RX has the classic GVHD scenario where there's a patient who weeks ago received a transplant and now has diarrhea, red macules all across body, jaundice, and hepatosplenomegaly. In the explanation they describe this as an "acute" GVHD.
I searched online and on prior GVHD threads on here and found that acute GVHD is more CD4+ and MHCII mismatched, whereas chronic GVHD is more CD8+ and MHCI mismatched. However, for acute transplant rejection, CD8+ cells mediate the response against donor antigens, causing vasculitis of graft vessels. And in chronic transplant rejection, CD4+ cells mediate a more long-term fibrosing and sclerotic response to blood vessels of donor organ, causing organ failure.
Why is it that acute GVHD is mediated by CD4+ cells while acute transplant rejection is CD8+ mediated? Similarly, I'm confused why chronic GVHD is mediated by CD8+ cells, whereas chronic transplant rejection is CD4+ mediated?
I searched online and on prior GVHD threads on here and found that acute GVHD is more CD4+ and MHCII mismatched, whereas chronic GVHD is more CD8+ and MHCI mismatched. However, for acute transplant rejection, CD8+ cells mediate the response against donor antigens, causing vasculitis of graft vessels. And in chronic transplant rejection, CD4+ cells mediate a more long-term fibrosing and sclerotic response to blood vessels of donor organ, causing organ failure.
Why is it that acute GVHD is mediated by CD4+ cells while acute transplant rejection is CD8+ mediated? Similarly, I'm confused why chronic GVHD is mediated by CD8+ cells, whereas chronic transplant rejection is CD4+ mediated?
