Diagnostic Markers of Haematuria in Children with Kidney Disease

Background: A great diagnostic value in the genesis of hematuria in children with nephropathy is the change in cell membranes of the nephroteliy, enzymuria and microglobulinuria Objective To determine the level of renospecific enzymes in serum and urine (malonic dialdehyde-MDA, cholinesterase-ChE, γ-glutamyltranspeptidase, β2-microglobulin- β2-MG) in children with haematuria syndrome as diagnostic markers. Methods We examined 58 children with acute and chronic glomerulonephritis, 50 children with tubulointerstitial nephritis and kristaluriya. Comparison group consisted of 20 children with no signs of kidney damage.

Results: In children with acute and chronic glomerulonephritis observed a significant increase in activity of ChE in the urine (20.5 ±0.55 and 9.11 ±0.40 U/mg creatinine respectively, p<0.05, Se 85-92%, Sp 70 %, NPV 85-95%) and MDA in serum (4.60±0.20 and 4.28±0.25 mmol/L, respectively, p<0.05, Se 78-87%, NPV 85-95%). Children with kristaluriya and tubulointerstitial nephritis diagnosed by higher values of MDA in serum (4.22±0.29 and 4.41±0.34 mmol/L respectively, p<0.05, Se 90-93%, NPV 95%), γ-glutamyltranspeptidase in urine (72.9±3.25 and 95.5±3.92 U/mg creatinine respectively, p<0.05, Se 94-100%, Sp 64-73%, PPV 72%, NPV 95-100%) and β2-MG in urine (44.1±1.37 and 77.6±1.64 ng/ml respectively, p<0.05, Se 88-100%, Sp 80 %, PPV 78%, NPV 95-100%). Correlation analysis revealed specific metabolic markers: the conditions of haematuria glomerular origin - of ChE activity in urine (r=0.693, p<0.05) while for tubular hematuria - the activity of γ-glutamyltranspeptidase (r=0.777, p <0.05) and the level of β2-MG in urine (r=0.669, p<0.05).

Conclusions: Increased urinary excretion of γ-glutamyltranspeptidase, β2-MG and increased content of MDA in serum of children with the syndrome of haematuria indicates damage of cell membranes nephrotelial proximal tubules of the kidneys and is an early marker of non-glomerular (tubular) haematuria. Increased urinary excretion of ChE with normal levels in urine β2-MG, γ-glutamyltranspeptidase and elevated levels of MDA in blood serum are markers of glomerular kidney damage.