An elevated anti-nuclear antibody (ANA) titre is suggestive but not necessarily diagnostic of a number of autoimmune diseases. False positives (an elevated titre with no disease) can happen.

Often a titre measurement is followed up by looking at the visual pattern (homogeneous, speckled, etc) of ANA staining in cell nuclei.

This information might help you http://www.racgp.org.au/afp/2013/oct...antibody-test/.

Thanks Kiwi- I only have as much information as I've posted here about my ANA - no breakdown yet.

I'm assuming that it is very significant in my case, given that I've been told by my previous rheumatologists that I can't have a connective tissue disease without it - despite raised inflammatory markers, paired o bands and many symptoms corresponding with connective tissue diseases. Also I have never understood how it is possible that we allow RA to be clinically diagnosed and treated in seronegative form - but not the others? I suspect this is because synovitis and RA erosion show up clearly in imaging so can't be refuted - unlike diseases such as Lupus or Sjogrens which can be much harder to confirm without the autoantibodies.

Yes, the specificity of elevated ANA varies a lot as a marker for different autoimmune diseases - it is highest (about 90%) for SLE and lowest (about 40%) for RA - Table 2 of the link above.