I'm always worried about giving advice incase I'm completely wrong but as we are talking alternative therapies I guess there is no harm.
I was given the advice here of trying to increase copper levels by eating copper rich food. There are links between low WBC and low copper so I would assume increasing this would be a good thing. Here is a great link of some examples.
If your haematologist hasn't requested a copper test yet I'd recommend you ask them to do one. It was normal in my wife's case but if it's a bit low it could be slowing your neutrophil development.
If it doesn't work at least sesame seeds and sunflower seeds are yummy
Hope this helps.