Comparison of clinical and immunogenetic features in familial versus sporadic psoriatic arthritis

Clin Exp Rheumatol. 2000 Jan-Feb;18(1):7-12.


Objective: To compare patients with familial versus sporadic psoriatic arthritis (PsA) with respect to clinical, radiological and immunogenetic features.

Methods: All patients were identified from the University of Toronto Psoriatic Arthritis Clinic. Familial and sporadic PsA were distinguished based on the proband's self-reported history. The probands were compared at presentation to clinic with respect to: demographic information, age of onset of psoriasis and inflammatory arthritis, disease activity, disease damage, laboratory variables, functional class and HLA antigens. The two groups were compared using a univariate analysis.

Results: In total 407 patients were included. Thirty-six patients (8.8%) were eliminated as they reported a family history of arthritis in the absence of psoriasis. Of the remaining 371 patients, 150 patients reported a positive family of either PsA or psoriasis. 221 patients (54.2%) had no family history of psoriatic arthritis, psoriasis, or "arthritis". The familial group were younger at presentation to clinic (p = 0.003), had an earlier age of onset of psoriasis (p = 0.001) and inflammatory arthritis (p = 0.001) and were more likely to be receiving treatment (p = 0.001). The mean number of actively inflamed joints was higher in the sporadic group (p = 0.035), along with a higher frequency of rheumatoid factor positivity (p = 0.04). Only the age of onset variables and medication use retained significance after correction for multiple comparisons.

Conclusions: In comparing probands with familial versus sporadic PsA, we noted a marked difference in the age of onset of psoriasis and inflammatory arthritis, along with other differences in several clinical variables. These differences may be helpful in identifying PsA patients with a stronger genetic predisposition.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age of Onset
  • Antirheumatic Agents / therapeutic use
  • Arthritis, Psoriatic / diagnostic imaging
  • Arthritis, Psoriatic / genetics*
  • Arthritis, Psoriatic / immunology*
  • Arthritis, Psoriatic / physiopathology
  • Female
  • HLA Antigens / analysis
  • Humans
  • Male
  • Medical Records
  • Middle Aged
  • Radiography
  • Rheumatoid Factor / blood
  • Severity of Illness Index


  • Antirheumatic Agents
  • HLA Antigens
  • Rheumatoid Factor