Objective: To identify predictors of early minimal disease activity in patients with psoriatic arthritis (PsA) receiving tumor necrosis factor-α (TNF-α) antagonists.
Methods: In total 146 consecutive patients with PsA eligible for anti-TNF-α therapy were enrolled. At baseline (T0) information about age, sex, PsA subset, disease duration, comorbidities, and treatments was collected. All subjects were tested for metabolic syndrome (MetS) and/or liver steatosis. A clinical and laboratory evaluation was performed at T0 and at 3 months (T3). Changes in all these variables were compared in subjects achieving minimal disease activity (MDA) and those who did not.
Results: Among 146 PsA subjects, 10 discontinued therapy before 3-month followup because of adverse events; thus 136 concluded the study. All clinical outcome measures changed significantly from T0 to T3. Erythrocyte sedimentation rate showed a significant reduction (p < 0.001). C-reactive protein (CRP), serum cholesterol, and triglycerides showed no significant variation (p > 0.05). The prevalence of MetS and liver steatosis showed no significant differences between subjects achieving MDA and those who did not (p = 0.347 and 0.053, respectively). Patients achieving MDA at T3 were younger than those not achieving MDA (p = 0.001). A lower baseline tender joint count (p = 0.001), swollen joint count (p = 0.013), Bath Ankylosing Spondylitis Disease Activity Index (p = 0.021), and Ritchie index (p = 0.006) were found in subjects achieving MDA. Age (OR 0.896, p = 0.003) and Bath Ankylosing Spondylitis Functional Index (BASFI) (OR 0.479, p = 0.007) inversely predicted, whereas CRP (OR 1.78, p = 0.018) directly predicted, achievement of MDA at T3.
Conclusion: In patients with PsA, age, CRP, and BASFI at the beginning of treatment were found to be reliable predictors of MDA after 3 months of TNF-α blocker therapy.