Abstract Number: PB0306
Meeting: ISTH 2022 Congress
Background: Secondary thrombotic thrombocytopaenic purpura (TTP) is a complication of infection with human immunodeficiency virus (HIV) with platelet-rich microvascular thrombosis and end-organ failure. TTP is caused by an absolute or relative deficiency of the von-Willebrand factor (VWF)-cleaving protease, a-disintegrin-and-metalloproteinase-with-thrombospondin-motifs 13 (ADAMTS-13). Controversy exists regarding the pathogenesis of HIV-associated TTP with both complement activation and endothelial dysfunction secondary to inflammation being postulated. TTP should be distinguished from other thrombotic microangiopathies notably disseminated intravascular coagulation (DIC) as treatment differs with plasma therapy being the mainstay of TTP treatment. Disease related biomarkers may be useful to assist in differentiating these conditions.
Aims: Investigate the derangement in biomarkers of inflammation and of activation of the coagulation system and endothelium in patients with HIV- associated TTP.
Methods: Venous blood was collected from 35 patients with HIV-associated TTP prior to commencement of therapeutic plasma exchange after informed signed consent was obtained (University of the Witwatersrand ethics approval number: M160134). Levels of the pro-inflammatory cytokine interleukin-6 (IL-6), fibrin degradation products (D-dimers) and the endothelial activation marker, Intercellular Adhesion Molecule-1 (ICAM-1), were measured on the samples. The median results of these biomarkers were compared with published results in HIV-infected cohorts without TTP to determine the significance of the changes in HIV infected patients with TTP. A p-value of < 0.05 was considered significant.
Results: IL-6, D-dimer and ICAM-1 levels were significantly higher in patients with HIV-associated TTP versus HIV infected individuals without TTP irrespective of exposure to anti-retroviral treatment (ART). (Table 1)
Conclusion(s): Patients with HIV-associated TTP had significantly elevated biomarkers of inflammation as well as of activation of the coagulation system and endothelium compared with published data in HIV infected cohorts without TTP. The pathogenesis of HIV-associated TTP therefore probably involves endothelial damage and local activation of the coagulation cascade and excessive release of VWF resulting in a relative deficiency of ADAMTS-13.
To cite this abstract in AMA style:Louw S, Gededzha M, Mayne A, Mayne E. Biomarkers of HIV-associated thrombotic thrombocytopaenic purpura (HIV-TTP) [abstract]. https://abstracts.isth.org/abstract/biomarkers-of-hiv-associated-thrombotic-thrombocytopaenic-purpura-hiv-ttp/. Accessed March 4, 2024.
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