Objectives To compare clinical and radiological manifestations of late onset ankylosing spondylitis (LOAS: >51 yrs) with classical onset ankylosing spondylitis (COAS:21–30 yrs).

Methods We identified twenty-nine (2,0%) pts with LOAS out of 1434 AS pts and they were matched for sex and disease duration with COAS pts. All pts fulfilled the diagnostic criteria of AS of the European Spondyloarthropathy study group (ESSG). Evaluation included clinical examination: inflammatory pain, spinal mobility (Schober test, chest expansion), peripheral arthritis and enthesitis, acute uveitis, family history; laboratory (ESR, HLA-B27); radiographs of the sacroiliac joints (SIJ), anteroposterior and lateral spine and affected peripheral joints). Statistical analysis was performed using Spearman rank correlation test and X- test.

Results Analysis revealed no significant differences (p > 0.005) in clinical manifestations between twenty-nine (27 m,2 f) pts with LOAS(mean age and disease duration 56,0 yrs (range 53–62) and 8, o yrs (range 8–12) respectively) and twenty-nine pts with COAS(mean age at onset 24,2 yrs and mean disease duration 7,8 yrs (range 4–16) rescpectively), except for spinal mobility (p < 0,005). No significant differences (p > 0,005) were found between groups of the laboratory findings. All pts had bilateral sacroiliitis. The results are shown in the Table 1.

The radiographic changes in SIJ (grade III and IV) were more frequent in LOAS pts than in COAS (p < 0,005), as well as on the spine (p < 0,005). The radiographic progression in the SIJ and the spine were more rapid in LOAS pts than in COAS pts, the difference was statistically significant (p < 0,005).

Conclusion According to our experince the onset of ankylosing spondylitis is uncommon after 51-st yr; LOAS and COAS have similar clinical manifestations; LOAS had clinically more progressive course and rapid radiopraphic progression leading to severe changes in the SIJ and spine (p < 0,005). the possible explanation for the difference observed is a clinically asymptomatic or ?silent? ankylosing spondylitis in patients with late onset of disease.

Reference

1. Caplanne D, Tubach F, Marie Le Parc J. Late onset spondyloarthropathy: Clinical and biologycal comparation with early onset patients. Ann Rheum Dis. 1997;56:176–9