To make matters more complex, patterns change.
I was ANA+ before my IVIG, but IVIG will cause +ANA, as will other meds. ANA has, I believe a 21-30 day half life. So it would take 4 months before the ANA could be done without the effect of IVIG.
ANA is somewhat subjective.
ANA by Elisa is very accurate, and is stated as a decimal number, has very few false +, BUT, it only results in having an ANA done by immunofluorescence since Elisa is not specific....it measures only antinuclear antibodies.
+ANA can be present normally in older people, but usually in low titers. By the time you exceed the 1:320, on more than one occassion, it is highly likely you have an autoimmune issue.
I think MANY people have +ANA and a negative result on ENA, or specific disease. UCTD will be a growing diagnosis.
With the current health care law, in terms of insurance, shortly, you should not be discriminated against with a pre-existing condition, but, who knows, things will change.
I wonder if seropositive SjS will be merged into Lupus?