Validity of the bath ankylosing spondylitis disease activity index for the evaluation of disease activity in axial psoriatic arthritis.

OBJECTIVE: To assess the validity of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) for the evaluation and definition of disease activity of axial psoriatic arthritis (PsA). METHODS: Fifty-four peripheral PsA, 46 axial PsA, and 103 primary ankylosing spondylitis (AS) patients were assessed. Patients were classified as having axial PsA if they had grade 2 or higher unilateral sacroiliitis in the presence of spinal symptoms. The 3 groups of patients were evaluated using several measurements for AS. Assessments of acceptability, data quality, internal consistency, construct validity, and responsiveness of the BASDAI were undertaken. Disease activity of the disease was assessed in peripheral PsA and axial PsA patients using the BASDAI, and compared with those with AS. RESULTS: For peripheral PsA patients, the Cronbach's alpha for the BASDAI was 0.783, for axial PSA patients it was 0.647, and for AS patients it was 0.786. The analysis of convergent validity showed that in peripheral PsA and axial PsA patients, the BASDAI was significantly correlated with other subjective disease activity parameters. For responsiveness, no association was found between changes in the BASDAI and changes in disease activity either in peripheral PsA or in axial PsA. BASDAI scores were similar in axial PsA and AS. Axial PsA patients with a BASDAI score >4 cm showed significant differences with peripheral PsA in terms of disease activity and were very similar to patients with AS. CONCLUSION: The BASDAI performed similarly in evaluating disease activity in both axial and peripheral PsA. The BASDAI does not seem to be a good index for evaluating disease activity in axial PsA.

Evaluation of ankylosing spondylitis spinal mobility measurements in the assessment of spinal involvement in psoriatic arthritis.

OBJECTIVE: To determine the clinical usefulness of spinal mobility measurements used for ankylosing spondylitis (AS) to assess spinal involvement in patients with psoriatic arthritis (PsA). METHODS: We assessed 100 patients with PsA and 103 patients with AS. Patients were classified as having axial PsA if they had grade 2 or higher unilateral sacroiliitis in the presence of spinal symptoms. All PsA patients, without taking the degree of joint involvement into consideration, were evaluated using several measurements for AS. Spinal measurements were compared with axial and peripheral forms of PsA, and the ability of the techniques to discriminate between the 2 forms of PsA was analyzed using the Mann-Whitney U test and the area under the receiver operating characteristic (ROC) curve. A logistic regression model was used to determine the best measurements for evaluating axial PsA. Finally, the results of measurements for axial PsA were compared with those for AS. RESULTS: Of the 100 PsA patients, 46 met the classification criteria for axial PsA, which presented more severe spinal measurement assessments compared with peripheral PsA. Modified Schober test, lumbar side flexion, chest expansion, and cervical rotation measurements performed best under the ROC curve. Modified Schober test, lumbar side flexion, and cervical rotation were the more suitable measurements for assessing axial PsA. There were only minor differences between axial PsA and AS. CONCLUSION: The spinal measurements used to evaluate AS performed well to assess spinal involvement in PsA. These measurements, notably the modified Schober test, lumbar side flexion, and cervical rotation, should be used in daily clinical practice to assess PsA patients with spinal involvement.

Validity, reproducibility, and responsiveness of a twelve-joint simplified power doppler ultrasonographic assessment of joint inflammation in rheumatoid arthritis.

OBJECTIVE: To investigate the validity, reproducibility, and responsiveness of a simplified power Doppler ultrasound (PDUS) assessment of joint inflammation compared with a comprehensive 44-joint PDUS assessment in patients with rheumatoid arthritis (RA) who started therapy with a biologic agent. METHODS: A total of 160 patients with active RA who started a biologic agent were prospectively recruited in 18 Spanish centers. The patients underwent clinical and laboratory assessment and blinded PDUS examination at baseline and 6 months. A PDUS examination of 128 synovial sites in 44 joints was performed. US synovitis and PD signal were semiquantitatively graded from 1 to 3 in all synovial sites. US count and index for synovitis and PD signal were obtained. PDUS intraobserver and interobserver reliability were evaluated. A process of data reduction based on the frequency of involvement of synovial sites by both synovitis and PD signal was conducted. Construct and discriminant validity of a simplified PDUS assessment was investigated. RESULTS: A PDUS simplified assessment including 24 synovial sites from 12 joints detected 100% of patients with synovitis and 91% of patients with PD signal. There was a highly significant correlation between the 44-joint count and index for synovitis and PD signal and the 12-joint count and index for synovitis and PD signal at baseline and 6 months (r = 0.84-0.90, P < 0.0005). The smallest detectable difference was lower than the mean change in simplified PDUS variables. CONCLUSION: A 12-joint PDUS assessment of RA joint inflammation may be a valid, feasible method for multicenter monitoring of therapeutic response to biologic agents.

Bilateral giant iliopsoas bursitis presenting as refractory edema of lower limbs.

A 69-year-old man with rheumatoid arthritis presented with bilateral leg swelling. Magnetic resonance studies revealed bilateral giant iliopsoas bursitis with intrapelvic expansion and compression of pelvic vessels and bladder. The case was refractory to intensive systemic and local medical treatment.