From the Guidelines

Antiphospholipid Syndrome (APS) diagnosis is dependent on the accurate detection and interpretation of antiphospholipid antibodies (aPL).

The laboratory criteria for APS include persistent lupus anticoagulant (LA), anticardiolipin (aCL), and anti-β2-glycoprotein I (aβ2GPI) antibodies 1.
Moderate and high titer thresholds are set at 40 Unit (U) and 80 U levels, respectively 1.
ELISA is the recommended method for measuring aCL and aβ2GPI 1.
Interpretation of aPL results should always be related to clinical symptoms 1.

Combined low-dose aspirin and prophylactic-dose heparin (usually LMWH) is recommended for patients meeting criteria for obstetric APS 1.
Low-dose aspirin and therapeutic-dose heparin (usually LMWH) is recommended for patients with thrombotic APS 1.
The addition of hydroxychloroquine (HCQ) to prophylactic-dose heparin or LMWH and low-dose aspirin therapy may be considered for patients with primary APS 1.

Classification criteria are distinct from the detection and interpretation of aPL in the day-to-day clinical setting 1.
Patients with lower-titer aCL and/or anti-β2 GPI who do not meet laboratory classification criteria may still have some degree of risk 1.
Decisions regarding therapy should be made on a case-by-case basis, taking into account additional relevant risk factors 1.

From the Research

The diagnosis of APS requires a combination of clinical manifestations (thrombotic events and/or pregnancy morbidity) and the presence of antiphospholipid antibodies (aPL) 2.
The clinical spectrum of APS encompasses various manifestations, including venous and arterial thrombosis, and pregnancy morbidity, which cannot be explained exclusively by a prothrombotic state 3.
Risk stratification is essential, with "triple positive" patients having the highest risk of recurrent thrombosis 2.

The primary goal of treatment is to reduce the risk of thrombotic events and pregnancy morbidity 4.
Treatment with vitamin K antagonists (VKA) with a target international normalized ratio (INR) of 2-3 is recommended for patients with APS and first unprovoked venous thrombosis 2, 5.
For patients with APS and first arterial thrombosis, treatment with VKA with INR 2-3 or INR 3-4 is recommended, considering the individual's bleeding/thrombosis risk 5.
Low-dose aspirin (LDA) is recommended for asymptomatic aPL carriers, patients with systemic lupus erythematosus without prior thrombotic or obstetric APS, and non-pregnant women with a history of obstetric APS only, all with high-risk aPL profiles 5.

Refractory forms of APS could benefit from adding hydroxychloroquine and/or intravenous immunoglobulin to anticoagulation therapy 3.
Increasing the anticoagulation intensity of VKA, switching to low-molecular-weight heparin, or adding antiplatelet treatment may be considered for patients with recurrent thrombosis despite adequate treatment 6.
Promising novel treatments include anti-B cell monoclonal antibodies, new-generation anticoagulants, and complement cascade inhibitors 3.

Combination treatment with LDA and prophylactic dosage heparin during pregnancy is recommended for women with prior obstetric APS 5.
Increase of heparin to therapeutic dose, addition of hydroxychloroquine, or addition of low-dose prednisolone in the first trimester may be considered for patients with recurrent pregnancy complications 5.