This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (November 2009)

Anti-nuclear antibodies (ANAs, also known as anti-nuclear factor or ANF) are antibodies directed against contents of the cell nucleus.^[1]

They are present in higher than normal numbers in autoimmune disease. The ANA test measures the pattern and amount of autoantibody which can attack the body's tissues as if they were foreign material. Autoantibodies are present in low titers in the general population, but in about 5% of the population, their concentration is increased, and about half of this 5% have an autoimmune disease.^{[citation needed]}

Contents 1 ANA test 2 Associated diseases 2.1 Sensitivity 3 ANA classification 4 History 5 See also 6 References 7 External links

[edit] ANA test

One can check for the presence of ANAs in blood serum by means of a laboratory test. There are also additional tests that allow one to test for individual ANAs. The general ANA test is usually one of two types: indirect immunofluorescence or ELISA. The indirect immunofluoresence is considered to be the more accurate of the two,^{[citation needed]} but the ELISA version is gaining popularity because of its lower cost.^{[citation needed]}

[edit] Associated diseases

The normal titer of ANA is 1:40 or less. Higher titers are indicative of an autoimmune disease. The presence of ANA is indicative of lupus erythematosus (present in 80-90% of cases), though they also appear in some other auto-immune diseases such as^{[citation needed]} Sjögren's syndrome (60%), rheumatoid arthritis, autoimmune hepatitis, scleroderma and polymyositis & dermatomyositis (30%), and various non-rheumatological conditions associated with tissue damage. ANA are also directed to the nuclear pore complex in primary biliary cirrhosis.^{[citation needed]} Other conditions with high ANA titre include^{[citation needed]} Addison disease, Idiopathic thrombocytopenic purpura (ITP), Hashimoto's, Autoimmune hemolytic anemia, Type I diabetes mellitus, Mixed connective tissue disorder.

[edit] Sensitivity

The following table list the sensitivity of different types of ANAs for different diseases, in this case what percentage of those with the disease have the ANA. Some ANAs appear in several types of disease, resulting in lower specificity of the test.

ANA type	Target antigen	Sensitivity
		SLE	Drug-induced LE	Diffuse systemic sclerosis	Limited Scleroderma	Sjögren syndrome	Inflammatory myopathy
All ANAs (by indirect IF)	Various	>95	>95	70-90	70-90	50-80	40-60
Anti-dsDNA	DNA	40-60	-	-	-	-	-
Anti-Sm	Core proteins of snRNPs	20-30	-	-	-	-	-
Anti-histone	Histones	50-70	>95	-	-	-	-
U1 RNP	snRNP	30-40	-	15	10	-	-
Scl-70	Type I topoisomerase	-	-	28-70	10-18	-	-
Anti-centromere	Centromeric proteins	-	-	22-26	90	-	-
SS-A (Ro)	RNPs	30-50	-	-	-	70-95	10
SS-B (La)	RNPs	10-15	-	-	-	60-90	-
Jo-1	Histidine-tRNA ligase	-	-	-	-	-	25
- = less than 5% sensitivity Unless else specified in boxes, then ref is: [2]

[edit] ANA classification

Following detection of a high titer of ANAs (e.g. 1:160), various subtypes are determined.^[3] This is typically done on cells of the HEp-2 cell line. Examples include:

• Anti-ENA (Extractable nuclear antigen)
  • Anti-Ro (SS-A)
  • Anti-La (SS-B)
  • Anti-Sm (Smith antigen)
  • Anti-nRNP (nuclear ribonucleoproteins)
  • Anti Scl-70 (topoisomerase I)
  • Anti-Jo
• Anti-gp-210 (nuclear pore gp-210)
• Anti-p62 (Nucleoporin 62)
• Anti-dsDNA (double-stranded DNA)
• Anti-centromere

[edit] History

The LE cell was discovered in bone marrow in 1948 by Hargraves et al.^[4] This was the first indication that processes affecting the cell nucleus were responsible for lupus erythematosus (LE).^{[citation needed]} In the 1950s, progressively more sensitive and specific ANA serology tests became available.

[edit] See also

• Rheumatoid factor
• Anti-neutrophil cytoplasmic antibody (ANCA)

[edit] References

1. ^ MeSH Antinuclear+Antibody
2. ^ Table 5-9 in: Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson. Robbins Basic Pathology. Philadelphia: Saunders. ISBN 1-4160-2973-7.  8th edition.
3. ^ Kavanaugh A, Tomar R, Reveille J, Solomon DH, Homburger HA. Guidelines for clinical use of the antinuclear antibody test and tests for specific autoantibodies to nuclear antigens. American College of Pathologists. Arch Pathol Lab Med 2000;124:71-81. PMID 10629135.
4. ^ Hargraves M, Richmond H, Morton R. Presentation of two bone marrow components, the tart cell and the LE cell. Mayo Clin Proc 1948;27:25–28.

[edit] External links

• Site with unique immunofluorescence images and slides -organ and non-organ specific
• MeSH Antinuclear+antibodies

v • d • e Antibodies: autoantibodies Anti-nuclear antibody PBC: Anti-gp210 · Anti-p62 · Anti-sp100 ENA: Anti-topoisomerase/Scl-70 · Anti-Jo1 · ENA4 (Anti-Sm, Anti-nRNP, Anti-Ro, Anti-La) Anti-centromere Anti-dsDNA Anti-mitochondrial antibody Anti-cardiolipin Anti-cytoplasm antibody Anti-neutrophil cytoplasmic · Anti-actin/smooth muscle · Antimicrosomal antibody Cell membrane Anti-ganglioside · Anti-GBM Extracellular Anti-thrombin · Lupus anticoagulant · Anti-transglutaminase · RA (Rheumatoid factor/anti-IgG, Anti-citrullinated peptide) Multiple locations Anti-phospholipid · Anti-apolipoprotein see also autoantigens