I had a couple thoughts after reading this. I have NO factual basis for thinking this and zero medical background. It just occurred to me that maybe you had past exposure to all the IGG positive components and your immune system took care of those. Maybe band 23 is a new exposure that you didn't have before OR your immune system simply failed to produce any protective antibodies against the band 23 component. (This is all completely off the cuff. I am not well versed on all the different bands and what they represent.).
I'm sure others will come along with much more intelligent answers.
Post note: Okay, I used the search button and found this reference in an old post regarding band 23: /www.ncbi.nlm.nih.gov/m/pubmed/8225587/
Post Edited (WalkingbyFaith) : 12/23/2017 10:56:06 AM (GMT-7)