[Prevalence of rheumatoid arthritis in North Sardinia: the Tempio Pausania's study]. / Prevalenza dell'artrite reumatoide nel Nord Sardegna: lo studio di Tempio Pausania.

OBJECTIVE: To estimate the prevalence of rheumatoid arthritis in an Italian general population. METHODS: The study was conducted in the years 2002-2003 in Tempio Pausania's health district located on the North Sardinia and involved 30264 subjects aged 18 years or more treated by 29 general practices (GP). The GP was contact first by phone and letter and secondly a Rheumatologist administered a structured interview that included a screening questionnaire for RA. Cases were defined by the 1987 American College of rheumatology criteria adapted to epidemiological surveys. Every cases were examined by Rheumatologist and General practices together. The age and sex distribution of the sample were similar to those of the Italian population from the 2001 census. RESULT: Of the 141 subjects who fulfilled the inclusion criteria, there were 113 women and 28 men, with a mean age at diagnosis of 45 years. The prevalence of RA was 0,46% in the general population, 0,73% in women and 0,19% in men. CONCLUSION: Our results suggest that the prevalence of RA is comparable to that reported in other Mediterranean countries. Women are more affected than men. Our prevalence is higher than that observed in Chiavari in 1992.

Diagnosis of calcium pyrophosphate dihydrate crystal deposition disease: ultrasonographic criteria proposed.

OBJECTIVE: To investigate by high frequency ultrasonography the appearance of calcium pyrophosphate dihydrate (CPPD) calcifications, in the most commonly affected sites in CPPD disease, and the relationship between ultrasonographic CPPD deposits and the presence of CPPD crystals in synovial fluid. METHODS: Three ultrasonographic patterns of CPPD calcification were identified and 11 patients enrolled. A control group comprised 13 patients with no evidence of CPPD deposits. Synovial fluid was aspirated from all patients and controls and examined for identification of crystals. All patients underwent a standard radiography examination at the same sites investigated by ultrasound. RESULTS: In all patients with ultrasonographically defined CPPD deposits, CPPD crystals were found in the synovial fluid. In two cases, standard radiographic examination did not show evidence of the calcific deposits that were identified by ultrasonography. CPPD crystals were not found in the synovial fluid of controls. In four control group patients, ultrasonography identified calcifications defined as deposits of another nature. CONCLUSIONS: The ultrasonographic pattern used in this study for the diagnosis of CPPD disease demonstrated a very high correlation with the presence of CPPD crystals in synovial fluid. Ultrasonography demonstrated a sensitivity and specificity at least equal to that of radiography in identifying CPPD crystal calcifications.