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© Dirk Biddle
Anti-nuclear antibodies (IgG-ANA) have been primarily associated with Systemic lupus erythematosus and generally associated with secondary vasculitis conditions. Further, a subset of antinuclear antibodies can directly cause overt nephritis (1). ANAs specifically react against components of a cell nucleus such as DNA, RNA, and histone or non-histone proteins. Detectable by indirect immunofluorescence assay or by ELISA, ANAs are usually found in association with secondary vasculitis conditions in Rheumatoid arthritis (25-60%), Scleroderma (75-80%), Sjögren's syndrome (45-75%), and Systemic Lupus Erythematosus (95-100%). They are generally not found in ANCA associated vasculitis conditions such as Wegener’s granulomatosis but have been noted in Polyarteritis nodosa (15-25%) (24). However, ANAs also occur in low titers in about 5% of the normal population, with higher prevalence in the elderly (40%) (2) so low and medium titers may not be of clinical or diagnostic relevance.
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1. http://rheumatology.oupjournals.org/cgi/content/full/38/8/691
2. http://www.alphalabs.co.uk/images/Product%20Inserts/AL109_110RatliverANA_29Nov99.pdf
Testing information: http://www.aruplab.com/guides/clt/tests/clt_113b.jsp#2615892
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DNA: (deoxyribonucleic acid) The molecule that encodes genetic information in the nucleus of cells. It determines the structure, function and behaviour of the cell.
DNA is a double-stranded molecule held together by weak bonds between base pairs of nucleotides. The four nucleotides in DNA contain the bases: adenine (A), guanine (G), cytosine (C), and thymine (T). In nature, base pairs form only between A and T and between G and C, thus the base sequence of each single strand can be deduced from that of its partner. (OMD)
RNA: (ribonucleic acid) A nucleic acid found in all living cells. Plays a role in transferring information from DNA to the protein -forming system of the cell. (OMD)
Histone: Any of various simple water-soluble proteins that are rich in the basic amino acids lysine and arginine and are complexed with DNA in the nucleosomes of eukaryotic chromatin and chromosomes. They may act as non-specific repressors of gene transcription. (OMD)