Avidity of anti-phospholipid antibodies in relation to their levels

Lenka FialovÁ; Oliver KuchaŘ; Milada PetrÁČkovÁ; Ivan Malbohan; TomÁŠ Zima

doi:10.5114/ceji.2020.97901

Avidity of anti-phospholipid antibodies in relation to their levels

Cent Eur J Immunol. 2020;45(2):136-143. doi: 10.5114/ceji.2020.97901. Epub 2020 Jul 27.

Authors

Lenka FialovÁ¹, Oliver KuchaŘ¹, Milada PetrÁČkovÁ¹, Ivan Malbohan¹, TomÁŠ Zima¹

Affiliation

¹ Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Czech Republic.

Abstract

Introduction: The heterogeneity of anti-phospholipid antibodies can be manifested not only in different antigenic specificities, but also in their avidities. The aim of the study was to investigate the relationship between anti-cardiolipin antibody (aCL) IgG avidities and levels within the range of their titres, from very low to high ones.

Material and methods: We analyzed 78 serum samples from 60 patients by ELISA with chaotropic agents, using urea concentration of 6 and 8 mol/l and single diluted serum samples. The changes of aCL levels and avidities were explored during a long-term follow-up in 14 patients.

Results: The avidities of aCLs did not differ in the groups of patients classified according to aCL levels. The higher avidity antibodies predominated in our patients and the fluctuation of avidities in the longitudinal follow-up did not show significant differences. No relationship between aCL levels and their avidities was found.

Conclusions: aCL avidities seem to have no relationship with aCL levels and high-avidity aCLs; the potentially deleterious effects might be present also in patients with low and extremely low aCL levels. Avidity of aCLs belongs to stable characteristics with insignificant changes in time.

Keywords: ELISA; anti-cardiolipin antibodies; anti-phospholipid antibodies; avidity; chaotropic agents; systemic lupus erythematosus; thrombosis; urea.