TTG IgA vs IgG

I read in a comment somewhere that IgA is more recent history vs IgG being more like a “memory cell”. Therefore IgA gives a more accurate picture of how you’re doing, and IgG could stay high for longer. Is this true? If so, does anyone have any scientific literature/reliable source on it? It makes sense based on what I’ve read but I haven’t seen anything that specifically says that in the literature.

I’m one year gf and my IgG is >250. My IgA is 68, down from >250. I was kind of freaked out by the IgG number. I thought I might have unresponsive celiac. My doctor didn’t explain the difference between the tests - she just said that the lab had changed so we couldn’t directly compare results from today to when I was diagnosed.

Any thoughts or resources are greatly appreciated. Thank you!