Rheumatoid arthritis phenotype at presentation differs depending on the number of autoantibodies present

Area of Science:

• Immunology
• Rheumatology
• Clinical Medicine

Background:

• Rheumatoid arthritis (RA) may present as distinct seropositive and seronegative forms.
• The impact of multiple autoantibodies on early RA clinical presentation is not well understood.
• Autoantibodies serve as indicators of the humoral autoimmune response.

Purpose of the Study:

• To investigate the association between the quantity of autoantibodies and the initial clinical phenotype in early RA.
• To analyze this association in two independent patient cohorts.
• To understand if a broader autoimmune response influences early disease characteristics.

Main Methods:

• Baseline autoantibody status (rheumatoid factor, anti-CCP, anti-CP) was assessed in two early RA cohorts (Leiden, n=828; BARFOT, n=802).
• Statistical analysis, including univariable and multivariable ordinal regression, was employed.
• The relationship between the number of autoantibodies and baseline clinical features was examined.

Main Results:

• A higher number of RA-associated autoantibodies was independently linked to younger age at presentation.
• Patients with more autoantibodies were more frequently smokers and had longer symptom duration.
• Increased autoantibody count correlated with a higher erythrocyte sedimentation rate.

Conclusions:

• The number of autoantibodies, reflecting humoral response breadth, is associated with RA's initial clinical presentation.
• Early clinical phenotype appears to reflect pre-disease pathophysiology.
• This finding supports distinct immunological profiles influencing RA presentation.