Laboratory evaluation of anti‐phospholipid syndrome: a preliminary prospective study of phosphatidylserine/prothrombin antibodies in an at‐risk patient cohort. (May 2015)

• Record Type: Journal Article
• Authors: Heikal, N. M.; Jaskowski, T. D.; Malmberg, E.; Lakos, G.; Branch, D. W.; Tebo, A. E.
• Is Part Of: Clinical and experimental immunology. Volume 180:Number 2(2015:May)
• Page Start: 218
• Page End: 226
• Publication Date: 2015-05
• Subjects: Immunopathology -- Periodicals; 616.079
• DOI: 10.1111/cei.12573
• Languages: English
• ISSNs: 0009-9104

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Immunoglobulin (Ig)G/IgM autoantibodies to phosphatidylserine/prothrombin (aPS/PT) were evaluated individually and in combination with criteria anti‐phospholipid (aPL) tests in a prospectively ascertained cohort of patients at risk for anti‐phospholipid syndrome (APS). One hundred and sixty (160) consecutive requests for lupus anti‐coagulant (LAC) from the University of Utah Health Sciences Center were identified during 8 weeks. Of these, 104 unique patients had additional requests for cardiolipin (aCL) and/or beta2 glycoprotein I (aβ<sub>2</sub>GPI) IgG and/or IgM; samples were retained and analysed for aPS/PT, aCL and/or aβ<sub>2</sub>GPI IgG and IgM antibodies. Following testing, a comprehensive chart review was performed and patients categorized according to their clinical diagnosis. Individual and combined sensitivities, specificities, odd ratios (OR), diagnostic accuracy for specific tests or combinations by receiver operating characteristic (ROC), area under the curve (AUC) analyses and correlations between test results were determined. The sensitivities of aPS/PT IgG/IgM (54·6/45·5%) were lower than LAC (81·8%) but higher relative to aCL IgG/IgM (27·3/0%) or aβ<sub>2</sub>GPI IgG/IgM (27·3/0%). The best correlation between LAC and any aPL test was observed with aPS/PT (<italic>P</italic> = 0·002). There was no significant difference in the diagnostic accuracies for any panel with LAC: LAC/aβ<sub>2</sub>GPI IgG/aCL IgG [AUC 0·979, OR 475·4, 95% confidence interval (CI) 23·1–9056·5, <italic>P</italic> = 0·0001 and LAC/aβ<sub>2</sub>GPI IgG/aPS/PT IgG or LAC/aPS/PT IgG/aCL IgG (AUC 0·962, OR 265·3, 14·2–4958·2, <italic>P</italic> = 0·0001). The high correlation between LAC and aPS/PT IgG/IgM in this preliminary study suggest that this marker may be useful in the evaluation of APS. More studies to determine the optimal aPL antibody tests combination are needed.</p> </abstract>