Background: Rheumatoid arthritis (RA), one of the most prevalent autoimmune diseases in the world, affects about 1% of population. It is shown that the titration of this antibody has some correlation with disease activity index. The goal of present study was to evaluate the correlation between anti-Cyclic citrullinated peptide (anti-CCP) titration and disease activity index.

Materials & Methods: In this cross-sectional study 105 RA patients were considered for American College of Rheumatology (ACR) criteria serum anti-CCP level, and ESR of all participants were checked after venipuncture. In addition, disease activity index form and Visual Analog Scale (VAS) were completed for each patient. The correlation between disease activity index (DAS28), ESR and VAS was evaluated. The numbers of tendered and swollen joints and anti-CCP level were analyzed using Kolomogrov-Smirnov, t test, Levene and Mann-Whitney statistical tests.

 Results: The mean disease activity index in positive and negative anti-CCP patients was 11.5±4.7 and 8.6±1.4, respectively (P=0.023). In positive and negative anti-CCP patients the mean swelling joints was 2.3±2.1 and 1.1±0.7, respectively (P=0.031). Mean tender joints in positive and negative anti-CCP patients was 6.1±4.6 and 3.6±1.8, respectively (P=0.046). In positive and negative anti-CCP patients the mean of ESR was 36.8±24.8 and 10.3±6.7, respectively (P<0.0001). Also the mean VAS in positive and negative anti-CCP patients was 42.1±32.8 and 18.8±9.1, respectively (P=0.007).

Conclusion: Considering the correlation between anti-CCP titration and disease activity index, this test can be used as a factor of disease activity in RA.

Background: Rheumatoid arthritis (RA) is one of the most prevalent autoimmune diseases in the world. Some of the researches have suggested that the serum vitamin D level may relate to disease activity. The current study was designed to identify the correlation between serum vitamin D level and the disease activity index (DAI).

Materials and Methods: In this sectional study, 108 patients (diagnosed based on the American Committee of Rheumatology criteria) were enrolled. In all cases after determining the serum vitamin D level and ESR, complete joint examination were done. The normal range of vitamin D was 47.7 - 144 nm/lit. Then, the specified disease activity form (DAS-28) and visual analog scales (VAS) were filled out. The correlation between disease activity index, (based on VAS, tendered or swelled joints and ESR) and serum vitamin D was analyzed using Chi square, Mann Whitney and t-tests.

Results: Seventy nine (73.14%) out of 108 patients had normal serum vitamin D and 29 (26.86%) had low serum vitamin D level. The mean age of patients with normal and low serum vitamin D level were 52.22±11.6 and 48.48±12.51, respectively (P=0.075). The mean DAI in normal and low vitamin D patients were 3.75±1.37 and 5.19±1.56, respectively (P=0.00). The mean number of swollen joints in normal and low vitamin D patients was 1.24±1.39 and 3.65±3.3, respectively (P=0.001). The mean number of tender joints in normal and low vitamin D patients were 6.84±4.41 and 9.44±3.62, respectively (P=0.042). The mean ESR in normal and low vitamin D patients were 19.40±12.40 and 37.91±21.72, respectively (P=0.002). Moreover, the mean VAS in normal and low vitamin D patients was 23.29±19.42 and 50.68±30.78, respectively (P=0.003).

Conclusion: The more active the RA, the less serum vitamin D level.