Best marker of SLE?: (A) Anti Sm antibodies, (B) Anti-ds DNA antibodies, (C) Anti-Histone antibodies, (D) Anti Ro (SS-A) antibodies
Answer is B. Ans. (b) Anti-ds DNA antibodies(Ref: Harrison 18th/chapter 319)Anti dsDNA is specific for SLE, only in high titers;But still, anti ds DNA is the best marker for SLE because its prevalence in SLE is 70%;Whereas, Anti Sm antibody, which is specific for SLE, but is seen in only 25% patients with SLE