January 2000, Volume 9, Issue 1, Pages 56 - 60

Paper

Class specific rheumatoid factors and antiphospholipid syndrome in systemic lupus erythematosus A Spadaro, V Riccieri, S Terracina, T Rinaldi, E Taccari & A Zoppini Department of Medical Therapy, Rheumatology Unit, University of Rome ‘‘La Sapienza’’, Rome, Italy     Correspondence to: Antonio Spadaro , Dipartimento di Terapia Medica, Divisione di Reumatologia, Università di Roma ‘‘La Sapienza,’’ Azienda Policlinico Umberto I, Viale del Policlinico 155, 00151 Rome, Italy. Tel/fax: (+39) 6 4462013

Keywords

rheumatoid factors;   anticardiolipin antibodies;   antiphospholipid syndrome

Abstract

The relationship of rheumatoid factors (RF) with antiphospholipid syndrome (aPLS) and anticardiolipin antibodies (aCL) has rarely been investigated in systemic lupus erythematosus (SLE). We found IgM-RF, IgG-RF, IgA-RF, IgM-aCL, IgG-aCL, IgA-aCL, respectively, in 35.4%, 35.4%, 33.8%, 23.1%, 23.1%, 20.0% of 65 SLE patients. Class specific RFs were negatively associated (P<0.05) with IgG-aCL. The frequency of definite or probable aPLS according to Alarcon-Segovia classification criteria was significantly (P<0.05) different (8.7% vs 30.9%) in patients with or without IgG-RF. Among the other clinical features of SLE, we found that patients with IgG-RF, compared to patients lacking this autoantibody, showed a lower frequency (P<0.05) of serositis (21.7% vs 52.4%) and hematologic (52.2% vs 80.9%) disorders. The levels of IgG-RF and IgM-RF negatively correlated with the number of ARA criteria (P<0.05) but not with the indices of diseases activity or damage. Our study shows that in SLE the presence of RFs are not markers of severity of the disease, but the negative association between IgG-RF and IgG-aCL suggests a distinct role of these autoantibodies in the pathology of SLE, whereas the presence of IgG isotype may identify a subset of SLE patients having a lower risk to develop some clinical manifestations such as aPLS. Lupus (2000) 9, 56-60

Received 15 June 1999; Accepted 15 September 1999

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