Method for treating malignancy and autoimmune disorders in humans using tac antibodies

A method of reducing levels of Tac-positive cells in patients with elevated levels of Tac-positive cells comprising the steps of,

• a) determining a dosage, said dosage comprising 5-15 mCi 90Y-conjugated anti-Tac in a total amount of 2-20 mg anti-Tac, wherein the dose is 2 mg total anti-Tac if said patient has sIL-2R levels of less than 2,000 units/ml, the dose is 5 mg total anti-Tac if said patient has sIL-2R levels of 2,000-10,000 units/ml, the dose is 10 mg of total anti-Tac if the patient has sIL2R levels of 10,000-50,000 units/ml, and the dose is 20 mg of total anti-Tac if said patient has sIL-2R levels of greater than 50,000 units/ml;
• and
• b) administering said dosage to said patient to eliminate disease-associated Tac-positive cells.