Influenza vaccine with adjuvant on disease activity in psoriatic arthritis patients under anti-TNF-α therapy.

Objectives: To evaluate the effects on disease activity of seasonal influenza vaccination with adjuvant in psoriatic arthritis (PsA) patients in stable disease activity on anti-TNF-α drugs as compared to not vaccinated PsA patients adequately matched.

Methods: An observational study was conducted on a cohort of PsA patients in stable disease activity who underwent administration of an adjuvanted vaccine for seasonal influenza. Cases (Group 1) were matched for age, sex, disease activity and therapy with not vaccinated PsA patients (Group 2). Analysis included patients data before vaccination (T0), and one month (T1) and three months (T3) after administration of the vaccination for Group 1 and at correspondent intervals for Group 2. Assessment of disease activity parameters was performed at each visit.

Results: Twenty-five vaccinated and 25 not vaccinated patients were included in the study. As a first approach, we analysed the data within groups. At T1, as compared to baseline, the group of vaccinated patients had a statistically significant increase in TJC (tender joint count) and ESR (erythrocyte sedimentation rate). At T3, a statistically significant difference from baseline characteristics was found only for the TJC. In Group 2, all the observed variables showed no significant differences when comparing baseline to T1 and T3. Analysis of the data between groups at T1, Group 1, as compared to Group 2, showed a significant increase of TJC, ESR, HAQ (Health Assessment Questionnaire), PtGA (patient global assessment) and PhGA (physician global assessment). These findings were also confirmed when comparing the two groups at T3 for ESR and PtGA, while they were not confirmed for TJC, HAQ and PhGA.

Conclusions: Influenza vaccination is clinically efficacious in PsA patients under anti-TNF-α therapy, but it could trigger a short-lasting exacerbation of the disease.