A new lupus anticoagulant neutralization test based on platelet-derived vesicles

Area of Science:

• Hematology
• Immunology
• Clinical Chemistry

Background:

• Distinguishing lupus anticoagulants (LA) from other coagulation inhibitors is crucial for accurate diagnosis and patient management.
• Existing methods may lack specificity or reproducibility, leading to diagnostic challenges.

Purpose of the Study:

• To develop and validate a novel, standardized, and reproducible assay for differentiating LA from coagulation factor inhibitors.
• To utilize platelet-derived microvesicles as a key component in this new diagnostic test.

Main Methods:

• Preparation of platelet-derived microvesicles via calcium ionophore A23187 incubation and differential centrifugation.
• Resuspension of vesicles in various plasma types (normal, LA, inhibitor, deficiency, anticoagulant/heparin treated).
• Performance of kaolin clotting time (KCT) with and without vesicles (KCTves) and calculation of ratios to mean normal times.

Main Results:

• High accuracy in segregating LA patients from those with factor inhibitors and congenital deficiencies.
• Successful differentiation of LA from heparinized patients using an additional thrombin time test.
• Demonstrated high reproducibility with intra- and inter-batch coefficients of variation below 6% for KCTves.

Conclusions:

• The developed LA neutralization test using platelet-derived microvesicles offers a reliable and reproducible method for distinguishing LA from other inhibitors.
• This assay improves diagnostic accuracy for lupus anticoagulants, particularly in complex cases involving heparin.
• The standardization and reproducibility of the method support its clinical applicability.