muramidase and Kidney-Calculi

To address whether a renal tubular dysfunction is encountered in a particular patient subgroup with urolithiasis, the following parameters of tubular function were measured in urine taken in the morning from 214 stone formers after fasting: pH, excretion of lysozyme and gamma-glutamyl transferase (gamma-GT); fractional excretion (FE) of glucose, insulin, Mg, K, and HCO3 after an alkali loading; and the renal threshold for phosphate (TmP/GFR). The following diagnoses were made in the patient group: primary hyperparathyroidism (N = 8), medullary sponge kidneys (N = 21), hyperuricemia (N = 10), cystinuria (N = 2), struvite stone disease (N = 6), idiopathic hypercalciuria of the absorptive (N = 25), dietary (N = 69) or renal (N = 7) type, and normocalciuric idiopathic urolithiasis (N = 66). In 31% of the patients TmP/GFR was below 0.80 mmole/liter and in 13% of the patients, FE HCO3 after alkali loading was above normal. Urinary excretion of lysozyme and that of gamma-GT both were elevated in 17% of the patients. FE glucose, FE insulin, FE Mg, and FE K were elevated in 8, 9, 3, and 7% of the patients, respectively. This study demonstrates that a significant number of stone formers present with signs of renal tubular dysfunction, primarily involving the proximal tubule since apparent leaks of phosphate and of bicarbonate were most frequently encountered. The defects were not specific for a given etiologic group of patients; on the other hand, occurrence was related to the presence of large stones in the pyelocaliceal system at the time data were gathered. Taken together these data suggest that the tubulopathy in nephrolithiasis is the consequence rather than the cause of the stone.

Topics: Adolescent; Adult; Aged; Bicarbonates; Fasting; Female; gamma-Glutamyltransferase; Glycosuria; Humans; Hydrogen-Ion Concentration; Insulin; Kidney Calculi; Kidney Diseases; Kidney Tubules; Magnesium; Male; Middle Aged; Muramidase; Phosphates; Potassium

To screen for the presence of biomarkers involved in tubular injury and kidney damage in children with urolithiasis (RS), and to validate these proteins by ELISA.. Prospective-controlled pilot study of children with urolithiasis and their age- and gender-matched controls (HC). Initial screening test was done by quantitative proteomic comparison of pooled urine from RS versus HC, using liquid chromatography-mass spectrometry. Proteins of interest were selected using the following criteria: (1) ≥5 spectral counts; (2) ≥2-fold difference in spectral counts; and (3) ≤.05 P value for the Fisher's Exact Test. Validation was performed by ELISA testing. Statistical analysis was performed by Student t-test and Mann-Whitney U test.. Proteomic analysis identified 3 proteins of interest, Cystatin C (CYTC), neutrophil gelatinase-associated lipocalin (NGAL) and lysozyme C that were significantly over-represented in RS group versus HC. ELISA analysis revealed significantly increased urinary levels of CYTC and NGAL, and nearly significantly increased urinary levels of lysozyme C in RS group (N = 24) compared to controls (N = 13). Subgroup analysis showed significantly higher urinary levels of CYTC in both hypercalciuria (N = 14) and hypocitraturia (N = 10) versus HC (P <.05).. Children with urolithiasis showed significant increase in urinary CYTC and NGAL irrespective of their normal serum creatinine. These biomarkers indicate tubular injury and early kidney damage and represent valid tools for early screening when traditional tests are normal.

Topics: Adolescent; Biomarkers; Case-Control Studies; Child; Cross-Sectional Studies; Cystatin C; Early Diagnosis; Female; Humans; Kidney Calculi; Lipocalin-2; Male; Muramidase; Pilot Projects; Prospective Studies; Proteomics

An investigation was carried out into renal injury caused by extracorporeal piezoelectric lithotripsy (EPL) using an EDAP lithotriptor. Four urinary proteins, with a molecular weight range of 160000-14500, immunoglobulin G (IgG), N-acetyl-beta-glucosaminidase (NAG), albumin and lysozyme, were monitored in 27 patients 1 day before and 1, 7, 30, 90 and 180 days after unilateral EPL treatment. All patients had non-obstructive renal stones, previously untreated. Apart from 5 patients with stablised hypertension and 6 with persistent urinary infections due to the infected stones, all patients appeared healthy, as confirmed by clinical, haematological and biochemical investigations. Only albumin levels increased significantly 1 day after treatment; statistically nonsignificant increases and decreases were recorded in the levels of NAG and lysozome respectively. IgG was beyond the limit of detection (less than 0.5 mg%) in all patients. The albumin level returned to normal 7 days after treatment. The EPL-induced increase in albumin was recorded in 88% of patients, compared with increased levels of NAG in 46% and lysozyme in 64%, mainly in those with infected stones. These findings indicated a transient glomerular injury after EPL treatment.

Topics: Acetylglucosaminidase; Adult; Aged; Aged, 80 and over; Albuminuria; Female; Humans; Immunoglobulin G; Kidney; Kidney Calculi; Lithotripsy; Male; Middle Aged; Muramidase; Proteinuria; Time Factors

We have examined amyloid-like kidney stones, commonly found in patients on maintenance hemodialysis. Extraction of protein from the stones and Western blot analysis were performed. beta 2-Microglobulin (beta 2MG), serum amyloid P component (SAP), lysozyme and PAS-positive substance were identified in the stones. It is suggested that calcium-mediated association of beta 2MG, lysozyme, SAP and PAS-positive substance may have an important role in the process of the formation of kidney stones in chronic hemodialysis patients.

Topics: Adult; beta 2-Microglobulin; Blotting, Western; Glomerulonephritis; Humans; Kidney Calculi; Male; Muramidase; Periodic Acid-Schiff Reaction; Proteins; Renal Dialysis; Serum Amyloid P-Component

Lysozyme in the urine in concentrations greater than 3 micrograms per milligram of creatinine reflects renal tubular disease or dysfunction in patients without bowel disease or leukemia. We therefore used urine lysozyme assays to assess renal response to percutaneous nephrostomy and stone removal in 42 patients. Eight patients had striking increases (4.2-21.1 [mean 7.58] micrograms/mg creatinine) immediately after nephrostomy puncture in urine obtained directly from the punctured kidney. Lysozyme declined sharply thereafter and was within normal limits in all cases by postoperative day 3. This increase appeared to result from bleeding into the urine from the tract. Five other patients had lysozymuria on admission, only 1 of whom had a sharp increase after nephrostomy puncture. In the remaining patients, the lysozyme levels remained within normal limits throughout the hospital course. These data are further evidence of the absence of significant deleterious effects of nephrostomy puncture on the kidney.

Topics: Acute Kidney Injury; Adult; Aged; Clinical Enzyme Tests; Dilatation; Evaluation Studies as Topic; Humans; Kidney Calculi; Middle Aged; Muramidase; Nephrostomy, Percutaneous; Specimen Handling

To investigate whether overall tubular dysfunction is encountered in a particular subgroup of patients with urolithiasis, the following parameters of renal tubular function have been measured in fasting morning urine in 124 male stone formers: excretion of lysozyme and gamma-glutamyl transpeptidase (gamma-GT), fractional excretion (FE) or glucose, insulin, bicarbonate after an alkali load, and theoretical phosphate threshold (TmP/GFR). The following have been diagnosed: primary hyperparathyroidism (n = 3), medullary sponge kidneys (n = 5), hyperuricemia (n = 8), cystinuria (n = 1), struvite nephrolithiasis (n = 2), idiopathic hypercalciuria of the absorptive (n = 16), dietary (n = 46) or renal (n = 5) type, and normocalciuric idiopathic urolithiasis (n = 38). Urinary excretion of lysozyme and of gamma-GT were elevated in 14% and 21% of patients respectively; FE glucose and FE insulin were elevated in 6% and 8% of patients respectively. In 62% of the patients TmP/GFR was below 0.95 mmol/l and in 52% of the patients FE HCO3 after alkali load was above normal. The findings show that a large number of stone formers have signs of renal tubular dysfunction; apparent renal leaks of phosphate and of bicarbonate are the most frequently encountered defects; while they are not specific for a given etiologic group of patients, they have been found in each group. The latter observation suggests that nephrolithiasis itself can damage renal tubular function.

Topics: Adult; Bicarbonates; gamma-Glutamyltransferase; Glycosuria; Humans; Insulin; Kidney Calculi; Kidney Tubules; Male; Muramidase

Topics: Bacteriuria; Follow-Up Studies; Humans; Kidney Calculi; Muramidase; Paraplegia; Proteinuria; Pyelonephritis; Pyuria; Spinal Cord Injuries

Topics: Ammonia; Amylases; Calcium; Chemistry Techniques, Analytical; Enzyme Induction; Humans; Hyaluronoglucosaminidase; In Vitro Techniques; Kidney Calculi; Mucoproteins; Muramidase; Oxalates; Pancreatic Elastase; Papain; Phosphates; Proteins; Trypsin