Augmented Anti-Bactericidal Permeability-Increasing Protein Antibody Levels in Rheumatoid Arthritis Patients...

Area of Science:

• Rheumatology
• Pulmonology
• Immunology

Background:

• Chronic lung diseases (CLDs) are extra-articular manifestations of rheumatoid arthritis (RA).
• Anti-bactericidal permeability-increasing protein antibodies (BPI Abs) have been implicated in lung involvement in RA and primary Sjögren's syndrome.
• Research on anti-BPI Abs in RA patients with CLD is limited.

Purpose of the Study:

• To evaluate the involvement of anti-BPI Abs in rheumatoid arthritis (RA) with chronic lung disease (CLD) complications.
• To investigate anti-BPI Abs as potential biomarkers for usual interstitial pneumonia (UIP) in RA.

Main Methods:

• Enzyme-linked immunosorbent assays (ELISAs) were employed to quantify anti-BPI Abs in RA patient sera.
• Receiver operating characteristic (ROC) curves were utilized to assess diagnostic performance.

Main Results:

• RA patients with usual interstitial pneumonia (UIP) exhibited significantly higher levels of anti-BPI Abs compared to those without CLD (10.4 ± 23.5 ng/mL vs. 1.3 ± 3.8 ng/mL, p = 0.0020).
• The diagnostic performance (Area Under the Curve) for anti-BPI Ab and Krebs von den Lungen-6 was comparable between RA with UIP and RA without CLD.
• A significant correlation was found between anti-BPI Ab and anti-carbamylated protein antibody levels in RA patients (rho = 0.3508, p < 1.47 × 10⁻¹⁴).

Conclusions:

• Anti-BPI Abs are associated with usual interstitial pneumonia (UIP) in rheumatoid arthritis (RA) patients.
• Anti-BPI Abs show potential as biomarkers for identifying UIP in RA.
• These findings suggest a role for anti-BPI Abs in the pathogenesis of UIP within the context of RA.