RESUMEN
Objective:To investigate the prevalence and significance of IgG-anti-cyclic citrullinated pep-tides (CCP) antibody in PSS patients .Methods:A total of 120 patients diagnosed with PSS were investi-gated in the first affiliated hospital of Baotou Medical College from March 2006 to December 2009.IgG-anti-CCP antibody was assayed by enzyme-linked immunosorbent assay (ELISA), also anti-Sj?gren’s syn-drome type A ( SSA) and Sj?gren’ s syndrome type B ( SSB) antibody were assayed by immunoblotting . Erythrocyte sedimentation rate ( ESR ) was assayed by westergren in serum , and C reactive protein (CRP), IgA, IgM, IgG and IgM-RF were detected by immune turbidimetric .At the same time, clinical symptoms and involvement of important organs were observed .Following up the patients above 3 years, the primary Sj?gren’ s syndrome ( PSS) patients who had progressed to rheumatoid arthritis ( RA) were evaluated .Results:The positive rate of anti-CCP antibody in the PSS patients was 19 .17%; After 3 years, more patients who were positive for anti-CCP antibody had progressed to RA (χ2 =5.015,P=0.022) than the patients in negative group;The patients in anti-CCP antibody positive group were more prone to joint involvement (χ2 =8.058,P0.05); The positive rate of anti-SSA and SSB antibody in anti-CCP antibody positive group and negative group had no significant difference (χ2 =0.008 and 0.56,P>0.05);Multiple linear regression showed that the level of anti-CCP antibody was positively correlated with IgM-RF levels in the PSS patients (B=0.61, 95%CI =0.36 -0.86, P0.05).There were no significant differences in the level of ESR, CRP, IgA, IgM and IgG between anti-CCP antibody positive group and negative group ( P >0.05), but the level of IgM-RF in anti-CCP antibody positive group was significantly higher than that in the negative group (U=623.50, P<0.05).Conclusion:Positive rate of IgG-anti-CCP antibody in PSS is 19 .17%, also it is associated with joint involvement and more prone to progressing to RA .