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/.