Diffusion tensor imaging in patients with obstetric antiphospholipid syndrome without neuropsychiatric symptoms.

Objectives: To evaluate white matter (WM) integrity in neurologically asymptomatic antiphospholipid syndrome (APS) using diffusion tensor imaging (DTI) in women with no thrombotic history but with pregnancy loss.

Methods: Imaging was performed with a 3 T scanner using structural MRI (T1-weighted, fluid attenuation inversion recovery [FLAIR]) and DTI sequences in 66 women with APS and a control group of 17 women. Women with APS were further categorized as positive for lupus anticoagulant (LA) and/or aβ2GPI-G antibodies (LA/aβ2GPI-G-positive, N = 29) or negative (LA/aβ2GPI-G-negative, N = 37) for both. Tract-based spatial statistics of standard DTI-based indices were compared among groups.

Results: Women with APS had significantly lower fractional anisotropy (p < 0.05) associated with higher mean diffusivity and radial diffusivity compared to the control group. There was a stronger association of abnormal DTI features among women positive for LA and/or aβ2GPI-IgG antibodies than those who were negative.

Conclusions: DTI appears sensitive to subtle WM changes in women with APS with no thrombotic history but with pregnancy loss, compatible with alterations in axonal structure and in the myelin sheath. The preferential association of abnormal DTI features with the two most pathogenic aPLAbs reinforces the pathophysiological relevance of our findings.

Key Points: • APS women exhibited lower FA and higher MD and RD than controls. • WM impairments are more severe in patients with positive LA or aβ2GPI-IgG. • An association exists between abnormal DTI features and LA or aβ2GPI-IgG positivity. • Diffusion tensor imaging detects microstructural white matter abnormalities in APS women.