Brian K. Agan

Comparisons of causes of death and mortality rates among HIV-infected persons : Analysis of the pre-, early, and late HAART (Highly active antiretroviral therapy) eras

Methods:Comparisons of death-related variables during the 3 eras were performed. Results:The number of deaths declined over the study period, with 987 deaths in the pre-HAART era, 159 deaths in the early HAART era (1997-1999), and 78 deaths in the late HAART era (2000-2003) (P < 0.01). The annual death rate peaked in 1995 (10.3 per 100 patients) and then declined to <2 deaths per 100 persons in the late HAART era (P < 0.01). The proportion of deaths attributable to infection decreased, but infection remained the leading cause of death in our cohort, followed by cancer. Of those who died, there was an increasing proportion of non-HIV-related deaths (32% vs. 9%; P < 0.01), including cardiac disease (22% vs. 8%; P < 0.01) and trauma (8% vs. 2%; P = 0.01) in the post-HAART versus pre-HAART era. Despite the absence of intravenous drug use and the low prevalence of hepatitis C coinfection in our cohort, an increasing proportion of deaths in the HAART era were attributable to liver disease, although the numbers are small. Conclusions:Despite increasing concerns regarding antiretroviral resistance, the death rate among HIV-infected persons in our cohort continues to decline. Our data show a lower death rate than that reported among many other US HIV-infected populations; this may be the result of open access to health care. A shift in the causes of death toward non-HIV-related causes suggests that a more comprehensive health care approach may be needed for optimal life expectancy; this may include enhanced screening for malignancy and heart disease as well as preventive measures for liver disease and accidents.

Trends in the Incidence of Cancers among HIV-Infected Persons and the Impact of Antiretroviral Therapy: A 20-Year Cohort Study

Objective:To describe trends in incidence rates of AIDS-defining cancers (ADCs) and non-AIDS-defining cancers (NADCs) during the HIV epidemic and to evaluate predictors, including the impact of antiretroviral therapy, of cancer development. Design:Retrospective analysis of a multicenter, prospective natural history study including 4498 HIV-infected US military beneficiaries with 33 486 person-years of follow-up. Methods:Predictors evaluated included demographics, clinical data, time-updated CD4 cell counts, HIV viral loads, and antiretroviral history. Time periods were classified as early pre (1984–1990), late pre (1991–1995), early post (1996–2000), and late post (2001–2006) HAART eras. Cox proportional hazard models were used to evaluate the association of specific factors with cancer. Results:Ten percent of HIV-infected persons developed cancer. ADC rates increased between the early and late pre-HAART eras (7.6 and 14.2 cases per 1000 person-years) and have since declined from 5.4 to 2.7 in the early and late HAART eras, respectively (P < 0.001). Rates of NADCs have risen over the four periods (2.9, 2.8, 4.2, 6.7, P = 0.0004). During the late HAART era, 71% of cancers were NADCs. Predictors for ADCs included low CD4 cell count, noncancer AIDS diagnosis, and lack of HAART. NADCs were predicted by increasing age and white race (due to skin cancers). Conclusion:Although the rate of ADCs continues to fall, the rate of NADCs is rising and now accounts for the majority of cancers in HIV-infected persons. The development of NADCs is associated with increasing age among HIV patients. HAART use is protective for ADCs, but did not significantly impact NADCs.

Clinical Outcomes of Elite Controllers, Viremic Controllers, and Long-Term Nonprogressors in the US Department of Defense HIV Natural History Study

Durable control of human immunodeficiency virus (HIV) replication and lack of disease progression in the absence of antiretroviral therapy were studied in a military cohort of 4586 subjects. We examined groups of elite controllers (ie, subjects with plasma HIV RNA levels of <50 copies/mL; prevalence, 0.55% [95% confidence interval {CI}, 0.35%-0.80%]), viremic controllers (ie, subjects with plasma HIV RNA levels of 50-2000 copies/mL; prevalence, 3.34% [95% CI, 2.83%-3.91%]), and subjects with a lack of disease progression (ie, long-term nonprogressors [LTNPs]) through 7 years of follow-up (LTNP7s; prevalence, 3.32% [95% CI, 2.70%-4.01%]) or 10 years of follow-up (LTNP10s; prevalence, 2.04% [95% CI, 1.52%-2.68%]). For elite and viremic controllers, spontaneous virologic control was established early and was typically observed when the initial viral load measurement was obtained within 1 year of estimated seroconversion. Elite controllers had favorable time to development of AIDS (P=.048), a CD4 cell count of 350 cells/microL (P= .009), and more-stable CD4 cell trends, compared with viremic controllers. LTNPs defined by 10-year versus 7-year criteria had a longer survival time (P=.001), even after adjustment for differing periods of invulnerability (P= .042). Definitions of controllers and LTNPs describe distinct populations whose differing clinical outcomes improve with the stringency of criteria, underscoring the need for comparability between study populations.

Incidence and risk factors for the occurrence of non‐AIDS‐defining cancers among human immunodeficiency virus‐infected individuals

The objective of this study was to determine the rates and predictors of non‐AIDS‐defining cancers (NADCs) among a cohort of human immunodeficiency virus (HIV)‐infected individuals.

CCL3L1 and CCR5 influence cell-mediated immunity and affect HIV-AIDS pathogenesis via viral entry-independent mechanisms

Although host defense against human immunodeficiency virus 1 (HIV-1) relies mainly on cell-mediated immunity (CMI), the determinants of CMI in humans are poorly understood. Here we demonstrate that variations in the genes encoding the chemokine CCL3L1 and HIV coreceptor CCR5 influence CMI in both healthy and HIV-infected individuals. CCL3L1-CCR5 genotypes associated with altered CMI in healthy subjects were similar to those that influence the risk of HIV transmission, viral burden and disease progression. However, CCL3L1-CCR5 genotypes also modify HIV clinical course independently of their effects on viral load and CMI. These results identify CCL3L1 and CCR5 as major determinants of CMI and demonstrate that these host factors influence HIV pathogenesis through their effects on both CMI and other viral entry–independent mechanisms.

Duffy Antigen Receptor for Chemokines Mediates trans-Infection of HIV-1 from Red Blood Cells to Target Cells and Affects HIV-AIDS Susceptibility

Duffy antigen receptor for chemokines (DARC) expressed on red blood cells (RBCs) influences plasma levels of HIV-1-suppressive and proinflammatory chemokines such as CCL5/RANTES. DARC is also the RBC receptor for Plasmodium vivax. Africans with DARC -46C/C genotype, which confers a DARC-negative phenotype, are resistant to vivax malaria. Here, we show that HIV-1 attaches to RBCs via DARC, effecting trans-infection of target cells. In African Americans, DARC -46C/C is associated with 40% increase in the odds of acquiring HIV-1. If extrapolated to Africans, approximately 11% of the HIV-1 burden in Africa may be linked to this genotype. After infection occurs, however, DARC-negative RBC status is associated with slower disease progression. Furthermore, the disease-accelerating effect of a previously described CCL5 polymorphism is evident only in DARC-expressing and not in DARC-negative HIV-infected individuals. Thus, DARC influences HIV/AIDS susceptibility by mediating trans-infection of HIV-1 and by affecting both chemokine-HIV interactions and chemokine-driven inflammation.

Anal Cancers among HIV-Infected Persons: HAART Is Not Slowing Rising Incidence

Objective:To evaluate the incidence rates of anal cancer over the HIV epidemic and assess the impact of HAART use on anal cancer events. Methods:We evaluated the incidence of and factors associated with anal cancer using longitudinal data from the prospective U.S. Military Natural History Study (1985–2008). Poisson regression and Cox proportional hazard models were utilized. Results:Among 4506 HIV-infected men with 37 806 person-years of follow-up, anal cancer rates (per 100 000 person-years) increased five-fold, from 11 in the pre-HAART to 55 in the HAART era (P = 0.02). Rates continued to increase, reaching 128 in 2006–2008. Persons with HIV infection for more than 15 years had a 12-fold higher rate than those with less than 5 years (348 vs. 28, P < 0.01). At cancer diagnosis (n = 19), median age was 42 years, median CD4 cell count was 432 cells/μl, 74% had a CD4 nadir cell count less than 200 cells/μl, 42% had a prior AIDS event, and 74% had received HAART. From separate models, prior AIDS event (hazard ratio 3.88, P = 0.01) and lower CD4 nadir (hazard ratio 0.85 per 50 cell, P = 0.03) were associated with anal cancer, with a trend for a history of gonorrhea (hazard ratio 2.43, P = 0.07). Duration of HAART use was not associated with a reduced risk of anal cancer (hazard ratio 0.94, P = 0.42). Conclusion:Incidence rates of anal cancer have progressively increased during the HIV epidemic. Persons with a longer duration of HIV infection have a substantially higher rate of anal cancer. As HIV-infected persons are experiencing longer life expectancies and HAART does not appear protective of anal cancer, studies on preventive strategies are needed.

Apolipoprotein (apo) E4 enhances HIV-1 cell entry in vitro, and the APOE ε4/ε4 genotype accelerates HIV disease progression

Originally recognized for their role in lipoprotein metabolism and cardiovascular disease, apolipoprotein (apo) E isoforms (apoE2, apoE3, and apoE4) have also been implicated to play a key role in several biological processes not directly related to their lipid transport function. For example, apoE4 contributes significantly to neurodegeneration in Alzheimers disease. However, the role of apoE in infectious diseases is less well defined. Here, by examining a large cohort of HIV+ European and African American subjects, we found that the APOE ε4/ε4 genotype is associated with an accelerated disease course and especially progression to death compared with the APOE ε3/ε3 genotype. However, an association between the ε4/ε4 genotype and HIV-associated dementia (HAD), a neurological condition with clinicopathological features similar to Alzheimers disease, was not detected. Consistent with the genotype–phenotype relationships observed, compared with recombinant apoE3, apoE4 enhanced HIV fusion/cell entry of both R5 and X4 HIV strains in vitro. These findings establish apoE as a determinant of HIV-AIDS pathogenesis and raise the possibility that current efforts to convert apoE4 to an “apoE3-like” molecule to treat Alzheimers disease might also have clinical applicability in HIV disease.

CCL3L1-CCR5 genotype influences durability of immune recovery during antiretroviral therapy of HIV-1-infected individuals

The basis for the extensive variability seen in the reconstitution of CD4+ T cell counts in HIV-infected individuals receiving highly active antiretroviral therapy (HAART) is not fully known. Here, we show that variations in CCL3L1 gene dose and CCR5 genotype, but not major histocompatibility complex HLA alleles, influence immune reconstitution, especially when HAART is initiated at <350 CD4+ T cells/mm3. The CCL3L1-CCR5 genotypes favoring CD4+ T cell recovery are similar to those that blunted CD4+ T cell depletion during the time before HAART became available (pre-HAART era), suggesting that a common CCL3L1-CCR5 genetic pathway regulates the balance between pathogenic and reparative processes from early in the disease course. Hence, CCL3L1-CCR5 variations influence HIV pathogenesis even in the presence of HAART and, therefore, may prospectively identify subjects in whom earlier initiation of therapy is more likely to mitigate immunologic failure despite viral suppression by HAART. Furthermore, as reconstitution of CD4+ cells during HAART is more sensitive to CCL3L1 dose than to CCR5 genotypes, CCL3L1 analogs might be efficacious in supporting immunological reconstitution.

Increasing Rates of Obesity among HIV-Infected Persons during the HIV Epidemic

Background The prevalence and factors associated with overweight/obesity among human immunodeficiency virus (HIV)-infected persons are unknown. Methods We evaluated prospective data from a U.S. Military HIV Natural History Study (1985–2004) consisting of early diagnosed patients. Statistics included multivariate linear regression and longitudinal linear mixed effects models. Results Of 1682 patients, 2% were underweight, 37% were overweight, and 9% were obese at HIV diagnosis. Multivariate predictors of a higher body mass index (BMI) at diagnosis included more recent year of HIV diagnosis, older age, African American race, and earlier HIV stage (all p<0.05). The majority of patients (62%) gained weight during HIV infection. Multivariate factors associated with a greater increase in BMI during HIV infection included more recent year of diagnosis, lower BMI at diagnosis, higher CD4 count, lower HIV RNA level, lack of AIDS diagnosis, and longer HIV duration (all p<0.05). Nucleoside agents were associated with less weight gain; other drug classes had no significant impact on weight change in the HAART era. Conclusions HIV-infected patients are increasingly overweight/obese at diagnosis and during HIV infection. Weight gain appears to reflect improved health status and mirror trends in the general population. Weight management programs may be important components of HIV care.