Anti-La (SS-B): a diagnostic criterion for Sjögren's syndrome?

Clin Exp Rheumatol. Mar-Apr 1989;7(2):181-4.

Abstract

We examined the diagnostic sensitivity and specificity of antibodies to Ro (SS-A) and La (SS-B) in Sjögren's syndrome (SS) by counterimmunoelectrophoresis and immunodiffusion. Anti-Ro was found in 56% and anti-La in 42% of patients with SS and in 38% and 6% respectively in SLE. Anti-La was rare (less than 1%) in other connective tissue diseases. As a more stringent test of diagnostic specificity, 88 patients whose sera contained anti-La and/or anti-Ro were carefully examined for evidence of Sjögren's syndrome. Of 35 patients whose sera contained anti-La, 29 (83%) fulfilled criteria for SS, and four out of 6 of the remainder showed some evidence of early disease. Of 53 patients with anti-Ro (without anti-La), only 42% had Sjögren's syndrome, 45% had SLE and 13% other connective tissue diseases. These data confirm that anti-La, but not anti-Ro, has a high diagnostic specificity for Sjögren's syndrome and merits inclusion as separate diagnostic criterion for the disease.

MeSH terms

  • Adult
  • Autoantibodies / analysis*
  • Autoantigens / immunology*
  • Diagnosis, Differential
  • Female
  • Humans
  • Lupus Erythematosus, Systemic / diagnosis
  • Male
  • Predictive Value of Tests
  • RNA, Small Cytoplasmic*
  • Ribonucleoproteins*
  • Sjogren's Syndrome / diagnosis*

Substances

  • Autoantibodies
  • Autoantigens
  • RNA, Small Cytoplasmic
  • RO60 protein, human
  • Ribonucleoproteins
  • SS-A antigen
  • SS-B antigen