Clinical and laboratory manifestations of elderly onset psoriatic arthritis: a comparison with younger onset disease

Objective-Although the influence of age on clinical and laboratory features has been widely demonstrated in many arthropathies, studies on elderly ons et (> 60 years) psoriatic arthritis (EOPsA) are rare. This study compares m anifestations at onset and two year outcome of EOPsA with those of younger onset PsA (YOPsA). Patients and Methods-Sixty six consecutive PsA patients with disease durati on < 1 year, 16 EOPsA (>60 years) and 50 YOPsA (less than or equal to 60 ye ars) were admitted to a prospective study. Clinical, laboratory, and radiog raphic assessment were carried out at admission and after two years. HLA cl ass I and bone scintigraphy were also recorded. In 10 patients with EOPsA a nd 24 with YOPsA it was possible to obtain synovial fluid, which was subseq uently analysed for local inflammatory indices, including interleukin (IL) 1 beta, IL6, and IL8. Results-Presenting manifestations of EOPsA differed from YOPsA in number of active joints (mean (SD)) (12.2 (6.3) v 6.7 (4.6), p<0.001), foot bone ero sions (2.7 (1.2) v 1.1 (1.1), p<0.001), erythrocyte sedimentation rate (64. 2 (35.3) v 30.5 (30.0) mm Ist h, p<0.001), C reactive protein (3.9 (2.0) v 1.3 (1.3) mg/dl, p<0.001) and synovial fluid IL1 beta (8.0 (4.7) v 3.0 (3.0 ) pg/ml, p<0.001) and IL6 (828.2 (492.6) v 469.3 (201.4) pg/ml, p<0.005). N o differences were found in the number of subjects with dactylitis, pitting oedema, HLA-B27, or signs of sacroiliac and sternoclavicular joint involve ment at bone scintigraphy. After two years, progression was more evident in EOPsA than in YOPsA, as the number of new erosions in the hands and also t he C reactive protein were higher in EOPsA patients. Conclusion-PsA has a more severe onset and a more destructive outcome in el derly people (onset >60 years) than in younger subjects. This behaviour may be influenced by immune changes associated with aging, as suggested by the higher concentrations of IL1 beta and IL6 found in the synovial fluid of E OPsA than in YOFsA.