banter and General Discussion, page-10232

The baseline level is a different number for each patient - it is a number but it could be 10,000 activated T cells per some small unit volume or blood weight of cell count for patient A and 9,000 activated T cells per whatever for patient B and so on.

So a 50% reduction after 28 days for patient A is a T cell count that is half what it was previously for patient A and the same for patient B.

Zero reduction and 100 percent reduction is the range you can't have a more than total reduction of the activated T cells which would be 100% reduction and you can't have less than no reduction.

I think you are interested in can the activated T cells actually go up such that rather than a reduction there would actually be an increase after 28 days? Well in healthy patients that didn't have a lot of activated T cells sure if they happened to be fighting an infection 28 days later that they didnt have before their T cells would be up - but that isn't the starting position here - because if the patients didn't already have relatively high T cell activation levels that would mean the T cells from the graft in their blood weren't actually attacking the host and so you wouldn't have GVHD in the first place.

When you are measuring T cell activation you are specifically measuring T cell based immunity specifically not inflammation. While inflammation and immunity can occur together they aren't the same. Other types of cells would be involved in inflammation.

The T cells are activated (in GVHD its believed) because they think they've encountered a foreign protein (a piece of the host cells that is only about 7 to 9 amino acids long - but those little pieces would be specific enough that the T cells from the graft responding to the foreign to them proteins that were proteins natural to the host but would not have been foreign to the graft that the T cells has come from.

This is not a perfect explanation but I believe its pretty accurate.