Association of capillaroscopic microhaemorrhages with clinical and immunological antiphospholipid syndrome

Patients with clinical signs of vasculopathy were screened with capillaroscopy for microangiopathy, and its presence was evaluated in the diagnosis of antiphospholipid syndrome (APS). For this purpose, autoantibody profiles in high risk patients with microhaemorrhages were correlated with thrombotic events.

738 patients from a Rheumatology Outpatients cohort were consecutively screened with capillaroscopy. Patients with microhaemorrhages were selected from the total of individuals screened and tested for anticardiolipin (αCL) and anti-beta2 glycoprotein 1 (anti-β2GP1) Abs. Positive autoantibody profile was subsequently correlated with arterial and venous thrombotic events. Patients with scleroderma were excluded from the analysis.

149 patients with various rheumatologic conditions and capillary microhaemorrhages were included in the study. Antiphospholipid profile screening in these individuals revealed a 15.4% of newly diagnosed secondary laboratory APS. αCL antibodies and anti-β2-glycoprotein 1 (anti-β2GP1 Abs were both found to independently correlate significantly with thrombotic events. Subanalysis of the type of anti-β2GP1 Abs indicated that the correlation with thrombotic events was significant for IgG-type (p<0.001) and IgM-type (p=0.051), but not IgA-type Abs (p=0.292).

In patients with microhaemorrhages, αCL and anti-β2GP1 Abs were associated with thrombotic events. The observation that, although IgA type-anti-β2GP1 Abs were detected in patients with microangiopathy, they lacked any significant association with thrombotic complications, suggests, that either the type/conformation of the autoantibodies and/or additional factors may be critical for the development of thromboses. In conclusion, capillaroscopy can aid diagnostically to screen for or verify APS in combination with other parameters.