Publications
2015
2015
2015
BACKGROUND
Other than Kaposi sarcoma (KS)-associated herpesvirus and CD4 T-cell lymphopenia, the mechanisms responsible for KS in the context of HIV are poorly understood. One recently explored pathway of HIV pathogenesis involves induction of the enzyme indoleamine 2,3-dioxygenase-1 (IDO), which catabolizes tryptophan into kynurenine and several other immunologically active metabolites that suppress T-cell proliferation. We investigated the role of IDO in the development of KS in HIV disease.
METHODS
In a case-control study among untreated HIV-infected Ugandans, cases were adults with KS and controls were without KS. IDO activity was assessed by the ratio of plasma kynurenine to tryptophan levels (KT ratio), measured by liquid chromatography-tandem mass spectrometry.
RESULTS
We studied 631 HIV-infected subjects: 222 KS cases and 409 controls. Non-KS controls had a higher median plasma KT ratio (130, interquartile range: 90 to 190 nM/μM) than KS cases (110, interquartile range: 90 to 150 nM/μM) (P = 0.004). After adjustment for age, sex, CD4 count, and plasma HIV RNA level, subjects with the highest (fourth quartile) plasma KT ratios had a 59% reduction (95% confidence interval: 27% to 77%) in the odds of KS compared with those with the lowest (first quartile) levels. KS was also independently associated with lower CD4 count, higher plasma HIV RNA, and men.
CONCLUSIONS
Among HIV-infected individuals, greater activity of the kynurenine pathway of tryptophan catabolism, as evidenced by higher levels of plasma KT ratio, was associated with lower occurrence of KS. Some consequences of immune activation in HIV infection might actually suppress certain cancers.
View on PubMed2015
2015
BACKGROUND
Alcohol use may accelerate HIV disease progression, but the plausible biological mechanisms have not been clearly elucidated.
METHODS
HIV-positive persons who were not on antiretroviral therapy (ART) completed the baseline assessment for a longitudinal study examining the association of alcohol use with HIV disease markers. Oversampling drinkers, baseline samples were tested for markers of monocyte activation (soluble CD14 [sCD14]), inflammation (interleukin-6 [IL-6]-6), and coagulation (d-dimer). We defined "unhealthy alcohol use" as testing positive using the Alcohol Use Disorders Identification Test-Consumption (≥3 for women and ≥4 for men) in the past 3 months or testing positive using a biomarker of heavy drinking, phosphatidylethanol (≥50 ng/ml). Multiple linear regression was used to examine the associations of unhealthy alcohol use with sCD14, log10 IL-6, and d-dimer.
RESULTS
Compared to those who were abstinent from alcohol, unhealthy drinkers had significantly higher sCD14 levels (mean = 1,676 vs. 1,387 ng/ml; mean difference [95% confidence interval (CI)] = 289 [83, 495], p < 0.01). In analyses adjusted for demographic factors, current cigarette smoking, and HIV disease markers, unhealthy drinkers continued to display significantly higher sCD14 levels compared to those who were abstinent from alcohol (adjusted mean = 1,670 vs. 1,406 ng/ml; adjusted mean difference [95% CI] = 264 [47, 480], p = 0.02). Unhealthy alcohol use was not significantly associated with IL-6 or d-dimer levels.
CONCLUSIONS
Unhealthy alcohol use was independently associated with a marker of monocyte activation (i.e., higher sCD14) that predicts mortality in treated HIV infection. Longitudinal research should examine whether unhealthy alcohol use predicts changes in sCD14 prior to and following ART initiation.
View on PubMed2015
2015
2015
OBJECTIVE
The successful scale-up of antiretroviral therapy (ART) in sub-Saharan Africa has led to increasing life expectancy, and thus increased risk of hypertension. We aimed to describe the incidence and predictors of hypertension in HIV patients receiving ART at a publicly funded clinic in rural Uganda.
METHODS
We abstracted data from medical records of adult patients who initiated ART at an HIV clinic in south-western Uganda during 2010-2012. We defined hypertension as at least two consecutive clinical visits, with a SBP at least 140 mmHg and/or SBP of at least 90 mmHg, or prescription for an antihypertensive medication. We calculated the incidence of hypertension and fit multivariable Cox proportional-hazards models to identify predictors of hypertension.
RESULTS
A total of 3389 patients initiated ART without a prior diagnosis of hypertension during the observation period. Over 3990 person-years of follow-up, 445 patients developed hypertension, for a crude incidence of 111.5/1000 (95% confidence interval 101.9-121.7) person-years. Rates were highest among men aged at least 40 years (158.8 per/1000 person-years) and lowest in women aged 30-39 years (80/1000 person-years). Lower CD4 cell count at ART initiation, as well as traditional risk factors including male sex, increasing age, and obesity, were independently associated with hypertension.
CONCLUSION
We observed a high incidence of hypertension in HIV-infected persons on ART in rural Uganda, and increased risk with lower nadir CD4 cell counts. Our findings call for increased attention to screening of and treatment for hypertension, along with continued prioritization of early ART initiation.
View on PubMed2015
2015