Disparity between ultrasound and clinical findings in psoriatic arthritis.

OBJECTIVE: To investigate the association between psoriatic arthritis (PsA)-specific clinical composite scores and ultrasound-verified pathology as well as comparison of clinical and ultrasound definitions of remission. METHODS: We performed a prospective study on 70 consecutive PsA patients. Clinical assessments included components of Disease Activity Index for Psoriatic Arthritis (DAPSA) and the Composite Psoriatic Disease Activity Index (CPDAI). Minimal disease activity (MDA) and the following remission criteria were applied: CPDAI joint, entheses and dactylitis domains (CPDAI-JED)=0, DAPSA≤3.3, Boolean's remission definition and physician-judged remission (rem-phys). B-mode and power Doppler (PD-) ultrasound findings were semiquantitatively scored at 68 joints (evaluating synovia, peritendinous tissue, tendons and bony changes) and 14 entheses. Ultrasound remission and minimal ultrasound disease activity (MUDA) were defined as PD-score=0 and PD-score ≤1, respectively, at joints, peritendinous tissue, tendons and entheses. RESULTS: DAPSA but not CPDAI correlated with B-mode and PD-synovitis. Ultrasound signs of enthesitis, dactylitis, tenosynovitis and perisynovitis were not linked with clinical composites. Clinical remission or MDA was observed in 15.7% to 47.1% of PsA patients. Ultrasound remission and MUDA were present in 4.3% and 20.0% of patients, respectively. Joint and tendon-related PD-scores were higher in patients with active versus inactive disease according to CPDAI-JED, DAPSA, Boolean's and rem-phys, whereas no difference was observed regarding enthesitis and perisynovitis. DAPSA≤3.3 (OR 3.9, p=0.049) and Boolean's definition (OR 4.6, p=0.03) were more useful to predict MUDA than other remission criteria. CONCLUSIONS: PsA-specific composite scores partially reflect ultrasound findings. DAPSA and Boolean's remission definitions better identify MUDA patients than other clinical criteria.

Weakly positive tests and chronologic variation of the QuantiFERON assay: a retrospective appraisal of usefulness.

OBJECTIVES: QuantiFERON Tb Gold IT (QFT) is routinely used as diagnostic tool for detecting immune reactivity towards Mycobacterium tuberculosis. When diagnosing a latent infection weakly positive results and test reproducibility must be considered. PURPOSE: To judge the frequency of useful information versus confusion gained by QFT in patients with immune-mediated diseases and in pulmonary outpatients. METHODS: We retrospectively analysed 1485 QFT-tests performed on 855 patients with autoimmune diseases prior to initiating biologics and on 447 pulmonary outpatients with a suspected tuberculosis infection over a period of 16 months. In 161 cases the IGRA test was erroneously repeated. After 18 months clinical, radiographic and bacteriologic evidence for tuberculosis was collected. RESULTS: Of all 1485 QFT-tests 247 (=16.63%) showed a positive result, 1186 (79.87%) were negative and 52 (3.50%) turned out to be indeterminate. Using the manufacturers cut-off value for the interferon-γ response, a cohort (n = 64) of weakly positive individuals (26% of all positives) was apparent. Repeated testing within ten weeks yielded negative reactivity in 69% of these patients. Of 25 IGRA positive patients who had a repeat test after one year without tuberculosis medication, 48% showed a reversion to a negative test. The frequency of indeterminate results of the IGRA was satisfying (3.5%). CONCLUSION: In case of only slightly elevated immune reactivity quantitative reporting of positive QFT-test results and a repeat test strategy might be of advantage for the usefulness of the test.

Therapeutic potential of regulatory T cells in autoimmune disorders.

Regulatory T cells (Tregs) play a dominant role in the regulation of immune responses. Quantitative and/or qualitative abnormalities of Tregs were observed in patients with autoimmune diseases and therapeutic interventions focusing Tregs are an attractive new target with the potential to cure these disorders. Biological agents approved for treatment of inflammatory rheumatic diseases transiently influence Treg prevalences and function and experimental therapies including novel biological agents, gene therapy, activation and ex vivo expansion of purified Tregs as well as substances influencing tolerogenic dendritic cells will be developed for selective Treg therapy. Although many of these interventions are effective in vitro, in animal models as well as in early clinical trials, significant concerns exist regarding the stability of Treg modifications as well as the long-term safety of Treg-based therapies.