TY - JOUR
T1 - Antiprothrombin antibodies
T2 - A comparative analysis of homemade and commercial methods. A collaborative study by the Forum Interdisciplinare per la Ricerca nelle Malattie Autoimmuni (FIRMA)
AU - Tincani, Angela
AU - Morozzi, Gabriella
AU - Afeltra, Afeltra
AU - Alessandri, Cristiano
AU - Allegri, Flavio
AU - Bistoni, Onelia
AU - Bizzaro, Nicola
AU - Caccavo, Domenico
AU - Galeazzi, Mauro
AU - Gerli, Roberto
AU - Giovannelli, Luigi
AU - Longobardo, Giovanni
AU - Lotzniker, Milvia
AU - Malacarne, Fabio
AU - Migliorini, Paola
AU - Parodi, Aurora
AU - Pregnolato, Francesca
AU - Radice, Antonella
AU - Riccieri, Valeria
AU - Ruffelli, Marina
AU - Sinico, Renato Alberto
AU - Tozzoli, Renato
AU - Villalta, Danilo
AU - Marcolongo, Roberto
AU - Meroni, Pierluigi
PY - 2007/3
Y1 - 2007/3
N2 - Objective: Prothrombin (PT) is a target for antibodies with lupus anticoagulant (LA) activity, suggesting the possible application of anti-prothrombin antibody (aPT) assays in patients with antiphospholipid syndrome (APS). Different methods - both homemade and commercial - for the detection of aPT are available, but they seem to produce conflicting results. The purpose of this study was to compare the performance of different assays on a set of well-characterized serum samples. Patients and methods: Sera were gathered from 4 FIRMA institutions, and distributed to 15 participating centres. Forty-five samples were from patients positive for LA and/or anticardiolipin antibodies (aCL) with or without APS, and 15 were from rheumatoid arthritis (RA) patients negative for antiphospholipid antibodies. The samples were evaluated for IgG and IgM antibodies using a homemade direct aPT assay (method 1), a homemade phosphatidylserine-dependent aPT assay (aPS/PT, method 2), and two different commercial kits (methods 3 and 4). In addition, a commercial kit for the detection of IgG-A-M aPT (method 5) was used. Results: Inter-laboratory results for the 5 methods were not always comparable when different methods were used. Good inter-assay concordance was found for IgG antibodies evaluated using methods 1, 3, and 4 (Cohen k > 0.4), while the IgM results were discordant between assays. In patients with thrombosis and pregnancy losses, method 5 performed better than the others. Conclusion: While aPT and aPS/PT assays could be of interest from a clinical perspective, their routine performance cannot yet be recommended because of problems connected with the reproducibility and interpretation of the results.
AB - Objective: Prothrombin (PT) is a target for antibodies with lupus anticoagulant (LA) activity, suggesting the possible application of anti-prothrombin antibody (aPT) assays in patients with antiphospholipid syndrome (APS). Different methods - both homemade and commercial - for the detection of aPT are available, but they seem to produce conflicting results. The purpose of this study was to compare the performance of different assays on a set of well-characterized serum samples. Patients and methods: Sera were gathered from 4 FIRMA institutions, and distributed to 15 participating centres. Forty-five samples were from patients positive for LA and/or anticardiolipin antibodies (aCL) with or without APS, and 15 were from rheumatoid arthritis (RA) patients negative for antiphospholipid antibodies. The samples were evaluated for IgG and IgM antibodies using a homemade direct aPT assay (method 1), a homemade phosphatidylserine-dependent aPT assay (aPS/PT, method 2), and two different commercial kits (methods 3 and 4). In addition, a commercial kit for the detection of IgG-A-M aPT (method 5) was used. Results: Inter-laboratory results for the 5 methods were not always comparable when different methods were used. Good inter-assay concordance was found for IgG antibodies evaluated using methods 1, 3, and 4 (Cohen k > 0.4), while the IgM results were discordant between assays. In patients with thrombosis and pregnancy losses, method 5 performed better than the others. Conclusion: While aPT and aPS/PT assays could be of interest from a clinical perspective, their routine performance cannot yet be recommended because of problems connected with the reproducibility and interpretation of the results.
KW - Anticardiolipin antibodies
KW - Antiphospholipid antibodies
KW - Antiphospholipid syndrome
KW - Antiprothrombin antibodies
KW - Lupus anticoagulant
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M3 - Article
C2 - 17543152
AN - SCOPUS:34249805121
VL - 25
SP - 268
EP - 274
JO - Clinical and Experimental Rheumatology
JF - Clinical and Experimental Rheumatology
SN - 0392-856X
IS - 2
ER -