Pegfilgrastim and Rituximab in Treating Patients With Untreated, Relapsed, or Refractory Follicular Lymphoma, Small Lymphocytic Lymphoma, or Marginal Zone Lymphoma

PRIMARY OBJECTIVES: I. To evaluate the safety of Pegfilgrastim in combination with rituximab in patients with untreated or relapsed/refractory follicular, SLL or MZL. SECONDARY OBJECTIVES: I. To evaluate the efficacy (including overall response rate and durability of objective responses) of Pegfilgrastim in combination with rituximab in patients with untreated or relapsed/refractory follicular, SLL or MZL. II. To evaluate functional and phenotypic characteristics of host neutrophils undergoing treatment with Pegfilgrastim and rituximab. III. To evaluate changes in cluster of differentiation (CD)20 antigen expression and density of expression in patients receiving Pegfilgrastim and rituximab. IV. To evaluate changes in serum levels of tumor necrosis factor (TNF), interferon alpha (INFalpha) and free radical levels in patients undergoing treatment with Pegfilgrastim and rituximab. OUTLINE: Patients receive pegfilgrastim subcutaneously (SC) followed by rituximab intravenously (IV) 3 days later in weeks 1, 3, 5, 7, 15, 23, 31, and 39. Treatment continues in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 4 months for 1 year, every 6 months for 2 years, and then yearly for 1 year.