Jensen PEH et al. – High correlation is demonstrated between the results obtained by the three methods, and the authors suggest the possibility of using ELISA measurements of binding antibodies (BAbs) to identify patients with high titres of anti–IFN&ndashβ antibodies that block the biological response to IFN–β. In patients with low titres, they suggest to supplement ELISA with measurement of MX1 mRNA to establish whether the bioavailability of IFN–β is preserved.Methods
- The authors measured BAbs and NAbs to IFN–β in 110 serum samples from 83 patients with MS treated with IFN–β, and in a subgroup, antibody titre was compared with corresponding expressions of MX1 mRNA.
- The methods used were capture ELISA assay, luciferase reporter gene assay and mRNA RT–PCR for MX1 gene expression.
- There were significant correlations between binding, neutralizing and MX1 results.
- Cut–off values are suggested for the definition of samples of BAbs and NAbs as negative, positive and grey zones.
- Naturally occurring groups of low and high antibody titres were identified by the correlation between BAbs and NAbs, probably as a result of an immunological maturation process of antibodies.
- The low–titre group had lower correlations between BAbs and NAbs than the high–titre group.