I have a friend who had a 9 year old boy who is normally active and very fit - races BMX and eats well - He has now been sick for 2 weeks - feeling tired all the time, fever, headaches and fainting after too much activity - he has had some blood test done and that has shown a ZERO white cell blood count - what could that mean - they have taken more blood test today to test his spleen and liver functions amongst some but did not tell my friend much else? Thank you in advance R.