- CAT level is significantly associated with Arabs, ages ≥40 and SLEDAI score <6 in SLE (104). - Increasing level of CAT is observed in SLE patients (111). - Increasing levels of IgG antibodies (Ab) against CAT is observed in SLE patients (111). - Primary cause of oxidative stress in SLE is due to excessive free radical production rather than impaired CAT activity (111). This evidence concerns the gene CAT and systemic lupus erythematosus.