title: Urine fetuin-A values in relation to the presence of urolithiasis.
abstract: OBJECTIVE
  To investigate the relationship of urine fetuin-A and other promotors and inhibitors of urine crystalization with urolithiasis, as fetuin-A inhibits the precipitation of hydroxyapatite from supersaturated solutions of calcium and phosphate in vitro but no information on urine fetuin-A in patients with urolithiasis is available.
  
  
  METHODS
  In all, 39 patients with urolithiasis and 22 individuals with no urolithiasis or probands with undetected stones were involved. All patients underwent kidney ultrasonography and X-ray examination, and body mass index (BMI) was calculated. Serum creatinine, parathyroid hormone, calcium, magnesium, anorganic phosphate, uric acid and urine creatinine, albumin, alpha(1)-microglobulin, sulphate, oxalate, citrate and fetuin-A (ELISA) were determined.
  
  
  RESULTS
  The patients with urolithiasis had lower urine fetuin-A levels (median 4.9 vs 0.77 mg/day; P < 0.01) and citraturia levels (1.7 vs 5.1 mmol/day; P = 0.02); and higher calciuria (6.5 vs 5.2 mmol/day) and oxaluria (0.47 vs 0.25; P = 0.04). Patients with fetuin-A levels in the lowest quartile had an odds ratio of 36 compared with individuals in the highest quartile. The sensitivity of the urine fetuin-A level for urolithiasis was 97.4% and specificity was 100% (area under the curve 0.99; 95% confidence interval 0.94-1.0) using a urine fetuin-A threshold of <or=2.1 mg/day. Values of urine fetuin-A did not correlate with gender, age or BMI.
  
  
  CONCLUSIONS
  Our study indicates, for the first time, that patients with documented urolithiasis had lower fetuin-A concentrations independent of other conventional promotors and inhibitors of urine crystallization.
authors.affiliation: Department of Laboratory Medicine, Sternbek Hospital, Sternberk, Czech Republic. david.stejskal@nemstbk.cz
authors.forename: David
authors.initials: D
authors.lastname: Stejskal
authors.forename: Michal
authors.initials: M
authors.lastname: Karpisek
authors.forename: Radovan
authors.initials: R
authors.lastname: Vrtal
authors.forename: Vladimir
authors.initials: V
authors.lastname: Student
authors.forename: Pavlina
authors.initials: P
authors.lastname: Solichova
authors.forename: Richard
authors.initials: R
authors.lastname: Fiala
authors.forename: Pavel
authors.initials: P
authors.lastname: Stejskal
mesh_terms: D016022:Case-Control Studies; D003460:Crystallization; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012680:Sensitivity and Specificity; D052878:Urolithiasis / Q000097:blood / Q000473:pathology* / Q000652:urine; D000509:alpha-Fetoproteins / Q000378:metabolism* / Q000652:urine
chemical_list: D000509:alpha-Fetoproteins