TY - JOUR
T1 - Heterogeneity of anti-β2-glycoprotein I antibodies. A factor of variability in test results
AU - Sanmarco, Marielle
AU - Bardin, Nathalie
AU - Blank, Miri
AU - Pascal, Veronique
AU - Alessi, Marie Christine
AU - Dignat-George, Françoise
AU - Shoenfeld, Yehuda
AU - Harlé, Jean Robert
PY - 2005/1
Y1 - 2005/1
N2 - The aim of this study was to evaluate the heterogeneity of IgG-anti-β2-glycoprotein I antibodies (IgG-aβ 2GPI) as regarding their reactivity pattern against different sources of human β2GPI, their avidity and their association with clinical events of antiphospholipid syndrome (APS). Three thousand six hundred and eighty-four consecutive patient sera were routinely tested for IgG-aβ2GPI over 1 year using an in-house ELISA with 2 different commercial preparations of human purified β2GPI. Of the 340 sera found positive, all those clinically documented were included in this study; 61 were positive with only one preparation (S1) and 59 with both (S2). The results of ELISA were confirmed by Western blot. Heterogeneity was stressed by testing sera with a human recombinant protein and 3 β2GPI-related peptides. No contribution of glycosylation in the binding to β2GPI was found. The avidity indices for each protein were significantly higher in S1 than in S2 (p = 0.0021). S2 were more associated with antiphospholipid antibodies than S1 (75% versus 21%; p <0.0001). A similar frequency of the main clinical features of APS was found in S1 and S2 sera (69% and 71%, respectively). In conclusion, our data show a heterogeneity in the antigenic reactivity pattern of IgG-aβ2GPI and a relationship between a binding profile and antibody avidity. This heterogeneity could represent a crucial factor of variability in test results and underlines the difficulty of getting standardisation.
AB - The aim of this study was to evaluate the heterogeneity of IgG-anti-β2-glycoprotein I antibodies (IgG-aβ 2GPI) as regarding their reactivity pattern against different sources of human β2GPI, their avidity and their association with clinical events of antiphospholipid syndrome (APS). Three thousand six hundred and eighty-four consecutive patient sera were routinely tested for IgG-aβ2GPI over 1 year using an in-house ELISA with 2 different commercial preparations of human purified β2GPI. Of the 340 sera found positive, all those clinically documented were included in this study; 61 were positive with only one preparation (S1) and 59 with both (S2). The results of ELISA were confirmed by Western blot. Heterogeneity was stressed by testing sera with a human recombinant protein and 3 β2GPI-related peptides. No contribution of glycosylation in the binding to β2GPI was found. The avidity indices for each protein were significantly higher in S1 than in S2 (p = 0.0021). S2 were more associated with antiphospholipid antibodies than S1 (75% versus 21%; p <0.0001). A similar frequency of the main clinical features of APS was found in S1 and S2 sera (69% and 71%, respectively). In conclusion, our data show a heterogeneity in the antigenic reactivity pattern of IgG-aβ2GPI and a relationship between a binding profile and antibody avidity. This heterogeneity could represent a crucial factor of variability in test results and underlines the difficulty of getting standardisation.
KW - Antiphospholipid syndrome
KW - Avidity
KW - Heterogeneity
KW - β2-glycoprotein I
UR - http://www.scopus.com/inward/record.url?scp=12344309367&partnerID=8YFLogxK
U2 - 10.1160/TH04-04-0230
DO - 10.1160/TH04-04-0230
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C2 - 15630495
AN - SCOPUS:12344309367
SN - 0340-6245
VL - 93
SP - 80
EP - 87
JO - Thrombosis and Haemostasis
JF - Thrombosis and Haemostasis
IS - 1
ER -