title: European League Against Rheumatism recommendations for calcium pyrophosphate deposition. Part I: terminology and diagnosis.
abstract: OBJECTIVE
  To agree terminology and to develop recommendations for the diagnosis of calcium pyrophosphate deposition (CPPD).
  
  
  METHODS
  The European League Against Rheumatism (EULAR) CPPD Task Force, comprising 15 experts from 10 countries, agreed the terms and recommendations for diagnosis of CPPD using a Delphi consensus approach. Evidence was systematically reviewed and presented in terms of sensitivity, specificity and positive likelihood ratio (LR) to support diagnosis; ORs were used for association. Strength of recommendation (SOR) was assessed by the EULAR visual analogue scale.
  
  
  RESULTS
  It was agreed that 'CPPD' should be the umbrella term that includes acute calcium pyrophosphate (CPP) crystal arthritis, osteoarthritis (OA) with CPPD and chronic CPP crystal inflammatory arthritis. Chondrocalcinosis (CC) defines cartilage calcification, most commonly due to CPPD and detected by imaging or histological examination. A total of 11 key recommendations were generated on the topics of clinical features, synovial fluid (SF) examination, imaging, comorbidities and risk factors. Definitive diagnosis of CPPD relies on identification of SF CPP crystals. Rapid onset inflammatory symptoms and signs are suggestive but not definitive for acute CPP crystal arthritis. Radiographic CC is not highly sensitive or specific, whereas ultrasonography appears more useful (LR=24.2, 95% CI 3.51 to 168.01) for peripheral joints. Recognised risk factors for CPPD include ageing, OA and metabolic conditions such as primary hyperparathyroidism, haemochromatosis and hypomagnesaemia; familial forms are rare. SORs varied from 53 to 99 (maximum 100).
  
  
  CONCLUSIONS
  New terms for CPPD were agreed and 11 key recommendations for diagnosis of CPPD were developed using research evidence and expert consensus.
authors.affiliation: Academic Rheumatology, University of Nottingham, Clinical Sciences Building, City Hospital, Nottingham NG5 1PB, UK. weiya.zhang@nottingham.ac.uk
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Doherty
authors.forename: T
authors.initials: T
authors.lastname: Bardin
authors.forename: V
authors.initials: V
authors.lastname: Barskova
authors.forename: P-A
authors.initials: PA
authors.lastname: Guerne
authors.forename: T L
authors.initials: TL
authors.lastname: Jansen
authors.forename: B F
authors.initials: BF
authors.lastname: Leeb
authors.forename: F
authors.initials: F
authors.lastname: Perez-Ruiz
authors.forename: J
authors.initials: J
authors.lastname: Pimentao
authors.forename: L
authors.initials: L
authors.lastname: Punzi
authors.forename: P
authors.initials: P
authors.lastname: Richette
authors.forename: F
authors.initials: F
authors.lastname: Sivera
authors.forename: T
authors.initials: T
authors.lastname: Uhlig
authors.forename: I
authors.initials: I
authors.lastname: Watt
authors.forename: E
authors.initials: E
authors.lastname: Pascual
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002805:Chondrocalcinosis / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D015897:Comorbidity; D003697:Delphi Technique; D019317:Evidence-Based Medicine / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D009626:Terminology as Topic