Serum Sirtuin 1 as a potential indicator of disease activity and severity in systemic lupus erythematosus patients.

The aetiology and pathophysiology of systemic lupus erythematosus (SLE), are yet unclear. Autoantibodies that target various organs and tissues are produced as a result of SLE patients' poor immunological tolerance. Sirtuin-1 (SIRT1) is a histone deacetylase that has a major role in immune responses, apoptosis, and cell differentiation, through alteration of various signalling cascades, including nuclear factor κ-light chain enhancer and activator protein 1 of activated B cells cascades. According to recent data, SIRT1 is an immune system regulator factor, and its impaired action probably play a role in SLE pathogenesis. This study intended to determine whether SIRT1 can be an indicator for SLE severity and activity. This study comprised 30 SLE patients, with a mean age of 28.23 ± 5.21 years and 3.21 ± 1.2 years as duration of the disease. The normal control group consisted of 30 matched adults, aged 27.3±6.22 years (p=0.266). There was a significantly increase in the mean±SD of SIRT1 in SLE patients (28.72±5.83), compared to the control group (22.1±5.59) (p<0.05). Serum SIRT1 was significantly correlated to disease duration, SLEDAI, Katz score, ESR, CRP and renal biopsy classes. However, it was negatively correlated to C3, C4 and there was no correlation with age. A significant elevation was noted in the mean±SD of SIRT1 in active SLE patients (22.7 ± 13.77) compared to inactive SLE patients (6.02±11.27) (p <0.05). Also, the mean±SD of SIRT1 was significantly raised in patients with high SLE disease severity (17.94 ± 15.64) in contrast to those with low SLE disease severity (10.78±13.76) (p<0.05). In conclusion, SIRT1 serum levels were higher in patients with SLE, both with high and low disease severity. Thus, SIRT1 may be a serological indicator for the severity and activity of SLE.