title: Predictive Factors for Spontaneous Stone Passage and the Potential Role of Serum C-Reactive Protein in Patients with 4 to 10 mm Distal Ureteral Stones: A Prospective Clinical Study.
abstract: OBJECTIVE
  We investigated possible predictive factors for spontaneous stone passage and the potential role of serum C-reactive protein and white blood count in patients with 4 to 10 mm distal ureteral stones.
  
  
  METHODS
  A total of 251 patients who presented with renal colic secondary to distal ureteral stone were included in study. Patients were grouped according to spontaneous stone passage. Serum C-reactive protein, white blood count and other possible factors were investigated for their potential predictive value for spontaneous stone passage at a followup of 5 weeks. Potential predictive factors for spontaneous stone passage were evaluated with univariate and multivariate analyses. ROC curve analysis was performed to find an optimal cutoff value for serum C-reactive protein according to spontaneous stone passage. Statistical significance was considered at p <0.05.
  
  
  RESULTS
  Spontaneous stone passage was observed in 135 patients (53.8%) in group 1 while 116 (46.2%) in group 2 did not expel the stone spontaneously. Median stone size was 5.7 mm. Stone size, serum C-reactive protein and white blood count were significantly higher in group 2 than in group 1. The number of patients with hydronephrosis and the number with spontaneous stone passage history were significantly lower in group 2 compared to group 1. The cutoff value of serum C-reactive protein provided by ROC analysis was 0.506 mg/l. Time to spontaneous stone passage was significantly higher in patients with serum C-reactive protein above the threshold and in patients with ureteral stones greater than 6 mm.
  
  
  CONCLUSIONS
  Stone size, previous spontaneous passage, hydronephrosis, serum C-reactive protein and white blood count can be used to predict spontaneous stone passage in patients with 4 to 10 mm distal ureteral stones. A serum C-reactive protein level of 0.506 mg/l can serve as a cutoff value to predict spontaneous stone passage.
authors.affiliation: Department of Urology, Keçioren Training and Research Hospital, Ankara, Turkey. Electronic address: cihatozcan@hotmail.com.
authors.forename: Cihat
authors.initials: C
authors.lastname: Özcan
authors.affiliation: Department of Urology, İzmir Bozyaka Training and Research Hospital, İzmir, Turkey.
authors.forename: Ozgu
authors.initials: O
authors.lastname: Aydoğdu
authors.affiliation: Department of Urology, Keçioren Training and Research Hospital, Ankara, Turkey.
authors.forename: Cagri
authors.initials: C
authors.lastname: Senocak
authors.affiliation: Department of Urology, Keçioren Training and Research Hospital, Ankara, Turkey.
authors.forename: Erman
authors.initials: E
authors.lastname: Damar
authors.affiliation: Department of Urology, Keçioren Training and Research Hospital, Ankara, Turkey.
authors.forename: Asir
authors.initials: A
authors.lastname: Eraslan
authors.affiliation: Department of Biostatistics, Ankara University, Ankara, Turkey.
authors.forename: Derya
authors.initials: D
authors.lastname: Oztuna
authors.affiliation: Department of Urology, Keçioren Training and Research Hospital, Ankara, Turkey.
authors.forename: Omer Faruk
authors.initials: OF
authors.lastname: Bozkurt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002097:C-Reactive Protein / Q000032:analysis*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012075:Remission, Spontaneous; D014514:Ureteral Calculi / Q000097:blood* / Q000473:pathology; D055815:Young Adult
chemical_list: D002097:C-Reactive Protein
keywords: C-reactive protein; calculi; leukocyte count; prognosis; ureter