What is the best instrument to measure disease activity in SLE? - SLE-DAS vs Easy BILAG.

Systemic lupus erythematosus (SLE) is a heterogeneous condition making assessment of disease activity challenging. However, thorough assessment is essential to evaluate patients longitudinally, to guide therapeutic decisions, and for clinical trials. Currently, the most popular disease activity index in clinical practice and trials is SLEDAI-2K. Its main advantage is ease of use, but significant weaknesses of SLEDAI-2K are omission of several serious manifestations, inability to capture change within an organ system, and fixed severity weightings that are often inappropriate. Recently several groups have developing improved tools. We report here the debate held at CORA meeting on this issue. SLE-DAS includes 17 weighted clinical and laboratory parameters including continuous measures in 4 items with an online calculator. A higher sensitivity to change compared to SLEDAI-2K has been demonstrated in its validation studies. Easy BILAG is an improved format of the BILAG-2004 that retains its content but greatly simplified. Its scoring using a single-page form that incorporates concise definitions for key terms next to clinical items. Easy-BILAG demonstrates higher accuracy and less variability and increased and better user feedback compared to the standard BILAG-2004 format. Both the indices discussed at CORA showed an advantage in measuring disease activity compared to SLEDAI.

Musculoskeletal manifestations of systemic lupus erythematosus.

MSK is the most common and impactful symptom of lupus at a population level. It has a variety of different presentations, but joint swelling is often not present despite imaging-proven synovitis. Imaging with US and MRI has been shown to improve detection of inflammation and identify treatment-responsive patients. In contrast, the SLEDAI shows poor sensitivity, specificity, and responsiveness. While BILAG and SLE-DAS are superior, they are still less accurate than imaging. These issues may explain why the evidence for conventional and biologic therapies for MSK lupus is complex. In clinical practice, physicians must take care not to underestimate MSK inflammation and consider using imaging. Future research should investigate new therapeutic targets specifically for synovitis and more sensitive outcome measures and trials to evaluate them.