This test was run on me last week and was the reason I was diagnosed with Lupus. "Extractable nuclear antigen" ? Has anyone else had this test done?

My understanding is that this is to evaluate whether or not you have the ssa/ro, ssb/la, ds dna or rnp, or sm antibodies. I've been trying to read up on this, but I'm confused. Can anyone shed any light on this for me?

Thanks a million and have a wonderful day!