A team of National Institute of Dental and Craniofacial Research (NIDCR) scientists reported in August 2009 that an experimental laboratory test called LIPS had correctly identified a key antibody associated with primary Sjögren’s syndrome 3 out of 4 times and with perfect accuracy. These data represented a significant improvement over the sensitivity and specificity of today’s standard enzyme-linked immunosorbant assay (ELISA). The scientists report in the October 2009 issue of the Journal of Translational Medicine that this 2-hour test just got a whole lot quicker. The scientists streamlined the assay’s 2 one-hour incubation steps to 5 minutes each. As the author’s reported, their quicker technique, called QLIPS, includes a 5 minute set-up, 2 5-minute incubation steps, 10 minutes of washing and reading of the [testing] plate with a luminometer for the results. Total testing time: about 25 minutes. Today’s ELISA tests typically range from 5 hours to a day to complete. The authors evaluated the ability of QLIPS to detect autoantibodies against 3 proteins—La, Ro60, and Ro52—that are often associated with primary Sjögren’s syndrome. They found that QLIPS detected the autoantibodies with a sensitivity of 49% for La, 56% for Ro60, and 70% for Ro52. The latter result was particularly noteworthy because it was a better diagnostic outcome than the longer-incubating LIPS technique. Moreover, QLIPS detected antibody titers from Ro52-positive Sjögren’s patients that were 1,000 times higher than those in healthy volunteers. Taken together, these results suggest that QLIPS could measure Ro52 levels alone to diagnose primary Sjögren’s syndrome. The data also suggest that QLIPS, with its speed and automated ease, has great potential as a point-of-care diagnostic test for this and other autoimmune disorders.
(Source: NIDCR, Science News in Brief, October 21, 2009)