Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study.

OBJECTIVE: To evaluate the discriminatory ability of ultrasound in calcium pyrophosphate deposition disease (CPPD), using microscopic analysis of menisci and knee hyaline cartilage (HC) as reference standard. METHODS: Consecutive patients scheduled for knee replacement surgery, due to osteoarthritis (OA), were enrolled. Each patient underwent ultrasound examination of the menisci and HC of the knee, scoring each site for presence/absence of CPPD. Ultrasound signs of inflammation (effusion, synovial proliferation and power Doppler) were assessed semiquantitatively (0-3). The menisci and condyles, retrieved during surgery, were examined microscopically by optical light microscopy and by compensated polarised microscopy. CPPs were scored as present/absent in six different samples from the surface and from the internal part of menisci and cartilage. Ultrasound and microscopic analysis were performed by different operators, blinded to each other's findings. RESULTS: 11 researchers from seven countries participated in the study. Of 101 enrolled patients, 68 were included in the analysis. In 38 patients, the surgical specimens were insufficient. The overall diagnostic accuracy of ultrasound for CPPD was of 75%-sensitivity of 91% (range 71%-87% in single sites) and specificity of 59% (range 68%-92%). The best sensitivity and specificity were obtained by assessing in combination by ultrasound the medial meniscus and the medial condyle HC (88% and 76%, respectively). No differences were found between patients with and without CPPD regarding ultrasound signs of inflammation. CONCLUSION: Ultrasound demonstrated to be an accurate tool for discriminating CPPD. No differences were found between patents with OA alone and CPPD plus OA regarding inflammation.

Female gout: age and duration of the disease determine clinical presentation.

OBJECTIVE: This study aimed to compare data and associated diseases between women and men with gout paired for age and duration of the disease. METHODS: Consecutive patients from outpatient gout clinics of 2 rheumatology departments were included in this case-control study. We identified 37 women with gout diagnosis and paired them by age and duration of the disease with 37 men with gout (American College of Rheumatology criteria). Variables were clinical data, associated diseases, and renal function evaluated by 3 methods: creatinine clearance, modification of diet in renal disease, and Cockcroft-Gault. RESULTS: Mean (SD) age was 54.47 (15.13) years in women versus 53.52 (15.23) years in males, and mean (SD) age at onset 46.77 (16.63) years versus 45.62 (16.16) years in women and men, respectively. Hypertension was found in 26 (73%) of 37 women and in 27 (70%) of 37 men, previous diuretics was found in only 1 man, and no significant differences were found between women and men in gout or associated metabolic diseases. Females had lower creatinine clearance than males did (49.8 [29.7] vs. 67.1 [35.5] mL/min, P = 0.039). But, when it was calculated by methods considering sex, there were no significant differences (Cockcroft-Gault 66.4 [37.6] vs. 78.8 [43.8] mL/min [P = 0.2] and modification of diet in renal disease 73.8 [64.6] vs. 73.1 [35.0] mL/min [P = 0.9], females vs. males, respectively). Thirteen women (35%) were premenopausal at onset, 2 had familial history of gout, and 2 had history of lithiasis; other variables were not different from postmenopausal women. CONCLUSIONS: Factors previously associated to female gout seem to be more related to age than to sex or to the disease itself. In our country, patients with gout (males and females) are younger at onset. Gender should be considered to evaluate renal function in females with gout. One third of our female patients with gout were premenopausal and had unexpected higher frequency of lithiasis; no other differences with postmenopausal women were found.