title: Ultrasound sensitivity to changes in gout: a longitudinal study after two years of treatment.
abstract: OBJECTIVE
  The goals of our study are to evaluate the urate-lowering therapy (ULT) effect on gout ultrasound (US) lesions and to explore US sensitivity to change in gout patients.
  
  
  METHODS
  Patients with chronic and symptomatic gout, confirmed by crystal identification, were prospectively included. Clinical and US assessments were performed at baseline and after 6, 12 and 24 months of ULT. The presence of double contour sign (DCS) and US- detectable tophi were assessed in the first metatarsophalangeals, the knees and patellar tendons. The mean and standard deviation were calculated for each parameter. The correlation between the clinical and US parameters was assessed by calculating Pearson's correlation coefficient. Sensitivity to change in the US examinations was assessed by estimating the smallest detectable difference (SDD).
  
  
  RESULTS
  Twenty-three consecutive patients were included (96% men; mean age 59 ± 11 years). DCS and US tophi were detected in 73.9% and 91.3% of patients at baseline. A significant parallel improvement in the serum urate, clinical parameters and US lesions was found at the follow-up assessment. The SDD values for the global DCS and tophi were 0.52 and 0.69, respectively, which were smaller than the differences achieved over the course of the two years. A significant correlation between DCS and clinical parameters was observed (r =0.49, p=0.038).
  
  
  CONCLUSIONS
  Ultrasound findings in gout patients show sensitivity to change and concurrent validity with uric acid reduction after ULT in gout patients. US can be a useful tool for gout tophus burden monitoring.
authors.affiliation: Rheumatology Unit, Hospital Universitario La Paz, Madrid, Spain. diapeitead@gmail.com.
authors.forename: Diana
authors.initials: D
authors.lastname: Peiteado
authors.affiliation: Rheumatology Unit, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Villalba
authors.affiliation: Rheumatology Unit, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Martín-Mola
authors.affiliation: Rheumatology Unit, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Balsa
authors.affiliation: Rheumatology Unit, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Eugenio
authors.initials: E
authors.lastname: De Miguel
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D015536:Down-Regulation; D005260:Female; D006073:Gout / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D006074:Gout Suppressants / Q000627:therapeutic use*; D006801:Humans; D007596:Joints / Q000000981:diagnostic imaging* / Q000187:drug effects* / Q000378:metabolism; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler; D014527:Uric Acid / Q000097:blood
chemical_list: D015415:Biomarkers; D006074:Gout Suppressants; D014527:Uric Acid