STUDY DESIGN: We investigated the association between ICAM-1, -2, -3 plasma 
levels and ankylosing spondylitis (AS) disease activity.
OBJECTIVE: In the present study, we aimed to investigate the association between 
ICAM-1, -2, -3 plasma levels and AS disease activity in the Chinese Han 
population.
SUMMARY OF BACKGROUND DATA: AS is a chronic inflammatory rheumatic disease that 
effects the sacroiliac joints and axial skeleton. The intercellular adhesion 
molecules (ICAMs) are members of the immunoglobulin superfamily and have been 
identified to play major roles in inflammation and immune responses.
METHODS: A total of 60 patients with AS and 60 healthy individuals were 
selected. The plasma levels of proinflammatory cytokines, including tumor 
necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and ICAM-1, -2, -3, were 
analyzed by ELISA. Disease severity-related indexes, including the Bath 
ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing 
spondylitis functional index (BASFI), and ankylosing spondylitis disease 
activity score (ASDAS), were assessed, along with the erythrocyte sedimentation 
rate (ESR) and C-reactive protein (CRP) level.
RESULTS: Both ICAM-1 and ICAM-2 levels in plasma were markedly increased in AS 
patients compared with levels in the plasma of controls. There was no difference 
between controls and patients in term of ICAM-3 levels. Furthermore, in 
patients, correlation analysis showed that TNF-α and IL-6 production, as well as 
the ESR and CRP levels, have positive relationships with ICAM-1 and ICAM-2 
plasma levels; the BASDAI, BASFI, and ASDAS scores were also found to be 
positively correlated with ICAM-2. However, no significant correlations between 
ICAM-1 levels and BASDAI, BASFI, or ASDAS were detected in our study.
CONCLUSION: The current findings suggest that ICAM-2 may be a potential 
biomarker reflecting disease activity and functional ability in AS patients.
LEVEL OF EVIDENCE: 5.