Background and Aims

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by vascular thrombosis and recurrent abortions in presence of antiphospholipid antibodies (aPL). A group of these patients have acute coronary syndrome (ACS) as their first and/or only thrombotic clinical manifestation, without statistically significant differences found in the literature regarding the association of ACS and the different aPL.

Recently, the concept of seronegative APS has been coined for those patients who present symptoms suggestive of APS and are positive for other non-criterion aPL that are not analyzed routinely. This group includes antiphosphatidylserine (aPS), antiprothrombin (PT), phosphatidylserine/prothrombin ratio (aPS/PT) and anti-beta-2 glycoprotein I isotype IgA (aB2GPI IgA).

In this study, we performed the analytical determination of aPL antibodies (IgA, IgM, IgG), lupus anticoagulant, aPS/PT, complement, immunoglobulins, ACPA, RF, ANCA, as well as interleukin levels in two groups of individuals: patients with ACS diagnosed with APS vs control of healthy individuals.

Methods

To compare both groups we analyzed the following parameters:

• Cytokines IL-1β, IL-17, TNF-α and IL-6 (Luminex® Multiplex Assays).

• Complement components and immunoglobulins (Nephelometry).

• Autoantibodies (ELIA or ELISA).

Results

Within the antibodies we found statistically significant differences in the levels of ACA IgA. We also found significant differences in the values ​​of IL-6, IL-17, MPO, PR3, antiCCP, C3, C4 and CRP. No differences were found in immunoglobulin levels.

Conclusions

Our study shows that some “non-criterion” aPL and the levels of IL-6 and IL-17 could be useful in diagnosing patients with ACS and underlying seronegative APS.