autoantibodies in systemic lupus erythmatosus (SLE)

Introduction

Autoantigen frequency

autoantigen	(frequency)
1) antinuclear antibody	(99%)
2) double-stranded DNA	(40%)
3) single stranded DNA	(70%)
4) histones	(70%)
5) Sm protein	(30%)
6) U1 snRNP	(32%)
7) SSA/Ro	(35%)
8) SSB/La	(15%)
9) Ku antigen	(10%)
10) Ki antigen	(31%)
11) proliferating cell nuclear antigen [PCNA]	( 3%)
12) ribosomal ribonucleoprotein	(10%)
- anti-ribosomal protein P	(15%)
13) heat shock protein Hsp-90	(50%)
14) ALu RNA protein	(rare)
15) ribosomal protein S10	(11%)
16) cardiolipin	(20-40%)

Autoantigen characteristics

• antinuclear antibody
  • multiple nuclear antigens
  • sensitive, not specific
• anti-dsDNA Ab
  • spefific for SLE with high titer
  • titer fluctuates with disease activity
  • titer fluctuates with lupus nephritis
• anti-ssDNA Ab: not specific
• anti-histone Ab: high fequency with drug-induces lupus
• anti-Sm Ab
  • Ab against small nuclear RNP associated with spliceosome
  • specific for SLE
  • activity does not fluctuate with disease activity
• anti-U1 snRNP Ab
  • associated with mixed connective tissue disease when sole autoantibody present
• anti-SSA/Ro Ab
  • associated with Sjogren's syndrome, neonatal lupus, & subacute cutaneous lupus
• anti-SSB/La Ab
  • associated with Sjogren's syndrome & neonatal lupus
• antiphospholipid antibody
  • associated with thrombosis & miscarriage
• antiribosomal protein P
  • 15% sensitivity for SLE
  • associated with CNS lupus & lupus hepatitis
• direct antiglobulin test: + anti-IgG & anti-C3d

More general terms

• autoantibodies in rheumatologic disease

Additional terms

• systemic lupus erythematosus