To investigate the prevalence and significance of
IgG-anti-cyclic citrullinated
peptides (CCP) antibody in PSS patients.
METHODS: A total of 120 patients diagnosed with PSS were investigated 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-
Sjogren's syndrome type A (SSA) and
Sjogren'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
Sjogren'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,P<0.05), more swollen joints (U=152.00, P<0.05) and longer morning stiffness (U=100.00, P<0.05) than the patients with negative
anti-CCP antibody, but the involvement of vital organs in the two groups had no significant difference (χ² = 0.208,0.099,0.000 and 0.122, P>0.05); 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, P<0.05), but had no significant correlation with ESR, CRP,
IgA,
IgM and
IgG levels (P>0.05).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: