A case-control study of virological and immunological effects of highly active antiretroviral therapy in HIV-infected patients with advanced age

Impact of age on CD4 recovery and viral suppression over time among adults living with HIV who initiated antiretroviral therapy in the African Cohort Study

INTRODUCTION

With increased use of antiretroviral therapy (ART), HIV mortality rates are declining and people living with HIV (PLWH) are surviving longer. We characterized CD4 recovery and viral suppression among adults aged < 50 and ≥ 50 years living with HIV who initiated ART in the African Cohort Study (AFRICOS).

METHODS

Beginning in January 2013, PLWH at twelve clinics in Kenya, Uganda, Tanzania and Nigeria underwent medical history review, CD4 and viral load testing as part of the ongoing African Cohort Study (AFRICOS). ART-naïve PLWH who initiated ART within 30 days of enrollment and had at least one year of follow-up were included in these analyses. To compare ART response in participants < 50 years and ≥ 50 years old, changes in CD4 count and viral load suppression after ART initiation were examined at different time points using linear and binomial regression with generalized estimating equations. Variables for time since ART initiation and the interaction between age group and time on ART were included in the model to evaluate longitudinal changes in CD4 recovery and viral suppression by age.

RESULTS

Between January 2013 and September 2019, 2918 PLHV were enrolled in the cohort. Of these, 443 were ART naïve and initiated on ART within 30 days of enrollment, with 90% (n = 399) aged < 50 years old at ART initiation. At ART initiation, participants aged 50 and older had a higher median CD4 count compared to participants younger than 50 years of age although it did not reach statistical significance (306 cells/mm3, IQR:130-547 vs. 277cells/mm3, IQR: 132-437). In adjusted models examining CD4 recovery and viral suppression there were no significant differences by age group over time. By the end of follow-up viral suppression was high among both groups of adults (96% of adults ≥ 50 years old and 92% of adults < 50 years old).

CONCLUSION

This study found no difference in long-term CD4 recovery or viral suppression by age at ART initiation. We found that particularly among younger adults participants had lower median CD4 counts at ART initiation, suggesting the importance of identifying and putting this population on treatment earlier in the disease course.

Dopaminergic impact of cART and anti-depressants on HIV neuropathogenesis in older adults

The success of combination antiretroviral therapy (cART) has transformed HIV infection into a chronic condition, resulting in an increase in the number of older, cART-treated adults living with HIV. This has increased the incidence of age-related, non-AIDS comorbidities in this population. One of the most common comorbidities is depression, which is also associated with cognitive impairment and a number of neuropathologies. In older people living with HIV, treating these overlapping disorders is complex, often creating pill burden or adverse drug-drug interactions that can exacerbate these neurologic disorders. Depression, NeuroHIV and many of the neuropsychiatric therapeutics used to treat them impact the dopaminergic system, suggesting that dopaminergic dysfunction may be a common factor in the development of these disorders. Further, changes in dopamine can influence the development of inflammation and the regulation of immune function, which are also implicated in the progression of NeuroHIV and depression. Little is known about the optimal clinical management of drug-drug interactions between cART drugs and antidepressants, particularly in regard to dopamine in older people living with HIV. This review will discuss those interactions, first examining the etiology of NeuroHIV and depression in older adults, then discussing the interrelated effects of dopamine and inflammation on these disorders, and finally reviewing the activity and interactions of cART drugs and antidepressants on each of these factors. Developing better strategies to manage these comorbidities is critical to the health of the aging, HIV-infected population, as the older population may be particularly vulnerable to drug-drug interactions affecting dopamine.

Antiretroviral Treatment Efficacy and Safety in Older HIV-Infected Adults

Highly active antiretroviral therapy (ART) and its widespread availability have revolutionized the landscape of HIV care and patient outcomes, transforming infection with HIV into a manageable chronic condition rather than a life-limiting disease. This transformation has created an older patient demographic. The effect that older age has on the outcomes of ART is not completely understood. Limited data are available in older individuals due to underrepresentation in clinical trials. To better understand this relationship, we conducted a literature search to assess the impact of older age on the outcomes of ART in the older HIV-infected population, including immunologic and virologic outcomes, mortality, disease progression, toxicity of ART, and pharmacokinetic considerations. In addition, package inserts of antiretroviral (ARV) medications were reviewed for efficacy, safety, and pharmacokinetic information pertaining to the older population. Most studies in older adults (50 yrs or older) demonstrated slower and blunted CD4 immune recovery but better virologic suppression in response to ART. Higher rates of mortality and faster disease progression have been observed in adults 50 years and older, particularly during the first year after ART initiation. HIV-infected patients aged 50 years and older appear to be at greater risk for certain ART-associated toxicities including nephrotoxicity, decline in bone mineral density and bone fracture, symptomatic peripheral neuropathy, and cardiovascular disease including myocardial infarction. The available literature suggests that clinicians should consider avoiding agents such as tenofovir disoproxil fumarate (TDF) in older patients with risk factors for renal impairment and/or osteoporosis. If TDF is used in patients aged 50 years or older, more frequent monitoring should be considered. Older age was a significant predictor for higher atazanavir exposure and higher lopinavir trough concentration at 24 weeks. The clinical implications of these findings are unknown. It is imperative that future development of novel ARV drug therapies includes a greater proportion of older subjects in clinical trials.

HIV Infection in the Elderly: Arising Challenges

Globally there is an increase in the number of people living with HIV at an advanced age (50 years and above). This is mainly due to prolonged survival following the use of highly active antiretroviral therapy. Living with HIV at an advanced age has been shown to be associated with a number of challenges, both clinical and immunological. This minireview aims at discussing the challenges encountered by elderly HIV-infected patients.

Immunological and Clinical Responses following the Use of Antiretroviral Therapy among Elderly HIV-Infected Individuals Attending Care and Treatment Clinic in Northwestern Tanzania: A Retrospective Cohort Study

Background. Limited information exists on adults ≥50 years receiving HIV care in sub-Saharan Africa despite their increasing number. We aimed at studying immunologic and clinical responses to ART in this population. Methods. Data of patients who initiated HAART between 30th of June 2004 and 1st of May 2008 at Sekou Toure Care and Treatment Clinic were retrospectively analyzed. Date of ART initiation was used as a baseline and 48 months as a follow-up date. Immune recovery was defined as a CD4 count of ≥350 cells/mm³ at 48 months and late presentation as presentation with WHO stage 3 or 4 at clinic enrollment. Proportions of patients reaching this endpoint were compared between the two groups. Results. A total of 728 patients were included in our study; of these 73 (10.0%) were aged 50 years and above. Late presentation was more common in elderly patients than young patients (65.7% versus 56.1%, P = 0.12). Proportion of patients with CD4 count ≥350 (immune recovery) was higher in younger patients than in elderly patients, although this was not statistically significant (54.5% versus 44.9%, P = 0.2). Median absolute increase in CD4 at 48 months was higher in younger patients than in elderly patients (+241.5 cells/mm³ versus +146 cells/mm³, P = 0.007). Conclusion. Elderly HIV patients have higher rates of late presentation, with lower immune recovery. Strategies to increase HIV testing in this group are required for early diagnosis and treatment to improve outcomes.

Perspectives on menopause and women with HIV

Since the implementation of effective combination antiretroviral therapy, HIV infection has been transformed from a life-threatening condition into a chronic disease. As people with HIV are living longer, aging and its associated manifestations have become key priorities as part of HIV care. For women with HIV, menopause is an important part of aging to consider. Women currently represent more than one half of HIV-positive individuals worldwide. Given the vast proportion of women living with HIV who are, and will be, transitioning through age-related life events, the interaction between HIV infection and menopause must be addressed by clinicians and researchers. Menopause is a major clinical event that is universally experienced by women, but affects each individual woman uniquely. This transitional time in women's lives has various clinical implications including physical and psychological symptoms, and accelerated development and progression of other age-related comorbidities, particularly cardiovascular disease, neurocognitive dysfunction, and bone mineral disease; all of which are potentially heightened by HIV or its treatment. Furthermore, within the context of HIV, there are the additional considerations of HIV acquisition and transmission risk, progression of infection, changes in antiretroviral pharmacokinetics, response, and toxicities. These menopausal manifestations and complications must be managed concurrently with HIV, while keeping in mind the potential influence of menopause on the prognosis of HIV infection itself. This results in additional complexity for clinicians caring for women living with HIV, and highlights the shifting paradigm in HIV care that must accompany this aging and evolving population.

Age, sex, and nutritional status modify the CD4+ T-cell recovery rate in HIV-tuberculosis co-infected patients on combination antiretroviral therapy

BACKGROUND

Baseline age and combination antiretroviral therapy (cART) were examined as determinants of CD4+ T-cell recovery during 6 months of tuberculosis (TB) therapy with/without cART. It was determined whether this association was modified by patient sex and nutritional status.

METHODS

This longitudinal analysis included 208 immune-competent, non-pregnant, ART-naive HIV-positive patients from Uganda with a first episode of pulmonary TB. CD4+ T-cell counts were measured using flow cytometry. Age was defined as ≤24, 25-29, 30-34, and 35-39 vs. ≥40 years. Nutritional status was defined as normal (>18.5kg/m(2)) vs. underweight (≤18.5kg/m(2)) using the body mass index (BMI). Multivariate random effects linear mixed models were fitted to estimate differences in CD4+ T-cell recovery in relation to specified determinants.

RESULTS

cART was associated with a monthly rise of 15.7 cells/μl (p<0.001). Overall, age was not associated with CD4+ T-cell recovery during TB therapy (p = 0.655). However, among patients on cART, the age-associated CD4+ T-cell recovery rate varied by sex and nutritional status, such that age <40 vs. ≥40 years predicted superior absolute CD4+ T-cell recovery among females (p=0.006) and among patients with a BMI ≥18.5kg/m(2) (p<0.001).

CONCLUSIONS

TB-infected HIV-positive patients aged ≥40 years have a slower rate of immune restoration given cART, particularly if BMI is >18.5kg/m(2) or they are female. These patients may benefit from increased monitoring and nutritional support during cART.

Mortality and immunological recovery among older adults on antiretroviral therapy at a large urban HIV clinic in Kampala, Uganda

BACKGROUND

We describe older (>50 years) HIV-infected adults after antiretroviral therapy (ART) initiation, evaluating immunological recovery by age category, considering individual trajectories based on the pretreatment CD4. We also describe mortality on ART and its risk factors by age category including the contribution of poor immunological recovery at a large urban clinic in Kampala, Uganda.

METHODS

We performed a cohort analysis of adult (>18 years) HIV-infected patients who initiated ART between January 1, 2004 and January 3, 2012. Immunological response was evaluated using mixed-effects linear regression. We described mortality using Kaplan-Meier survival methods analyzing for risk factors of mortality using multivariate Weibull survival regression stratified by age category.

RESULTS

Among 9806 individuals who initiated ART, mean age was 37 years (SD: 8.8), average follow-up 5.7 years (SD: 1.7), and median baseline CD4 was 115 cells per cubic millimeter (interquartile range: 42-184). Adults younger than 50 years had on average a higher CD4 increase of 45 cells per cubic millimeter (95% confidence interval: 17 to 72; P = 0.001) compared with counterparts aged 60 years and older. Mortality was highest among older adults compared with younger counterparts. Only CD4 count <100 cells per cubic millimeter after 1 year on ART and a CD4 count less than baseline were associated with a statistically significant higher rate of death among older adults.

CONCLUSIONS

Older adults had a slower immunological response, which was associated with mortality, but this mortality was not typically associated with opportunistic infections. Future steps would require more evaluation of possible causes of death among these older individuals if survival on ART is to be further improved.

The influence of race and comorbidity on the timely initiation of antiretroviral therapy among older persons living with HIV/AIDS

OBJECTIVES

We examined whether the timely initiation of antiretroviral therapy (ART) differed by race and comorbidity among older (≥ 50 years) people living with HIV/AIDS (PLWHA).

METHODS

We conducted frequency and descriptive statistics analysis to characterize our sample, which we drew from 2005-2007 Medicaid claims data from 14 states. We employed univariate and multivariable Cox regression analyses to evaluate the relationship between race, comorbidity, and timely ART initiation (≤ 90 days post-HIV/AIDS diagnosis).

RESULTS

Approximately half of the participants did not commence ART promptly. After we adjusted for covariates, we found that older PLWHA who reported a comorbidity were 40% (95% confidence interval = 0.26, 0.61) as likely to commence ART promptly. We found no racial differences in the timely initiation of ART among older PLWHA.

CONCLUSIONS

Comorbidities affect timely ART initiation in older PLWHA. Older PLWHA may benefit from integrating and coordinating HIV care with care for other comorbidities and the development of ART treatment guidelines specific to older PLWHA. Consistent Medicaid coverage helps ensure consistent access to HIV treatment and care and may eliminate racial disparities in timely ART initiation among older PLWHA.

Predictors of virologic response in persons who start antiretroviral therapy during recent HIV infection

OBJECTIVE

Despite evidence supporting antiretroviral therapy (ART) in recent HIV infection, little is known about factors that are associated with successful ART. We assessed demographic, virologic, and immunologic parameters to identify predictors of virologic response.

DESIGN

A 24-week observational study of ART on persons enrolled within 6 months of their estimated date of infection (EDI) evaluated baseline demographics and the collection of blood and gut specimens.

METHODS

Flow cytometry analyses of blood and gut lymphocytes allowed characterization of CD4 and CD8 T cells at study entry and end. Additional assessments included soluble CD14 (sCD14), lipopolysaccharide, CD4 T-cell counts, and HIV RNA levels.

RESULTS

Twenty-nine participants initiated ART, and 17 achieved undetectable HIV RNA by study end. A longer time from EDI to ART, older age, higher sCD14, lower proportions of central memory CD4 T cells, and higher proportions of activated CD8 T cells were associated with detectable viremia. Multivariable logistic regression found only older age and elevated sCD14 were independently associated with persistent viremia. Additionally, we observed that ART in recent infection did not result in discernible recovery of CD4 T cells in the gut.

CONCLUSION

In persons who started ART within 3-33 weeks from EDI, age and microbial translocation were associated with detectable HIV RNA. As observed in other cohorts, ART in recent infection did not improve proportions of total CD4 T cells in gut-associated lymphoid tissue (GALT). This lends support to further evaluate the use of more potent ART or regimens that protect the GALT in recent HIV infection.

Treatment of HIV infection in the older patient

The number of HIV patients over the age of 50 years is increasing due to increased longevity in patients treated with highly active antiretroviral therapy (HAART), in addition to new primary infections in older patients. Numerous studies have demonstrated worse HIV disease progression and mortality in older HIV patients compared with younger patients. While HAART therapy has been shown to be effective at reducing HIV-1 RNA, the immunologic benefits in older patients may be reduced compared to younger patients. Older patients are more likely to suffer comorbidities requiring concomitant medications than younger patients. Toxicities from HAART, particularly dyslipdemia, insulin resistance, and pancreatitis may also be worse in older HIV patients. Controlled trials on epidemiology, pathogenesis, and therapeutic and clinical outcomes in the elderly are needed. As the HIV-infected population ages, there is a growing need to better determine the efficacy of HAART in older patients, and to investigate factors associated with a more rapid course of HIV infection in patients over the age of 50 years.

HIV and Menopause: A Systematic Review of the Effects of HIV Infection on Age at Menopause and the Effects of Menopause on Response to Antiretroviral Therapy

More than half of persons living with HIV infection in the United States (U.S.) will be ≥50 years of age by 2020, including postmenopausal women. We conducted a systematic literature review about the effects of (1) HIV infection on age at menopause and (2) menopause on antiretroviral therapy (ART) response, in order to inform optimal treatment strategies for menopausal women living with HIV infection. We used the Ovid Medline database from 1980 to 2012. We included studies that focused on HIV-infected persons, included postmenopausal women, and reported outcome data for either age at menopause or response to ART across menopause. We identified six original research articles for age at menopause and five for response to ART across menopause. Our review revealed that current data were conflicting and inconclusive; more rigorous studies are needed. Disentangling the effects of menopause requires well-designed studies with adequate numbers of HIV-infected and HIV-uninfected women, especially disproportionately affected women of color. Future studies should follow women from premenopause through menopause, use both surveys and laboratory measurements for menopause diagnoses, and control for confounders related to normal aging processes, in order to inform optimal clinical management for menopausal women living with HIV.

Aging, antiretrovirals, and adherence: a meta analysis of adherence among older HIV-infected individuals

INTRODUCTION

Older adults are generally considered to be at greater risk for medication non-adherence due to factors such as medication complexity, side effects, cost, and cognitive decline. However, this generalization may not apply to older adults with human immunodeficiency virus (HIV). Regardless of age, suboptimal adherence to antiretroviral therapy (ART) can lead to increased viral load, immunosuppression, drug-resistant viral strains, co-morbidities, and opportunistic infections. Understanding trends of adherence to ART among older adults is critical, especially as the population of people living with HIV grows older.

OBJECTIVES

The purpose of this systematic review and meta-analysis is to determine if older individuals with HIV are less likely to be non-adherent to antiretroviral therapy than younger individuals with HIV.

DESIGN

A systematic search in PubMed, Embase, and PsycINFO was conducted to identify peer-reviewed articles evaluating adherence to ART in older adults. Two independent reviewers screened abstracts, applied inclusion criteria, and appraised study quality. The bibliographies of qualifying studies were searched. Data were abstracted from studies by two independent authors. Meta-analyses were conducted, and adherence levels were reported as the relative risk of non-adherence in older individuals compared to younger individuals.

RESULTS

The systematic search yielded 1,848 abstracts. Twelve studies met full inclusion criteria. The overall meta-analysis found that older age reduced risk for nonadherence by 27 % (relative risk (RR) 0.72, 95 % confidence interval (CI) 0.64–0.82). Studies assessing both short-term and long-term adherence demonstrated a significant reduction in non-adherence among older patients (RR 0.75, 95 % CI 0.64–0.87 and RR 0.65, 95 % CI 0.50–0.85, respectively).

CONCLUSIONS

Older adults with HIV have a reduced risk for non-adherence to ART than their younger counterparts. Future studies should seek to elucidate contributing factors of adherence among older individuals with HIV.

Older HIV-infected patients--an underestimated population in northern Greece: epidemiology, risk of disease progression and death

OBJECTIVES

HIV prevalence among older people is on the increase. The aim of this study was to evaluate the epidemiological and clinical features at diagnosis and survival of older patients.

METHODS

This was a retrospective analysis of the data of 558 newly diagnosed antiretroviral-naïve patients between January 1998 and December 2008. Patients were divided into two groups according to their age at diagnosis: ≥50 years (n=103) and 18-49 years (n=455).

RESULTS

The most common risk factor for older patients was heterosexual contact (p<0.013). Older patients were more likely to suffer from hypertension (33.0% vs. 5.1%, p<0.0005), cardiovascular disease (20.4% vs. 2.9%, p<0.0005), neurological disorders (11.7% vs. 5.5%, p=0.02), renal dysfunction (12.6% vs. 5.3%, p=0.01), and infections (66.0% vs. 49.7%, p=0.003) than their younger counterparts, and to have more hospital admissions during follow-up (47.5% vs. 19.6%, p<0.0005). Older patients had a shorter survival time (p<0.0005). A statistically significant increase in CD4+ cell number through time was observed in both groups (p<0.0005). Younger patients reached higher magnitudes of absolute numbers of CD4+ cells during follow-up (p<0.0005) after the initiation of antiretroviral therapy. The total number of patients with clinical AIDS from baseline throughout the study period was also higher in the older age group (35.9% vs. 25.0%).

CONCLUSIONS

HIV-infected people aged ≥50 years differ in epidemiological and clinical features to younger HIV-infected people. The issue of increasing prevalence of HIV infection is a matter of concern due to existing comorbidities, which probably lead to higher mortality rates and faster progression to clinical AIDS.

Impact of age on markers of HIV-1 disease

Aging is a complicated process characterized by a progressive loss of homeostasis, which results in an increased vulnerability to multiple diseases. HIV-1-infected patients demonstrate a premature aging phenotype and develop certain age-related diseases earlier in their lifespan than what is seen in the general population. Age-related comorbidities may include the development of bone disease, metabolic disorders, neurologic impairment and immunosenescence. Age also appears to have an effect on traditional markers of HIV-1 disease progression, including CD4+ T-cell count and viral load. These effects are not only a consequence of HIV-1 infection, but in many cases, are also linked to antiretroviral therapy. This review summarizes the complex interplay between HIV-1 infection and aging, and the impact that aging has on markers of HIV-1 disease.

Prevention of HIV Among Older Adults

Objective:

This study reviews the existing literature on the prevention of HIV among older adults, including universal and indicated prevention programs and prevention strategies.

Method:

A literature search was conducted between September and October of 2011 to identify studies for this review. Several different electronic databases and a combination of keywords were used to conduct the search. In addition, the reference section of each article was reviewed for additional articles.

Results:

A total of 18 articles were identified and reviewed. Three of the articles examined universal prevention, five of the articles examined indicated prevention, and the remainder of the articles provided strategies and recommendations for the prevention of HIV among older adults.

Discussion:

The existing studies document evidence for preventing future cases of HIV/AIDS among older adults. Additional studies and universal and selected interventions are needed in an effort to reduce the number of older adults being diagnosed with HIV.

Definition of advanced age in HIV infection: looking for an age cut-off

The age of 50 has been considered as a cut-off to discriminate older subjects within HIV-infected people according to the Centers for Disease Control and Prevention (CDC). However, the International AIDS Society (IAS) mentions 60 years of age and the Department of Health and Human Services (DHHS) makes no consideration. We aimed to establish an age cut-off that could differentiate response to highly active antiretroviral therapy (HAART) and, therefore, help to define advanced age in HIV-infected patients. CoRIS is an open, prospective, multicenter cohort of HIV adults naive to HAART at entry (January 2004 to October 2009). Survival, immunological response (IR) (CD4 increase of more than 100 cell/ml), and virological response (VR) (HIV RNA less than 50 copies/ml) were compared among 5-year age intervals at start of HAART using Cox proportional hazards models, stratified by hospital and adjusted for potential confounders. Among 5514 patients, 2726 began HAART. During follow-up, 2164 (79.4%) patients experienced an IR, 1686 (61.8%) a VR, and 54 (1.9%) died. Compared with patients aged <25 years at start of HAART, those aged 50-54, 55-59, 60-64, 65-59, and 70 or older were 32% (aHR: 0.68, 95% CI: 0.52-0.87), 29% (aHR: 0.71, 95% CI: 0.53-0.96), 34% (aHR: 0.66, 95% CI: 0.46-0.95), 39% (aHR: 0.61, 95% CI: 0.37-1.00), and 43% (aHR: 0.57, 95% CI: 0.31-1.04) less likely to experience an IR. The VR was similar across all age groups. Finally, patients aged 50-59 showed a 3-fold increase (aHR: 3.58; 95% CI: 1.07-11.99) in their risk of death compared to those aged <30 years. In HIV infection, patients aged ≥50 years have a poorer immunological response to HAART and a poorer survival. This age could be used to define medically advanced age in HIV-infected people.

Lung Disease in Older Patients with HIV

Successful treatment of HIV with combination antiretroviral therapy (ART) has resulted in an aging HIV-infected population. As HIV-infected patients are living longer, noninfectious pulmonary diseases are becoming increasingly prevalent with a proportional decline in the incidence of opportunistic infections (OIs). Pulmonary OIs such as Pneumocystis jirovecii pneumonia (PCP) and tuberculosis are still responsible for a significant proportion of pulmonary diseases in HIV-infected patients. However, bacterial pneumonia (BP) and noninfectious pulmonary diseases such as chronic obstructive pulmonary disease (COPD), lung cancer, pulmonary arterial hypertension (PAH), and interstitial lung disease (ILD) account for a growing number of pulmonary diseases in aging HIV-infected patients. The purpose of this chapter is to discuss the spectrum and management of pulmonary diseases in aging HIV-infected patients, although limited data exists to guide management of many noninfectious pulmonary diseases in HIV-infected patients. In the absence of such data, treatment of lung diseases in HIV-infected patients should generally follow guidelines for management established in HIV-uninfected patients.

Anti-retroviral treatment outcomes among older adults in Zomba district, Malawi

BACKGROUND

There are approximately 3 million people aged 50 and older in sub-Saharan Africa who are HIV-positive. Despite this, little is known about the characteristics of older adults who are on treatment and their treatment outcomes.

METHODS

A retrospective cohort analysis was performed using routinely collected data with Malawi Ministry of Health monitoring tools from facilities providing antiretroviral therapy services in Zomba district. Patients aged 25 years and older initiated on treatment from July 2005 to June 2010 were included. Differences in survival, by age group, were determined using Kaplan-Meier survival plots and Cox proportional hazards regression models.

RESULTS

There were 10,888 patients aged 25 and older. Patients aged 50 and older (N = 1419) were more likely to be male (P<0.0001) and located in rural areas (P = 0.003) than those aged 25-49. Crude survival estimates among those aged 50-59 were not statistically different from those aged 25-49 (P = 0.925). However, survival among those aged 60 and older (N = 345) was worse (P = 0.019) than among those 25-59. In the proportional hazards model, after controlling for sex and stage at initiation, survival in those aged 50-59 did not differ significantly from those aged 25-49 (hazard ratio 1.00 (95% CI: 0.79 to 1.27; P = 0.998) but the hazard ratio was 1.46 (95% CI: 1.03 to 2.06; P = 0.032) for those aged 60 and older compared to those aged 25-49.

CONCLUSIONS

Treatment outcomes of those aged 50-59 are similar to those aged 25-49. A better understanding of how older adults present for and respond to treatment is critical to improving HIV services.

Aging and HIV infection

INTRODUCTION

Population aging has become a global phenomenon, and HIV infection among older individuals is also increasing. Because age can affect the progression of HIV infection, we aimed to evaluate the present knowledge on HIV infection in older patients.

METHODS

Literature review of the last 20 years.

RESULTS

Older HIV-infected patients have lower CD4(+) T cell counts, higher viral load and are more frequently symptomatic at diagnosis. The infection progresses more rapidly, with higher morbidity and lethality rates. However, older patients are more compliant to antiretroviral treatment; they experience a better virologic response, and treatment represents a positive clinical impact. Aging affects the complex interaction between HIV infection and the immune system. Both conditions contribute to the dysfunction of immune cells, including a decrease in the phagocytes' microbicidal capability, natural killer cells' cytolytic function, expression of toll-like receptors and production of interleukin-12. Chronic immune activation responsible for the depletion of CD4(+) and CD8(+) T cells in HIV infection appears to worsen with senescence. Older patients also exhibit a less robust humoral response, with the production of less avid and specific antibodies.

CONCLUSION

Both HIV and aging contribute to immune dysfunction, morbidity and mortality. However, highly active antiretroviral therapy (HAART) is beneficial for older patients, and treatment of older patients should not be discouraged.

Virologic and immunologic response to HAART, by age and regimen class

OBJECTIVE

To determine the impact of age and initial HAART regimen class on virologic and immunologic response within 24 months after initiation.

DESIGN

Pooled analysis of data from 19 prospective cohort studies in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD).

METHODS

Twelve thousand, one hundred and ninety-six antiretroviral-naive adults who initiated HAART between 1998 and 2008 using a boosted protease inhibitor-based regimen or a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen were included in our study. Discrete time-to-event models estimated adjusted hazard odds ratios (aHOR) and 95% confidence intervals (CIs) for suppressed viral load (≤500 copies/ml) and, separately, at least 100 cells/μl increase in CD4 cell count. Truncated, stabilized inverse probability weights accounted for selection biases from discontinuation of initial regimen class.

RESULTS

Among 12 196 eligible participants (mean age = 42 years), 50% changed regimen classes after initiation (57 and 48% of whom initiated protease inhibitor and NNRTI-based regimens, respectively). Mean CD4 cell count at initiation was similar by age. Virologic response to treatment was less likely in those initiating using a boosted protease inhibitor [aHOR = 0.77 (0.73, 0.82)], regardless of age. Immunologic response decreased with increasing age [18-<30: ref; 30-<40: aHOR = 0.92 (0.85, 1.00); 40-<50: aHOR = 0.85 (0.78, 0.92); 50-<60: aHOR = 0.82 (0.74, 0.90); ≥60: aHOR = 0.74 (0.65, 0.85)], regardless of initial regimen.

CONCLUSION

We found no evidence of an interaction between age and initial antiretroviral regimen on virologic or immunologic response to HAART; however, decreased immunologic response with increasing age may have implications for age-specific when-to-start guidelines.

HIV infection in the elderly

The prevalence of HIV in patients over the age of 50 years is increasing. Although older patients may achieve equal or better virologic suppression at equal rates compared with younger patients, the immunologic benefit of highly active antiretroviral therapy (HAART) in older patients may be reduced compared with younger patients. Comorbidities are more common in older patients than younger patients and can impact management of HIV in these patients. Providers must be cognizant of drug-drug interactions and side effects of HAART regimens when selecting an antiretroviral regimen in older HIV patients. As the HIV-infected population ages, there is a growing need to better determine the ideal HAART regimen and timing of HAART initiation in older patients.

Human immunodeficiency virus (HIV) in older people

The number of older people living with human immunodeficiency virus (HIV) in the UK is rising. Older people are at risk of acquiring HIV infection for a multitude of reasons. This, combined with effective HIV treatment which has significantly prolonged life expectancy, means that health care professionals working in the UK can expect to see increasing numbers of older people with HIV infection. In this review article, we summarise the epidemiology of HIV amongst older people, including data from our local cohort in the city of Sheffield, UK. We discuss specific and practical issues in older patients including why older people are at risk, how to make a diagnosis and the importance of doing so early, guidelines for HIV testing and an update on anti-retroviral therapy including drug interactions and side effects.

Reconciling conflicting clinical studies of antioxidant supplementation as HIV therapy: a mathematical approach

BACKGROUND

Small, highly reactive molecules called reactive oxygen species (ROS) play a crucial role in cell signalling and infection control. However, high levels of ROS can cause significant damage to cell structure and function. Studies have shown that infection with the human immunodeficiency virus (HIV) results in increased ROS concentrations, which can in turn lead to faster progression of HIV infection, and cause CD4+ T-cell apoptosis. To counteract these effects, clinical studies have explored the possibility of raising antioxidant levels, with mixed results.

METHODS

In this paper, a mathematical model is used to explore this potential therapy, both analytically and numerically. For the numerical work, we use clinical data from both HIV-negative and HIV-positive injection drug users (IDUs) to estimate model parameters; these groups have lower baseline concentrations of antioxidants than non-IDU controls.

RESULTS

Our model suggests that increases in CD4+ T cell concentrations can result from moderate levels of daily antioxidant supplementation, while excessive supplementation has the potential to cause periods of immunosuppression.

CONCLUSION

We discuss implications for HIV therapy in IDUs and other populations which may have low baseline concentrations of antioxidants.

Pharmacologic consideration for the use of antiretroviral agents in the elderly

The prevalence of human immunodeficiency virus (HIV) infection among people older than 50 years is increasing. HIV-infected patients require lifelong treatment with antiretroviral agents to suppress viral replication and maintain immune function. The use of antiretroviral agents in the elderly can be complicated by multiple chronic comorbidities and coadministered non-HIV medications. The pharmacokinetics of antiretroviral agents may be altered due to age-related decrements in hepatic and renal function. The elderly may be more sensitive than younger people to antiretroviral drug toxicity. A better understanding of the pharmacokinetics of antiretroviral agents in the elderly is of importance for the successful management of complex antiretroviral regimens in this population.

[HIV Infection in the elderly]

HIV infection is increasingly common in the elderly. This population is a heterogeneous group with particular epidemiologic characteristics and often with associated comorbidities, which frequently delay diagnosis and lead to poor immunological status at the start of highly active antiretroviral therapy (HAART). There are no differences between elderly and young HIV infected patients in the recommended antiretroviral regimens. Tolerance to treatment is good and the virological and immunological response to HAART is positive, although immunological response is slower and lower than in younger patients. Treatment adherence, which has been shown to be the only protective independent factor related to virological failure, is better in the elderly.

Epidemiology of HIV and response to antiretroviral therapy in the middle aged and elderly

HIV is increasing in prevalence in the middle aged and older population owing to both increased longevity, and new infections in these populations. Highly active antiretrorival therapy (HAART) therapy may be less effective at restoring immune function in older patients compared with younger patients. There are significant toxicities associated with HAART therapy that, combined with decreased renal and liver function in older patients, may be more problematic in older HIV-infected patients. Comorbid disease is becoming an increasing problem with coadministration of multiple drugs and significant drug-drug interactions. Psychosocial issues in the older patient are often different than those in younger HIV-infected patients and providers should try to address these issues early. Finally, future research should work to identify the ideal timing and type of HAART regimens for older HIV-infected individuals.

Effect of age and HAART regimen on clinical response in an urban cohort of HIV-infected individuals

OBJECTIVES

The prevalence of HIV infection in older patients (> or =50 years) is increasing due to HAART, and new HIV infections in older patients. Some earlier studies suggest that older patients respond differently to HAART than younger patients. The objective of this study is to compare the effectiveness of HAART in older and younger HIV patients.

DESIGN

Retrospective analysis of an observational clinical cohort.

METHODS

Virologic and immunologic response, progression to AIDS and mortality were compared between 670 younger patients (<40 years) and 149 older patients (> or =50 years) by t-test, Kaplan-Meier methods, and multivariate Cox proportional hazards analysis.

RESULTS

Compared with younger patients, older patients were more likely to be on nonnucleoside reverse transcriptase inhibitors based versus protease inhibitor based regimens (42 vs. 29%, P < 0.01). Time to HIV-1 RNA virologic suppression was less in older than in younger patients (3.2 vs. 4.4 months, P < 0.01). Immunologic response did not differ by age. Older patients had fewer AIDS-defining opportunistic infections (22 vs. 31%, P < 0.01), but higher mortality (36 vs. 27%, P = 0.04) and shorter survival (25th percentile survivor function 36.2 vs. 58.5 months, P = 0.02) than younger patients. Older age was associated with more rapid virologic suppression [adjusted hazard ratio = 1.33 (1.09-1.63)] and earlier mortality [adjusted hazard ratio = 1.56 (1.14-2.14)]. Nonnucleoside reverse transcriptase inhibitors based regimens were associated with more rapid virologic suppression [adjusted hazard ratio = 1.22 (1.03-1.44)].

CONCLUSION

Time to virologic suppression after HAART initiation was shorter in older patients, although CD4 response did not differ by age. Older patients had fewer opportunistic infections, but survival was shorter. Our data suggest a need to better understand causes of mortality in older patients.

Increasing age at HIV seroconversion from 18 to 40 years is associated with favorable virologic and immunologic responses to HAART

BACKGROUND

Studies evaluating the effect of age on response to highly active antiretroviral therapy (HAART) have been limited by their inability to control for duration of human immunodeficiency virus (HIV) infection. We examined the effect of age at HIV seroconversion on response to HAART.

METHODS

A retrospective analysis of a longitudinal US military cohort of HIV-infected subjects. Time to and maintenance of viral suppression, rate of CD4 cell increase, and rate of progression to acquired immunodeficiency syndrome or death were compared across age groups using time-to-event methods.

RESULTS

Five hundred sixty-three HIV-infected adults who seroconverted after January 1, 1996, and started HAART were included. Increasing age at seroconversion was significantly associated with faster time to viral suppression (P = 0.002). Increasing age also correlated with duration of suppression, with a 35% reduction in risk of viral rebound for every 5-year increase in age above 18 years (hazard ratio: 0.65, 95% confidence interval 0.55 to 0.75). The rate of CD4 cell increase from 6 to 84 months post-HAART was significantly greater in those who seroconverted at older ages (P = 0.0002). Rates of progression to acquired immunodeficiency syndrome or death did not differ between groups.

CONCLUSIONS

Increasing age at seroconversion was associated with shorter time to and longer maintenance of viral suppression and a faster increase in CD4 cell count.

Mortality of the elderly is still exceedingly high at diagnosis of AIDS despite favourable outcomes after highly active antiretroviral therapy in Recife, Brazil

This study aimed to compare the outcome of an elderly group of AIDS patients with that of a younger group and their features at the time of the diagnosis of AIDS. We evaluated 58 patients aged >60 years and 114 aged 20-39 years, followed for 35.3 months. There was an obvious delay in diagnosing the elderly as they had more AIDS-defining diseases at diagnosis and their most frequent opportunistic infection was pulmonary tuberculosis. Mortality at the time of the diagnosis of AIDS was four times higher in the elderly (24.1% versus 6.1%, P < 0.001). However, when comparing only those submitted to highly active antiretroviral therapy, there was a similar frequency of favourable outcomes; 76.9% in the elderly against 83.1% in the young (P = 0.455). Mean CD4 lymphocyte was 438 cells/mm(3) at the end of follow up in the young when compared with 442 cells/mm(3) in the elderly (P = 0.945). The types of antiretroviral schema and the number of antivirals per patient were similar in both groups.

The eldest of older adults living with HIV: response and adherence to highly active antiretroviral therapy

OBJECTIVE

The study objective was to analyze the characteristics and the response to therapy in the eldest of the older adults living with human immunodeficiency virus.

METHODS

The study included a cohort of patients with human immunodeficiency virus aged 55 years or more on initiating highly active antiretroviral therapy (HAART). Immunologic and virologic response, morbidity, and mortality were assessed. Patients were categorized as aged less than 65 years and 65 years or more.

RESULTS

A total of 112 patients were included (82 patients aged<65 years and 30 patients aged> or =65 years). There were no differences between the age groups in baseline characteristics, survival, and virologic response. There was a trend toward better adherence and a lower CD4+ cell increase after HAART in the older group.

CONCLUSION

A relationship was found between lower CD4+ cell increase after HAART and advanced age. We found the best adherence to treatment in the eldest of the older adults, and this has been shown to be the only protective independent factor related to virologic failure.

Aging and infectious diseases: workshop on HIV infection and aging: what is known and future research directions

Highly active antiretroviral treatment has resulted in dramatically increased life expectancy among patients with HIV infection who are now aging while receiving treatment and are at risk of developing chronic diseases associated with advanced age. Similarities between aging and the courses of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome suggest that HIV infection compresses the aging process, perhaps accelerating comorbidities and frailty. In a workshop organized by the Association of Specialty Professors, the Infectious Diseases Society of America, the HIV Medical Association, the National Institute on Aging, and the National Institute on Allergy and Infectious Diseases, researchers in infectious diseases, geriatrics, immunology, and gerontology met to review what is known about HIV infection and aging, to identify research gaps, and to suggest high priority topics for future research. Answers to the questions posed are likely to help prioritize and balance strategies to slow the progression of HIV infection, to address comorbidities and drug toxicity, and to enhance understanding about both HIV infection and aging.

HIV infection in the elderly

In the US, an estimated 1 million people are infected with HIV, although one-third of this population are unaware of their diagnosis. While HIV infection is commonly thought to affect younger adults, there are an increasing number of patients over 50 years of age living with the condition. UNAIDS and WHO estimate that of the 40 million people living with HIV/AIDS in the world, approximately 2.8 million are 50 years and older. With the introduction of highly active antiretroviral therapy (HAART) in the mid-1990s, survival following HIV diagnosis has risen dramatically and HIV infection has evolved from an acute disease process to being managed as a chronic medical condition. As treated HIV-infected patients live longer and the number of new HIV diagnoses in older patients rise, clinicians need to be aware of these trends and become familiar with the management of HIV infection in the older patient. This article is intended for the general clinician, including geriatricians, and will review epidemiologic data and HIV treatment as well as provide a discussion on medical management issues affecting the older HIV-infected patient.

Human T cell reconstitution in DiGeorge syndrome and HIV-1 infection

The thymus is essential for proper development and maintenance of a broad T cell repertoire capable of recognizing a wide-range of foreign antigens. Recent advances in multicolor flow cytometry, non-invasive imaging techniques, and molecular assessments of thymic function have enabled a more comprehensive characterization of human thymic output in clinical settings than in the past. These techniques have been particularly valuable in monitoring human T cells after therapeutic thymic grafting for complete DiGeorge syndrome and during HIV-1 infection and AIDS. By defining the degree and mechanisms of T cell reconstitution in these settings, clinical investigators and primary caregivers have been able to better diagnose, treat and care for individuals with congenital or acquired immune deficiencies associated with loss of thymic function.

Immunologic and clinical responses to highly active antiretroviral therapy in patients with HIV infection aged >50 years

We analyzed the effect of age on highly active antiretroviral therapy efficacy and tolerance in 639 patients with human immunodeficiency virus (HIV) infection (99 of whom were aged >50 years, and 540 of whom were aged <50 years). Late testing, which was more frequent in the older age group, was the only independent factor associated with immunologic and clinical evolution of infection. Age >50 years was associated with earlier treatment discontinuation.

HIV and Aging

Between 2001 and 2004, the percentage of all HIV cases in patients aged >or=50 years increased from 17% to 23%. This concerning increase is expected to continue over the next decade. The increasing prevalence of HIV in these patients is a result of increased longevity in patients treated with highly active antiretroviral therapy (HAART) as well as new primary infections in older patients. While older patients may achieve virological suppression at the same rate as younger patients, the immunological benefit of HAART in older patients may be reduced compared with younger patients. In addition, the toxicities associated with HAART may be worse in older HIV patients, particularly those with underlying renal or hepatic insufficiency. All previous studies evaluating the virological and immunological benefits of HAART in older patients have had relatively small sample sizes and none has compared efficacy or rates of toxicity by HAART treatment class. Co-morbidities are more common in older than in younger patients and can impact on the management of HIV in these patients. Providers must be cognisant of drug-drug interactions and potential adverse effects of HAART regimens when selecting an ideal antiretroviral regimen for older HIV patients. Given the increased longevity and rates of malignancies in HIV-infected patients, providers should also be particularly vigilant in maintaining routine health screening in older HIV patients. Controlled trials on HIV epidemiology, pathogenesis, and therapeutic and clinical outcomes are also needed in older patients. As the HIV-infected population ages, there is a growing need to better determine the effectiveness of HAART in older patients, and to investigate factors associated with a more rapid course of HIV infection in patients aged >50 years.

HIV infection in older patients in the HAART era

An increasing number of patients over 50 years of age are now living with HIV, owing to highly active antiretroviral therapy (HAART) that prolongs survival on the one hand and to late diagnosis of patients living with occult HIV infection on the other hand. Most studies have shown that compared with younger patients, patients over 50 generally have a slower immunological response to HAART and experience more rapid clinical progression, despite a better virological response. Low thymic output probably plays a role in the poorer CD4 cell response in patients initiating HAART over 50 years. Management of HIV infection in older patients is particularly complex, mainly because they are more likely to have co-morbidities necessitating specific medications that may interact with antiretroviral drugs. More controlled studies of HAART efficacy and tolerability in such patients are needed to establish specific management guidelines. Information campaigns targeting older patients and their doctors are also needed to ensure timely diagnosis of HIV infection and antiretroviral treatment initiation.

Perspective on HIV infection and aging: emerging research on the horizon

A greater prevalence of human immunodeficiency virus (HIV)-infected individuals aged >50 years is projected. This epidemiologic trend will continue to increase as a result of not only greater survival rates among HIV-infected patients who receive treatment, but also of delayed recognition of older individuals with occult HIV disease. Historically, it was thought that, despite viral responses to highly active antiretroviral therapy (HAART) among older individuals that approximate those of younger individuals, older persons infected with HIV could not mount as vigorous an immune response as do younger HIV-infected individuals. However, recent evidence suggests that older HIV-infected individuals may do just as well, because they may be more compliant with their antiretroviral regimens. Limited data are available on the safety and tolerability of HAART in this population. Emerging evidence suggests that metabolic, neuropsychiatric, and cardiovascular morbidities could be exacerbated by use of antiretrovirals or by HIV infection itself. Additional research is needed to optimize the care of older HIV-infected patients.

Older age does not influence CD4 cell recovery in HIV-1 infected patients receiving highly active antiretroviral therapy

BACKGROUND

Diagnosis of HIV infection is recently occurring with increasing frequency in middle-aged and in older individuals. As HAART became available, a minimal beneficial effect on immunological outcome in older in respect of younger subjects has been reported. In fact, both the intensity and the rapidity of the immunological response appeared to be reduced in elderly subjects. On the contrary, only few reports have indicated a similar immunological outcome both in older and younger HIV-positive subjects. Interestingly, older age did not seem to significantly affect the long-term virological outcome of HAART treated subjects.

METHODS

To characterise epidemiological and clinical features of older HIV+ subjects, a prospective case-control study was performed: 120 subjects >/= 50 and 476 between 20 and 35 years were initially compared. Subsequently, to better define the impact of HAART on their viro-immunological response, 81 older were compared with 162 younger subjects.

RESULTS

At baseline cases presented significantly lower TCD4+ cell number and were more frequently affected by comorbid conditions. Under HAART a statistically significant increase in TCD4+ cell number was observed in cases and controls. At multivariate analysis, there was no statistically significant difference between cases and controls regarding viro-immunological response.

CONCLUSIONS

Although older subjects present a more severe HIV infection, they can achieve, under HAART, the same viro-immunological success as the younger individuals.

Immunologic and clinical responses to highly active antiretroviral therapy over 50 years of age. Results from the French Hospital Database on HIV

OBJECTIVE

To study immunologic and clinical responses to HAART in patients over 50 years old.

DESIGN AND METHODS

A prospective cohort study which included 68 hospitals in France. A total of 3015 antiretroviral-naive patients, 401 of whom were aged 50 years or over, were enrolled following initiation of HAART. The influence of age on the mean CD4 cell count increase on HAART was studied by using a two-slope mixed model. Progression, defined by the occurrence of a new AIDS-defining event (ADE) or death, was studied by Cox multivariate analyses.

RESULTS

Among patients with baseline HIV RNA above 5 log copies/ml, CD4 mean increase during the first 6 months on HAART was +42.9 x 10(6) cells/l per month in patients under 50 years and +36.9 x 10(6) cells/l per month in patients over 50 years (P < 0.0001); subsequently, the respective monthly changes were +17.9 and +15.6 x 10(6) cells/l per month (P < 0.0001). Similar trends were observed in patients with baseline HIV RNA below 5 log copies/ml, and also after stratification for the baseline CD4 cell count. After a median follow-up of 31.5 months, 263 patients had a new ADE and 44 patients died. After adjustment for baseline characteristics, older patients had a significantly higher risk of clinical progression (hazard ratio (HR) = 1.52 [95% confidence interval (CI), 1.15-2.00]) and were more likely to achieve a viral load below 500 copies/ml [HR = 1.23, (95% CI, 1.11-1.38)].

CONCLUSION

Patients over 50 years of age have an immunologic response to HAART. However, their CD4 cell reconstitution is significantly slower than in younger patients, despite a better virologic response. This impaired immunologic response may explain their higher risk of clinical progression.

HIV infection and advanced age emerging epidemiological, clinical, and management issues

While the mean age of HIV/AIDS patients at first diagnosis is progressively rising, no updated epidemiological estimates, controlled clinical data, and randomized therapeutic trials, are available regarding clinical and laboratory response to antiretroviral therapy, safety of anti-HIV compounds and their associations, potential drug-drug interactions, short- and long-term toxicity, consequences on underlying disorders, or interactions with concomitant pharmacological regimens, in the elderly. The life expectancy of HIV-infected persons treated with highly active antiretroviral therapy (HAART) now approximates that of general population matched for age, while also AIDS definition itself has lost most of its epidemiological and clinical significance, thanks to the immunoreconstitution resulting from the large-scale use of potent HAART regimens. The increased survival of HIV-infected patients, the late recognition of other subjects with missed or delayed diagnosis are responsible for a further expected rise of mean age of HIV-infected individuals, so that the patient population aged 60-70 years or more is expected to increase in coming years. Unfortunately, the majority of therapeutic trials involving antiretroviral therapy, as well as antimicrobial chemoprophylaxis for AIDS-related opportunistic complications, have advanced age and/or concurrent end-organ disorders among main exclusion criteria, or the design of these studies does not allow to extrapolate data regarding older patients, compared with younger ones. The very limited data presently available seem to demonstrate that HAART has a virological efficacy in the elderly comparable with that of younger adults, but immunological recovery is often slower and blunted, although several studies clearly demonstrated that thymic function is preserved until late adult age. When facing an HIV-infected patient with advanced age, health care givers have to pay careful attention to eventual end-organ disorders, all possible pharmacological interactions, overlapping toxicity due to concurrent drug administration. All these issues may significantly interfere with HAART activity, patient's adherence to prescribed medications, and frequency and severity of untoward effects. The guidelines of antiretroviral therapy and those of treatment and prophylaxis of AIDS-related diseases deserve appropriate updates, paralleling the increasing mean age of HIV-infected population. Moreover, epidemiological figures need an increased focus on older age, while clinical trials specifically targeting on the elderly population are mandatory to have reliable data on all aspects of HAART administration in advanced age.