Prognostic and therapeutic considerations of antibodies against c-ter apolipoprotein A-1 in the general population.

OBJECTIVES

Autoantibodies against apolipoprotein A1 (anti-apoA1 IgGs) and its C-terminal region (cter apoA1) have emerged as an independent biomarker for cardiovascular disease. Cter apoA1 mimetic peptides were shown to reverse the deleterious anti-apoA1 IgG effects . We evaluated the association of anti-cter apoA1 IgGs with overall mortality in the general population and tested the ability of a cter apoA1 mimetic peptide to reverse the anti-apoA1 IgG-induced inflammatory response and mortality and , respectively.

METHODS

Anti-cter apoA1 IgGs were measured in serum samples of 6386 participants of the CoLaus study of which 5220 were followed for a median duration of 5.6 years. The primary outcome was overall mortality. The peptide inhibitory concentration 50% (IC) was determined on HEK-Blue-4 and RAW cells. ApoE mice were exposed to 16 weeks of anti-apoA1IgG passive immunisation with and without peptide co-incubation.

RESULTS

Anti-cter apoA1 IgGs were associated with higher interleukin 6 levels and independently predicted overall mortality; an increase of one standard deviation of anti-cter apoA1 IgG level was associated with an 18% increase in mortality risk (hazard ratio: 1.18, 95% confidence interval: 1.04-1.33;  = 0.009). The cterApoA1 analogue reversed the antibody-mediated inflammatory response with an IC of 1 µm but did not rescue the significant anti-apoA1 IgG-induced mortality rate (69% vs. 23%, LogRank  = 0.02).

CONCLUSION

Anti-cter apoA1 IgG independently predicts overall mortality in the general population. Despite being effective , our cter apoA1 analogue did not reverse the anti-apoA1 IgG-induced mortality in mice. Our data suggest that these autoantibodies are not readily treatable through cognate peptide immunomodulation.