Tdap booster to adolescents with juvenile idiopathic arthritis on and off anti-TNF agents is safe and immunogenic

Introduction: The response to vaccines in juvenile idiopathic arthritis (JIA) patients on and off anti-tumor necrosis factor (anti-TNF) agents remains highly discussed. There are no published studies on the immune response following a Tdap booster dose in JIA patients so far.

Objective: To evaluate the immune response and safety after a Tdap booster in JIA patients and in healthy adolescents.

Methods: Nineteen adolescents with JIA according to the ILAR criteria on anti-TNF medication, 19 adolescents with JIA off anti-TNF medication, and 27 healthy adolescents (control group) were compared after a Tdap booster. Adverse events and disease activity were evaluated. Lymphocyte immunophenotyping was performed by flow cytometry. Tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with whole-cell pertussis, and supernatants were assessed for cytokines by xMAP.

Results: The three groups showed a similar frequency of adverse events. There was no disease reactivation after the Tdap booster. Tetanus, diphtheria and pertussis antibodies showed a significant response when D0 and D14 concentrations were compared in both JIA groups and controls. Over time, a different pattern of response to the Tdap booster was observed among the groups for tetanus antibodies (p = 0.005) but not for diphtheria and pertussis antibodies. In contrast to the protection attained for tetanus and diphtheria, in the three groups, not all individuals showed pertussis seroconversion at either D14 or D28. In addition, the seroconversion of three subjects with JIA on anti-TNF medication was not maintained at D28. JIA patients off anti-TNF showed a higher percentage of naive CD8 + T cells (p = 0.007) and central memory CD8 + cells (p = 0.003) and a lower percentage of effector CD8 + T cells (p = 0.003) and NK cell numbers (p = 0.018) than the control group. The JIA group off anti-TNF medication had fewer B lymphocytes than both the JIA group on anti-TNF medication and the control group (p = 0.016). Cellular immunity to Bordetella pertussis showed that IFNγ levels were significantly lower in both JIA groups than in the control group (p = 0.003), IL10 levels were higher in the JIA off anti-TNF group (p = 0.009), IL17A and IL5 levels were lower in the JIA on anti-TNF group than in the control group (p = 0.018 and p = 0.016, respectively); however, an increase in IFNγ (p = 0.008), IL17A (p = 0.030) and TNFα (p = 0.041) levels was observed at D14 in both patient groups. Both JIA groups showed higher levels of IL21 than the control group (p = 0.023).

Conclusion: We conclude that individuals with JIA on or off anti-TNF agents showed a good response to a booster dose for the three antigens studied in the absence of major adverse events and without the reactivation of the disease.