Validation of Musculoskeletal Ultrasound in the Assessment of Experimental Gout Synovitis

The objective of this study was to validate musculoskeletal ultrasound (US) in a rabbit model of acute gout. Acute gout was induced by intra-articular injection of monosodium urate (MSU) crystals in 10 rabbits; the 3 controls received vehicle. Rabbit knees were assessed by B-mode and power Doppler (PD) US 24 and 72?h after injections. After 72?h, all rabbits were euthanized. US discriminated between the MSU-injected and control groups with respect to the different inflammatory findings at both at 24 and 72?h and for MSU crystal-related findings after 24?h of injection. US synovial thickening, intra-synovial power Doppler signal and global joint distension significantly correlated with the synovial global histopathological score (r?=?0.47, p?=?0.0188), tissue vascularization measured by CD31 immunohistochemical-positive staining (r?=?0.46, p?=?0.0172) and tissue levels of interleukin-1β (r?=?0.53, p?=?0.0078), respectively. US is a valid method for assessment of synovial inflammation in experimental gouty arthritis in rabbits.     

Increased risk of tuberculosis in patients with rheumatoid arthritis

OBJECTIVE: To quantify the risk of tuberculosis (TB) in an unselected sample of patients with rheumatoid arthritis (RA) compared to the risk in the general population. METHODS: The incidence of TB in the general population of Spain was obtained from the National Network of Epidemiological Surveillance reports. The incidence of TB was ascertained from a cohort of 788 patients with RA selected randomly from the registries of 34 participating centers throughout Spain. A patient was considered a TB case only if information about disease symptoms, microorganism identification, and TB treatment were confirmed in the clinical records. The relative risk of TB in RA was calculated by dividing the standardized mean incidence of TB from 1990 to 2000 in the RA cohort by the mean incidence of TB in Spain during the same years. RESULTS: The mean incidence of TB in the general population of Spain from 1990 to 2000 was 23 cases per 100,000. Seven cases of TB were identified in the RA cohort, yielding a mean annual incidence (1990-2000) of 134/100,000 patients. The incidence risk ratio of pulmonary TB in patients with RA compared to the general population is 3.68 (95% CI 2.36-5.92). CONCLUSION: We found a 4-fold increased risk of TB infection in patients diagnosed with RA. These results might help to interpret the magnitude of the problem attributable to the introduction of new therapies in RA.     

Factors Influencing the Rate of Fibrosis Progression in Chronic Hepatitis C

Alcohol consumption, age at infection, and male gender have been identified as risk factors for faster fibrosis progression in patients with chronic hepatitis C (CHC). Yet the influence of liver steatosis, light to moderate alcohol consumption, or iron overload on this progression remains controversial. To analyze the effect of individual risk factors and their interaction on fibrosis progression in a group of patients with CHC and a definite date of infection, we studied 133 consecutive untreated patients. Covariates included were age, body mass index (BMI), gender, age at infection, alcohol intake, serum lipids, glycemia, serum ALT, AST, GGT, iron, and ferritin, grade and stage (METAVIR and Scheuer), and hepatic stainable iron (Perl's stain). The rate of fibrosis progression was inferred from the METAVIR score. By logistic regression analysis, hepatic steatosis (odds ratio [OR], 3.035; 95% confidence interval [CI], 1.16-7.93), serum ferritin levels higher than 290 ng/ml (OR, 5.5; 1.6-18.65), and light to moderate ethanol intake (1-50 g/day) (OR, 5.22; 1.5-17.67) were independently associated with faster fibrosis progression. There was no effect of interaction between these variables on the rate of fibrosis progression. Liver steatosis, serum ferritin levels, and light to moderate alcohol intake are associated with faster fibrosis progression in chronic hepatitis C. Combination of these factors did not further accelerate this progression. The impact of modification of these factors on progression should be tested in longitudinal studies.     

Power Doppler ultrasonographic monitoring of response to anti-tumor necrosis factor therapy in patients with rheumatoid arthritis

OBJECTIVE: To evaluate the validity, responsiveness, and predictive value of power Doppler ultrasonography (PDUS) monitoring of response to tumor necrosis factor (TNF) blocking agents in rheumatoid arthritis (RA). METHODS: Three hundred sixty-seven RA patients were prospectively recruited at 25 Spanish centers; complete clinical, laboratory, and PDUS data were obtained on 278 patients. The patients underwent clinical, laboratory, and PDUS assessment at baseline and after 1, 3, 6, and 12 months of anti-TNF treatment, and radiographic assessment of the hands and feet at baseline and 12 months. The Disease Activity Score in 28 joints (DAS28) was recorded at each visit. PDUS examination included 86 intraarticular and periarticular sites in 28 joints. US synovial fluid (SF), synovial hypertrophy (SH), and PD signal were scored in all synovial sites. US count and index for SF, SH, and PD signal were obtained. Sensitivity to change of the PDUS variables was assessed by estimating the smallest detectable difference (SDD) from the intraobserver variability. RESULTS: A significant parallel improvement in DAS28 and PDUS parameters was found at followup assessment (P < 0.0005 for within-subject between-visit changes). The SDD for PDUS parameters was lower than the mean changes throughout followup. Time-integrated values of US joint count for PD signal and rheumatoid factor (RF) showed predictive value in relation to progression of radiographic erosion (R = 0.64), and time-integrated values of US joint count for PD signal, RF, and erythrocyte sedimentation rate were predictors of progression of the total radiographic score (R = 0.59). CONCLUSION: These findings indicate that PDUS is a valid method for monitoring response to anti-TNF therapy in RA; results obtained by PDUS are reproducible and sensitive to change. PDUS findings may have predictive value in relation to radiologic outcome.