Abstract
OBJECTIVE: The American College of Rheumatology and the European League Against Rheumatism embarked on a project to reevaluate classification criteria for systemic lupus erythematosus (SLE). The first phase of the classification project involved generation of a broad set of items potentially useful for classification of SLE and their selection for use in a subsequent forced-choice decision analysis. METHODS: A large international group of expert lupus clinicians was invited to participate in a 2-step process to generate, rate, and select items based on their importance in diagnosing early and established SLE, via a web-based survey. RESULTS: A total of 135 and 147 experts were invited to participate in the item-generation and item-reduction process, respectively. Of 145 items generated, item reduction resulted in 40 candidate items moving forward to the next phase. Key features for classifying both early and established SLE included characteristic autoantibodies, specific renal features, and skin manifestations. A small majority (51%) stated that 1 organ system would be sufficient for classifying SLE, but that additional typical laboratory features (antinuclear antibody, anti-double-stranded DNA) would be required. Notably, 85% of the expert group would positively classify SLE if renal pathology alone showed lupus nephritis. CONCLUSION: The Delphi exercise resulted in a set of 40 candidate criteria for the classification of SLE for subsequent assessment. This study comprised the largest panel ever involved in the development of SLE classification criteria, providing a broadly representative view of the current approach to classification of SLE.