Objective: To determine the rate of grade 4, potentially life-threatening events not attributable to AIDS, cardiovascular disease (CVD), or non-AIDS cancer among participants on antiretroviral therapy and to describe associations of these events with interleukin-6 (IL-6) and D-dimer.
Design: Cohort study.
Methods: HIV-infected participants on antiretroviral therapy (N = 3568) with an HIV-RNA level ≤ 500 copies/mL were followed for grade 4, AIDS, CVD, non-AIDS cancer, and all-cause mortality events. Grade 4 events were further classified masked to biomarker levels as reflecting chronic inflammation-related disease (ChrIRD) or not (non-ChrIRD). Associations of baseline IL-6 and D-dimer with events were studied using Cox models.
Results: Over a median follow-up of 4.3 years, 339 participants developed a grade 4 event (22.9 per 1000 person-years); 165 participants developed a ChrIRD grade 4 event (10.7 per 1000 person-years). Grade 4 events were more common than AIDS (54 participants), CVD (132), and non-AIDS cancer (80) events, any of which developed in 252 participants (17.1 per 1000 person-years). Grade 4 and AIDS events were associated with similar risks of death. Higher IL-6 [hazard ratio (HR) = 1.19 per doubling of biomarker; P = 0.003] and D-dimer (HR = 1.23; P < 0.001) levels were associated with an increased risk of grade 4 events. IL-6 associations were stronger for ChrIRD (HR = 1.38; P < 0.001) than non-ChrIRD grade 4 events (HR = 1.11; P = 0.21).
Conclusions: Morbidity and mortality associated with activation of inflammatory and coagulation pathways include conditions other than AIDS, CVD, and non-AIDS cancer events. Effective inflammation-dampening interventions could greatly affect the health of people with HIV.