Anti-annexin A5 antibodies and 25-hydroxy-cholecalciferol in female patients with primary antiphospholipid syndrome

Vascular antiphospholipid syndrome (VAPS) and obstetric (OAPS) are different entities because some patients only develop thrombosis (without recurrent pregnancy losses) and vice versa. Only two articles have reported that low 25-hydroxy-cholecalciferol (vitamin D3, VD3) levels were not correlated with the presence of conventional antiphospholipid antibodies (aPL Abs: anticardiolipin (aCL), anti-beta2glycoprotein I (aβ2gpI), and lupus anticoagulant (LA)), but no article analyzed the association of VD3 and anti-annexin A5 (aanxA5) Abs. The aim of our study was to investigate the association between VD3, multiple positivity of conventional aPL and aanxA5 Abs levels only in female OAPS vs. VAPS. Our study included 62 consecutive female PAPS patients. Concentrations of Abs were measured by ELISA, while VD3 levels were determined by immunochemiluminescence. Only 10/62 (16.13%) had sufficient (≥ 30 ng/ml) VD3 levels, while 48/62 (77.42%) and 4/62 (6.45%) had insufficiency and VD3 deficiency, respectively. Statistically significant VD3 deficiency was noticed in VAPS (vs. OAPS, P = 0.013). A negative correlation between VD3 levels and the age of patients was noticed (r = - 0.493, P = 0.032) only in VAPS subgroup. Multiple positivity of aPL and aanxA5 Abs was not associated with VD3 deficiency. Newly emerging aPL Abs, such as aanxA5 Abs, or their combinations with classical aPL Abs are not associated with VD3 deficiency in neither OAPS nor VAPS patients. Due to its immunomodulatory roles in B-Ly homeostasis, supplementation with VD3 should be considered in APS, at least in subgroup with severe form of the disease, i.e., VAPS.

The IgM isotype of anti-annexin A5 antibodies and multiple positivity of conventional antiphospholipid antibodies: increasing the number of clinical manifestations of primary antiphospholipid syndrome

We evaluated the importance of anti-annexin A5 antibodies (aanxA5 Abs) for clinical (thrombosis and/or recurrent pregnancy loss) and serologic (presence of antiphospholipid antibodies: lupus anticoagulant (LA), anticardiolipin (aCL), and anti-β2 glycoprotein I (aβ2GPI) antibodies) features of patients with primary antiphospholipid syndrome (PAPS). Our study included 70 patients with PAPS according to the international consensus criteria for APS. The mean age of the analyzed patients was 45.97 ± 12.72. The disease duration above 5 years was present in 31/70 of patients. Concentrations of analyzed antibodies were measured by ELISA. Cutoff values were set in accordance to the manufacturers' recommendations. History of recurrent pregnancy loss was associated with double positivity for aanxA5 IgM and LA (χ (2) = 4.000, P = 0.046) and triple positivity for aanxA5 IgM + LA + aβ2GPI IgM (χ (2) = 4.168, P = 0.041). Venous thromboses were associated with triple positivity for aanxA5 IgM + aCLIgG + aβ2GPI IgM (χ (2) = 3.965, P = 0.046). The IgG isotype of aanxA5 Abs was in positive correlation with aCL Abs of the IgG (r = 0.310, P = 0.009) and IgM (r = 0.254, P = 0.034) isotype. The presence of the clinical manifestations of PAPS is increasing with the number of positive conventional aPL and the IgM aanxA5 Abs tests. This new combination of Abs is beneficial even when the number of patients with positivity for aanxA5 Abs is low. This is important in further detection of patients prone to recurrence of thrombotic episodes.