Hi Deb
They are more commonly called a CRP:
http://en.wikipedia.org/wiki/C-reactive_protein
Basically it tells you if you have an infection in your bloodstream. Rachel was around the 150 mark when she first went in and I think she peaked at well over 200 before the IV antibiotics took control.
0.5 neutrophils is a reasonably good amount, any less and your body can't trigger an immune response to infections so normal antibiotics won't work.
Chris