Anti-argonaute2 (Ago2/Su) and -Ro antibodies identified by immunoprecipitation in primary anti-phospholipid syndrome (PAPS)

Angela Ceribelli, Angela Tincani, Ilaria Cavazzana, Franco Franceschini, Roberto Cattaneo, Brad A. Pauley, Jason Y F Chan, Edward K L Chan, Minoru Satoh

Research output: Contribution to journalArticlepeer-review


Objectives. Primary anti-phospholipid syndrome (PAPS) is an autoimmune condition defined by anti-phospholipid antibodies (aPL) and thrombotic or obstetric events. Some PAPS can evolve into systemic lupus erythematosus (SLE) during follow-up. Few studies systematically examined lupus autoantibodies and their clinical significance in PAPS. The aim of our study is to analyze the clinical and laboratory correlations with lupus-related autoantibodies, detected by immunoprecipitation (IP), a technique not yet systematically applied to investigate autoantibodies in this condition.Methods. Sera from 52 PAPS patients were screened by indirect immunofluorescence (IIF) antinuclear antibodies (ANA), IP of 35S-labeled K562 cell extract, and ELISA [anti-Argonaute2 (Ago2, Su), 60kRo, 52kRo, La, dsDNA)]. Anti-Ago2/Su positive sera were also tested for anti-GW bodies (GWBs) by IIF double staining, using rabbit anti-Rck/p54 serum.Results. First, 56% of PAPS patients (29/52) were ANA positive, mainly with speckled pattern. Anti-Ago2/Su antibodies were found in 13% (7/52), anti-Ro/SSA in 10% (5/52), anti-La in one case. The clinical profile of patients did not seem to be related to the presence of these antibody specificities. However, levels of IgG anti-β2 glycoprotein I antibodies were lower in anti-Ago2/Su positive patients (p = 0.02). None of anti-Ago2/Su or -Ro patients developed SLE during a 2-year follow-up. Ago2 is a key component of GWBs, however, only 1/7 anti-Ago2/Su serum showed a typical cytoplasmic GWBs staining.Conclusions. Anti-Ago2/Su and -Ro antibodies are the two autoantibodies detected by IP in our PAPS cohort. Clarifying why Ago2/Su and Ro are specific targets of autoimmunity may help to understand the mechanisms of autoantibody production.

Original languageEnglish
Pages (from-to)90-97
Number of pages8
Issue number2
Publication statusPublished - Mar 2011


  • anti-Ago2/Su
  • anti-phospholipid antibodies
  • anti-Ro/SSA
  • Argonaute 2
  • primary anti-phospholipid syndrome
  • systemic lupus erythematosus

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


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