Which are the three major antiphospholipid antibodies (APL) forms?

Which are the three major antiphospholipid antibodies (APL) forms?

• A. IgG, IgM, IgA
• B. IgG, IgA, IgM
• C. IgM, IgA, IgG
• D. IgG, IgM, IgD

Answer: (B)

Antiphospholipid antibodies come in three immunoglobulin classes, so the major forms are IgG, IgM, and IgA. These isotypes can be directed against phospholipid-protein complexes, such as anticardiolipin and anti-β2-glycoprotein I. IgG is often the most clinically impactful in terms of thrombosis risk, but IgM and IgA antibodies against these targets are also detected in testing. IgD is not a typical antiphospholipid antibody isotype, so it isn’t considered a major form.

Antiphospholipid antibodies come in three immunoglobulin classes, so the major forms are IgG, IgM, and IgA. These isotypes can be directed against phospholipid-protein complexes, such as anticardiolipin and anti-β2-glycoprotein I. IgG is often the most clinically impactful in terms of thrombosis risk, but IgM and IgA antibodies against these targets are also detected in testing. IgD is not a typical antiphospholipid antibody isotype, so it isn’t considered a major form.