The described invention provides a method and kit for treating a lupus condition with N-acetyl-L-cysteine (NAC) compositions that improve lupus disease activity driven by a decrease in the activity of the mammalian target of rapamycin (mTOR). The compositions of the described invention is effective to: (1) reduce fatigue (2) reduce cognitive/inattentive component of attention deficit and hyperactivity (ADHD) self-report scale (ASRS) (3) reduce inflammation, for example, as measured by the systemic lupus erythematosus disease activity index (SLEDAI), and the British Isles Lupus Assessment Group (BILAG) score (4) modulate mitochondrial potential and (5) reduce T cell cycle dysfunction driven by a decrease in the activity of the mammalian target of rapamycin (mTOR) in patients suffering from systemic lupus erythematosus (SLE).
