Anti-annexin v antibodies: association with vascular involvement and disease outcome in patients with systemic sclerosis.

Abstract

Systemic Sclerosis (SSc) is characterized by skin thickening, fibrosis and vascular obliteration. The onset and course are heterogeneous. Prominent features include autoimmunity, inflammation and vascular damage. To measure the level of serum Anti-Annexin V antibodies in SSc patients and to study its significance in relation to vascular damage in these patients. Twenty patients with SSc (12 with diffuse SSc and 8 with the limited form) and 10 healthy age and sex matched volunteers as controls were all subjected to routine laboratory testing and immunological profiling including antinuclear, anti-Scl-70, anticentomere, anticardiolipin antibodies and anti-annexin V antibodies titres. Vascular damage was assessed by clinical examination and assessment of the disease activity score, nailfold capillaroscopy and colour flow Doppler of the renal arteries; Doppler echocardiography was used for assessing pulmonary hypertension. Anti-annexin V antibodies were detected in 75% of patients. Comparisons between anti-annexin V in diffuse and limited subgroups showed no significance; however a statistically significant positive correlation was found between Anti-annexin V titre and the degree of vascular damage in SSc patients. Anti-annexin V increased significantly in patients with severe vascular damage in comparison with those less affected (15.3 ± 6.6 vs. 11.25 ± 3.6, P < 0.05). A significant positive correlation was found between Anti-annexin V titre and both the ACL titre (r = 0.79, P < 0.001) and the resistive index of the main renal artery (r = 0.42, P < 0.05). Anti-annexin V antibodies were significantly present in sera of patients with SSc. Patients with more severe forms of vascular damage had higher titres of these antibodies. Anti-annexin V antibodies are a sensitive predictor of vascular damage in SSc and could serve as a useful parameter in discriminating patients with a higher risk of vascular affection from those without.