<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A substance produced by certain white blood cells in reaction to contact with HIV, the human immunodeficiency virus.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Produced by B-cells, human immunodeficiency virus (HIV) antibodies reacts with HIV antigens. HIV is a virus which affects white blood cells and eventually destroys the body's natural ability to fight infections.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>