Do you use anti-DFS70 Ab to help reduce the posttest probability of ANA-positive patients having a systemic autoimmune disease if other autoantibodies are negative?  

ANA patients referred to rule out CTD is a work-intensive, costly referral type. If they are positive for Anti-Dense Fine Speckled Protein 70 kDa (DFS70) Ab yet negative for other autoantibodies, the vast majority do not have a systemic autoimmune disease (somewhere around 92% of them). It is like a "rule out" test, which we do not have available yet for SLE, etc. I see it has recently become available from commercial labs and was wondering what others think about the data validity. If it works as the data suggest, this could potentially streamline these referrals, possibly save money for the healthcare system, reduce work for clinicians, and ease the minds of patients worried about their positive ANA.