Response to HAART in treatment-naive HIV-infected patients with a prior diagnosis of tuberculosis or other opportunistic infections

The effect of tuberculosis treatment on virologic and CD4+ cell count response to combination antiretroviral therapy: a systematic review

OBJECTIVE

To determine the impact of tuberculosis (TB) treatment at the time of combination antiretroviral therapy (cART) initiation on virologic and CD4 cell count response to cART.

METHODS

Systematic review and meta-analysis of studies reporting HIV RNA and CD4 cell count response, stratified by TB treatment status at cART initiation. Stratified random-effects and meta-regression analyses were used when possible.

RESULTS

Twenty-five eligible cohort studies reported data on 49 578 (range 42-15 646) adults, of whom 8826 (18%) were receiving TB treatment at cART initiation. Seventeen studies reported virologic response; 21 reported CD4 cell count response. The summarized random-effects relative risk (RRRE) of virologic suppression in those receiving vs. not receiving TB treatment at different time points following cART initiation was 1.06 (0.86-1.29) at 1-4 months, 0.91 (0.83-1.00) at 6 months, 0.99 (0.94-1.05) at 11-12 months, and 0.99 (0.77-1.28) at 18-48 months. The overall RRRE at 1-48 months was 0.97 (95% confidence interval 0.92-1.03). Available data regarding the effect of TB treatment on virologic failure were heterogeneous and inconclusive (13 estimates). Differences in median CD4 cell count gain between those receiving vs. not receiving TB treatment ranged from -10 to 60 cells/μl (median 27) by 6 months (seven estimates) and -10 to 29 (median 6) by 11-12 months (five estimates), although the heterogeneity of the response measures did not support meta-analysis.

CONCLUSION

Patients receiving TB treatment at cART initiation experience similar virologic suppression and CD4 cell count reconstitution as those not receiving TB treatment, reinforcing the need to start cART during TB treatment and allowing more confidence in clinical decision-making.

Outcomes among HIV-1 infected individuals first starting antiretroviral therapy with concurrent active TB or other AIDS-defining disease

Background

Tuberculosis (TB) is common among HIV-infected individuals in many resource-limited countries and has been associated with poor survival. We evaluated morbidity and mortality among individuals first starting antiretroviral therapy (ART) with concurrent active TB or other AIDS-defining disease using data from the “Prospective Evaluation of Antiretrovirals in Resource-Limited Settings” (PEARLS) study.

Methods

Participants were categorized retrospectively into three groups according to presence of active confirmed or presumptive disease at ART initiation: those with pulmonary and/or extrapulmonary TB (“TB” group), those with other non-TB AIDS-defining disease (“other disease”), or those without concurrent TB or other AIDS-defining disease (“no disease”). Primary outcome was time to the first of virologic failure, HIV disease progression or death. Since the groups differed in characteristics, proportional hazard models were used to compare the hazard of the primary outcome among study groups, adjusting for age, sex, country, screening CD4 count, baseline viral load and ART regimen.

Results

31 of 102 participants (30%) in the “TB” group, 11 of 56 (20%) in the “other disease” group, and 287 of 1413 (20%) in the “no disease” group experienced a primary outcome event (p = 0.042). This difference reflected higher mortality in the TB group: 15 (15%), 0 (0%) and 41 (3%) participants died, respectively (p<0.001). The adjusted hazard ratio comparing the “TB” and “no disease” groups was 1.39 (95% confidence interval: 0.93–2.10; p = 0.11) for the primary outcome and 3.41 (1.72–6.75; p<0.001) for death.

Conclusions

Active TB at ART initiation was associated with increased risk of mortality in HIV-1 infected patients.

The effect of tuberculosis treatment at combination antiretroviral therapy initiation on subsequent mortality: a systematic review and meta-analysis

OBJECTIVE

We aimed to perform a systematic review and meta-analysis examining the impact of TB treatment at the time of combination antiretroviral therapy (cART) initiation on subsequent mortality.

METHODS

We searched PubMed, EMBASE, and selected conference proceedings for studies that report adult mortality on cART, stratified by TB treatment status at cART initiation. Stratified random-effects and meta-regression analyses were used to examine the influence of study and population characteristics.

RESULTS

22 eligible cohort studies reported data on 98,350 (range 74-15,225) adults, of whom 14,779 (15%) were receiving TB treatment at cART initiation. Studies of those receiving vs. not receiving TB treatment had an average mortality relative risk of 1.10 (95% confidence interval 0.87-1.40) at 1-3 months (based upon 8 estimates), 1.15 (0.94-1.41) at 6-12 months (11 estimates), and 1.33 (1.02-1.75) at 18-98 months (10 estimates) following cART initiation. However, there was a wide range of estimates and those at later time points were markedly heterogeneous. Meta-regression identified factors associated with elevated average risk estimates: lower median baseline CD4 counts and adjustment for baseline hemoglobin at 1-3 months; longer length of follow-up and women-only studies at 6-12 months; and not adjusting for BMI/weight at 18-98 months.

CONCLUSIONS

Patients receiving TB treatment at cART initiation did not have a statistically significant estimated increase in short-term risk of all-cause mortality as compared to those not receiving TB treatment. TB treatment was significantly associated with increased mortality after about a year of cART, suggesting that patients with concurrent TB treatment at cART initiation may benefit from continued support after TB treatment completion.

Virologic and immunologic outcome of HAART in Human Immunodeficiency Virus (HIV)-1 infected patients with and without tuberculosis (TB) and latent TB infection (LTBI) in Addis Ababa, Ethiopia

BACKGROUND

HIV/TB coinfection remains a major challenge even after the initiation of HAART. Little is known about Mycobacterium tuberculosis (Mtb) specific immune restoration in relation to immunologic and virologic outcomes after long-term HAART during co-infections with latent and active TB.

METHODS

A total of 232 adults, including 59 HIV patients with clinical TB (HIV + TB+), 125 HIV patients without clinical TB (HIV + TB-), 13 HIV negative active TB patients (HIV-TB+), and 10 HIV negative Tuberculin Skin TST positive (HIV-TST+), and 25 HIV-TST- individuals were recruited. HAART was initiated in 113 HIV + patients (28 TB + and 85 TB-), and anti-TB treatment for all TB cases. CD4+ T-cell count, HIV RNA load, and IFN-γ responses to ESAT-6/CFP-10 were measured at baseline, 6 months (M6), 18 months (M18) and 24 months (M24) after HAART initiation.

RESULTS

The majority of HIV + TB- (70%, 81%, 84%) as well as HIV + TB + patients (60%, 77%, 80%) had virologic success (HIV RNA < 50 copies/ml) by M6, M18 and M24, respectively. HAART also significantly increased CD4+ T-cell counts at 2 years in HIV + TB + (from 110.3 to 289.9 cells/μl), HIV + TB- patients (197.8 to 332.3 cells/μl), HIV + TST- (199 to 347 cells/μl) and HIV + TST + individuals (195 to 319 cells/μl). Overall, there was no significant difference in the percentage of patients that achieved virologic success and in total CD4+ counts increased between HIV patients with and without TB or LTBI. The Mtb specific IFN-γ response at baseline was significantly lower in HIV + TB + (3.6 pg/ml) compared to HIV-TB + patients (34.4 pg/ml) and HIV + TST + (46.3 pg/ml) individuals; and in HIV-TB + patients compared to HIV-TST + individuals (491.2 pg/ml). By M18 on HAART, the IFN-γ response remained impaired in HIV + TB + patients (18.1 pg/ml) while it normalized in HIV + TST + individuals (from 46.3 to 414.2 pg/ml).

CONCLUSIONS

Our data show that clinical and latent TB infections do not influence virologic and immunologic outcomes of ART in HIV patients. Despite this, HAART was unable to restore optimal TB responsiveness as measured by Mtb specific IFN-γ response in HIV/TB patients. Improvement of Mtb-specific immune restoration should be the focus of future therapeutic strategies.

Prevalent tuberculosis and mortality among HAART initiators

The effect of tuberculosis on mortality in people initiating highly-active antiretroviral therapy (HAART) remains unclear; here, we strengthened a previous cohort analysis. Multivariate Cox proportional hazards models were used to assess the association of baseline tuberculosis and time to all-cause mortality among HAART initiators. In reanalysis, treatment for tuberculosis at time of HAART initiation remained unassociated with increased risks of all-cause mortality, with adjusted hazard ratios ranging from 1.00 to 1.09.