Exploratory study of anti-pneumococcal immune response in patients with Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) immunized according to new vaccine recommendations (i.e. with a combined vaccine schedule (13-valent conjugate pneumococcal vaccine -PCV13- followed by a 23-valent non-conjugate pneumococcal vaccine -PPV23- 8 weeks later).
The purpose of this study is to determine whether this vaccination schedule induces sufficient protective immunity (serotype-specific enzyme linked immunosorbent assay (ELISA) and opsonophagocytosis (OPA) response rates) in AAV-patients receiving immunosuppressive therapy.
Study Type
OBSERVATIONAL
Enrollment
30
AP-HP ; Cochin Hospital
Paris, Île-de-France Region, France
RECRUITINGAnti-pneumococcal immunity after combined anti-pneumococcal immunization
Proportion of responder patients at V1 (12-weeks after PCV13 injection) to at least 6 of the 10 shared serotypes (i.e. 3, 4, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F) included both in PCV13 and PPV23. A serotype is considered positive if the ELISA immunoglobulins G (IgG) antibody titter shows a two-fold increase from baseline (V0) to V1 and is ≥ 1 μg/ml
Time frame: visit V1 (12 to 16 weeks after V0 (Day 0))
To assess serotype 3, 4, 6B, 7F, 9V, 14, 18C, 19 A, 19F and 23F-specific immune responses after vaccination
ELISA specific antibody titres to serotype 3, 4, 6B, 7F, 9V, 14, 18C, 19 A, 19F and 23F.
Time frame: visit V0 (Day 0), visit V1 (12 to 16 weeks after V0) and visit V2 (48 to 56 weeks after V0).
To assess serotype coverage increase after PPV23 injection
Serotype 10A and 12F (e.g. 2 PPV23-specific serotypes) ELISA antibody concentrations
Time frame: visit V0 (Day 0), visit V1 (12 to 16 weeks after V0) and visit V2 (48 to 56 weeks after V0).
For the following serotypes (4, 6B, 9V, 14, 18C, 19F and 23F), to assess the proportion of ELISA-responding patients who also show in vitro opsonophagocytic antibody activity.
For each of the following serotypes (4, 6B, 9V, 14, 18C, 19F and 23F), OPA titers will be measured in ELISA-responding patients at V0, V1, V2. Opsonophagocytic antibody activity is considered positive if the antibody titer shows a four-fold increase from V0 and is above a serotype-specific predefined threshold.
Time frame: visit V0 (Day 0), visit V1(12 to 16 weeks after V0) and visit V2 (48 to 56 weeks after V0).
Change Outcome Measures-To assess the sustainability and evolution over time of the vaccine-induced immune response (ELISA and OPA)
For ELISA-responding patients at V1, antibody ELISA concentrations and OPA titers will be measured 52 weeks after PCV13 injection (V2).
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Time frame: visit V2 (48 to 56 weeks after V0).
Composite Outcome Measures - To identify epidemiologic, clinic and biologic predictive factors that may influence vaccine-induced immune response.
Analysis of epidemiological, clinical and biological data collected during follow-up: age, sex, history of immunosuppressive therapy, time since previous PPV23 injection, number of previous PPV23 immunizations, AAV activity and severity according to Birmingham Vasculitis Activity Score and Vasculitis Damage Index, results of biological analyses
Time frame: visit V0 (Day 0), visit V1 (12 to 16 weeks after V0) and visit V2 (48 to 56 weeks after V0).