Psoriasis to psoriatic arthritis in terms of complement proteins: A single center experience.

There are previously stated risk factors for the transition from psoriasis to psoriatic arthritis, but the immune mechanisms in this regard have not been adequately explained. In this study, we aimed to investigate this transition in terms of the complement system. Study was planned as a prospective analytical type. 46 psoriasis and 45 psoriatic arthritis patients were included in this study. Morning stiffness, nail involvement, disease activation questionnaire scores, neutrophil and lymphocyte percentage, neutrophil-lymphocyte rate, high-density lipoprotein, low-density lipoprotein, triglyceride, erythrocyte sedimentation rate, C-reactive protein, uric acid, complement 3 (C3) and 4 (C4) values were evaluated. Enthesis clinical assessment was done with the Leeds enthesis index (LEI). Ultrasonography was used to evaluate the enthesis sites. The severity of skin involvement in psoriasis was evaluated with the psoriasis area severity index (PASI). PASI scores were higher in psoriasis patients, while LEI scores, erythrocyte sedimentation rate and C-reactive protein levels were higher in psoriatic arthritis patients (P = .016, P = <.001, P = .016, P = .027, P = .020, respectively). Among psoriasis patients, C3 levels were higher in the patients with nail involvement (P = .035). C3 levels of psoriasis patients showed a moderate positive correlation between PASI and LEI scores (r = 0.368, r = 0.404, respectively). In psoriasis patients, high-density lipoprotein values were found to be moderately negatively correlated with both C3 and C4 (r = -0.311, r = -0.388, respectively). As a result of this study, C3 levels may play a role in the progression to psoriatic arthritis.