Accuracy of Anticardiolipin Antibodies in Identifying a History of Thrombosis Among Patients With Systemic Lupus Erythematosus

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      To measure the accuracy of anticardiolipin antibodies (aCL) in identifying a history of thrombosis among patients with systemic lupus erythematosus (SLE) or the primary antiphospholipid syndrome (PAPS).

      patients and methods

      Patients with SLE or PAPS who attended our rheumatology clinic between April 1992 and March 1994 were included in a retrospective analysis of the relationship between thrombotic events and aCL. All aCL measurements were performed in the same laboratory by enzyme-linked immunosorbent assay, blinded as to the presence or absence of thrombosis. The diagnostic accuracy of IgG, IgM, and IgA aCL was quantified by means of the receiver operating characteristic area under the curve (ROC AUC) for each isotype. Stratum-specific likelihood ratios and their 95% confidence intervals were calculated to define strata with optimal discriminant power. results: During the period of study, aCL was measured in 117 patients (113 SLE and 4 PAPS), of whom 24 (20.5%) had experienced thrombotic events. The ROC AUC ± the standard error for IgG aCL was 0.81 ± 0.05, signifying an 81% accuracy in the identification of a history of thrombosis. In contrast, the accuracy of the IgM and IgA aCL was significantly lower (0.60 ± 0.08 and 0.54 ± 0.07, respectively, P < 0.05). Using stratumspecific likelihood ratios, we defined three strata in the IgG aCL scale that discriminate between patients with low, indeterminate, and high probabilities of thrombosis. For IgG aCL levels below 21.4 IgG phospholipid (GPL) U/mL, the posttest probability of thrombosis was 0.07, whereas for IgG aCL levels ≥65.1 GPL U/mL, the posttest probability of thrombosis was 0.75. For IgG aCL values between 21.4 and 65.0 GPL U/mL, the probability of thrombosis was 0.20, equivalent to the entire cohort.


      The IgG aCL determinations perform well in the identification of thrombosis in SLE or PAPS, while the IgM and IgA aCL have poor diagnostic accuracy. These findings may have implications for management of these patients.
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        • Harris EN
        • Gharavi AE
        • Boey ML
        • et al.
        Anticardiolipin antibodies: detection by radioimmunoassay and association with thrombosis in systemic lupus erythematosus.
        Lancet. 1983; 2: 1211-1214
        • Harris EN
        • Gharavi AE
        • Patel SP
        • Hughes GRV
        Evaluation of the anti-cardiolipin antibody test: report of an international workshop held 4 April 1986.
        Clin Exp Immunol. 1987; 68: 215-222
        • Harris EN
        The second international anti-cardiolipin standardization workshop/ the Kingston anti-phospholipid antibody study (KAPS) group.
        Am J Clin Pathol. 1990; 94: 476-484
        • Love PE
        • Santoro SA
        Antiphospholipid antibodies: anticardiolipin and the lupus anticoagulant in systemic lupus erythematosus and related disorders.
        Ann Intern Med. 1990; 112: 682-698
        • Harris EN
        • Chan JK
        • Asherson RA
        • et al.
        Thrombosis, recurrent fetal loss and thrombocytopenia. Predictive value of the anticardiolipin antibody test.
        Arch Intern Med. 1986; 146: 2153-2156
        • Laesa S
        • McRea JD
        • Rudge AC
        • et al.
        Measurement of anti-cardiolipin antibodies by an enzyme-linked immunosorbent assay (ELISA): standardization and quantitation of results.
        Clin Exp Immunol. 1985; 62: 738-745
        • Long AA
        • Ginsberg JS
        • Brill-Edwards P
        • et al.
        The relationship of antiphospholipid antibodies to thromboembolic disease in systemic lupus erythematosus: a cross sectional study.
        Thromb Haemost. 1991; 66: 520-524
        • Kalunian KC
        • Peter JB
        • Middlekauff HR
        • et al.
        Clinical significance of a single test for anti-cardiolipin antibodies in patients with systemic lupus erythematosus.
        Am J Med. 1988; 85: 602-608
        • Alarcon-Segovia D
        • Delezé M
        • Oria CV
        • et al.
        Antiphospholipid antibodies and the antiphospholipid syndrome in systemic lupus erythematosus. A prospective analysis of 500 consecutive patients.
        Medicine. 1989; 68: 353-365
        • Levine SR
        • Salowich-Palm L
        • Sawaya KL
        • et al.
        Outcome following anticardiolipin antibody (aCL) associated cerebral ischemia: effect of IgG aCL titer.
        Stroke. 1994; 25: 258-272
        • Centor RM
        Signal detectability: the use of ROC curves and their analysis.
        Med Decis Making. 1991; 11: 102-106
        • Metz CE
        Basic principles of ROC analysis.
        in: Semin Nucl Med.8. 1978: 283-298
        • Swets JA
        Measuring the accuracy of diagnostic systems.
        Science. 1988; 240: 1285-1293
        • Peirce JC
        • Cornell RG
        Integrating stratum-specific likelihood ratios with the analysis of ROC curves.
        Med Decis Making. 1993; 13: 141-151
        • Alarcón-Segovia D
        • Sánchez-Guerrero J
        Primary antiphospholipid syndrome.
        J Rheumatol. 1989; 16: 482-488
        • Escalante A
        • Dreiner U
        • Mingrone M
        Performance of a brief health status questionnaire in a bilingual rheumatology clinic.
        Arthritis Rheum. 1993; 36 (suppl) (D10. Abstract): 233
        • Tan EM
        • Cohen AS
        • Fries JF
        • et al.
        The 1982 revised criteria for the classification of systemic lupus erythematosus (SLE).
        Arthritis Rheum. 1982; 25: 1271-1277
        • Brey RL
        • Hart RG
        • Sherman DC
        • Tegeler C
        Stroke in young people: role of anticardiolipin antibodies and lupus anticoagulants.
        Neurology. 1993; 40: 1190-1196
        • Hanley JA
        • McNeil BJ
        The meaning and use of the area under the receiver operating characteristic (ROC) curve.
        Radiology. 1983; 143: 29-36
        • Hanley JA
        • McNeil BJ
        A method of comparing the areas under the receiver operating characteristic curves derived from the same cases.
        Radiology. 1983; 148: 839-843
        • Radack KL
        • Rouan G
        • Hedges J
        The likelihood ratio: an improved measure for evaluating diagnostic test results.
        Arch Pathol Lab Med. 1986; 110: 689-693
        • Zweig MH
        • Broste SK
        • Reinhart RA
        ROC curve analysis: an example showing the relationships among serum lipid concentrations in identifying patients with coronary artery disease.
        Clin Chem. 1992; 38: 1425-1428
        • Centor RM
        • Whitherspoon JM
        • Dalton HP
        The diagnosis of strep throat in adults in the emergency room.
        Med Decis Making. 1981; 1: 239-246
        • Abrams HL
        • Siegelman SS
        • Adams DF
        • et al.
        Computed tomography versus ultrasound of the adrenal gland: a prospective study.
        Radiology. 1982; 143: 121-128
        • Derksen RH
        • Hasselaar O
        • Blokzijl L
        • et al.
        Coagulation screen is more specific than the anticardiolipin antibody ELISA in defining a thrombotic subset of lupus patients.
        Ann Rheum Dis. 1988; 47: 364-371
        • MacGregor AJ
        • Dhillon VB
        • Binder A
        • et al.
        Fasting lipids and anticardiolipin antibodies as risk factors for vascular disease in systemic lupus erythematosus.
        Ann Rheum Dis. 1992; 51: 160-161
        • Viard JP
        • Amoura Z
        • Bach JF
        Association of anti-β2glycoprotein I antibodies with lupus-type circulating anticoagulant and thrombosis in systemic lupus erythematosus.
        Am J Med. 1992; 93: 181-186
        • Drenkard C
        • Sánchez-Guerrero J
        • Alarcón-Segovia D
        Fall in antiphospholipid antibody at time of thromboocclusive episodes in systemic lupus erythematosus.
        J Rheumatol. 1989; 16: 614-617
        • Diamond GA
        Affirmative actions: can the discriminative accuracy of a test be determined in the face of selection bias?.
        Med Decis Making. 1991; 11: 48-56