Long-Term Changes in Autoantibody Profile After Pandemic Unadjuvanted Influenza A/H1N1 Vaccine in Sjogren's Syndrome

Abstract

Background/Purpose: Despite WHO recommendations about the A/California/7/2009/H1N1-like virus vaccination, there are no studies evalu- ating its possible influence on clinical manifestations and autoantibody profile in (primary) Sjögren’s syndrome (SS). Objectives: To evaluate short/long-term effect of influenza A/California/7/2009/H1N1-like virus vaccination on clinical manifestations and autoantibody profile in SS. Methods: Thirty-six SS patients (The American-European Consensus Group Criteria, 2002) and 36 gender-, age-, matched-healthy controls were evaluated before and 21-days after vaccination with unadjuvanted influenza A/H1N1-like virus regarding seroprotection/seroconversion, factor increase in geometric mean titre (FI-GMT) and side effects. New onset of parotiditis, arthritis, vasculitis, pneumonitis or neurological disorders and autoantibody profile [antinuclear antibodies (ANA), rheumatoid factor (RF), anti-dsDNA, anti-Ro(SS-A)/La(SS-B), anti-alpha-fodrin, anti-RNP, anti-Sm and anticar-diolipin] were assessed before, 21-days and 1-year after vaccination. Results: Patients and controls had similar rates of seroconversion (78 vs. 69%, p=0.42), seroprotection (83 vs. 72%, p=0.26) and FI-GMT (p=0.85). Pre-vaccination evaluation revealed that disease duration, glucocorticoid (mean dose 10.15.1 mg/day), methotrexate (up to 17.5 mg/week) or azathioprine (up to 100 mg/day) did not affect seroconversion (p> 0.05). Regarding short-term analysis, no change in the frequency or levels of autoantibodies was observed (p>0.05) and only mild side effects were observed in comparable rates to controls (p> 0.05). At 1-year follow-up, the rate of new disease flares was similar to the previous year (11 vs. 19%, p 0.51) and four seroconverted patients developed positivity to one of the following specificities: anti-Ro/SS-A, anti-La/SS-B, anti-alpha-fodrin, or IgM anticardiolipin. None developed other specific lupus autoantibodies. Of note, a significant increase in the mean levels of anti-Ro/SS-A (p< 0.0001) and anti-La/SS-B (p< 0.002) was detected after 1-year with no change in the other autoantibodies. Conclusion: This is the first study to indicate that influenza A/H1N1 vaccine induces long-term changes in autoantibody profile restricted to SS spectrum without a deleterious effect in disease course.