Single-step autoantibody profiling in antiphospholipid syndrome using a multi-line dot assay

Area of Science:

• Immunology
• Clinical Diagnostics
• Serology

Background:

• Antiphospholipid syndrome (APS) diagnosis is challenging due to the diverse range of antiphospholipid antibodies (aPL).
• Accurate detection of aPL is crucial for meeting diagnostic criteria and managing APS patients.

Purpose of the Study:

• To evaluate a novel multi-line dot assay (MLDA) for the simultaneous detection of multiple aPL.
• To compare the performance of MLDA with traditional enzyme-linked immunosorbent assays (ELISA) for aPL detection.

Main Methods:

• A multi-line dot assay (MLDA) was developed using phosphatidylserine (PS), phosphatidylinositol (PI), cardiolipin (CL), and beta2-glycoprotein I (β2 GPI) to detect IgG and IgM aPL.
• ELISA was used to detect anti-CL and anti-β2 GPI IgG and IgM for comparative analysis.
• The study included 85 APS patients, 65 disease controls, and 79 blood donors.

Main Results:

• MLDA demonstrated good to very good agreement with ELISA for anti-CL IgG and anti-β2 GPI IgG, and moderate agreement for IgM antibodies.
• Discrepancy rates between MLDA and ELISA were low across all tested antibody types.
• MLDA showed higher sensitivity and positive likelihood ratios compared to ELISA for diagnosing APS, particularly when detecting multiple aPL.
• A higher frequency of specific IgM antibodies detected by MLDA was associated with cerebral transient ischemia in APS patients.

Conclusions:

• The novel MLDA is a sensitive, readily available, and single-step diagnostic tool for multiplex aPL detection in APS.
• MLDA represents a potential alternative to single aPL antibody testing by ELISA, offering improved diagnostic capabilities.