Antineutrophil cytoplasmic autoantibodies and clinical activity in Cuban patients with rheumatoid arthritis

Introduction: Antibodies against neutrophil cytoplasm are normally detected in patients with vasculitis. Although these antibodies can be present in a wide number of diseases associated with inflammatory and autoimmune conditions such as rheumatoid arthritis, their clinical significance has not been demonstrated. Objective: To evaluate the usefulness of different antigenic specificities of antibodies against neutrophil cytoplasm to measure the clinical activity in Cuban patients with rheumatoid arthritis. Material and Methods: A cross-sectional study was conducted on 77 Cuban patients with rheumatoid arthritis. Erythrocyte sedimentation rate, C-reactive protein, the clinical indicator of disease activity, anti-citrullinated protein antibodies, rheumatoid factor, and antibodies against neutrophil cytoplasm against different specificities were determined. Results: The largest number of patients with elevated disease activity (> 5.1) belonged to the group of antibodies against neutrophil cytoplasm positive patients (p=0.0364). Patients with anti-lactoferrin antibodies had higher disease activity values (p=0.0304). Through multivariate analysis, the influence of positive anti-lysozyme antibodies (p=0.0391), of double positivity of anti-citrullinated protein and anti-lactoferrin antibodies (p=0.0282), as well as that of double positivity of anti-citrullinated protein and anti-elastin antibodies (p=0.0182) on disease activity were demonstrated. Conclusion: The antibodies against neutrophil cytoplasm that recognize the antigenic specificities of lysozyme, lactoferrin and elastin are related to higher clinical activity in patients with rheumatoid arthritis.