PATIENT CHARACTERISTICS: Age: 6 to under 60 Performance status: Karnofsky 70%-100% (over age 16) Lansky 70%-100% (ages 6-16) Hematopoietic: Not specified Hepatic: Bilirubin less than 2.0 mg/dL AST or ALT less than 5 times normal PT and aPTT normal (consult with principal investigator if abnormal) Renal: Creatinine clearance at least 50 mL/min/1.73 sqm Cardiovascular: No evidence of myocardial infarction or ischemia on EKG Other: No active infection at time of leukapheresis Able to tolerate anticoagulation