Rheumatology International

, Volume 27, Issue 7, pp 649–654

Determination of ANA specificity using multiplexed fluorescent microsphere immunoassay in patients with ANA positivity at high titres after infliximab treatment: preliminary results

Authors

    • Dipartimento di Medicina Clinica e SperimentaleUniversità di Verona
    • Istituto Medicina Interna BPoliclinico G.B. Rossi
  • Orazio Ruzzenente
    • Dipartimento di Scienze Morfologico-BiomedicheUniversità di Verona
  • Sara Pieropan
    • Dipartimento di Medicina Clinica e SperimentaleUniversità di Verona
  • Alessandro Volpe
    • Dipartimento di Medicina Clinica e SperimentaleUniversità di Verona
  • Antonio Carletto
    • Dipartimento di Medicina Clinica e SperimentaleUniversità di Verona
  • Lisa Maria Bambara
    • Dipartimento di Medicina Clinica e SperimentaleUniversità di Verona
  • Domenico Biasi
    • Dipartimento di Medicina Clinica e SperimentaleUniversità di Verona
Original Article

DOI: 10.1007/s00296-006-0271-8

Cite this article as:
Caramaschi, P., Ruzzenente, O., Pieropan, S. et al. Rheumatol Int (2007) 27: 649. doi:10.1007/s00296-006-0271-8

Abstract

To evaluate ANA specificity using the fully automated multiplexed fluorescent microsphere immunoassay in patients affected either by rheumatoid arthritis or ankylosing spondylitis who developed strong positivity for ANA as assessed by indirect immunofluorescent method on HEp-2 cells during infliximab treatment. Three men affected by ankylosing spondylitis and 12 women affected by rheumatoid arthritis who developed ANA positivity at high titres during infliximab treatment underwent the identification of ANA specificity by multiplexed fluorescent microsphere immunoassay; moreover anti-DNA and anti-ENA antibodies were tested by indirect immunofluorescence and ELISA method, respectively. In 4 out of 15 cases, the determination of ANA reactivity by multiplexed fluorescent microsphere immunoassay was also performed on the serum collected before infliximab administration. One patient affected by rheumatoid arthritis showed multiple ANA reactivities against SS-A, SS-B, RNP, Sm, Jo-1 and histones; one patient affected by ankylosing spondylitis resulted positive for the same autoantibodies, except for anti-Sm antibody. Moreover, two patients, one with rheumatoid arthritis and one with ankylosing spondylitis, showed single antibody specificity to SS-B and RNP, respectively. The remaining 11 cases did not show any positivity. Instead, all the patients resulted negative for anti-ENA antibodies by the ELISA method. In the four cases tested for ANA specificity by multiplexed fluorescent microsphere immunoassay before and after infliximab administration no difference was found. The search for anti-DNA antibody always resulted negative by both the traditional immunofluorescent assay and the novel technique. The use of multiplexed fluorescent microsphere immunoassay in patients treated with infliximab with ANA positivity at high titres allowed to find some ANA specificities which were not revealed by ELISA method. Nevertheless, the majority of patients resulted negative in spite of ANA positivity at high titres; the molecular target of ANA which develop after infliximab administration still remains to be identified.

Keywords

Antinuclear antibodiesMultiplexed fluorescent microsphere immunoassayInfliximabRheumatoid arthritisAnkylosing spondylitis

Copyright information

© Springer-Verlag 2006