Changes in inflammation but not in T cell activation precede non-AIDS-defining events in a case-control study of patients on long-term antiretroviral therapy.

Background

We examine changes in soluble inflammatory cytokines and T-cell activation after antiretroviral therapy (ART) initiation in an ACTG nested case-control study.

Methods

Cases were 143 HIV-infected adults who developed a non-AIDS event; 315 controls remained event-free. Specimens were tested pre-ART, year 1 post-ART and at the visit preceding the event. Conditional logistic regression evaluated the associations of biomarker changes with non-AIDS events.

Results

Inflammatory and most activation biomarkers declined from pre-ART to year 1 for cases and controls. Subsequently, inflammatory biomarkers remained mostly stable in controls but not cases. Cellular activation markers generally declined for both cases and controls between year 1 and the pre-event sampling. Controls with greater pre-ART RNA levels or lower CD4+ levels had higher biomarker levels while also experiencing greater biomarker declines in the first year of ART. Changes in biomarkers to year 1 showed no significant associations with non-AIDS events. Cases, however, had significantly greater increases in all plasma biomarkers (but not cellular activation) from year 1 to the visit preceding the event.

Conclusions

Inflammation increases prior to non-AIDS events in treated HIV-infected adults. These biomarker changes may reflect subclinical disease processes or other alterations in the inflammatory environment that causally contribute to disease.

Clinical Trials registration

NCT00001137 https://clinicaltrials.gov/ct2/show/NCT00001137.