trough level showed no evidence of gentamicin accumulation. There was no patient who showed his daily serum creatinine and $Beta_2$-microglobulin rise significantly. But 24-hour urine $Beta_2$-microglobulin showed significant rise from basal level (mean $5.8{\pm}1.62{\times}$) on the 5 th day of gentamicin treatment. Thus, serial monitoring of proximal tubular function with urinary $Beta_2$-microglobulin excretion has potential value in the assessment of insults of gentamicin to this site. But clinical significance of raised urinary $Beta_2$-microglobulin excretion in relation to the serum creatinine should be further studied.

• Childhood Kidney Diseases
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• v.1 no.1
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• pp.38-45
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• 1997

Purpose : Vesicoureteral reflux(VUR) in childhood may be the primary cause of recurrent urinary tract infection and renal scarring. Renal ultrasonography, DMSA, and voiding cystourethrogram are the standard clinical methods for detection of vesicoureteral reflux. But these methods have many disadvantages such as invasiveness and high cost. So, we studied to observe the significance of urine ${\beta}_2$-microglobulin in association with other non-radiologic methods for predictng vesicoureteral reflux. Methods : We evaluated 40 patients with urinary tract infection who were admitted to Korea university Hospital from July 1993 to June 1994. Among them, 24 patients revealed urinary tract infection and vesicoureteral reflux(group A), 16 patients revealed only urinary tract infection(group B). Both groups were compared by presence of fever, hematuria, and proteinuria, positivity of CRP, and level of BUN, Cr, GFR by 99mTc-DTPA, urine ${\beta}_2$-microglobulin, 24 hours urine albumin. Results : 1) Among 24 patients who had vesicoureteral reflux, 14 had unilateral VUR, 10 had bilateral VUR, three kidneys with grade I, nine with grade II, eleven with grade III, eleven with grade IV by classification of International Reflux Study Committee. Among them, 14 patients had renal scar, five with type A, five with type B, four with type C, none with type D by Smellie's classification. 2) The mean of GFR, BUN, Cr, 24hrs urine albumin and the presence of hematuria and proteinuria showed no significant difference between group A and group B. The mean of urine ${\beta}_2$ microglobulin in group A and group B were $283.6{\pm}195.8{\mu}g/l$ and $78.7{\pm}48.5{\mu}g/l$ respectively, showing that group A had a higher value than group B (p<0.01). In case of ${\beta}_2$ microglobulin > $120{\mu}g/l$ and CRP(+), the sensitivity was 93.3% and the specificity is 77.8% for detecting of VUR. In case of ${\beta}_2$-microglobulin>$120{\mu}g/l$ and fever(+), the sensitivity was 92.2%, and the specificity was 62.5% for detecting of VUR Conclusions : If the level of urinary ${\beta}_2$-microglobulin is more than 120ug/l in children with urinary tract infection in association with fever(+) or CRP(+), it can predict VUR. So we can use it for early detection of VUR.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.143-149
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• 2008

Purpose : Urinary N-acetyl-beta-D-glucosaminidase(NAG) and beta 2-microglobulin(B2M) is considered to be a marker of tubulointerstitial injury. The aim of this study was to examine the urinary levels of NAG and B2M in children with various renal diseases. Methods : We studied 21 children(8.9$\pm$4.5 years, Male:Female=14:7) and they were divided into three groups: group I(steroid-sensitive nephrotic syndrome-4 patients), group II(various kinds of glomerulonephritis-4 patients), and group III(normal urinalysis or non-glomerular renal diseases-13 patients). Results : Urinary NAG levels in groups I and II were significantly higher than those in group III(19.4$\pm$11.5 and 30.0$\pm$30.1 vs. 4.7$\pm$3.9, P=0.01), while urinary B2M levels did not differ among the 3 groups, although urinary NAG levels were positively correlated with urinary B2M levels(r=0.49, P=0.03). Urinary NAG and B2M levels were all correlated with proteinuria(r=0.79, P<0.001 and r=0.68, respectively, P=0.001) serum albumin(r=-0.72, P<0.001 and r=-0.57, respectively, P=0.01) and cholesterol(r=0.58, P=0.006 and r=0.56, respectively, P=0.013) levels. Conclusions : Urinary excretions of NAG and B2M are increased in children with steroidsensitive nephrotic syndrome and various kinds of glomerulonephritis, suggesting tubular dysfunction might be present in these diseases.

• Journal of Yeungnam Medical Science
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• v.33 no.2
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• pp.105-111
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• 2016

Background: Neutropenic fever is one of the most common and potentially severe complications of chemotherapy in pediatric oncology patients, while urinary tract infection (UTI) is one of the most prevalent bacterial infections in these patients. Therefore, this study was conducted to investigate features of UTI with neutropenic fever in pediatric oncology patients. Methods: We retrospectively reviewed and analyzed the medical records, laboratory results and image findings of cases of neutropenic fever in the Department of Pediatrics of Yeungnam University Medical Center, South Korea between November 2013 and May 2015. Episodes were divided into two groups, UTI vs. non-UTI group according to the results of urine culture. The results were then compared between groups. The analysis was performed using IBM SPSS 23.0. A p-value <0.05 was considered to indicate a significant difference between groups. Results: Overall, 112 episodes of neutropenic fever were analyzed, among which 22 episodes (19.6%) showed organisms on urine culture and were classified as UTI. The remaining 90 episodes were classified as non-UTI. Only four episodes (18.2%) of the UTI group showed pyuria on urine analysis. In the UTI group, 76.5% were sensitive to the first line antibiotics and showed higher clinical response than the non-UTI group. Among hematologic malignancy patients, the UTI group revealed higher serum ${\beta}2$-microglobulin levels than the non-UTI group ($1.56{\pm}0.43mg/L$ vs. $1.2{\pm}0.43mg/L$, p<0.028). Conclusion: UTI in pediatric neutropenic fever responds well to antibiotics. Hematologic malignancy cases with UTI reveal increased serum ${\beta}2$-microglobulin level. These results will be helpful to early phase diagnosis of UTI.

• Clinical and Experimental Pediatrics
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• v.55 no.4
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• pp.136-142
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• 2012

Purpose: Urinary excretion of N acetyl-beta-D glucosaminidase (NAG) and ${\beta}_2$-microglobulin (${\beta}_2$-M) was increased in the presence of proximal tubular damage. Based on these urinary materials, we investigated the ability of expecting renal function in chronic glomerular diseases. In this study, we evaluated the relationship between glomerular filtration rate (GFR) urinary NAG, and urinary ${\beta}_2$-M. Methods: We evaluated 52 children with chronic kidney disease at the Chung-Ang University Hospital between January 2003 and August 2009. We investigated the 24-hour urinalysis and hematologic values in all 52 patients. Serum creatinine, creatinine clearance (Ccr), serum cystatin C, urinary ${\beta}_2$-M and urinary NAG were measured. Results: Out of 52 patients, there were 13 children with minimal change in disease, 3 children with focal segmental glomerulosclerosis, 17 children with immunoglobulin A nephropathy, 15 children with Henoch-Sch$\ddot{o}$nlein purpua nephritis, 3 children with poststreptococcal glomerulonephritis, and 1 child with thin glomerular basement membrane disease. In these patients, there were significant correlation between the Ccr and urinary NAG (r=-0.817; $P$ <0.01), and between the GFR (as determined by Schwartz method) and urinary NAG (r=-0.821; $P$ <0.01). In addition, there was a significant correlation between the GFR (as determined by Bokencamp method) and urinary NAG (r=-0.858; $P$ <0.01). Conclusion: In our study, there was a significant correlation between the GFR and urinary NAG, but there was no correlation between the GFR and urinary ${\beta}_2$-M, suggesting that the GFR can be predicted by urinary NAG in patients with chronic glomerular disease.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.72-79
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• 1999

Renal scarring associated with vesico-ureteral reflux(VUR) is one of the major causes of end stage renal failure and renal hypertension in children. Urinary ${\beta}_2$-microglobulin(MG) has been suggested as a potential marker for presence of renal tubular damage. This study was designed to evaluate the significance of random urine ${\beta}_2$-MG as a predictor of presence of vesico-ureteral reflux in children with urinary tract infection(UTI). 57 children with urinary tract infection were studied. Patients were devided into two groups; 35($78.9\%$) children have UTI without VUR and 12($21.1\%$) children have UTI and VUR. Beta2-MG and creatinine in random urine sample was measured to decide the excretion ratio(${\beta}_2$-MG/creatinine). Among the 57 children with UTI, 44 children were confirmed by urine culture study and 13 children suspected by compatible clinical feature. Random urine ${\beta}_2$-MG of VUR group ($2.2{\pm}5.91$ mg/L) were significantly higher than that of simple UTI group($0.19{\pm}0.16mg/L$)(P=0.03). The ${\beta}_2$-MG/creatinine ratio of VUR group($32.41{\pm}25.7$) were significantly higher than that of simple UTI group($3.93{\pm}3.44$)(P=0.007). In conclusion, random urine ${\beta}_2$-MG and excretion ratio deserved early predictor of presence of VUR in children with UTI. And this method was more simple and inexpensive than the method of measuring ${\beta}_2$-MG with 24 hour urine collection, so might be a useful screening test for VUR in children with UTI.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.977-982
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• 2003

Purpose : This study aimed to examine the excretion of various urinary proteins in children with a history of urinary tract infection(UTI), with or without vesicoureteral reflux(VUR) or reflux nephropathy, and to identify means of predicting the severity of VUR or the presence of reflux nephropathy as indicated by these markers, and to know how these markers are changed after resolution of VUR. Methods : We studied 30 children with previous UTI, without VUR and renal scarring(group I), 12 children with VUR, without evidence of renal scarring(group II), and 34 children with VUR and renal scarring(group III). 24-hour or 12-hour urine ${\beta}_2$ microglobulin(${\beta}_2$ MG), microalbumin and N-acetyl-${\beta}$-D-glucosaminidase(NAG) were measured in each child. Urinary protein excretions were analyzed according to the degree of VUR(mild VUR : a grade reflux I-III, severe VUR : a grade reflux IV-V). Cases of bilateral VUR were graded by the higher grade of reflux detected. A total of 46 children with primary VUR were followed. Among these patients, VUR was completely resolved in 16 children. Voiding cystourethrography(VCUG) and DMSA scan were performed every year. Values for urinary markers were estimated every year. Results : 24 or 12 hour urine microalbumin and NAG excretions were significantly increased in group III compared to group I(microalbumin : $27.7{\pm}26.0mg/gCr$ vs $15.0{\pm}10.7mg/gCr$, P<0.05, NAG : $15.2{\pm}18.7U/gCr$ vs $3.4{\pm}2.2U/gCr$, P<0.05). Urinary ${\beta}_2$ MG excretions were not significantly different between groups. Urinary NAG excretions were elevated in the group of children with severe VUR compared to mild VUR($26.8{\pm}27.1U/gCr$ vs $7.6{\pm}3.8U/gCr$, P<0.05). After resolution of VUR, urinary microalbumin and NAG excretions were decreased(P<0.05). Conclusion : Urinary microalbumin and NAG may be useful clinical indicators to predict the presence of reflux nephropathy and the resolution of VUR. Especially, urinary NAG excretions may be used as a possible method to predict the severity of VUR.

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.56-62
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• 2009

Purpose : The aim of this study was to evaluate the clinical usefulness of measurement of ${\beta}_2$ microglobulin (${\beta}_2$ MG), N-acetyl-$\beta$-D-glucosaminidase (NAG) of spot urine samples as indices of renal tubular damage and microalbumin of spot urine samples as a parameter of glomerular damage in children with vesicoureteral reflux (VUR) or renal defects. Methods : We studied 91 children with previous UTI. The children were classified as 62 children without VUR and renal defects (group I), 10 children with VUR, without renal defects (group II), and 19 children with VUR and renal defects (group III). Patients having VUR were separated according to the degree of VUR (mild VUR: VUR grade I-III, severe VUR: VUR grade IV-V). Urinary excretion of ${\beta}_$ microglobulin (${\beta}_2$ MG), microalbumin, N-acetyl-$\beta$-D-glucosaminidase (NAG), creatinine were measured in samples of morning urine specimens. Children with VUR or renal defects detected by voiding cystourethrography (VCUG) and DMSA renal scan were investigated. Results : Microalbumin/Cr ratio of spot urine was significantly increased in group III compared group I ($42.3{\pm}27.2\;mg/gCr$ vs $25.2{\pm}10.9\;mg/gCr$, P<0.05). NAG/Cr ratio of spot urine was significantly increased in group II compared group I ($3.70{\pm}23.4\;mg/gCr$ vs $18.7{\pm}12.7\;mg/gCr$, P<0.05). There was no statistically significant difference of ${\beta}_2$ MG/Cr ratio among three groups. Conclusion : Urinary microalbumin excretion of morning urine sample may be a simple and reliable clinical indicators for early identification of renal damage in children with VUR and renal defects. Urinary microalbumin excretion may be useful marker to predict the the severity of VUR.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.424-439
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• 1998

Urinary cadmium is used as a sensitive indicator for internal Cd dose, and increased excretion of $N-acetyl-\beta-D-glucosaminidase(NAG)$, $\beta_2-microglobulin(MG)$ and total protein are useful indices for renal dysfunction by chronic exposure to Cd. The target group was 184 inhabitant(82 men and 102 women) in an abandoned mine area known as exposure to low level Cd. The control group was took 160 individuals(64 men and 96 women) in Cd not-exposed area. Urinary Cd concentration was significantly higher in the target group than the control. The geometric mean of urinary Cd for male was $2.56{\mu}g/\ell,\;2.80{\mu}g/g$ creatinine and $2.50{\mu}g/S.G.$ in the target group and $1.19{\mu}g/\ell,\;1.36{\mu}g/g$ creatinine and $1.17{\mu}g/S.G.$ in the control. For female $2.69{\mu}g/\ell,\;3.94{\mu}g/g$ creatinine and $2.63{\mu}g/S.G.$ in the target group and $1.27{\mu}g/\ell,\;1.97{\mu}g/g$ creatinine and $1.25{\mu}g/S.G.$ in the control, respectively. In addition, urinary Cd of the target group had affected by the period of residence and dietary habit for the rice and the vegetables from the target area. These findings suggest the chronic exposure to Cd of the target population. Mean excretion of urinary NAG, $\beta_2-MG$ and total protein were not significant between two groups. In the target group, urinary NAG activity and total protein were significantly correlated with urinary Cd, but $\beta_2-MG$ was not related. Urinary excretion of NAG, $\beta_2-MG$ and total protein were significantly increased in $10\leqq$ than in <2 of urinary Cd level. In $2\sim10$ group of urinary Cd level, the excretion of NAG significantly increased while not showed for $\beta_2-MG$. In present study, urinary excretion of NAG was relatively sensitive than $\beta_2-MG$ in chronic exposure population to low level Cd.

• Toxicological Research
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• v.32 no.1
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• pp.57-64
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• 2016

Recently several studies reported that the renal toxicity of lead (Pb) and cadmium (Cd) may exist in even a low level exposure. In terms of the deterioration of tubular function, it affects the loss of divalent metals and leads to other complications, so renal tubular effect of heavy metals should be well managed. Considering the exposure to heavy metals in reality, it is hard to find the case that human is exposed to only one heavy metal. We designed a cross-sectional study using Korean Research Project on the Integrated Exposure Assessment (KRIEFS) data to investigate the renal effects of multiple metal exposure in general population. We used blood Pb and urinary Cd as exposure measures, and urinary N-acetyl-${\beta}$-D-glucosaminidase (NAG) and ${\beta}_2$-microglobulin (${\beta}_2$-MG) as renal tubular impairment outcome. We conducted linear regression to identify the association between each heavy metal and urinary NAG and ${\beta}_2$-MG. And then, we conducted linear regression including the interaction term. Of 1953 adults in KRIEFS (2010~2011), the geometric mean of blood Pb and urinary Cd concentration was $2.21{\mu}g/dL$ (geometric $SD=1.49{\mu}g/dL$) and $1.08{\mu}g/g\;cr$ (geometric $SD=1.98{\mu}g/g\;cr$), respectively. In urinary Cd, the strength of the association was also high after adjusting (urinary NAG: ${\beta}=0.44$, p < 0.001; urinary ${\beta}_2$-MG: ${\beta}=0.13$, p = 0.002). Finally, we identified the positive interactions for the two renal biomarkers. The interaction effect of the two heavy metals of ${\beta}_2$-MG was greater than that of NAG. It is very important in public health perspective if the low level exposure to multiple heavy metals has an interaction effect on kidney. More epidemiological studies for the interaction and toxicological studies on the mechanism are needed.