• 1
    Miyakis S, Lockshin MD, Atsumi T, Branch DW, Brey RL, Cervera R, et al. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). J Thromb Haemost 2006; 4: 295306.
  • 2
    Pierangeli SS, Harris EN. A protocol for determination of anticardiolipin antibodies by ELISA. Nat Protoc 2008; 3: 8408.
  • 3
    Wong RC, Gillis D, Adelstein S, Baumgart K, Favaloro EJ, Hendle MJ, et al. Consensus guidelines on anti-cardiolipin antibody testing and reporting. Pathology 2004; 36: 638.
  • 4
    Wong RC, Favaloro EJ, Adelstein S, Baumgart K, Bird R, Brighton TA, et al. Consensus guidelines on anti-β2 glycoprotein I testing and reporting. Pathology 2008; 40: 5863.
  • 5
    Wong RC, Adelstein S, Gillis D, Favaloro EJ. Development of consensus guidelines for anticardiolipin and lupus anticoagulant testing. Semin Thromb Hemost 2005; 31: 3948.
  • 6
    Tincani A, Allegri F, Balestrieri G, Reber G, Sanmarco M, Meroni P, et al. Minimal requirements for antiphospholipid antibodies ELISAs proposed by the European Forum on Antiphospholipid Antibodies. Thromb Res 2004; 114: 5538.
  • 7
    Reber G, Tincani A, Sanmarco M, de Moerloose P, Boffa MC. Proposals for the measurement of anti-β2glycoprotein I antibodies: Standardization Group of the European Forum on Antiphospholipid Antibodies. J Thromb Haemost 2004; 2: 18602.
  • 8
    Reber G, Schousboe I, Tincani A, Sanmarco M, Kveder T, de Moerloose P, et al. Inter-laboratory variability of anti-β2 glycoprotein I measurement: a collaborative study in the frame of the European Forum on Antiphospholipid Antibodies Standardization Group. Thromb Haemost 2002; 88: 6673.
  • 9
    Favaloro EJ, Silvestrini R. Assessing the usefulness of anticardiolipin antibody assays: a cautious approach is suggested by high variation and limited consensus in multilaboratory testing. Am J Clin Pathol 2002; 118: 54857.
  • 10
    Kutteh WH, Franklin RD. Assessing the variation in antiphospholipid antibody (APA) assays: comparison of results from 10 centers. Am J Obstet Gynecol 2004; 191: 4408.
  • 11
    Wong R, Favaloro E, Pollock W, Wilson R, Hendle M, Adelstein S, et al. A multi-centre evaluation of the intra-assay and inter-assay variation of commercial and in-house anti-cardiolipin antibody assays. Pathology 2004; 36: 18292.
  • 12
    Reber G, Tincani A, Sanmarco M, de Moerloose P, Boffa MC. Variability of anti-β2glycoprotein I antibodies measurement by commercial assays. Thromb Haemost 2005; 94: 66572.
  • 13
    Harris EN, Gharavi AE, Patel SP, Hughes GR. Evaluation of the anti-cardiolipin antibody test: report of an international workshop held 4 April 1986. Clin Exp Immunol 1987; 68: 21522.
  • 14
    Harris EN. The second international anti-cardiolipin standardization workshop: the Kingston Antiphospholipid Antibody Study (KAPS) Group. Am J Clin Pathol 1990; 94: 47684.
  • 15
    Harris EN, Pierangeli SS. Revisiting the anticardiolipin test and its standardization. Lupus 2002; 11: 26975.
  • 16
    Pierangeli SS, de Groot PG, Dlott J, Favaloro E, Harris EN, Lakos G, et al. ‘Criteria’ aPL tests: report of a task force and preconference workshop at the 13th International Congress on Antiphospholipid Antibodies, Galveston, Texas, April 2010. Lupus 2011; 20: 18290.
  • 17
    Pierangeli SS, Harris EN. A quarter of a century in anticardiolipin antibody testing and attempted standardization has led us to here, which is? Semin Thromb Hemost 2008; 34: 31328.
  • 18
    De Moerloose P, Reber G, Musial J, Arnout J. Analytical and clinical performance of a new, automated assay panel for the diagnosis of antiphospholipid syndrome. J Thromb Haemost 2010; 8: 15406.
  • 19
    Harris EN, Gharavi AE, Boey ML, Patel BM, Mackworth-Young CG, Loizou S, et al. Anticardiolipin antibodies: detection by radioimmunoassay and association with thrombosis in systemic lupus erythematosus. Lancet 1983; 2: 12114.
  • 20
    Matsuura E, Igarashi Y, Fujimoto M, Ichikawa K, Koike T. Anticardiolipin cofactor(s) and differential diagnosis of autoimmune disease. Lancet 1990; 336: 1778.
  • 21
    Brandt JT, Triplett DA, Alving B, Scharrer I, on behalf of the Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibody of the Scientific and Standardisation Committee of the ISTH. Criteria for the diagnosis of lupus anticoagulants: an update. Thromb Haemost 1995; 74: 118590.
  • 22
    Pengo V, Tripodi A, Reber G, Rand JH, Ortel TL, Galli M, et al. Update of the guidelines for lupus anticoagulant detection. J Thromb Haemost 2009; 7: 173740.
  • 23
    Adcock DM, Hoefner DM, Kottke-Marchant K, Marlar RA, Szamosi DI, Warunek DJ. Collection, transport, and processing of blood specimens for testing plasma-based coagulation assays and molecular hemostasis assays; approved guideline—fifth edition. CLSI document H21-A5. Wayne (PA): Clinical and Laboratory Standards Institute; 2008.
  • 24
    Lewis DA, Pound ML, Ortel TL. The reactivity of paired plasma and serum samples are comparable in the anticardiolipin and anti-β2 glycoprotein I ELISAs. J Thromb Haemost 2006; 4: 2657.
  • 25
    Hasselaar P, Triplett DA, LaRue A, Derksen RH, Blokzijl L, de Groot PG, et al. Heat treatment and serum or plasma induce false-positive results in the antiphospholipid antibody ELISA. J Rheumatol 1990; 17: 18691.
  • 26
    Brey RL, Cote SA, McGlasson DL, Triplett DA, Barna LK. Effects of repeated freeze-thaw cycles on anticardiolipin antibody immunoreactivity. Am J Clin Pathol 1994; 102: 5868.
  • 27
    Kiechle FL, Betsou F, Blakeney J, Calam RR, Catalasan IM, Raj P, et al. Procedures for the handling and processing of blood specimens for common laboratory tests; approved guideline—fourth edition. CLSI document H18-A4. Wayne (PA): Clinical and Laboratory Standards Institute; 2010.
  • 28
    Danowski A, de Azevedo MN, de Souza Papi JA, Petri M. Determinants of risk for venous and arterial thrombosis in primary antiphospholipid syndrome and in antiphospholipid syndrome with systemic lupus erythematosus. J Rheumatol 2009; 36: 11959.
  • 29
    Swadzba J, Iwaniec T, Szczeklik A, Musial J. Revised classification criteria for antiphospholipid syndrome and the thrombotic risk in patients with autoimmune diseases. J Thromb Haemost 2007; 5: 18839.
  • 30
    Tincani A, Andreoli L, Casu C, Cattaneo R, Meroni P. Antiphospholipid antibody profile: implications for the evaluation and management of patients. Lupus 2010; 19: 4325.
  • 31
    Zoghlami-Rintelen C, Vormittag R, Sailer T, Lehr S, Quehenberger P, Rumpold H, et al. The presence of IgG antibodies against β2glycoprotein I predicts the risk of thrombosis in patients with the lupus anticoagulant. J Thromb Haemost 2005; 3: 11605.
  • 32
    Pierangeli SS, Liu XW, Barker JH, Anderson G, Harris EN. Induction of thrombosis in a mouse model by IgG, IgM and IgA immunoglobulins from patients with the antiphospholipid syndrome. Thromb Haemost 1995; 74: 13617.
  • 33
    Tajima C, Suzuki Y, Mizushima Y, Ichikawa Y. Clinical significance of immunoglobulin A antiphospholipid antibodies: possible association with skin manifestations and small vessel vasculitis. J Rheumatol 1998; 25: 17306.
  • 34
    Shen YM, Lee R, Frenkel E, Sarode R. IgA antiphospholipid antibodies are an independent risk factor for thromboses. Lupus 2008; 17: 9961003.
  • 35
    Samarkos M, Davies KA, Gordon C, Loizou S. Clinical significance of IgA anticardiolipin and anti-β2GPI antibodies in patients with systemic lupus erythematosus and primary antiphospholipid syndrome. Clin Rheumatol 2006; 25: 199204.
  • 36
    Wilson WA, Faghiri Z, Taheri Z, Gharavi AE. Significance of IgA antiphospholipid antibodies. Lupus 1998; 7 Suppl 2: S1103.
  • 37
    Lopez LR, Santos ME, Espinoza LR, La Rosa FG. Clinical significance of immunoglobulin A versus immunoglobulins G and M anti-cardiolipin antibodies in patients with systemic lupus erythematosus: correlation with thrombosis, thrombocytopenia and recurrent abortion. Am J Clin Pathol 1992; 98: 44954.
  • 38
    Kumar S, Papalardo E, Sunkureddi P, Najam S, Gonzalez EB, Pierangeli SS. Isolated elevation of IgA anti-β2glycoprotein I antibodies with manifestations of antiphospholipid syndrome: a case series of five patients. Lupus 2009; 18: 10114.
  • 39
    Mehrani T, Petri M. Association of IgA anti-β2glycoprotein I with clinical and laboratory manifestations of systemic lupus erythematosus. J Rheumatol 2011; 38: 648.
  • 40
    Bertolaccini ML, Amengual O, Atsumi T, Binder WL, de Laat B, Forastiero R, et al. ‘Non-criteria’ aPL tests: report of a task force and preconference workshop at the 13th International Congress on Antiphospholipid Antibodies, Galveston, TX, USA, April 2010. Lupus 2011; 20: 191205.
  • 41
    Sammaritano LR, Lockshin MD, Gharavi AE. Antiphospholipid antibodies differ in aPL cofactor requirement. Lupus 1992; 1: 8390.
  • 42
    Chamley LW, Pattison NS, McKay EJ. Anomalous anticardiolipin antibody results may be due to cofactor variability. Am J Hematol 1991; 37: 289.
  • 43
    Schlame M, Haller I, Sammaritano LR, Blanck TJ. Effect of cardiolipin oxidation on solid-phase immunoassay for antiphospholipid antibodies. Thromb Haemost 2001; 86: 147582.
  • 44
    Matsuura E, Igarashi Y, Yasuda T, Triplett DA, Koike T. Anticardiolipin antibodies recognize β2glycoprotein I structure altered by interacting with an oxygen modified solid phase surface. J Exp Med 1994; 179: 45762.
  • 45
    Roubey RA, Eisenberg RA, Harper MF, Winfield JB. “Anticardiolipin” antibodies recognize β2glycoprotein I in the absence of phospholipid: importance of Ag density and bivalent binding. J Immunol 1995; 154: 95460.
  • 46
    Findlay JW, Dillard RF. Appropriate calibration curve fitting in ligand binding assays. AAPS J 2007; 9: E2607.
  • 47
    Lewis S, Keil LB, Binder WL, DeBari VA. Standardized measurement of major immunoglobulin class (IgG, IgA and IgM) antibodies to β2glycoprotein I in patients with antiphospholipid syndrome. J Clin Lab Anal 1998; 12: 2937.
  • 48
    Ichikawa K, Tsutsumi A, Atsumi T, Matsuura E, Kobayashi S, Hughes GR, et al. A chimeric antibody with the human γ1 constant region as a putative standard for assays to detect IgG β2-glycoprotein I–dependent anticardiolipin and anti–β2-glycoprotein I antibodies. Arthritis Rheum 1999; 42: 246170.
  • 49
    Ichikawa K, Khamashta MA, Koike T, Matsuura E, Hughes GR. β2-glycoprotein I reactivity of monoclonal anticardiolipin antibodies from patients with the antiphospholipid syndrome. Arthritis Rheum 1994; 37: 145361.
  • 50
    Forastiero R, Papalardo E, Watkins M, Nguyen H, Crisostomo M, Vandam W, et al. Evaluation of the performance of monoclonal and polyclonal antibody standards in different assays for the detection of antiphospholipid (aPL) antibodies: report of a wet workshop at the 13th International Congress on Antiphospholipid Antibodies. [abstract]. Arthritis Rheum 2010; 62 Suppl: S946.
  • 51
    Vesper HW, Thienpont LM. Traceability in laboratory medicine. Clin Chem 2009; 55: 106775.
  • 52
    Westgard JO. Use and interpretation of common statistical tests in method comparison studies. Clin Chem 2008; 54: 612.
  • 53
    Tholen DW, Kroll M, Astles JR, Caffo AL, Happe TM, Krouwer J, et al. Evaluation of the linearity of quantitative measurement procedures: a statistical approach; approved guideline. CLSI/NCCLS document EP6-A. Wayne (PA): Clinical and Laboratory Standards Institute; 2003.
  • 54
    Carey RN, Anderson FP, George H, Hartmann AE, Janzen VK, Kallner A, et al. User verification of performance for precision and trueness; approved guideline—second edition. CLSI document EP15-A2. Wayne (PA): Clinical and Laboratory Standards Institute; 2005.
  • 55
    Pierangeli SS, Harris EN. Clinical laboratory testing for the antiphospholipid syndrome. Clin Chim Acta 2005; 357: 1733.
  • 56
    Hay ID, Bayer MF, Kaplan MM, Klee GG, Larsen PR, Spencer CA, the Committee on Nomenclature of the American Thyroid Association. American Thyroid Association assessment of current free thyroid hormone and thyrotropin measurements and guidelines for future clinical assays. Clin Chem 1991; 37: 20028.
  • 57
    Horowitz GL, Altaie S, Boyd JC, Ceriotti F, Garg U, Horn P, et al. Defining, establishing, and verifying reference intervals in the clinical laboratory; approved guideline—third edition. CLSI document C28-A3. Wayne (PA): Clinical and Laboratory Standard Institute; 2008.
  • 58
    Tate J, Ward G. Interferences in immunoassay. Clin Biochem Rev 2004; 25: 10520.
  • 59
    Berth M, Bosmans E, Everaert J, Dierick J, Schiettecatte J, Anckaert E, et al. Rheumatoid factor interference in the determination of carbohydrate antigen 19-9 (CA 19-9). Clin Chem Lab Med 2006; 44: 11379.
  • 60
    Meurman OH, Ziola BR. IgM-class rheumatoid factor interference in the solid-phase radioimmunoassay of rubella-specific IgM antibodies. J Clin Pathol 1978; 31: 4837.
  • 61
    Gerna I, Zannino M, Revello MG, Petruzzelli E, Dovis M. Development and evaluation of a capture enzyme-linked immunosorbent assay for determination of rubella immunoglobulin M using monoclonal antibodies. J Clin Microbiol 1987; 25: 10338.
  • 62
    Galperin I, Fortin PR, Subang R, Newkirk MM, Rauch J. A subset of rheumatoid factors crossreacts with cardiolipin in patients positive for IgM rheumatoid factor and anticardiolipin antibodies. J Rheumatol 2000; 27: 8201.
  • 63
    Agopian MS, Boctor FN, Peter JB. False-positive test result for IgM anticardiolipin antibody due to IgM rheumatoid factor [letter]. Arthritis Rheum 1988; 31: 12123.
  • 64
    Lakos G, Teodorescu M. IgM, but not IgA rheumatoid factor interferes with anti-cardiolipin and anti-β2glycoprotein I measurements: a quantitative analysis. Lupus 2011; 20: 6149.
  • 65
    Ruffatti A, Olivieri S, Tonello M, Bortolati M, Bison E, Salvan E, et al. Influence of different IgG anticardiolipin antibody cut-off values on antiphospholipid syndrome classification. J Thromb Haemost 2008; 6: 16936.
  • 66
    Budd R, Harley E, Quarshie A, Henderson V, Harris EN, Pierangeli SS. A re-appraisal of the normal cut-off assignment for anticardiolipin IgM tests. J Thromb Haemost 2006; 4: 22104.
  • 67
    Tincani A, Andreoli L, Casu C, Cattaneo R, Meroni P. Antiphospholipid antibody profile: implications for the evaluation and management of patients. Lupus 2010; 19: 4325.
  • 68
    Roubey RA. Risky business: the interpretation, use, and abuse of antiphospholipid antibody tests in clinical practice. Lupus 2010; 19: 4405.
  • 69
    Neville C, Rauch J, Kassis J, Chang ER, Joseph L, Le Comte M, et al. Thromboembolic risk in patients with high titre anticardiolipin and multiple antiphospholipid antibodies. Thromb Haemost 2003; 90: 10815.
  • 70
    Escalante A, Brey RL, Mitchell BD, Dreiner U. Accuracy of anticardiolipin antibodies in identifying a history of thrombosis among patients with systemic lupus erythematosus. Am J Med 1995; 98: 55865.
  • 71
    Levine SR, Salowich-Palm L, Sawaya KL, Perry M, Spencer HJ, Winkler HJ, et al. IgG anticardiolipin antibody titer >40 GPL and the risk of subsequent thrombo-occlusive events and death: a prospective cohort study. Stroke 1997; 28: 16605.