Biomedical subjects

Meredith E Childers

Publications and source records attributed to Meredith E Childers.

4 recordsLinked to original sources

PubMed2004

Enhancing antiretroviral therapy for human immunodeficiency virus cognitive disorders.

The benefits of combination antiretroviral therapy (ART) for HIV cognitive disorders vary substantially between individuals. This study evaluated whether cerebrospinal fluid (CSF) drug penetration and CSF virological suppression influence the extent of neuropsychological (NP) improvement during ART. Overall performance on a battery of NP tests administered at baseline and follow-up (median 15 weeks) was computed by using the global deficit score (GDS) methods in 31 cognitively impaired, HIV-infected individuals who began new ART regimens. Virological suppression (attaining undetectable viral load by RT-PCR at follow-up) was assessed separately for plasma and CSF. Subjects on regimens containing greater numbers of CSF-penetrating drugs showed significantly greater reduction in CSF viral load. Subjects attaining CSF virological suppression demonstrated greater GDS improvement than those who did not (median GDS change, 0.62 vs 0.23; p = 0.01). A similar trend for plasma did not reach statistical significance (p = 0.053). NP improvement was greater in ART-naive versus treatment-experienced subjects. In a multivariate model (overall p = 0.0008), significant, independent predictors of GDS reduction were CSF HIV RNA suppression, baseline antiretroviral history, and their interaction. Including CSF-penetrating drugs in the ART regimen and monitoring CSF viral load may be indicated for individuals with HIV-associated cognitive impairment.

Adult↗

PubMed2003

Increased human immunodeficiency virus loads in active methamphetamine users are explained by reduced effectiveness of antiretroviral therapy.

Abuse of methamphetamine (METH) is a frequent comorbidity among individuals infected with human immunodeficiency virus (HIV) type 1. In cell cultures and animal models, METH accelerates retroviral replication. To determine whether METH increases HIV replication in humans, we evaluated HIV loads in HIV-positive METH users and nonusers. We studied 3 groups: Tox+, active METH use and positive urine toxicology results; METH(+)Tox-, previous METH dependence/abuse and negative urine toxicology results; METH(-)Tox-, no METH dependence/abuse and negative urine toxicology results. Tox+ subjects' plasma virus loads were significantly higher than METH(+)Tox- and METH(-)Tox- subjects'; cerebrospinal fluid virus loads showed a similar but nonsignificant trend. Stratification by use of highly active antiretroviral therapy (HAART) revealed that virus loads were higher only in those Tox+ subjects who reported receiving HAART. In contrast, abstinent former METH abusers (METH(+)Tox-) receiving HAART effectively suppressed viral replication. These data suggest that abstinence programs are a key component of effective treatment of HIV in METH-abusing populations.

Anti-HIV Agents↗

PubMed2003

Human immunodeficiency virus-1 RNA levels in cerebrospinal fluid exhibit a set point in clinically stable patients not receiving antiretroviral therapy.

To characterize, over time, cerebrospinal fluid (CSF) virus-load change in clinically stable patients, human immunodeficiency virus (HIV)-1 RNA levels were measured in serial CSF samples and in plasma samples obtained, during periods of 20 days-6 years, from 17 HIV-infected individuals not receiving antiretroviral treatment. Longitudinal trends were analyzed by linear regression and restricted maximum-likelihood techniques. CSF HIV-1 RNA levels varied within a restricted range (+/-0.5 log(10) copies/mL) around each subject-specific mean. Although 16 of the 17 subjects had CSF slopes not significantly different from zero, slopes that were more positive were associated with lower CD4 counts. In an individual patient, a CSF virus-load change >0.5 log(10) copies/mL may be clinically significant. Furthermore, our data suggest that, if the CSF virus load reflects the size of the reservoir of infected cells in the central nervous system, this reservoir may increase in those individuals with advanced immunosuppression but is stable, over several years, in patients without AIDS.

Adult↗

PubMed2002

Progression to neuropsychological impairment in human immunodeficiency virus infection predicted by elevated cerebrospinal fluid levels of human immunodeficiency virus RNA.

BACKGROUND: If cerebrospinal fluid (CSF) human immunodeficiency virus (HIV) RNA levels are elevated before the development of neuropsychological (NP) impairment, such an observation would support prospective monitoring of CSF HIV RNA levels as well as therapeutic interventions designed to lower CSF HIV levels. OBJECTIVE: To determine whether increased CSF HIV RNA levels at an earlier time predict subsequent progression to NP impairment in HIV-infected subjects. METHODS: We examined 139 subjects in a prospective cohort study. Comprehensive NP, neuromedical, and laboratory evaluations were performed at initial and follow-up visits at least 6 months apart. Human immunodeficiency virus RNA levels in plasma and CSF were measured with a commercially available, polymerase chain reaction-based assay. To assess the robustness of our findings, we analyzed changes in NP performance over time in 2 ways. First, we used masked clinical ratings of global NP performance to identify individuals who were initially NP normal, and then determined, in a similarly blinded fashion, which of these subjects subsequently became NP impaired. Second, in a separate analysis, we assessed change in subjects' raw scores on each of a series of NP test measures between baseline and follow-up. RESULTS: Among subjects who were not impaired at the initial visit, higher levels of HIV RNA in CSF significantly predicted progression to global NP impairment at the follow-up evaluation. Cerebrospinal fluid HIV RNA levels outperformed other clinical and laboratory measures in predicting progression to NP impairment. Higher CSF HIV RNA levels were associated with worsening performance on tests of attention, learning, and motor function. CONCLUSION: Because elevated CSF HIV RNA levels (>or=200 copies/mL) predict subsequent progression to NP impairment, monitoring of CSF viral load and therapy to reduce CSF HIV RNA levels may be clinically warranted, even if impairment is not identified at the time of lumbar puncture.

Adult↗