Clinical, laboratory and immunogenetic aspects of post-traumatic psoriatic arthritis: a study of 25 patients

In a previous study we demonstrated that the prevalence of trauma preceding arthritis was higher in patients with psoriatic arthritis (PsA) than in patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS); of 300 consecutive patients with PsA, 25 (8%) had a history of trauma before (< 3 months) the onset of the disease. The present study was carried out to characterize the clinical, laboratory and immunogenetic profiles of post-traumatic (PT)-PsA.

The clinical and laboratory features of 25 patients with PT-PsA were studied at onset (first 6 months) and after a follow-up period of 1-7 years, and were compared with those of 275 PsA patients without any history of trauma (nonPT-PsA). HLA typing was performed in PT-PsA patients, and synovial fluid (SF) analysis, including interleukin (IL)-1 and IL-6 determinations, was carried out in 12 subjects with PT-PsA and in 32 with nonPT-PsA.

No differences were observed between PT-PsA and nonPT-PsA patients with regard to their clinical evolution. ESR (p < 0.0001) and CRP (p = 0.005) were higher in PT-PsA than in nonPT-PsA patients at disease onset but not after follow-up. No differences were found in the other blood indices. SF analysis revealed higher IL-6 levels in PT-PsA than in nonPT-PsA patients (p < 0.0005).

Our study demonstrates that the prevalence of trauma preceding arthritis is higher in PsA than in RA or AS. Clinical and laboratory findings in patients with PT-PsA differed from those with nonPT-PsA only at disease onset (first six months), however, showing an abrupt clinical presentation and a more acute phase response. This pattern may be related to the higher levels of IL-6 found in the SF of PT-PsA than in nonPT-PsA patients. However, during the follow-up period the two groups became indistinguishable, and no difference was observed between PT-PsA and nonPT-PsA regarding the evolution of the disease.