Association between CD4, CD4/CD8 ratio and viral blips among virally
suppressed HIV patients – a joint disease progression and time-to-event
model
Abstract
Aim Viral blips that occur among virally suppressed
HIV-positive patients suggest immune activation and inflammation and
associated with slower CD4 count and CD4/CD8 ratio normalisation. With
the advances in HIV treatment, lifestyle and comorbidities begin to be a
concern despite successful antiretroviral therapy. We reported a study
incorporating the effect of CD4 and CD4/CD8 ratio normalisation on viral
blips in joint disease progression (DP) and time-to-event (TTE) model.
Methods A total of 152 HIV-positive patients receiving
efavirenz therapy were recruited. Joint DP and TTE models on viral blip
were developed for CD4 and CD4/CD8 ratio separately. Risk factors, such
as smoking status, pack-year and comorbidity scores, were included in
the analysis. Results Gompertz model best described the CD4 and
CD4/CD8 ratio DP models, while viral blips data were fitted with the Cox
proportional hazard model. History of opportunistic infections and
changing of antiretroviral regimen significantly affect the baseline CD4
and CD4/CD8 ratio. Comorbidity score was significant in both CD4
(asymptote CD4) and CD4/CD8 ratio DP model (recovery rate). Increase in
cumulative pack-year resulted in lower CD4/CD8 ratio recovery rate (β
-0.02, 95%CI: -0.03 to -0.01; p<0.001). Active smokers
with slow CD4 or CD4/CD8 ratio normalisation associated with more viral
blips. Conclusion CD4 and CD4/CD8 ratio are significant risk
factors of viral blips and potential markers of non-AIDS related
morbidities in virally suppressed patients. Early identification of
high-risk group with repeated viral load testing, lifestyle modification
and comorbidities management should be emphasised in the HIV treatment
long-term care plan.