Abstract: Objective  To investigate the expression level and clinical significance of the serum follistatinlike protein 1(FSTL1) in patients with Sjgren’s syndrome (SS). Methods  The levels of serum FSTL1 in 41 SS patients and 30 healthy controls were tested by using enzymelinked immunosorbent assay (ELISA). The differences between patients group and  normal controls were analyzed and the correlation was explored. Results  The serum FSTL1 was significantly higher in SS patients (2.54±0.30) ng/ml than that in normal controls  (2.08±0.82)  ng/ml(P=0.0035). The expression of serum FSTL1 was positively correlated with IgG(r=0.332，P=0.039)  and IgA  (r=0.368，P=0.021). The expression of serum FSTL1 was negatively correlated with C3(r=-0.319，P=0.045). Serum FSTL1 level was not significantly associated with ESR， IgM， C4， peripheral white blood cells， peripheral blood platelets， peripheral blood hemoglobin and RF (P>0.05). There was no significant difference in FSTL1 level between ANA titer 1∶160 group and ANA titer 1∶320 group， antiSSB positive group and antiSSB negative group (P>0.05). The correlation among interstitial lung injury， hematological system， endocrine system， arthritis and FSTL1 were not statistically significant (P>0.05). Conclusion  These results suggested  that the serum FSTL1 may be the candidate biomarker in reflecting activities of SS.

Key words: Sjgren’s syndrome, follistatinrelated proteins； clinical , Significance