Glycosaminoglycan Excretion In Patients Research Articles

Urinary Excretion of Glycosaminoglycans in Patients with Urolithiasis

The interaction between tubular epithelial cells and calcium oxalate crystals or oxalate ions is a very precarious event in the lithogenesis. Urine contains ions, glycoproteins and glycosaminoglycans that inhi bit the crystallization process and may protect the kidney against lithogenesis. Hundred patients (24 women and 76 men) with a history of stone disease and hundred controls (25 women and 75 men) were evaluated for urinary GAG concentration. By using a new dye-binding assay, the total GAG concentration in the urine was measured and corrected to urinary creatinine levels (milligram of GAG per gram creatinine). There was a preponderance of urinary stones in males ; the highest incidence being in Group 2. Excretion of GAGs in 24-hour urine sample was significantly lower in patients compared to controls, for males in all age groups and for females, however, there was no statistically significant difference in the urinary GAGs value between males and females in a given age group for either controls or patients. The urinary GAGsexcretion idecreased with age in controls, but the levels in patients were lower. Conclusion: This study shows that low urinary GAGsareassociated with urinary stones in patients.Our studylead us to propose that urinary GAG may play an important role in

Mucopolysaccharidoses in northern Brazil: Targeted mutation screening and urinary glycosaminoglycan excretion in patients undergoing enzyme replacement therapy

Mucopolysaccharidoses (MPS) are rare lysosomal disorders caused by the deficiency of specific lysosomal enzymes responsible for glycosaminoglycan (GAG) degradation. Enzyme Replacement Therapy (ERT) has been shown to reduce accumulation and urinary excretion of GAG, and to improve some of the patients’ clinical signs. We studied biochemical and molecular characteristics of nine MPS patients (two MPS I, four MPS II and three MPS VI) undergoing ERT in northern Brazil. The responsiveness of ERT was evaluated through urinary GAG excretion measurements. Patients were screened for eight common MPS mutations, using PCR, restriction enzyme tests and direct sequencing. Two MPS I patients had the previously reported mutation p.P533R. In the MPS II patients, mutation analysis identified the mutation p.R468W, and in the MPS VI patients, polymorphisms p.V358M and p.V376M were also found. After 48 weeks of ERT, biochemical analysis showed a significantly decreased total urinary GAG excretion in patients with MPS I (p < 0.01) and MPS VI (p < 0.01). Our findings demonstrate the effect of ERT on urinary GAG excretion and suggest the adoption of a screening strategy for genotyping MPS patients living far from the main reference centers.

Urinary glycosaminoglycan excretion in patients with primary nocturnal enuresis

AimThe aim of this study was to determine whether primary nocturnal enuresis (PNE) leads to alterations in glycosaminoglycan (GAG) excretion.MethodsTwenty subjects (mean age 8.7 years, M/F 15/5) with PNE were included in the study. Twenty-two healthy subjects were selected as a control group (mean age 8.7 years, M/F 14/8). Urinary GAG excretion was measured using a modified dimethylmethylene blue (DMD) assay of 24-hour urine.ResultsThe mean urinary GAG content was 33.9 mg/g and 23.8 mg/g creatinine in patients with PNE and controls, respectively; patients with PNE thus had a higher mean GAG excretion than did age-matched controls (p < 0.05). The association between GAG level and enuresis frequency bordered on significance (p = 0.068).ConclusionsGAG excretion in patients with PNE was significantly higher than in normal children, suggesting that measurement of urinary GAG may be useful in evaluating physiopathological conditions of the bladder wall. Further studies are needed to confirm this finding.

Urinary excretion of glycosaminoglycans in patients with isolated nocturnal enuresis or combined with diurnal incontinence.

To determine variations in the amount of glycosaminoglycans (GAGs) excreted by patients with nocturnal enuresis and/or diurnal incontinence. The study included 27 patients (aged 5-15 years) with nocturnal enuresis and/or diurnal incontinence, and 27 healthy age-matched children. Their urinary GAG excretion was assessed over 24 h using the sodium tetraborate-carbazole method. Patients with nocturnal enuresis and/or diurnal incontinence had higher mean values of urinary GAG excretion than age-matched controls. There were significant differences in GAG excretion between those with nocturnal enuresis and diurnal incontinence and those with nocturnal enuresis alone. GAG excretion in patients with nocturnal enuresis and/or diurnal incontinence was significantly higher than in normal children, suggesting that measuring urinary GAGs may be useful in evaluating physiopathological conditions of the bladder wall, and hence in monitoring potential damage in the bladder mucosa.

Urinary Glycosaminoglycan Excretion in Rheumatic Diseases

We used Alcian Blue (AB) and dimethylmethylene blue (DMB) methods to measure glycosaminoglycan (GAG) excretion in the first morning urine specimens of patients with osteoarthritis (OA), ankylosing spondylitis (AS), and rheumatoid arthritis (RA) in different stages of disease. By the AB method, urinary GAG excretion in patients with RA was not different from healthy control subjects. However, the DMB method showed significant differences (in milligrams of GAG per gram of creatinine) for OA (median 25.4, range 14.3-44.0, P less than 0.01, n = 23) and RA patients (median 33.0; range 10.0-147.6; P less than 0.001, n = 63) in comparison with unaffected individuals (median 20.2; range 8.9-41.4, n = 38). We noted a significant difference in urinary GAG excretion between RA and OA patients (P less than 0.01) and between RA and AS (P less than 0.01) patients. The DMB method was further investigated by clinical decision analysis. The DMB method is simple and rapid and may be useful in diagnosing RA by distinguishing between RA and OA or AS.