A 26-year-old woman develops a red rash over her cheeks and pain, and swelling in both wrists as well as several small joints in her hands. The rash gets worse on sun exposure and involves her cheeks, nose, ears, and chin. Medical evaluation reveals oral ulceration and 3+ proteinuria. Which of the following is the most specific test for diagnosis of this condition?
lupus erythematosus (LE) cells antinuclear antibody (ANA) anti-Sm antibody anti-Ro antibody