We now propose to investigate the combination of CHOP-Rituxan plus PEG-Filgrastim (PEG-filgrastim) and GM-CSF. PEG-Filgrastim would be given in order to allow us to administer the chemotherapy courses every 2 weeks with the practical advantage of requiring only one dose of PEG-filgrastim instead of daily doses of G-CSF.