PB0793 - Establishing reference intervals of coagulation biomarkers in Human immunodeficiency virus infection

Background: Chronic inflammation associated with viral infections are associated with pathogenic thrombosis. Specifically, human immunodeficiency virus (HIV) infection is associated with cardiovascular disease, venous thromboembolism and microvascular thrombosis. HIV-related chronic inflammation may also contribute to elevation levels of procoagulant factors, endothelial activation markers and fibrin degradation products (D-dimers). In order to assess the diagnostic and prognostic utility of biomarkers of coagulation in people living with HIV (PLWH), it is important to define baseline levels of these markers in PLWH without significant additional comorbid disease.

Aims: This study aimed to define reference intervals of 2 common coagulation biomarkers in people living with HIV

Methods: A systematic review of the published levels of interleukin-6 (IL-6) and D-dimers in ART naïve PLWH without comorbid diseases was performed and the results were compared with the reference indices provided in the package inserts of the test reagents. Published studies were weighted by participant number and the results were utilised to calculate a median value. Data values were recorded in Microsoft Excel® 2016 and formally analysed with STATA® 15.1 (StataCorp, College Station, Texas).

Results: The review considered 229 publications. Summary data for D-dimer levels (15 papers) and IL-6 (16 papers) are included in Table 1. IL-6 levels exceeded the established normal reference index in 8 of the studies but D-dimer levels were below the laboratory reference range of 0.5 mg/ml in all studies.

Conclusion(s): In PLWH without underlying evidence of pathologic cardiovascular disease, D-dimer levels are typically normal although IL-6 levels may be elevated. This suggests that D-dimers would still have high negative predictive value in the diagnosis of venous thromboembolism and may be prognostic in PLWH. The value of IL-6 in monitoring for HIV-related cardiovascular risk requires additional investigation.