Katarzyna Taranta-Janusz

Markers of systemic inflammation in children with hyperuricemia

Aim:  The purpose of the study was to investigate serum concentrations of the monocyte chemoattractant protein‐1 (MCP‐1) and high‐sensitivity CRP (hs‐CRP) in children with hyperuricemia and to evaluate its association with obesity.

Urinary monocyte chemoattractant protein-1 excretion in children with glomerular proteinuria

Abstract Objective. The aim of the study was to examine the urinary levels and clinical significance of monocyte chemoattractant protein-1 (uMCP-1) in children according to histological diagnosis and degree of proteinuria. Material and methods. Group I comprised 20 children with idiopathic nephrotic syndrome (INS), examined twice (A, during INS relapse; and B, after proteinuria subsided). Group II comprised 17 children with persistent proteinuria due to focal segmental glomerulosclerosis (FSGS). Group III included 12 children with immunoglobulin A nephropathy (IgAN). The control group (C) contained 22 healthy children. uMCP-1 was determined by enzyme-linked immunosorbent assay and expressed in pg/ml. Results. The median uMCP-1/creatinine ratio (uMCP-1/cr) in children with minimal change disease in relapse (IA) was significantly higher than in controls (p < 0.05), but when controlling for cyclosporine A (CsA) treatment the median uMCP-1 in children with INS, who were not treated with CsA, was 12.01 pg/mg cr (range 1.82–261.56 pg/mg cr) and did not differ from healthy controls. In examination IB the uMCP-1/cr concentration decreased and did not differ from healthy controls (p > 0.05). Children from groups II and III also had higher uMCP-1/cr levels than groups I and C (p < 0.01). uMCP-1/cr positively correlated with serum total cholesterol, low-density lipoprotein and protein/creatinine ratio in relapse (IA), and with serum cholesterol level in group B. A positive correlation between uMCP-1/cr and protein/creatinine ratio was also confirmed in groups II and III. Conclusion. Increased uMCP-1 was found in children with IgAN and FSGS correlated with proteinuria. A slight increase in uMCP-1 in children with INS was probably associated with CsA treatment.

Urinary angiotensinogen as a novel marker of obstructive nephropathy in children

Obstructive nephropathy due to congenital or acquired urinary tract obstruction is one of the most important causes of chronic renal failure in children. There is a need for identification of new noninvasive urinary biomarkers to provide the clinician with fast, specific and reliable diagnostic and prognostic tool.

New tubular injury markers in children with a solitary functioning kidney

BackgroundThe present study aimed to assess whether the urinary profiles of the lysosomal exoglycosidases N‑acetyl‑β‑hexosaminidase (HEX) and its isoenzymes A (HEX A) and B (HEX B), α-fucosidase (FUC), β-galactosidase (GAL), α-mannosidase (MAN), and β- glucuronidase (GLU) are useful biomarkers of tubular dysfunction in children with a solitary functioning kidney (SFK).MethodsWe measured the urinary activity of HEX, its isoenzymes HEX A, HEX B, and FUC, GAL, MAN, and GLU in 52 patients with SFK. Patients were subdivided into two groups: congenital SFK (cSFK)—unilateral renal agenesis and acquired SFK (aSFK)—unilateral nephrectomy. The reference group (RG) contained 60 healthy sex- and age-matched children.ResultsUrinary activity of all exoglycosidases in SFK was significantly higher than in RG (p < 0.05). There were no differences in exoglycosidase activity between cSFK and aSFK (p > 0.05). HEX and its isoenzymes HEX A and HEX B correlated negatively with estimated glomerular filtration rate (eGFR), and all estimated parameters correlated positively with albumin/creatinine ratio (p < 0.001).ConclusionUrinary activity of HEX, its isoenzymes HEX A and HEX B, and FUC, GAL, MAN, and GLU is elevated in children with SFK. Long-term follow-up studies in larger groups of children with SFK may help us to better understand their clinical significance.

Asymmetric and symmetric dimethylarginine in adolescents with hyperuricemia.

The purpose of this work was to investigate if in adolescents with hyperuricemia serum levels of asymmetric and symmetric dimethylarginine (ADMA, SDMA) are increased and if their levels correlate with serum uric acid (UA). Patients and Methods. The study group consisted of 58 hyperuricemic patients aged median 16.15 Q1–Q3 (14–17). The reference group contained 27 healthy individuals with normal serum UA level. ADMA and SDMA were measured by immunoenzymatic ELISA commercial kits and expressed in μmol/L. Serum UA was measured by the colorimetric method. Results. In hyperuricemic patients serum ADMA values did not differ between two estimated groups (P > 0.05); however, SDMA was significantly higher than in reference group (P < 0.01). Serum ADMA and SDMA correlated positively with UA (r = 0.34, P < 0.01) (r = 0.31, P < 0.01) and hs-CRP (r = 0.20, P < 0.05) (r = 0.36, P < 0.01), respectively. Conclusion. We demonstrated increased SDMA but not ADMA levels in adolescents with hyperuricemia and their correlation with serum uric acid levels. However, at the moment it is difficult to answer the question if it is just coexistence of these factors or any mechanism linking uric acid and methylated arginines really exists.

Osteopontin and symmetric dimethylarginine plasma levels in solitary functioning kidney in children

Aim:  The present study aimed to examine whether plasma osteopontin (pOPN) and symmetric dimethylarginine (pSDMA) are useful biomarkers of renal dysfunction in children with solitary functioning kidney (SFK).

Pediatric reference data on activity of urinary N-acetyl-β-D-hexosaminidase and its isoenzymes

PURPOSE The objective of the study was to establish age - dependent values of the urinary lysosomal exoglycosidases activities: N-acetyl-β-D-hexosaminidase (HEX) and its isoenzyme A (HEX A) as well as isoenzyme B (HEX B) in healthy children and adolescents. MATERIAL AND METHODS The study was performed using a random sample of 203 healthy children and adolescents (girls=99, boys=104), aged six months to 17.9 years. The activities of HEX, HEX A and HEX B were determined by a colorimetric method. The activities of the urinary HEX and its isoenzymes were expressed in pKat/μg of creatinine (pKat/μg Cr). RESULTS Median concentrations of urinary HEX, and its HEX A, HEX B isoenzymes in particular age groups were analyzed using ANOVA. Urinary HEX, HEX A and HEX B activities (pKat/μg Cr) were the highest in children below 3 years, in comparison to remaining age groups. There were statistically significant negative correlations between urinary HEX, HEX A as well as HEX B and age (r=-0.24, p<0.001 (HEX); r=-0.20, p<0.01 (HEX A); r=-0.26, p<0.001 (HEX B), respectively. We constructed the reference values for urinary activity of HEX, HEX A and HEX B (pKat/μg Cr) in centiles according to age, in three-year intervals. CONCLUSIONS Reported data present, for the first time, reference values for urinary activities of HEX and its isoenzymes HEX A and HEX B in children and adolescent.

Urine exoglycosidases are potential markers of renal tubular injury in children with ureteropelvic junction obstruction

Hydronephrosis caused by ureteropelvic junction obstruction (UPJO) is an important problem in children and young adults. The aim of this pilot study was to determine the urine profiles of a number of lysosomal exoglycosidases to see whether they indicated tubular renal damage in children with UPJO.

Is plasma symmetric dimethylarginine a suitable marker of renal function in children and adolescents

Abstract Objective. The purpose of this cross-sectional study was to identify whether plasma symmetric dimethylarginine (pSDMA) is a useful marker of renal function in children. Material and methods. The study group consisted of 35 patients with chronic kidney disease (CKD) stages 1–5 (median age 11.5 years), classified on the basis of estimated glomerular filtration rate (eGFR) and divided into three groups: group A, patients with CKD stages 1 and 2; group B, CKD stage 3; and group C, CKD stages 4 and 5. A control group included 42 age-matched healthy children. Commercial enzyme-linked immunosorbent assay kits were used to measure pSDMA and serum cystatin C (sCysC) concentrations. Results. The pSDMA and sCysC levels were significantly elevated in all CKD patients in comparison with healthy controls (p < 0.05). The pSDMA level in children was increased in the mild CKD (group A) (p < 0.01). There were also a significant difference in pSDMA concentration between groups A and B (p < 0.01). No differences in pSDMA levels were found between groups B and C. Receiver operating characteristics analyses showed that pSDMA was a better diagnostic tool than sCysC for identifying CKD stage among all the examined children and for detecting patients from group A (eGFR >60 ml/min/1.73 m2). Conclusions. Increased pSDMA and sCysC levels were found in CKD children. Further studies are required to confirm potential applications of pSDMA and CysC as useful biomarkers for the diagnosis and progression of CKD.

Salivary Biomarkers of Oxidative Stress in Children with Chronic Kidney Disease

There are still missing non-invasive biomarkers of chronic kidney disease (CKD) in children. Therefore, the aim of the study was to evaluate oxidative stress indicators in the non-stimulated (NWS) and stimulated saliva (SWS) of CKD children (n = 25) and healthy controls (n = 25). Salivary antioxidants (catalase (CAT), peroxidase (Px), superoxide dismutase (SOD), uric acid (UA), reduced glutathione (GSH), albumin), redox status (total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI)), and oxidative damage products (advanced glycation end products (AGE), advanced oxidation protein products (AOPP), malondialdehyde (MDA)) were evaluated. We have demonstrated the significantly higher activity of SWS GPx and SOD, as well as elevated concentrations of UA and albumin in NWS and SWS of CKD children vs. the control group. TAC, TOS and OSI were significantly higher only in SWS, while oxidative damage products (AGE, AOPP and MDA) were significantly higher in both NWS and SWS of CKD children. ROC analysis showed a considerably high diagnostic value of AOPP in both NWS and SWS of CKD children compared to controls (AUC = 0.92; 0.98). CKD is responsible for disturbances in salivary antioxidant systems and oxidative damage to proteins and lipids. Salivary AOPP can be a potential biomarker of CKD in children.