Early clinical markers and CD4 percentage in subjects with human immunodeficiency virus infection

Association of cell free mitochondrial DNA and caspase-1 expression with disease severity and ARTs efficacy in HIV infection

HIV infection is a global health concern. Current HIV-diagnostics provide information about the disease progression and efficacy of anti-retroviral therapies (ARVs), but this information is very limited and sometimes imprecise. Present study assessed the potential role of mononuclear cell (MNC) death, expression of caspases (1&3) and cell free mitochondrial DNA (CF mt-DNA) in HIV infected individuals. Apoptosis, cell-count, expression of caspases and CF mt-DNA were measured through flow cytometry and qPCR, respectively, in HIV infected individuals (n = 120) divided in two groups i.e. ARVs-receiving (treated, n = 87), ART-naïve (untreated, n = 37) and healthy individuals (n = 47). Data showed significant (p < 0.0001) cell death in untreated individuals than treated and healthy individuals. CD4-positive T-cell percentage declined (p < 0.0001) in untreated as compared to treated individuals. Caspase-1, an indicator of pyroptosis, and CF mt-DNA were also elevated in untreated HIV infected individuals. Untreated individuals when administered with ARVs showed improved CD4-positive T-cell percentage, lower caspase-1, CF mt-DNA and cell death. Data elucidated positive co-relation between cell death and CF mt-DNA in treated and untreated HIV infected individuals. While CD4-positive T-cell percentage was negatively correlated with caspase-1 expression and CF mt-DNA. Elevated levels of CF mt-DNA and caspase-1 in HIV infected individuals, positive correlation between cell death and CF mt-DNA, negative correlation of CD4-positive T-cell percentage with CF mt-DNA and caspase-1 expression clearly indicated the potential of CF mt-DNA and caspase-1 as a novel disease progression and ARTs effectiveness biomarkers in HIV.

Factors associated with discordance between absolute CD4 cell count and CD4 cell percentage in patients coinfected with HIV and hepatitis C virus

BACKGROUND

Liver cirrhosis has been associated with decreased absolute CD4 cell counts but preserved CD4 cell percentage in human immunodeficiency virus (HIV)-negative persons. We evaluated factors associated with discordance between the absolute CD4 cell count and the CD4 cell percentage in a cohort of patients coinfected with HIV and hepatitis C virus (HCV).

METHODS

Baseline data from 908 participants in a prospective, Canadian, multisite cohort of individuals with HIV-HCV coinfection were analyzed. Absolute CD4 cell count and CD4 cell percentage relationships were evaluated. We defined low and high discordance between absolute CD4 cell count/CD4 cell percentage relationships as CD4 cell percentages that differed from the expected CD4 cell percentage, given the observed absolute CD4 cell count, by ±7 percentage points; we defined very low and very high discordance as differences of ±14 percentage points. Factors associated with high or very high discordance, including either end-stage liver disease or aspartate transaminase to platelet ratio index (APRI) of >1.5, were analyzed using multivariate logistic regression models and compared to groups with concordant and low discordant results.

RESULTS

High/very high discordance was seen in 31% (n = 286), while 35% (n = 321) had concordant values. Factors associated with very high discordance at baseline included history of end-stage liver disease (adjusted odds ratio [aOR], 6.52; 95% confidence interval [CI], 2.27-18.67) and APRI of >1.5 (aOR 4.69; 95% CI, 1.64-13.35). Compared with those with detectable HCV RNA, those who cleared HCV spontaneously were less likely to have very high discordance.

CONCLUSIONS

Discordance between absolute CD4 cell count and CD4 cell percentage is common in an HIV/HCV-coinfected population and is associated with advanced liver disease and ongoing HCV replication.

Misclassification of first-line antiretroviral treatment failure based on immunological monitoring of HIV infection in resource-limited settings

BACKGROUND

The monitoring of patients with human immunodeficiency virus (HIV) infection who are treated with antiretroviral medications in resource-limited settings is typically performed by use of clinical and immunological criteria. The early identification of first-line antiretroviral treatment failure is critical to prevent morbidity, mortality, and drug resistance. Misclassification of failure may result in premature switching to second-line therapy.

METHODS

Adult patients in western Kenya had their viral loads (VLs) determined if they had adhered to first-line therapy for >6 months and were suspected of experiencing immunological failure (ie, their CD4 cell count decreased by 25% in 6 months). Misclassification of treatment failure was defined as a 25% decrease in CD4 cell count with a VL of <400 copies/mL. Logistic and tree regressions examined relationships between VL and 4 variables: CD4 T cell count (hereafter CD4 cell count), percentage of T cells expressing CD4 (hereafter CD4 cell percentage), percentage decrease in the CD4 T cell count (hereafter CD4 cell count percent decrease), and percentage decrease in the percentage of T cells expressing CD4 (hereafter CD4% percent decrease).

RESULTS

There were 149 patients who were treated for 23 months; they were identified as having a 25% decrease in CD4 cell count (from 375 to 216 cells/microL) and a CD4% percent decrease (from 19% to 15%); of these 149 patients, 86 (58%) were misclassified as having experienced treatment failure. Of 42 patients who had a 50% decrease in CD4 cell count, 18 (43%) were misclassified. In multivariate logistic regression, misclassification odds were associated with a higher CD4 cell count, a shorter duration of therapy, and a smaller CD4% percent decrease. By combining these variables, we may be able to improve our ability to predict treatment failure.

CONCLUSIONS

Immunological monitoring as a sole indicator of virological failure would lead to a premature switch to valuable second-line regimens for 58% of patients who experience a 25% decrease in CD4 cell count and for 43% patients who experience a 50% decrease in CD4 cell count, and therefore this type of monitoring should be reevaluated. Selective virological monitoring and the addition of indicators like trends CD4% percent decrease and duration of therapy may systematically improve the identification of treatment failure. VL testing is now mandatory for patients suspected of experiencing first-line treatment failure within the Academic Model Providing Access to Healthcare (AMPATH) in western Kenya, and should be considered in all resource-limited settings.

CD4 percentage is an independent predictor of survival in patients starting antiretroviral therapy with absolute CD4 cell counts between 200 and 350 cells/microL

OBJECTIVE

To determine the prognostic value of baseline CD4 percentage in terms of patient survival in comparison to absolute CD4 cell counts for HIV-positive patients initiating highly active antiretroviral therapy (HAART).

METHODS

A population-based cohort study of 1,623 antiretroviral therapy-naïve HIV-positive individuals who initiated HAART between 1 August 1996 and 30 June 2002 was conducted. Cumulative mortality rates were estimated using Kaplan-Meier methods. Cox proportional hazards regression was used to model the effect of baseline CD4 strata and CD4 percentage strata and other prognostic variables on survival. A subgroup analysis was conducted on 417 AIDS-free subjects with baseline CD4 counts between 200 and 350 cells/microL.

RESULTS

In multivariate models, low CD4 percentages were associated with increased risk of death [CD4%<5, relative hazard (RH)=4.46; CD4% 5-14, RH=2.43; P<0.01 for both] when compared with those subjects with an initial CD4 fraction of 15% or greater, but had less predictive value than absolute CD4 counts. In subgroup analyses where absolute CD4 strata were not associated with mortality, a baseline CD4 fraction below 15% [RH=2.71; 95% confidence interval (CI) 1.20-6.10], poor adherence to therapy and baseline viral load >100,000 HIV-1 RNA copies/mL were associated with an increased risk of death.

CONCLUSION

CD4 percentages below 15% are independent predictors of mortality in AIDS-free patients starting HAART, including those with CD4 counts between 200 and 350 cells/microL. CD4 percentage should be considered for inclusion in guidelines used to determine when to start therapy.