Systemic sclerosis (SSc) is a systemic autoimmune disease in which inflammation and fibrosis play a crucial role and lead to severe damage and failure of multiple organs such as the skin, joints, tendons, gastrointestinal tract, lungs, heart, blood vessels, and kidneys. It primarily affects women but disease is often more severe in males.

Systemic sclerosis (SSc) is a systemic autoimmune disease in which inflammation and fibrosis play a crucial role and lead to severe damage and failure of multiple organs such as the skin, joints, tendons, gastrointestinal tract, lungs, heart, blood vessels, and kidneys. It primarily affects women but disease is often more severe in males.

Sirtuins are a class of nicotinamide adenine dinucleotide-consuming enzymes that are implicated in numerous biological pathways .

Sirtuins are considered among the most promising targets for modulating aging-associated cellular and molecular processes and disease pathologies , The majority of studies have shown decreased SIRT expression in tissues and fibroblasts from patients with SSc compared to controls and in experimental fibrosis in mice .

Decreased SIRT3 levels and activity were observed in fibrotic areas of SSc and IPF lung tissues and SSc skin biopsies and explanted fibroblasts compared to controls , Wyman et al investigated the expression of all seven mammalian SIRTs in lung tissues and fibroblasts from patients with SSc and IPF and found a tendency for SIRTs to be decreased in patients with fibrosis compared to controls , with a particularly notable decline in SIRT7 .

Inclusion Criteria:

• Patients with systemic sclerosis diagnosed by 2013 ACR\EULAR classification criteria of systemic sclerosis
• Patients' age >18
• 25 rheumatoid arthritis patients as a control .

Exclusion Criteria:

-Overlap or mixed connective tissue diseases.