The urinary excretion of glycosaminoglycans and heparan sulphate in lupus nephritis.
Renal involvement in systemic lupus erythematosus (SLE) affects the disease outcome. In order to advance the diagnosis and the initiation of therapy, non-invasive diagnostic techniques are required. In this study, urinary glycosaminoglycans (GAG) and heparan sulphate (HS) were measured in 26 patients with biopsy-proven lupus nephritis and compared to 16 healthy controls. Uronic acid as a representative of GAGs in urine was determined spectrophotometrically with the meta-hydroxydiphenyl, following acid treatment. HS was determined as hexosamine by the method of Smith and Gilkerson. The median values of GAG (3.99 mg/g crea./day) and HS (2.41 mg/g crea./day) in patients were significantly ( P = 0.001) higher than in the control group (1.98 and 0.87, respectively). There was a positive correlation between GAG and HS values ( P = 0.000, r = 0.924) in SLE patients. There were no differences in HS excretion, microalbuminuria and SLE-DAI scores between different classes of lupus nephritis. However, GAG values in class 3 nephritis were significantly ( P = 0.033) higher than from both class 2 and class 4 lupus nephritis. There were no differences in all the measured parameters between normoalbuminuric, microalbuminuric and macroproteinuric patients. Furthermore, there were no correlations between GAG, HS excretions and SLE-DAI scores or microalbuminuria. These results suggest that urinary GAG and HS may serve as useful, independent and non-invasive markers of lupus nephritis.
Department of Clinical Biochemistry, Ege University Faculty of Medicine, Bornova, Izmir, Turkey. zparildar@yahoo.com
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Parildar
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Uslu
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Tanyalcin
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Doganavsargil
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Kutay
D000293:Adolescent; D000328:Adult; D004185:Disability Evaluation; D005260:Female; D006025:Glycosaminoglycans / Q000652:urine*; D006497:Heparan Sulfate / Q000652:urine*; D006595:Hexosamines / Q000032:analysis; D006801:Humans; D008181:Lupus Nephritis / Q000145:classification / Q000503:physiopathology / Q000652:urine*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D014574:Uronic Acids / Q000032:analysis
D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D006595:Hexosamines; D014574:Uronic Acids