ADAMTS13 and thrombotic thrombocytopenic purpura: The study analysed 59 frozen citrate plasma samples from HIV‐associated TTP patients in South Africa, measuring ADAMTS13 activity using Technozyme® ADAMTS13 activity test, total immunoglobulin (Ig) M and IgA antibodies levels using ELISA kit and purifying IgG antibodies using NAbTM Protein G spin columns.