Exaggerated Mg2+ inhibition of Kir2.1 as a consequence of reduced PIP2 sensitivity in Andersen syndrome.

OBJECTIVES

To assess the efficacy and safety of the influenza virus vaccine in systemic sclerosis (SSc) patients compared to healthy controls.

METHODS

Twenty-six SSc patients and 16 healthy controls were vaccinated with a trivalent influenza subunit vaccine (H1N1 A/Brisbane/59/2007(TGA 2008/81B) (H1N1), H3N2 A/Uruguay/716/2007 (A/Brisbane/10/2007-like, NIBSC8/124) (H3N2) and B B/Brisbane/60/2008 (TGA 2009/82/B) (B)). The subjects were evaluated on the day of vaccination and 6 weeks later. Disease activity was assessed by the Rodnan score, number of ulcers, number of tender and swollen joints, the presence of dyspnea, cough, dyspepsia and dysphagia, and patient (PDAI) and physician (PHDAI) disease activity evaluation by the visual activity score (VAS), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level. The humoral response was evaluated by haemagglutination inhibition (HI).

RESULTS

At baseline, 62%, 15% and 88% of the SSc patients had protective levels against H1N1, H3N2 and B, respectively, versus 56%, 62% and 87% for controls. Six weeks later, the proportion of responders to H1N1 was significantly higher in the SSc patients (73%) compared to controls (37.5%) (p=0.0225). The proportion of responders to H3N2 and B was similar in both groups, and both had a significant increase in geometric mean titers for each antigen. A lower response to H1N1 was associated with interstitial lung disease, while patients on combination calcium channel blockers and iloprost therapy showed significantly better response to H1N1 and B antigens. Most underlying disease activity parameters remained unchanged.

CONCLUSIONS

The influenza virus vaccine was safe and generated a satisfactory humoral response in SSc patients.