title: Calcium pyrophosphate deposition disease mimicking polymyalgia rheumatica: a prospective followup study of predictive factors for this condition in patients presenting with polymyalgia symptoms.
abstract: OBJECTIVE
  To assess the characteristics of calcium pyrophosphate deposition disease (CPDD) with proximal involvement mimicking polymyalgia rheumatica (PMR), and to identify the best predictive factors for the presence of a clinical pattern of CPDD in patients presenting with polymyalgia symptoms.
  
  
  METHODS
  Patients diagnosed with either PMR or CPDD at the Rheumatology Division of Hospital Meixoeiro (Vigo, Spain) over a 7-year period (1997-2003) were prospectively followed for at least 12 months.
  
  
  RESULTS
  The study group comprised 118 patients with PMR features and 112 patients with CPDD. Eighty-two of the 118 patients with PMR manifestations were diagnosed as having pure PMR, and 36 met the diagnostic criteria for both PMR and CPDD. Patients with CPDD mimicking PMR were older (P = 0.02) and had peripheral arthritis more frequently (P = 0.004) than those with pure PMR. Radiologic osteoarthritic changes in the hands and knees, including more advanced radiologic grade of knee osteoarthritis, and tendinous calcifications were more frequent in patients with PMR/CPDD (P < 0.001). The best predictive factors for the occurrence of this atypical pattern of CPDD in a patient presenting with PMR features were the age at diagnosis and the presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis.
  
  
  CONCLUSIONS
  Involvement of proximal joints may be the clinical presentation of CPDD. CPDD should be included in the spectrum of diseases mimicking PMR. The presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis are clues that may alert the clinician to the presence of CPDD in an elderly patient presenting with PMR manifestations.
authors.affiliation: Hospital Meixoeiro, Vigo, Spain. jose.maria.pego.reigosa@sergas.es
authors.forename: Jose M
authors.initials: JM
authors.lastname: Pego-Reigosa
authors.forename: Maria
authors.initials: M
authors.lastname: Rodriguez-Rodriguez
authors.forename: Zaraida
authors.initials: Z
authors.lastname: Hurtado-Hernandez
authors.forename: Jaime
authors.initials: J
authors.lastname: Gromaz-Martin
authors.forename: Daniel
authors.initials: D
authors.lastname: Taboas-Rodriguez
authors.forename: Carlos
authors.initials: C
authors.lastname: Millan-Cachinero
authors.forename: Iñigo
authors.initials: I
authors.lastname: Hernandez-Rodriguez
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Gonzalez-Gay
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000473:pathology; D001168:Arthritis / Q000150:complications / Q000473:pathology; D002131:Calcium Pyrophosphate / Q000378:metabolism*; D002805:Chondrocalcinosis / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D015897:Comorbidity; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D020370:Osteoarthritis, Knee / Q000150:complications / Q000473:pathology; D011111:Polymyalgia Rheumatica / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D013585:Synovitis / Q000150:complications / Q000473:pathology; D013710:Tendons / Q000378:metabolism / Q000473:pathology
chemical_list: D002131:Calcium Pyrophosphate