Clinical expression, but not disease outcome, may vary according to age at disease onset in psoriatic spondylitis

Joint Bone Spine. 2008 Oct;75(5):544-7. doi: 10.1016/j.jbspin.2007.11.005. Epub 2008 May 5.


Objectives: To investigate whether the clinical expression and disease outcome in psoriatic spondylitis (PsS) may vary according to age at disease onset.

Methods: This study included 70 patients from a unique outpatient spondylitis clinic followed on a regular basis with a standard protocol. Patients were diagnosed with PsS according to ESSG criteria plus radiographic sacroiliitis (SI). Outcome parameters included: disease activity, functional evaluation, radiological damage, mobility restriction, and enthesitis score. Patients were divided into those with disease onset before 40 years (young-onset PsS) and those with onset over this age (late-onset PsS). Clinical features and outcome parameters were compared between groups.

Results: There were 44 men and 26 women. Thirty-nine (M:F ratio 1.8) patients had disease onset before 40 years and 31 (M:F ratio 1.6) over this age. HLA-B27 correlated with PsS susceptibility (34% vs 7%, RR 6.4, p<0.0004), but it was found over-represented in young-onset PsS compared to late-onset cases (51% vs 13%, p=0.001). Young-onset cases tended to have a higher frequency of family history (26% vs 13%), bilateral SI (62% vs 29%, p=0.013), isolated axial pattern (31% vs 13%), and enthesitis (54% vs 29%, p=0.09). In late-onset PsS there was a higher frequency of unilateral SI (71% vs 38%, p=0.013), polyarthritis (45% vs 23%, p=0.022), and silent axial disease (32% vs 10%, p=0.022). Outcome parameters were similar between groups.

Conclusions: Clinical picture but not outcome parameters, varies according to age at disease onset in PsS. The correlation between HLA-B27 and young-onset PsS supports the notion that disease susceptibility and disease expression are not driven by the same gene in this entity.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Age of Onset
  • Arthritis, Psoriatic / diagnosis*
  • Arthritis, Psoriatic / genetics
  • Arthritis, Psoriatic / physiopathology
  • Disease Progression
  • Female
  • Genetic Predisposition to Disease
  • HLA-B27 Antigen / genetics
  • Humans
  • Joints / pathology
  • Joints / physiopathology
  • Male
  • Middle Aged
  • Outpatients
  • Radiography
  • Sacroiliac Joint / diagnostic imaging
  • Sacroiliac Joint / pathology
  • Severity of Illness Index
  • Spain / epidemiology
  • Spondylitis / diagnosis*
  • Spondylitis / genetics
  • Spondylitis / physiopathology
  • Young Adult


  • HLA-B27 Antigen