Rheumatoid Arthritis (RA) is the most common type of chronic inflammatory
arthritis with unknown etiology marked by a symmetric, peripheral polyarthritis. Calprotectin
also can be used as a biomarker of disease activity in inflammatory arthritis and other autoimmune
In this study, we evaluated the association between serum calprotectin level and severity
of RA activity.
A cross-sectional study was conducted on 44 RA patients with disease flare-up. Serum
samples were obtained from all patients to measure calprotectin, ESR, CRP prior to starting the
treatment and after treatment period in the remission phase. Based on Disease Activity Score 28
(DAS28), disease activity was calculated.
Of 44 RA patients, 9(20.5%) were male and 35(79.5%) were female. The mean age of our
cases was 53±1.6 years. Seventeen (38.6%) patients had moderate DAS28 and 27(61.4%) had high
DAS28. The average level of calprotectin in the flare-up phase was 347.12±203.60 ng/ml and
188.04±23.58 ng/ml in the remission phase. We did not find any significant association between
calprotectin and tender joint count (TJC; P=0.22), swollen joint count (SJC; P=0.87), and general
health (GH; P=0.59), whereas significant associations were found between the calprotectin level
and ESR (p=0.001) and DAS28 (p=0.02). The average calprotectin level in moderate DAS28
(275.21±217.96 ng/ml) was significantly lower than that in high DAS28 (392.4±183.88 ng/ml)
We showed that the serum level of calprotectin can be a useful and reliable biomarker
in RA activity and its severity. It also can predict treatment response.