Presence of Antibodies Predicts Rheumatoid Arthritis

A new study published in the journal Arthritis & Rheumatism reveals that certain antibodies may predict future rheumatoid arthritis.

Antibodies against peptidyl arginine deiminase type 4 (PAD-4) are a specific early marker of rheumatoid arthritis.

The study was conducted by researchers at the University of Colorodo Denver in Aurora.

The goal of the research was to determine whether antibodies against PAD-4 “are present in the preclinical phase of rheumatoid arthritis (RA).” The team also sought to “compare the timing and extent of their appearance with those of other preclinical autoantibodies.

The team evaluated prediagnosis serum samples from 83 patients with RA for the presence of anti-PAD-4 antibody, anti-cyclic citrullinated peptide (anti-CCP) antibody, and rheumatoid factor. A control group was also used and consisted of 83 patients matched by age, sex, and number of serum samples. Duration of serum storage was also tested. The group wanted to verify the presence of anti—PAD-4 antibody to determine its sensitivity and specificity for the subsequent development of RA.

They found that 15 out of 83 patients with RA (18.1%) had at least one prediagnosis sample that tested positive for anti-PAD-4. Only one out of 83 control subjects had at least one positive sample. The findings result in a sensitivity and specificity of 18.1% and 98.8%, respectively, of anti-PAD-4 for the future development of RA. PAD-4 remained in the serum prioir to clinical diagnosis for 4.67 years. Anti-PAD-4 positivity was also associated with anti-CCP positivity. Those who had positive prediagnosis samples for both antibodies, had anti-CCP antibodies present earlier than anti-PAD-4 in 9 out of 13 cases (69%).

The authors concluded that, “Autoantibodies to PAD-4 are present during the preclinical phase of RA in a subset of patients and are associated with anti-CCP positivity. Further exploration is needed regarding the timing of, appearance, and disease-related effects of PAD-4 autoimmunity.”

These findings may lead to further research into predictors of rheumatoid arthritis and shed light on the process of the disease. Rheumatoid arthritis affects 1.3 million Americans. The disease occurs when the body’s immune attacks the synovium. The result can be joint damage, pain, inflammation, loss of function and disability. The joints most commonly affected by RA are those of the hands, feet, wrists, knees, elbows, knees and ankles.