DISEASE CHARACTERISTICS:

• Histologically confirmed B-cell diffuse large cell lymphoma

  • L-26 positive (i.e., CD20-positive)
• Failed 2 prior chemotherapy regimens

• At least 1 measurable lesion

  • At least 2 cm by physical exam or CT scan
• No active lymphomatous meningitis or other CNS involvement by lymphoma
• No significant marrow involvement (i.e., more than 20% of hematopoietic marrow elements from iliac crest biopsy)

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Karnofsky 60-100%

Life expectancy:

• At least 3 months

Hematopoietic:

• WBC at least 3,500/mm3
• Granulocyte count at least 1,500/mm3
• Platelet count at least 125,000/mm3

Hepatic:

• Bilirubin no greater than 2 times upper limit of normal (ULN)
• AST/ALT no greater than 3 times ULN
• Alkaline phosphatase no greater than 3 times ULN

Renal:

• Creatinine no greater than 2 times ULN

Cardiovascular:

• No electrocardial evidence of Q-wave myocardial infarction within the past 6 months
• No congestive heart failure
• No New York Heart Association class III or IV heart disease

Other:

• HIV negative
• Negative human anti-mouse antibodies (i.e., less than 74 ng/mL)
• No known antiplatelet antibodies
• No other malignancy except basal cell skin cancer or carcinoma in situ of the cervix
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior bone marrow or peripheral blood stem cell transplantation
• No prior radioimmunotherapy
• Prior unlabeled monoclonal antibody therapy allowed
• At least 120 hours since prior filgrastim (G-CSF) or sargramostim (GM-CSF)
• At least 1 month since prior epoetin alfa

Chemotherapy:

• See Disease Characteristics
• No concurrent chemotherapy

Endocrine therapy:

• Not specified

Radiotherapy:

• See Biologic therapy
• No prior total body irradiation (TBI)
• At least 6 months since prior radiotherapy (over 3,00 cGy) to more than 20% of marrow-bearing space (i.e., pelvis and spine)
• No concurrent large-field radiotherapy (i.e., TBI, hemibody radiation, or radiation fields that include more than 20% of active marrow to a dose of over 3,000 cGy)
• Concurrent localized radiotherapy is allowed to current or impending serious complication (e.g., bronchial obstruction by hilar lymph nodes or impending fracture due to lytic bone lesions)

Surgery:

• Not specified

Other:

• Recovered from prior anti-lymphoma therapy
• At least 120 hours since prior whole blood or platelet transfusion
• No concurrent anticoagulants or antiplatelet drugs
• No concurrent medications known to inhibit blood clotting or platelet aggregation (e.g., aspirin)