An anti-CCP antibody test may help with early detection of ILD by Margarida Maia, PhD 
People with systemic scleroderma (SSc) who test positive for cyclic citrullinated peptide (CCP) antibodies are more likely than those who test negative to develop interstitial lung disease (ILD) — when the lungs become scarred — and have worse lung function.
That’s according to data from a South Korean study that included people with systemic lupus erythematosus (SLE) or myositis, disorders with symptoms that sometimes overlap with scleroderma.
The study, “A retrospective analysis of the relationship between anti-cyclic citrullinated peptide antibody and interstitial lung disease in systemic sclerosis,” was published in Scientific Reports.
A CCP antibody test looks for anti-CCP antibodies in the blood. They are a type of autoantibody that wrongfully turns against healthy tissues in the joints. A positive test for anti-CCP antibodies in the blood can indicate rheumatoid arthritis, an autoimmune disease that causes pain, swelling, and stiffness in the joints. It can also indicate the likelihood of developing symptoms outside the joints, such as ILD.
Scleroderma occurs when autoantibodies attack the skin’s connective tissue, the body’s framework. In scleroderma, producing a protein called collagen in excessive amounts makes the skin harden and scar. In SSc, a type of scleroderma, the attack includes other organs. If the joints are affected, patients may have arthritis-like symptoms.
It’s not known if anti-CCP antibodies play a role in developing SSc. What the researchers knew is that anti-CCP antibodies in the blood are linked to lung fibrosis (scarring) with SSc. They report now that “an anti-CCP antibody test may be helpful for early detection of ILD in SSc patients.”
The study included 260 people with a diagnosis of SSc, 936 people with SLE, and 156 with polymyositis/dermatomyositis (PM/DM), two types of myositis, who received care at a Seoul hospital between January 2005 and May 2021.