Determination of clinically significant tests for antiphospholipid antibodies and cutoff levels for obstetric antiphospholipid syndrome

Lupus. 2015 Dec;24(14):1505-19. doi: 10.1177/0961203315595128. Epub 2015 Jul 9.

Abstract

Objective: The objective of this paper is to determine which kinds of assays for antiphospholipid antibodies (aPL) should be tested for clinical practice for patients with recurrent pregnancy loss (RPL).

Materials and methods: We studied 560 patients with a history of RPL prospectively. We determined the obstetric significance of 11 commercially available tested assays for lupus anticoagulant (LA)-aPTT StaClot, phosphatidylserine-dependent antiprothrombin (aPS/PT) IgG, IgM, classical cardiolipin (CL) IgG, IgM, CL IgG, IgM, IgA, and β2glycoprotein I (β2GPI) IgG, IgM, IgA Phadia. Obstetric significance was defined as the potential for anticoagulant therapy to improve the subsequent live birth rate, or a difference in the live birth rate between positive and negative untreated cases.

Results: The LA-aPTT StaClot assay and aPS/PT IgG assay, but not CL IgG, were found to have obstetric significance. Our conventional tests covered positive cases with the aPS/PT IgM and classical CL IgG assays. The results of the LA-aPTT StaClot, LA-aPTT and LA-RVVT assays showed different distributions, although strong or moderate correlation was observed.

Conclusion: LA-aPTT StaClot and aPS/PT IgG might be suitable for use in routine practice for patients with RPL. Each test for aPL should be ascertained for obstetric significance, because similar assays may have different outcomes.

Keywords: Antiphospholipid antibodies; lupus anticoagulant; phosphatidylserine-dependent antiprothrombin antibody; recurrent pregnancy loss.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abortion, Habitual / immunology*
  • Adult
  • Antibodies, Anticardiolipin / blood
  • Antibodies, Antiphospholipid / analysis*
  • Antiphospholipid Syndrome / immunology*
  • Female
  • Humans
  • Obstetrics* / methods
  • Pregnancy
  • Pregnancy Complications / immunology*
  • Pregnancy Rate
  • Reagent Kits, Diagnostic*

Substances

  • Antibodies, Anticardiolipin
  • Antibodies, Antiphospholipid
  • Reagent Kits, Diagnostic