 Adequate blood counts if undergoing apheresis HIV positive volunteers and volunteers with vasculitis or other inflammatory diseases: hemoglobin greater than or equal to 9.0 gdL, HCT greater than or equal to 28, platelets greater than or equal to 50,000; HIV negative volunteers: hemoglobin greater than or equal to 12.5 gdL, HCT greater than or equal to 38, platelets greater than or equal to 150,000 