Seroprevalence of P-ANCA autoantibodies in Iraqi rheumatoid arthritis patients

Abstract

Objectives: Analyzing the changes in cytoplasmic neutrophil auto-antibodies (ANCA) titer profile in rheumatoid arthritis individuals with different disease stages. Study Methodology: More than one hundred rheumatoid arthritis subjects including different stages (early=22, late =52, and refractory referred to biological therapy=63) were collected from those patients attending the rheumatology clinic / Baghdad teaching hospital against fifty tested healthy matched subjects as controls. Serum samples were tested for P-ANCA vasculitis markers anti lactoferrin, anti cathpsin G, anti elastase) using indirect ELIZA technique. Results: A statistically significant increase in P-ANCA autoantibodies in rheumatoid arthritis patients has been observed and registered in comparison to matched healthy control subjects. This rise in P-ANCA autoantibodies was statistically significant for all tested three markers; anti-lactoferrin, anti cathpsin G, anti-elastase autoantibodies. Cytoplasmic neutrophil autoantibodies mean and frequency variation were statistically considerable when categorized according to RA disease stages, anti-cathpsin and anti-lactoferin seropositivity was the highest in refractory RA patients referred to biological therapy compared to other disease stages, contrary to anti-elastase autoantibodies which reached the highest positivity in late RA subgroups. Conclusion: The high prevalence of P-ANCA autoantibodies may reflect the high level of immune dysregulation in RA patients with progressive disease stages, P-ANCA may correlate with disease activity and indicate acute flare up and amplified inflammatory response as noticed by rising titer and frequency of P-ANCA in late and refractory (don’t respond to DMARD therapy with worsening state) RA disease stages.