Little is known about the thrombospondin type-1 motif, member 13 (ADAMTS-13) enzymatic activity in subjects with suspected/confirmed thrombotic thrombocytopenic purpura (TTP) in the Arabian Gulf and Colombia. The retrospective analysis of ADAMTS13 enzymatic activity results in a population with thrombotic thrombocytopenic purpura disease in the Arabian Gulf and Colombia (APOLO study) aimed to report on ADAMTS-13 enzymatic activity, subject demographics, and the turnaround time for results. This evidence concerns the gene ADAMTS13 and thrombotic thrombocytopenic purpura.