Long-term treatment with GM-CSF in patients with chronic lymphocytic leukemia and recurrent neutropenic infections

In this prospective study we evaluated the multiple effects of long term GM -CSF therapy on blood counts, granulocyte functions and disease progression in patients with chronic lymphocytic leukemia (CLL) with chronic neutropen ia and recurrent bacterial infections. The treatment duration varied from 2 to 12 weeks. The neutrophil count was raised in all patients, by the media n of 6.6-fold. The neutrophil level of 1.0 x 10(9)/I was usually reached af ter two weeks. The initial dose of GM-CSF was 5 mu g/kg/day, and 1-7 mu g/k g/day was required to maintain the neutrophil level above 1.0 x 10(9)/1. Gr anulocyte functions, i.e, chemiluminescence (CL), random migration, and fML P-stimulated chemotaxis were initially depressed in all patients when compa red to healthy controls. GM-CSF enhanced significantly CL even when given a t small doses (less than 1 mu g/kg/day), even lower than the dose required to promote granulopoiesis. We conclude that GM-CSF is effective in improvin g CLL associated chronic neutropenia and also enhances impaired granulocyte chemiluminescence. Thus, GM-CSF could be helpful for giving chemotherapy w ithout neutropenic delays and for prophylaxis of infectious complications i n CLL patients.