Role of Inhibitor Deficiency in Urolithiasis

A very simple analytical procedure with dimethylmethylene blue as photometric reagent was applied for the evaluation of glycosaminoglycan (GAG) urinary excretions and concentrations in both sexes, calcium oxalate stone formers, and a control group. The GAG concentrations varied significantly in stone formers (males and females) and in the control group; moreover, in some individual cases, a deficit of urinary GAGs was clearly detected. Apart from important inhibitory effects of GAGs on heterogenous calcium oxalate nucleation, the low urinary GAG content could be the cause of a pathological epithelium, favoring stone formation. The dimethylmethylene blue method is recommended as a quick screening procedure to determine a GAG deficit.

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“…In short, while some authors found no difference at all [7][8][9][10]. Others claimed that stone formers have a lower GAG excretion [II.…”

Section: Introductionmentioning

confidence: 99%

Glycosaminoglycans and Oxalocalcic Urolithiasis

Grases

Llompart²,

Conte³

et al. 1994

Nephron

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“…Lithogenic protection in children’s urine is higher compared with adults due to a higher excretion of macromolecules, including increased excretion of Cit, GAG and fibronectin [ 2 , 4 , 43 , 44 ]. Elevated GAGs excretion in infants and toddlers’ urine is explained by increased excretion of proteoglycans in longitudinally growing bones [ 43 ]. This protective role of GAGs is consistent with observation for the lowest incidence of urinary stone formation in children 0–3 years [ 45 ].…”

Section: Discussionmentioning

confidence: 99%

“…This protective role of GAGs is consistent with observation for the lowest incidence of urinary stone formation in children 0–3 years [ 45 ]. Articles describing excretion of GAGs in urine are scarce and with no clear consensus [ 16 , 42 , 43 , 44 , 46 ]. Reduced excretion of GAGs’ in urine is rarely reported in children [ 15 , 42 , 44 , 46 ].…”

Section: Discussionmentioning

confidence: 99%

Age-Specific Excretion of Calcium, Oxalate, Citrate, and Glycosaminoglycans and Their Ratios in Healthy Children and Children with Urolithiasis

et al. 2021

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We analyzed children with urolithiasis with age- and gender-matched healthy children. Calcium (mmol/mmol creatinine) and the calcium/citrate ratio (mol/mmol) are the only variables that differentiate children before puberty from healthy children (ROC analysis confirmed only calcium/citrate as a significant variable with cut-off value > 0.84). Peri-pubertal children are distinguished from age- and gender-matched healthy children by the following variables: citrate (mmol/mol creatinine), calcium/citrate (mol/mmol), oxalate/glycosaminoglycans (mmol/g), oxalate/citrate ratios (mmol/mmol) and oxalate/(citrate × glycosaminoglycans) (mol oxalate × mol creatinine)/(mol citrate × g glycosaminoglycans). All variables were confirmed by ROC analysis with cut-off values ≤ 327.87, >1.02, >11.24, >0.12 and >0.03, respectively. These results indicate a different risk of urinary stones development before puberty vs. pubertal/postpubertal children and increasing importance (deficiency) of citrate and glycosaminoglycans in such children. J48 classifier confirmed the importance of the oxalate/(citrate × glycosaminoglycans) and the calcium/citrate ratios (Ox/Cit × GAG 0.22 and Cit/GAG 0.612) with the practically applicable classification tree for distinguishing between pubertal/postpubertal children with urolithiasis with age- and gender-matched healthy children.

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“…We have not mentioned macromolecular promoters and inhibitors or the concept of inhibitory macromolecule deficiency, but routine determination of such substances is impractical (90)(91)(92)(93)(94). In the future, macromolecular factors may eventually be incorporated in the Equil2 program.…”

Section: Discussionmentioning

confidence: 99%

Urinary saturation and risk factors for calcium oxalate stone disease based on spot and 24-hour urine specimens

Ogawa

Yonou²,

Hokama³

et al. 2003

Front Biosci

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In 222 random spot urine specimens, the calcium concentration and calcium oxalate saturation [DG(CaOx)] were significantly higher among stone formers than among non-stone formers, while the citrate and creatinine-corrected citrate concentrations were lower. In 188 24-hour urine specimens, magnesium excretion was lower among stone formers than non-stone formers, while the creatinine-corrected calcium concentration and DG(CaOx) were higher. Among stone formers, there was no gender difference in the urinary concentrations of calcium, oxalate, citrate, magnesium, and DG(CaOx), but the creatinine-corrected calcium, citrate, and magnesium concentrations were higher in women, as well as 24-hour citrate excretion. The levels of calcium and oxalate have a major influence on DG(CaOx), while citrate and magnesium levels have a minor influence. DG(CaOx) was correlated with calcium and oxalate excretion, as well as with the creatinine-corrected calcium and oxalate concentrations. Approximately 5% of 24-hour urine specimens showed critical supersaturation, 80% showed metastable supersaturation, and 15% were unsaturated. Hypercalciuria or hyperoxaluria was fairly common (30% and 40%) in critically supersaturated urine, while it was less common (22.4% and 8.6%) in metastably supersaturated urine and was not detected in unsaturated urine. Hypocitraturia and/or hypomagnesiuria was more common (63.8-80%) at any saturation. The urinary calcium, oxalate, and citrate concentrations, as well as the creatinine-corrected calcium, oxalate, citrate, and magnesium concentrations and DG(CaOx), showed a significant correlation between 57 paired early morning spot urine and 24-hour urine specimens. The creatinine-corrected calcium and citrate concentrations of the early morning urine specimens were significantly correlated with the levels of calcium and citrate excretion in the paired 24-hour urine specimens. In conclusion, no parameter other than urinary saturation gives more than a vague indication of the risk of lithogenesis, so DG(CaOx) in either early morning urine or 24-hour urine specimens appears to be the best predictor of stone risk. Finally, the creatinine-corrected calcium and citrate concentrations in early morning urine can be used as a substitute for measuring 24-hour excretion.

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Role of Inhibitor Deficiency in Urolithiasis

Cited by 29 publications

References 14 publications

Glycosaminoglycans and Oxalocalcic Urolithiasis

Glycosaminoglycans and Oxalocalcic Urolithiasis

Age-Specific Excretion of Calcium, Oxalate, Citrate, and Glycosaminoglycans and Their Ratios in Healthy Children and Children with Urolithiasis

Urinary saturation and risk factors for calcium oxalate stone disease based on spot and 24-hour urine specimens

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