SS-A

Ro (SS-A) is also known as Sjögren’s autoantibody and are considered extractable nuclear antigens, given that they can be purified in isotonic saline. Ro is 52 kDa in weight and is considered an RNA binding protein in the cell. Autoantibody titers of Ro are measured in patients who present with antinuclear antibodies as part of the differential diagnosis supporting a Sjögren disease diagnosis or other connective autoimmune disorders.