Antinuclear antibodies, immunoblot (IgG autoantibodies to 14 different antigens: nRNP/Sm, Sm, SS-A (SS-A native and Ro-52), SS-B, Scl-70, Jo-1, PM-Scl, centromere protein B, PCNA, dsDNA, nucleosomes, histones, ribosomal protein P, AMA-M2)(Qualitative)
Antinuclear (or anti-nuclear) antibodies (ANA) are special proteins produced by the immune system when it mistakenly attacks the body's own cells. In particular, these antibodies target components of the cell nucleus. This condition is characteristic of autoimmune diseases, in which the immune system ‘loses its bearings’ and begins to perceive its own tissues as foreign.
ANA is often detected in diseases such as:
- Systemic lupus erythematosus (SLE)
- Sjogren's syndrome (SS)
- Systemic sclerosis (SS)
- Dermatomyositis and polymyositis (DM/PM)
- Mixed connective tissue disease (MCTD)
Also possible in primary biliary cholangitis (PBC)
What is an immunoblot and why is it needed?
An immunoblot is a laboratory method that allows you to accurately determine which antigens autoantibodies are produced against. The test detects IgG antibodies to 14 important antigens associated with various forms of autoimmune diseases.
This test:
- Helps confirm the presence of an autoimmune process
- Specifies the type of disease
- Allows the doctor to make a correct diagnosis more quickly
Autoantibodies included in the immunoblot:
|
Autoantibodies to: |
Autoimmune disease |
Prevalence |
|
nRNP/Sm |
MCTD |
95% |
|
Sm |
SLE |
5% - 40% |
|
SS-A |
SS or SLE |
40% - 95% or 20% - 60% |
|
Neonatal lupus |
95% - 100% |
|
|
Ro-52 |
SS or SLE |
70% - 90% or 40% - 60% |
|
СС or idiopathic inflammatory myopathy |
20% or 20% - 40% |
|
|
SS-B |
SS or SLE |
40% - 95% or 10% - 20% |
|
Neonatal lupus |
75% |
|
|
Scl-70 |
SS |
25% - 75% |
|
Diffuse or limited form of SS |
40% - 65% or 5% - 15% |
|
|
PM-Scl |
SS, including cross syndrome |
10% - 20% or 5% - 20% |
|
Jo-1 |
Myositis (polymyositis/dermatomyositis) |
25% - 35% |
|
CENP B |
SS - limited form or SS - diffuse form |
80% - 95% or 8% |
|
PBC |
10% - 30% |
|
|
PCNA |
SLE |
3% |
|
dsDNA |
SLE |
40% - 90% |
|
Nucleosomes |
SLE |
40% - 70% |
|
Histones |
Drug-induced lupus erythematosus SLE or rheumatoid arthritis |
95% - 100% |
|
Ribosomal R protein |
SLE |
10% |
|
AMA-M2 |
PBC or other chronic liver diseases SS |
Up to 96% or 30% 7% - 25% |