Objective

To evaluate the short- and long-term effects of highly active antiretroviral therapy (HAART) on tuberculosis (TB) risk, compared to risk without HAART in a low TB incidence setting.

Design

An observational cohort study among HIV-infected persons in care at the Comprehensive Care Center (Nashville, TN) between January 1998 and December 2008.

Methods

A marginal structural model was used to estimate the effect of HAART on short- (≤180 days) and long-term (>180 days) TB risk, with CD4+ lymphocyte count incorporated as a time-updated covariate.

Results

Of 4,534 HIV-infected patients, 34 developed TB (165/100,000 p-y; 20,581 person-years [p-y] of follow-up). Seventeen cases occurred among persons not on HAART or >30 days after HAART discontinuation (212/100,000 p-y; 8,019 p-y of follow-up). Seventeen occurred among persons on HAART (135/100,000 p-y; 12,562 p-y of follow-up); ten in the first 180 days (402/100,000 p-y; 2,489 p-y of follow-up) and 7 after more than 180 days (69/100,000 p-y; 10,073 p-y of follow-up). After adjusting for the most recent CD4+ lymphocyte count, the risk of TB in the first 180 days of HAART exposure relative to no HAART was 0.68 (0.14–3.22, p=0.63).

Conclusions

In this low TB incidence setting, the TB rate in the first 180 days of HAART was almost twice as high as persons not on HAART. However, after adjusting for most recent CD4+ count there was no significant difference in TB risk between these two groups. This suggests that low recent CD4+ lymphocyte count influences TB risk during the first 180 days of HAART.

Objective

To evaluate a model for predicting time to AIDS or death among HIV-infected persons initiating highly active antiretroviral therapy (HAART).

Study Design and Setting

The model was constructed from 1,891 HAART initiators in the Collaborations in HIV Outcomes Research/US (CHORUS) cohort. The model's predictive ability was assessed using internal bootstrap validation techniques and data from 716 HAART initiators at Johns Hopkins HIV Clinical Cohort (JHHCC) in whom HIV disease was, in general, more advanced.

Results

The estimated concordance statistic was 0.632 with the bootstrap method and 0.625 in JHHCC. Mean predicted and observed 3-year AIDS-free survival for JHHCC was 0.76 and 0.73 (95% CI 0.69−0.77), respectively; mean predicted and observed 5-year AIDS-free survival was 0.69 and 0.57 (95% CI 0.52−0.62). Sensitivity analyses showed that the discrepancy between predicted and observed AIDS-free survival after 3 years could be due to differences in lost-to-follow-up rates between cohorts.

Conclusion

The model was fair at using baseline characteristics to order patients’ risk of disease progression, but did not accurately predict AIDS-free survival >3 years after HAART initiation. Different variable definitions, patient characteristics, and loss-to-follow-up highlight the challenges of using data from one cohort to predict AIDS-free survival in an independent cohort.

Background

Pregnancy has been associated with a decreased risk of HIV disease progression in the highly active antiretroviral therapy (HAART) era. The effect of timing of HAART initiation relative to pregnancy on maternal virologic, immunologic and clinical outcomes has not been assessed.

Methods

We conducted a retrospective cohort study from 1997–2005 among 112 pregnant HIV-infected women who started HAART before (N = 12), during (N = 70) or after pregnancy (N = 30).

Results

Women initiating HAART before pregnancy had lower CD4+ nadir and higher baseline HIV-1 RNA. Women initiating HAART after pregnancy were more likely to receive triple-nucleoside reverse transcriptase inhibitors. Multivariable analyses adjusted for baseline CD4+ lymphocytes, baseline HIV-1 RNA, age, race, CD4+ lymphocyte count nadir, history of ADE, prior use of non-HAART ART, type of HAART regimen, prior pregnancies, and date of HAART start. In these models, women initiating HAART during pregnancy had better 6-month HIV-1 RNA and CD4+ changes than those initiating HAART after pregnancy (−0.35 vs. 0.10 log10 copies/mL, P = 0.03 and 183.8 vs. −70.8 cells/mm3, P = 0.03, respectively) but similar to those initiating HAART before pregnancy (−0.32 log10 copies/mL, P = 0.96 and 155.8 cells/mm3, P = 0.81, respectively). There were 3 (25%) AIDS-defining events or deaths in women initiating HAART before pregnancy, 3 (4%) in those initiating HAART during pregnancy, and 5 (17%) in those initiating after pregnancy (P = 0.01). There were no statistical differences in rates of HIV disease progression between groups.

Conclusions

HAART initiation during pregnancy was associated with better immunologic and virologic responses than initiation after pregnancy.

After changes to assay and specimen-processing methods, plasma human immunodeficiency virus type 1 (HIV-1) RNA was frequently detectable in patients who previously had well-suppressed HIV-1 RNA levels. This artifact is attributable to shipping frozen plasma in primary plasma preparation tubes and is not caused by the HIV-1 RNA detection assay; it can be avoided by shipping plasma in a secondary tube.