Current laboratory tests include a number of lupus-specific autoantibodies, and antinuclear antibody (ANA) is frequently used. Around 95 percent of all lupus patients test positive for ANA, but the antibody is also found in 14 percent of the general population and 15 percent to 25 percent of fibromyalgia patients. Other tests also suffer from poor sensitivity or specificity.
CB-CAPs have already been established as a means to distinguish between lupus and other rheumatic disorders. The study's authors recently combined CB-CAPs with standard rheumatic disease autoantibodies to produce a multi-analyte assay with algorithm (MAAA). The assay has been shown to be more sensitive in diagnosing lupus compared to current tests. The study, "Systemic lupus erythematosus and primary fibromyalgia can be distinguished by testing for cell-bound complement activation products," wanted to test whether the new assay could distinguish between lupus and fibromyalgia.