Age at diagnosis, age at anti-RNA helicase A (anti-RHA) test, and years between diagnosis and anti-RHA test. Demographic data of anti-RHA-positive (n = 14) and -negative (n = 48) systemic lupus erythematosus (SLE) patients were compared. (a) Age at diagnosis. (b) Age at anti-RHA test. (c) Years from diagnosis to anti-RHA test. (d) Years from diagnosis to anti-RHA test versus levels of anti-RHA. (e) Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) in anti-RHA (+) versus (-) patients. (f) Correlation of SLEDAI and levels of anti-RHA. Anti-RHA levels were measured as integrated density of RHA protein band using phosphorimager as described in Materials and methods. y, years.