4. Preserved renal function (creatinine less than or equal to 2.5 mg/dL; less than or equal to 3+ proteinuria); preserved hepatic function (bilirubin less than or equal to 2.0 mg/dl); preserved hematologic function (WBC greater than or equal to1000/mm^3;granulocytes greater than or equal to 500/mm^3; platelets greater than or equal to 100,000; hematocrit greater than or equal to 25). Of note, patients with PID often have associated chronic thrombocytopenia. Patients with stable chronic thrombocytopenia will be eligible for collection, at the investigator s discretion, with the caveat that patients with platelet count <40,000 the day prior to collection will be transfused with platelets on the morning of collection. Platelets may also be given to these patients following the collection if medically indicated..