The main purposes of the AIDA protocol are to test the role of intermittent maintenance therapy with ATRA, standard maintenance chemotherapy with methotrexate and 6-mercaptopurine of both in PCR negative patients at the end of the consolidation phase and to evaluate the role of allogeneic or autologous bone marrow transplantation in PCR positive patients at the end of the consolidation phase.

Inclusion Criteria:

• Age > 12 months (1 year) and < 75 years
• Morphological newly diagnosis of APL
• Presence of the PML-RARa transcript
• No cardiac contraindications to anthracycline chemotherapy
• Serum creatinine <=2.5 mg/dL
• Serum alkaline phosphatase <= 3 times the normal upper limit
• Serum bilirubin <= 3 times the normal upper limit
• Serum SGOT <= 3 times the upper normal limit
• Negative pregnancy test
• Informed consent

Exclusion Criteria:

• Age <= 12 months and >=75 years
• absence of the PML-RARa transcript
• Pregnant of lactating women
• Presence of active serious infections that are not controlled by antibiotics
• Prior treatment with antileukemic therapy (excluded corticosteroids)
• Presence of severe concomitant psychiatric disease
• Presence of other concomitant malignant tumors, except basal cell carcinoma
• Concurrent treatment with cytotoxic chemotherapy or radiotherapy
• Cardiac contraindications to anthracycline chemotherapy
• Serum creatinine >2.5 mg/dL
• Serum alkaline phosphatase > 3 times the normal upper limit
• Serum bilirubin > 3 times the normal upper limit
• Serum SGOT > 3 times the upper normal limit
• Positive pregnancy test
• Absence of informed consent