Peptidyl-arginine deiminase-type IV as a diagnostic and prognostic marker in rheumatoid arthritis patients

Abstract Aim of the work To measure serum peptidyl arginine deiminase (PADI4) enzyme level in rheumatoid arthritis (RA) patients and to assess its role in diagnosis and monitoring patient improvement. Patients and methods The study included 31 RA patients and 10 age and sex matched healthy controls. Serum PADI4 and anti-cyclic citrullinated peptide (anti-CCP) were measured. Disease activity score (DAS28) was calculated. Patients were followed-up at 3 months with measurement of serum PADI4, anti-CCP and DAS28. Results Mean age of the patients was 42.4 ± 7.8 years, female:male = 5.2:1 and disease duration 8.1 ± 5.4 years. The DAS28 was 5 ± 1.2 and modified health assessment questionnaire (MHAQ) was 0.8 ± 0.6. Mean anti-CCP (129.3 ± 74.8 ng/ml) and PADI-4 levels (532.9 ± 240.9 pg/ml) in patients were significantly higher than in controls (8.4 ± 4.4 ng/ml and 156 ± 31 pg/ml respectively; p  Conclusion Serum PADI4 was diagnostic for RA and comparable with anti-CCP. It correlated with disease activity and could be a promising follow up marker of remission.