The purpose of the study is to evaluate the efficacy of an intensified first-line treatment, with conventional chemotherapy (CHOP) plus monoclonal antibody anti CD20, followed by high dose chemotherapy and PBSC transplantation in HIV-related aggressive non-Hodgkin lymphoma at "high risk" , according to the international prognostic index (IPI).

HIV associated NHL show particularly aggressive clinical features and a worse prognosis compared to the general population. The recent introduction of highly active antiretroviral therapy (HAART)has improved HIV positive patients' clinical conditions and reduced the risk of opportunistic infections, thus making HIV+ patients more similar to HIV- patients. Several studies have shown that the early use (as first line treatment) of high dose chemotherapy (HDT) with peripheral blood stem cell transplantation (PBSCT) is superior in the HIV negative setting to conventional dose chemotherapy, at least in patients with poor prognostic factors at diagnosis. Recently, several experiences have shown the feasibility, safety and efficacy of HDT and PBSCT, in association with HAART, as salvage therapy in HIV positive patients with lymphoma who maintain a chemosensitive disease after first-line treatment failure. It is rationale therefore to explore the use of this treatment strategy earlier, within the upfront treatment of HIV-associated lymphoma, in those patients with poor prognostic factors at diagnosis, according to the international prognostic score (IPI).

Inclusion Criteria:

• HIV positivity
• "Large cell"histology (DLBCL, Immunoblastic, Plasmablastic, Anaplastic lymphoma)
• Age 18-60 years
• Age-adjusted IPI 2-3
• Ann Arbor stage I B-IV
• Written informed consent.

Exclusion Criteria:

• Burkitt lymphoma
• Lymphoblastic lymphoma
• Primary effusion lymphoma
• Age-adjusted IPI 0-1
• Performance Status (WHO) >2 (if not related to lymphoma)
• Inadequate cardiac function (V.E.F. < 50%) or clinically evident cardiac disease
• Inadequate pulmonary function (DLCO < 50% and/or O2 < 96%)
• Inadequate renal function (creatinine > 2 mg/dl)
• Inadequate liver function (AST/ALT > 3 ULN and/or PT < 70%, if not related to lymphoma)
• Inadequate marrow function (neutrophils < 1500/cmm; platelets < 100.000/cmm, if not related to lymphoma)
• Virologic failure to HAART (including at least one NRTI, one NNRTI and two PI) and/or CD4 count < 50/cmm.
• CNS or meningeal lymphoma
• Active opportunistic infections
• Pregnancy
• Other evolutive malignancy (except of localized non-melanoma skin cancer and in situ portio carcinoma)
• Any other condition that contraindicates this treatment program at discretion of physician
• HBsAg positivity with active viral replication (HBV-DNA positivity)