Evidence of ongoing immune reconstitution in subjects with sustained viral suppression following 6 years of lopinavir-ritonavir treatment

Advances in Mechanism of HIV-1 Immune Reconstitution Failure: Understanding Lymphocyte Subpopulations and Interventions for Immunological Nonresponders

In individuals diagnosed with AIDS, the primary method of sustained suppression of HIV-1 replication is antiretroviral therapy, which systematically increases CD4+ T cell levels and restores immune function. However, there is still a subset of 10-40% of people living with HIV who not only fail to reach normal CD4+ T cell counts but also experience severe immune dysfunction. These individuals are referred to as immunological nonresponders (INRs). INRs have a higher susceptibility to opportunistic infections and non-AIDS-related illnesses, resulting in increased morbidity and mortality rates. Therefore, it is crucial to gain new insights into the primary mechanisms of immune reconstitution failure to enable early and effective treatment for individuals at risk. This review provides an overview of the dynamics of key lymphocyte subpopulations, the main molecular mechanisms of INRs, clinical diagnosis, and intervention strategies during immune reconstitution failure, primarily from a multiomics perspective.

Characterizing HIV status documentation among cancer patients at regional cancer centers in Malawi, Zimbabwe, and South Africa

INTRODUCTION

In East and Southern Africa, people with HIV (PWH) experience worse cancer-related outcomes and are at higher risk of developing certain cancers. Siloed care delivery pathways pose a substantial barrier to co-management of HIV and cancer care delivery.

METHODS

We conducted cross-sectional studies of adult cancer patients at public radiotherapy and oncology units in Malawi (Kamuzu Central Hospital), Zimbabwe (Parirenyatwa Group of Hospitals), and South Africa (Charlotte Maxeke Hospital) between 2018 and 2019. We abstracted cancer- and HIV-related data from new cancer patient records and used Poisson regression with robust variance to identify patient characteristics associated with HIV documentation.

RESULTS

We included 1,648 records from Malawi (median age 46 years), 1,044 records from South Africa (median age 55 years), and 1,135 records from Zimbabwe (median age 52 years). Records from all three sites were predominately from female patients; the most common cancers were cervical (Malawi [29%] and Zimbabwe [43%]) and breast (South Africa [87%]). HIV status was documented in 22% of cancer records from Malawi, 92% from South Africa, and 86% from Zimbabwe. Patients with infection-related cancers were more likely to have HIV status documented in Malawi (adjusted prevalence ratio [aPR]: 1.92, 95% confidence interval [CI]: 1.56-2.38) and Zimbabwe (aPR: 1.16, 95%CI: 1.10-1.22). Patients aged ≥ 60 years were less likely to have HIV status documented (Malawi: aPR: 0.66, 95% CI: 0.50-0.87; Zimbabwe: aPR: 0.76, 95%CI: 0.72-0.81) than patients under age 40 years. Patient age and cancer type were not associated with HIV status documentation in South Africa.

CONCLUSION

Different cancer centers have different gaps in HIV status documentation and will require tailored strategies to improve processes for ascertaining and recording HIV-related information in cancer records. Further research by our consortium to identify opportunities for integrating HIV and cancer care delivery is underway.

Characterizing HIV status documentation among cancer patients at regional cancer centers in Malawi, Zimbabwe, and South Africa

Introduction

In East and Southern Africa, people with HIV (PWH) experience worse cancer-related outcomes and are at higher risk of developing certain cancers. Siloed care delivery pathways pose a substantial barrier to co-management of HIV and cancer care delivery.

Methods

We conducted cross-sectional studies of adult cancer patients at public radiotherapy and oncology units in Malawi (Kamuzu Central Hospital), Zimbabwe (Parirenyatwa Group of Hospitals), and South Africa (Charlotte Maxeke Hospital) between 2018-2019. We abstracted cancer- and HIV-related data from new cancer patient records and used Poisson regression with robust variance to identify patient characteristics associated with HIV documentation.

Results

We included 1,648 records from Malawi (median age 46 years), 1,044 records from South Africa (median age 55 years), and 1,135 records from Zimbabwe (median age 52 years). Records from all three sites were predominately from female patients; the most common cancers were cervical (Malawi [29%] and Zimbabwe [43%]) and breast (South Africa [87%]). HIV status was documented in 22% of cancer records from Malawi, 92% from South Africa, and 86% from Zimbabwe. Patients with infection-related cancers were more likely to have HIV status documented in Malawi (adjusted prevalence ratio [aPR]: 1.92, 95% confidence interval [CI]: 1.56-2.38) and Zimbabwe (aPR: 1.16, 95%CI: 1.10-1.22). Patients aged ≥60 years were less likely to have HIV status documented (Malawi: aPR: 0.66, 95% CI: 0.50-0.87; Zimbabwe: aPR: 0.76, 95%CI: 0.72-0.81) than patients under age 40 years. Patient age and cancer type were not associated with HIV status documentation in South Africa.

Conclusion

Different cancer centers have different gaps in HIV status documentation and will require tailored strategies to improve processes for ascertaining and recording HIV-related information in cancer records. Further research by our consortium to identify opportunities for integrating HIV and cancer care delivery is underway.

Immune recovery among Romanian HIV/AIDS patients receiving darunavir/ritonavir or darunavir/cobicistat regimens in cART management: A three-year study

Approximately two-thirds of Romanian HIV patients were parenterally infected with the F subtype of HIV in early childhood. They are now in the context of immunological aging, with immunosuppression posing an additional challenge in developing the most effective and well-tolerated regimens. The risk of an improper immune recovery is higher in these patients than in newly diagnosed patients. The primary goal of this retrospective study was to conduct a comparative analysis of the immune recovery, measured at three time points, on 462 HIV-infected patients who were registered at the "Matei Balş National Institute of Infectious Diseases", Bucharest, Romania, between 2018 and 2021, as follows: darunavir (DRV) 600 mg plus ritonavir (RTV) 100 mg (twice daily) was given to 384 patients, while DRV 800 mg plus cobicistat (COBI) 150 mg was given to 78 patients (once daily). The immune response was assessed by counting T lymphocytes, CD4 count cells/mm³, and the CD4/CD8 lymphocyte count ratio. Additionally, the study assessed the relationship between the immune and virological responses to therapy. Using various statistical tests, the results revealed that the immune response is normal in both groups, but with a statistically significant difference (p < 0.05) for the DRV/c group. Statistical associations between RNA viral plasma load and immune response (CD4 count and CD4/CD8 ratio) were assessed at all three visits and showed an insignificant association for the first two time points; however, at the final visit, the outcomes changed and reached statistical significance for both groups.

Etiology of Persistent Microalbuminuria in Nigeria (P_MICRO study): protocol and study design

BACKGROUND

Microalbuminuria is an independent risk factor for cardiovascular and kidney disease and a predictor of end organ damage, both in the general population and in persons with HIV (PWH). Microalbuminuria is also an important risk factor for mortality in PWH treated with antiretroviral therapy (ART). In the ongoing Renal Risk Reduction (R3) study in Nigeria, we identified a high prevalence of microalbuminuria confirmed by two measurements 4-8 weeks apart in ART-experienced, virologically suppressed PWH. Although Stage 1 or 2 hypertension and exposure to potentially nephrotoxic antiretroviral medications were common in R3 participants, other traditional risk factors for albuminuria and kidney disease, including diabetes, APOL1 high-risk genotype, and smoking were rare. Co-infection with endemic pathogens may also be significant contributors to albuminuria, but co-infections were not evaluated in the R3 study population.

METHODS

In Aim 1, we will cross-sectionally compare the prevalence of albuminuria and established kidney disease risk factors in a cohort of PWH to age- and sex-matched HIV-negative adults presenting for routine care at the Aminu Kano Teaching Hospital in Kano, Nigeria. We will leverage stored specimens from 2500 R3 participants and enroll an additional 500 PLWH recently initiated on ART (≤ 24 months) and 750 age- and sex-matched HIV-negative adults to determine the contribution of HIV, hypertension, and other comorbid medical conditions to prevalent albuminuria. In Aim 2, we will follow a cohort of 1000 HIV-positive, ART-treated and 500 HIV-negative normoalbuminuric adults for 30 months to evaluate the incidence and predictors of albuminuria.

DISCUSSION

The findings from this study will support the development of interventions to prevent or address microalbuminuria in PWH to reduce kidney and cardiovascular morbidity and mortality. Such interventions might include more intensive monitoring and treatment of traditional risk factors, the provision of renin-angiotensin aldosterone system or sodium-glucose cotransporter-2 inhibitors, consideration of changes in ART regimen, and screening and treatment for relevant co-infections.

Cerebral and spinal cord changes observed through magnetic resonance imaging in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis: a systematic review

To verify brain and spinal changes using magnetic resonance imaging in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis. This was a systematic review. The descriptors used were tropical spastic paraparesis and magnetic resonance image. The keyword HTLV-1-associated myelopathy was also used. Twenty-three articles were included: 16 detected brain changes and 18 detected spinal changes. White matter lesions were the most frequent finding in the brain. Brain injuries were most frequently identified in the periventricular region, in the subcortical region, in the centrum semiovale, in the brain stem, and corpus callosum. Atrophy was the most frequent finding of the spinal cord, affecting the thoracic and cervical regions, and was associated with a longer evolution of myelopathy. White matter lesions in these regions were also observed. Cortical white matter lesions and thoracic spinal cord atrophy were the most frequently reported changes in patients with HTLV-1-associated myelopathy.

Impact of Antiretroviral Therapy on Cancer Treatment Outcomes among People Living with HIV in Low- and Middle-Income Countries: a Systematic Review

PURPOSE OF REVIEW

The relationship between antiretroviral therapy (ART) and cancer treatment outcomes among people living with HIV (PLWH) in low- and middle-income countries (LMICs) is complex and poorly understood for many cancers. We aimed to summarize existing evidence from LMICs regarding the benefit of ART on cancer treatment-related outcomes.

RECENT FINDINGS

We included twelve observational studies that reported associations between ART status and cancer treatment outcomes among HIV-positive patients in LMICs. Most confirmed ART was associated with improved cancer treatment outcomes. Heterogeneity in cancers under study, outcome measurement, categorization of ART status, and reporting of HIV-related immune function made formal comparison between studies untenable. Where evaluated, ART generally has a positive effect on cancer outcomes in people with HIV in LMICs. However, there remains a substantial gap in the literature regarding the impact of ART on treatment outcomes for most cancer types. Future research should focus on the optimal timing and integration of ART and cancer treatment for PLWH with strategies applicable to constrained-resource settings.

Long-term evolution of CD4+ cell count in patients under combined antiretroviral therapy

OBJECTIVE

Combined antiretroviral treatment (cART) results in profound immunologic improvement, but it is unclear whether CD4 cell counts return to levels similar to those of HIV-negative individuals. We explore long-term CD4 cell count evolution post-cART and its association with baseline levels, virologic suppression, pre-cART cumulative viremia and other factors.

DESIGN

Data were derived from the AMACS. Included individuals were adults who started cART, at least 2003, while previously ART-naive.

METHODS

Changes in CD4 cell counts were modeled through piecewise linear mixed models.

RESULTS

A total of 3405 individuals were included. The majority was male (86.0%), homosexual (58.8%) with median (IQR) age at cART initiation 36 (31-44) years and a median (IQR) follow-up of 3.9 (2.0-6.9) years. Most persons (57%) starting cART with less than 200 cells/μl did not reach 600 cells/μl after 7 years of treatment. Those starting cART with 200-349 CD4 cells/μl could reach 600 cells/μl within less than 2 years of fully suppressive treatment. Probability of CD4 normalization (i.e. >800 cells/μl) after 7 years of suppressive treatment was 24 and 46% for those starting treatment with less than 200 or 200-349 CD4 cells/μl, respectively. Lower pre-cART cumulative viremia was associated with faster CD4 recovery. CD4 cell count increases after 4 years were either insignificant or very slow, irrespectively of baseline levels.

CONCLUSION

cART initiation before CD4 cell count drops below 350 cells/μl is crucial for achieving normal CD4 levels. These findings underline the importance of timely diagnosis and cART initiation as the risk of both AIDS and non-AIDS-related morbidity/mortality remains increased in patients with incomplete CD4 recovery.

Efficacy and safety of lopinavir/ritonavir-based antiretroviral therapy in HIV-1-infected subjects with advanced disease: a systematic review and meta-analysis

ABSTRACT 

Aim: We examined the literature for the efficacy, safety and tolerability of lopinavir/ritonavir (LPV/r)-based regimens in antiretroviral therapy naive HIV-1-infected subjects with advanced disease. Materials & methods: Virologic and immunologic efficacy and adverse event results from prospective, randomized controlled trials evaluating LPV/r + two nucleoside reverse transcriptase inhibitors were examined using random-effects meta-analyses. Emergence of resistance was determined using data extracted from published material. Results: Thirteen studies (including ten 96-week studies) met search criteria. Virologic responses were similar at 96 weeks between subjects with HIV-1 infection treated with LPV/r-based antiretroviral therapy when stratified by baseline HIV-1 RNA or CD4+ T-cell count; immunologic responses were similar when stratified by CD4+ T-cell count. Conclusion: Through 96 weeks of treatment, the efficacy, safety and tolerability of LPV/r-based regimens were comparable in subjects with and without advanced HIV-1 disease.

Immunological function restoration with lopinavir/ritonavir versus efavirenz containing regimens in HIV-infected patients: a randomized clinical trial

CD4(+) count increase has been reported to be different with lopinavir/r (LPV/r) and efavirenz (EFV)-containing regimens. The different effect of these two regimens on other immune function parameters and the relationship with the gain of CD4(+) count have not been assessed in a randomized clinical trial. Fifty antiretroviral treatment (cART) naïve HIV-infected individuals were randomized to receive LPV/r or EFV both with tenofovir/emtricitabine for 48 weeks. A substudy of immunological function restoration was performed in 22 patients (LPV/r n=10 and EFV n=12). Activation, thymic function, apoptosis, senescence, exhaustion, Treg cells, interleukin (IL)-7-receptor/IL-7 system, thymic volume, and lymphoid tissue fibrosis were evaluated at baseline and at week 48. Both groups experienced a CD4(+) count increase that was higher in the EFV group (ΔCD4(+) 88 vs. 315 cells/μl LPV/r vs. EFV, respectively, p<0.001). Despite this difference in CD4(+) gain, the change in other immune function parameters was similar in both treatment groups. Most of parameters evaluated tended to normalize after 48 weeks of cART. A significant decrease in levels of activation, senescence, exhaustion, and apoptosis on CD4(+) and CD8(+) T cells (p<0.001 for all) and a significant increase in markers of thymic function, IL-7 receptor, and in the levels of central memory CD4(+) T cells and naive subsets of CD8(+) T cells (p<0.001 for all) with respect to baseline values were observed without any difference between groups. These data indicate that the differences in CD4(+) gain with different cART regimens are not immunologically meaningful and might explain the similar clinical efficacy of these regimens.

Soluble markers of inflammation and coagulation but not T-cell activation predict non-AIDS-defining morbid events during suppressive antiretroviral treatment

BACKGROUND

Defining the association of non-AIDS-defining events with inflammation and immune activation among human immunodeficiency virus (HIV)-infected persons with antiretroviral therapy (ART)-associated virological suppression is critical to identifying interventions to decrease the occurrence of these events.

METHODS

We conducted a case-control study of HIV-infected subjects who had achieved virological suppression within 1 year after ART initiation. Cases were patients who experienced non-AIDS-defining events, defined as myocardial infarction, stroke, non-AIDS-defining cancer, non-AIDS-defining serious bacterial infection, or death. Controls were matched to cases on the basis of age, sex, pre-ART CD4(+) T-cell count, and ART regimen. Peripheral blood mononuclear cells and plasma specimens obtained at the visit before ART initiation (hereafter, baseline), the visit approximately 1 year after ART initiation (hereafter, year 1), and the visit immediately preceding the non-AIDS-defining event (hereafter, pre-event) were analyzed for activated CD4(+) and CD8(+) T cells, plasma interleukin 6 (IL-6) level, soluble tumor necrosis factor receptor I (sTNFR-I) level, sTNFR-II level, soluble CD14 level, kynurenine-to-tryptophan (KT) ratio, and D-dimer level. Conditional logistic regression analysis was used to study the association between biomarkers and outcomes, with adjustment for potential confounders.

RESULTS

Higher IL-6 level, sTNFR-I level, sTNFR-II level, KT ratio, and D-dimer level at year 1 were associated with the occurrence of a non-AIDS-defining event. Significant associations were also seen between non-AIDS-defining events and values of these biomarkers in specimens obtained at baseline and the pre-event time points. Effects remained significant after control for confounders. T-cell activation was not significantly related to outcomes.

CONCLUSIONS

Interventional trials to decrease the incidence of non-AIDS-defining events among HIV-infected persons with virological suppression should consider targeting the pathways represented by these soluble markers. Clinical Trials Registration. NCT00001137.

T-cell subset distribution in HIV-1-infected patients after 12 years of treatment-induced viremic suppression

OBJECTIVE

Residual immune activation and skewed T cell maturation may contribute to excess comorbidity and mortality in successfully treated HIV-infected patients, and long-term effects of combination antiretroviral therapy (cART) on immune reconstitution remain a debated issue. Quantitative T cell reconstitution and activation and its association with residual viremia in patients with 12 years of viremic suppression were investigated.

DESIGN

Blood samples collected cross-sectionally from 71 HIV-infected patients with cART-induced viremic suppression through 12 years were compared with samples from 16 healthy controls.

METHODS

Several different subsets of naive, memory, and activated T cells were analyzed in fresh whole blood by 6-color flowcytometry, and ultrasensitive quantification of HIV RNA was performed.

RESULTS

HIV-infected patients had lower absolute and relative CD4 T cell counts and higher absolute and relative CD8 T cell counts than controls. HIV-infected patients had lower concentrations of naive CD4 cells than controls, but proportions were similar. HIV-infected patients had higher concentrations of CD8 T cells than controls in all the examined subsets but only a higher proportion of CD8 cells in the intermediately differentiated and activated subsets. Residual viremia did not correlate to proportions of naive CD4, CD4 recent thymic emigrants, or activated CD8 T cells.

CONCLUSIONS

This study demonstrated some degree of T cell imbalance even after 12 years of successful cART. Large longitudinal studies are needed to establish whether these discrete changes have clinical relevance.

Virologically suppressed HIV patients show activation of NK cells and persistent innate immune activation

FcRγ is an ITAM-containing adaptor required for CD16 signaling and function in NK cells. We have previously shown that NK cells from HIV patients receiving combination antiretroviral therapy (cART) have decreased FcRγ expression, but the factors causing this are unknown. We conducted a cross-sectional study of cART-naive viremic patients (ART(-)), virologically suppressed patients receiving cART (ART(+)), and HIV-uninfected controls. CD8(+) T cells were activated, as assessed by CD38(+)HLA-DR(+) expression, in ART(-) patients (p < 0.0001), which was significantly reduced in ART(+) patients (p = 0.0005). In contrast, CD38(+)HLA-DR(+) NK cells were elevated in ART(-) patients (p = 0.0001) but did not decrease in ART(+) patients (p = 0.88). NK cells from both ART(-) and ART(+) patients showed high levels of spontaneous degranulation in ex vivo whole blood assays as well as decreased CD16 expression (p = 0.0001 and p = 0.0025, respectively), FcRγ mRNA (p < 0.0001 for both groups), FcRγ protein expression (p = 0.0016 and p < 0.0001, respectively), and CD16-dependent Syk phosphorylation (p = 0.0001 and p = 0.003, respectively). HIV-infected subjects showed alterations in NK activation, degranulation, CD16 expression and signaling, and elevated plasma markers of inflammation and macrophage activation, that is, neopterin and sCD14, which remained elevated in ART(+) patients. Alterations in NK cell measures did not correlate with viral load or CD4 counts. These data show that in HIV patients who achieve viral suppression following cART, NK cell activation persists. This suggests that NK cells respond to factors different from those driving T cell activation, but which are associated with inflammation in HIV patients.

Increased oxidative stress condition found in different stages of HIV disease in patients undergoing antiretroviral therapy in Umuahia (Nigeria)

CONTEXT

Effective diagnostic tools for management of HIV disease progression in Sub-Saharan Africa is inadequate considering the endemic nature of the infection in the region.

OBJECTIVE

To elucidate the clinical implication of oxidative stress (measured as Malondialdehyde, MDA) as additional biomarker of HIV disease progression and its implication in HIV clinical management.

MATERIALS AND METHODS

A total of 250 individuals were recruited for the study. FACScan cytometry and spectrophotometric methods were employed in assessing T-lymphocytes (CD3, CD4, CD8) and MDA respectively.

RESULTS

MDA concentration increased significantly (P < 0.05) in highly active antiretroviral therapy (HAART) subjects by 12.72% in category 1, 9.75% in III and in category II (4.63%) on comparison with non-HAART subjects. In subjects taking HAART, 22.2%, 56.3%, and 22.2% were found to be in category I, II and III, respectively, with a corresponding non-HAART values of 15.6%, 45.6% and 38.9%. However, Spearman's rank correlation (P < 0.001) statistics of MDA and HIV categories showed a negative correlation in all the categories (I, II and III).

DISCUSSION AND CONCLUSION

These findings suggest that MDA may be an additional clinical factor in assessing progression of HIV disease; however, necessary fortification of regimen with antioxidant may help reduce the high MDA concentration in the disease progression of the infection.

Treatment intensification with raltegravir in subjects with sustained HIV-1 viraemia suppression: a randomized 48-week study

BACKGROUND

Residual viraemia is a major obstacle to HIV-1 eradication in subjects receiving HAART. The intensification with raltegravir could impact latent reservoirs and might lead to a reduction of plasma HIV-1 viraemia (viral load [VL]), complementary DNA intermediates and immune activation.

METHODS

This was a prospective, open-label, randomized study comprising 69 individuals on suppressive HAART randomly assigned 2:1 to add raltegravir during 48 weeks.

RESULTS

Total and integrated HIV-1 DNA, and ultrasensitive VL remained stable despite intensification. There was a significant increase in episomal HIV DNA at weeks 2-4 in the raltegravir group returning to baseline levels at week 48. Median CD4(+) T-cell counts increased 124 and 80 cells/µl in the intensified and control groups after 48 weeks (P=0.005 and P=0.027, respectively), without significant differences between groups. No major changes were observed in activation of CD4(+) T-cells. Conversely, raltegravir intensification significantly reduced activation of CD8(+) T-cells at week 48 (HLA-DR(+)CD38(+), P=0.005), especially in the memory compartment (CD38(+) of CD8(+)CD45RO(+), P<0.0001). Linear mix models also depicted a larger decrease in CD8(+) T-cell activation in the intensification group (P=0.036 and P=0.010, respectively). Raltegravir intensification was not associated to any particular adverse event.

CONCLUSIONS

Intensification of HAART with raltegravir during 48 weeks was safe and associated with a significant decrease in CD8(+) T-cell activation, and a transient increase of episomal HIV-1 DNA. However, raltegravir did not significantly contribute to changes in CD4(+) T-cell counts, ultrasensitive VL, and total and integrated HIV-1 DNA. These findings suggest that raltegravir impacts residual HIV-1 replication and support new strategies to impair HIV-1 persistence. ClinicalTrials.gov identifier: NCT00554398.

Antiretroviral treatment of US children with perinatally acquired HIV infection: temporal changes in therapy between 1991 and 2009 and predictors of immunologic and virologic outcomes

BACKGROUND

Advances in therapy have allowed children with perinatal HIV infection in the United States to survive into adolescence. We sought to describe the disease status of a large cohort of such children and identify predictors of their current CD4 count and HIV viral load (VL).

METHODS

The Pediatric HIV/AIDS Cohort Study AMP Protocol is an ongoing prospective study conducted at 15 sites in the United States. Between 2007 and 2009, we enrolled a population-based sample of 451 children with perinatal HIV who were 7-16 years of age at entry.

RESULTS

The median age of subjects at entry was 12.2 years, 53% were female, 70% were African-American, and 24% Hispanic. Their median entry CD4% was 33%, and 78% had a CD4% ≥25%; 68% had a suppressed VL. The more recent birth cohorts (1994-2002) had a significantly higher CD4% over time than the earliest birth cohort (1991-1993). The significant independent predictors of a higher CD4% at entry were a suppressed entry VL, a higher nadir CD4%, and starting antiretroviral therapy at a younger age. The mean CD4% at entry for children with a nadir CD4% ≥25% was 9.5% higher than for those with a nadir CD4% <15% (P < 0.001). Independent predictors of a suppressed entry VL were membership in a recent birth cohort, male gender, highly active combination antiretroviral therapy use at entry, and fewer prior antiretroviral therapy regimens.

CONCLUSIONS

Most children with perinatal HIV maintain virologic suppression and good CD4 values. Earlier treatment results in better immune outcome.

A randomized, placebo controlled, double masked phase IB study evaluating the safety and antiviral activity of aprepitant, a neurokinin-1 receptor antagonist in HIV-1 infected adults

BACKGROUND

Neurokinin-1 receptor (NK1R) antagonists have anti-HIV activity in monocyte-derived macrophages, decrease CCR5 expression and improve natural killer cell function ex vivo. Aprepitant is a NK1R antagonist approved by FDA as an antiemetic.

METHODS

We conducted a phase IB randomized, placebo controlled, double masked study to evaluate the safety, antiviral activity, pharmacokinetics and immune-modulatory effects of aprepitant in HIV-infected adults not receiving antiretroviral therapy, with CD4+ cell count ≥350 cells/mm(3) and plasma viral load ≥2,000 copies/ml. Subjects were stratified by viral load (< vs. ≥20,000 copies/ml) and randomized within each stratum to receive aprepitant at 125 mg QD(Low), or 250 mg QD(High), or placebo(PL) for 14 days, and followed for 42 days.

RESULTS

Thirty subjects were randomized and 27 completed treatment (9, 8, 10 subjects in 125 (Low), 250 (High), and PL groups). 63% were male; 37% white; mean (SD) age 43 (9.3) years. Geometric mean baseline viral load (copies/ml) for Low, High, and PL was 15,709, 33,013, and 19,450, respectively. Mean (95%CI) change in log10 viral load at day 14 for Low, High, and PL was -0.02(-0.24,+0.20), -0.05(-0.21,+0.10), and +0.04(-0.08,+0.16), respectively. The number of subjects with AEs was 4(44.4%), 5(62.5%), and 1(10%) for Low, High, and PL. No Grade 4 AEs occurred.

CONCLUSIONS

Adverse events of aprepitant were more common in the treated groups. At the dose used in this two-week phase IB study, aprepitant showed biological activity, but no significant antiviral activity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00428519.

Central memory CD4 cells are an early indicator of immune reconstitution in HIV/AIDS patients with anti-retroviral treatment

The number of central memory cells among the CD4+ T cells and the of activation of CD8+ T cells is believed to be a better indicator of immune restoration in patients on antiretroviral therapy (ART) than the absolute numbers of CD4(+) and CD8+ T cells alone. In the current study, we investigated the changes in the CD4(+) T cell subsets and their association with immune reconstitution and immune activation at early stages of ART. A prospective study was performed in 21 asymptomatic treatment-naive HIV-infected patients with CD4(+) T cells less than 350 cells/μl. Blood samples were evaluated at base line, and at 2, 4, 8 and 12 weeks' post antiretroviral therapy (ART). A biphasic increase of CD4(+) T cells, central memory CD4 cells (CD4 CM) and CD4 naïve cells were observed after ART, with a rapid increase before week 4. Change in CD4 CM at week 4 positively correlated with the change in CD4(+) T cells at weeks 12 post ART, and negatively correlated with the change in CD8(+)CD38(+) T cells at weeks 12 post ART. We conclude that CD4 CM cells are a major contributor to early immune reconstitution in treatment-naive HIV-infected patients with delayed ART, and might be an early indicator for immune reconstitution.

[Enhancing immune restoration in human immunodeficiency virus infection]

The primary objective of antiretroviral therapy has recently evolved from a virologic endpoint towards the achievement of normal CD4T cell count (greater than 500/mm(3)) to avoid progression to AIDS. This shift in the primary objective is supported by many clinical and epidemiological studies. Recent data have shown that HIV-infected adults with a CD4T cell count greater than 500cells/mm(3) on long-term combination antiretroviral therapy reach same mortality rates as the general population. However, less than 50% of patients receiving long-term suppressive antiretroviral combination reach such a CD4T cell level. New antiretroviral strategies to improve immune reconstitution, such as specific or non-specific immune-based therapy on one hand and the use of novel antiretroviral drugs from new classes on the other hand are currently under investigation. Here we review several current strategies that may improve immune reconstitution, keeping in mind that the best way to reach normal CD4T cell count is an early treatment initiation.

Long-term CD4+ lymphocyte response following HAART initiation in a U.S. Military prospective cohort

Background

Among HIV-infected persons initiating highly active antiretroviral therapy (HAART), early CD4+ lymphocyte count increases are well described. However, whether CD4+ levels continue to increase or plateau after 4-6 years is controversial.

Methods

To address this question and identify other determinants of CD4+ response, we analyzed data for 1,846 persons from a prospective HIV military cohort study who initiated HAART, who had post-HAART CD4+ measurements, and for whom HIV seroconversion (SC) date was estimated.

Results

CD4+ count at HAART initiation was ≤ 200 cells/mm³ for 23%, 201-349 for 31%, 350-499 for 27%, and ≥500 for 19%. The first 6 months post-HAART, the greatest CD4+ increases (93-151 cells) occurred, with lesser increases (22-36 cells/year) through the first four years. Although CD4+ changes for the entire cohort were relatively flat thereafter, HIV viral load (VL) suppressors showed continued increases of 12-16 cells/year. In multivariate analysis adjusting for baseline CD4+ and post-HAART time interval, CD4+ responses were poorer in those with: longer time from HIV SC to HAART start, lower pre-HAART CD4+ nadir, higher pre-HAART VL, and clinical AIDS before HAART (P < 0.05).

Conclusions

Small but positive long-term increases in CD4+ count in virally suppressed patients were observed. CD4+ response to HAART is influenced by multiple factors including duration of preceding HIV infection, and optimized if treatment is started with virally suppressive therapy as early as possible.

Long-term increase in CD4+ T-cell counts during combination antiretroviral therapy for HIV-1 infection

OBJECTIVE

To inform guidelines concerning when to initiate combination antiretroviral therapy (ART), we investigated whether CD4(+) T-cell counts (CD4 cell counts) continue to increase over long periods of time on ART. Losses-to-follow-up and some patients discontinuing ART at higher CD4 cell counts hamper such evaluation, but novel statistical methods can help address these issues. We estimated the long-term CD4 cell count trajectory accounting for losses-to-follow-up and treatment discontinuations.

DESIGN

The study population included 898 US patients first initiating ART in a randomized trial (AIDS Clinical Trials Group 384); 575 were subsequently prospectively followed in an observational study (AIDS Clinical Trials Group Longitudinal Linked Randomized Trials).

METHODS

Inverse probability of censoring weighting statistical methods were used to estimate the CD4 cell count trajectory accounting for losses-to-follow-up and ART discontinuations, overall and for pretreatment CD4 cell count categories (<or=200, 201-350, 351-500, and >500 cells/microl).

RESULTS

Median CD4 cell count increased from 270 cells/microl pre-ART to an estimated 556 cells/microl at 3 and 532 cells/microl at 7 years after starting ART in analyses ignoring treatment discontinuations, and to 570 and 640 cells/microl, respectively, had all patients continued ART. However, even had ART been continued, an estimated 25, 9, 3, and 2% of patients with pretreatment CD4 cell counts of 200 or less, 201-350, 351-500, and more than 500 cells/microl would have had CD4 cell counts of 350 cells/microl or less after 7 years.

CONCLUSION

If patients remain on ART, CD4 cell counts increase in most patients for at least 7 years. However, the substantial percentage of patients starting therapy at low CD4 cell counts who still had low CD4 cell counts after 7 years provides support for ART initiation at higher CD4 cell counts.

Abacavir and tenofovir disoproxil fumarate co-administration results in a nonadditive antiviral effect in HIV-1-infected patients

OBJECTIVES

To evaluate a potential pharmacodynamic/pharmacokinetic interaction between abacavir (ABC) and tenofovir disoproxil fumarate (TDF).

DESIGN AND METHODS

This randomized trial compared 7 days of ABC or TDF monotherapy, separated by a 35-day washout, with 7 days of ABC + TDF dual-therapy in treatment-naive, HIV-1-infected patients. During each 7-day course, the slope of the phase I viral decay was estimated and steady-state intracellular concentrations of carbovir triphosphate (CBV-TP), deoxyguanosine triphosphate (dGTP), tenofovir diphosphate (TFV-DP) and deoxyadenosine triphosphate (dATP) were determined.

RESULTS

Twenty-one participants were randomized to initial monotherapy with ABC (n = 11) or TDF (n = 10). The addition of TDF did not increase the slope of viral decay compared to ABC alone (-0.15 log10 per day vs. -0.16 log10 per day, respectively). No decrease in CBV-TP or TFV-DP between monotherapy and dual-therapy was observed. However, intracellular dATP concentrations increased between monotherapy and dual-therapy [median dATP (fmol/10 cells) 3293 vs. 4638; P = 0.08], although this difference was significant only among patients randomized to TDF [median dATP (fmol/10 cells) 3238 vs. 4534; P = 0.047]. A lower TFV-DP-to-dATP ratio was associated with reduced viral decay during dual-therapy (rho = -0.529; P = 0.045).

CONCLUSION

In this study, the viral decay during ABC and TDF dual-therapy was similar to that during ABC therapy alone, suggesting a nonadditive antiviral effect. This negative pharmacodynamic interaction was not explained by changes in CBV-TP or TFV-DP concentrations. Rather, modest increases in endogenous dATP pools were associated with reduced antiviral potency of TDF during co-administration with ABC.

Poor baseline immune function predicts an incomplete immune response to combination antiretroviral treatment despite sustained viral suppression

OBJECTIVES

To determine the prevalence and predictors of an incomplete immune response in patients with sustained viral suppression after starting their first or second combination antiretroviral treatment (cART) regimen.

METHODS

All patients were recruited to the Australian HIV Observational Database (AHOD) by March 2006. Data were analyzed to assess the prevalence of an incomplete immune response (<350 cells/microL) in the 12-24 months after starting the first or second cART regimen. Factors associated with an incomplete immune response were assessed using logistic regression and time to AIDS/death was assessed using survival analysis.

RESULTS

Of the 2493 patients recruited to AHOD by March 2006, 590 were eligible for the analysis. Twenty-eight percent of patients with a baseline CD4 count <350 cells per microliter had an incomplete immune response 12-24 months after starting their first or second cART regimen. Lower baseline CD4 count before starting the cART regimen was predictive of an incomplete immune response. There was a nonsignificant trend toward faster AIDS or death in incomplete immune responders.

CONCLUSIONS

An incomplete immune response in patients with sustained viral suppression is associated with poorer immune function before starting cART. Type of cART or individual antiretroviral drug was not associated with an incomplete immune response.

Replication capacity in relation to immunologic and virologic outcomes in HIV-1-infected treatment-naive subjects

OBJECTIVES

To evaluate the association between baseline (BL) replication capacity (RC) (RCBL) and immunologic/virologic parameters (at BL and after 48 weeks on therapy) in HIV-1-infected subjects initiating antiretroviral therapy.

METHODS

RCBL was determined using a modified Monogram PhenoSense HIV drug susceptibility assay on plasma HIV-1 from 321 treatment-naive subjects from AIDS Clinical Trials Group 384. Univariate and multivariable analyses were performed to determine the association of RCBL with BL and on-therapy virologic and immunologic outcomes.

RESULTS

Higher RCBL was associated with lower baseline CD4 (CD4BL) (r = -0.23, P < 0.0001), higher baseline HIV-1 RNA (r = 0.25, P < 0.0001), higher CD4BL activation percent (r = 0.23, P < 0.0001), and lower CD4BL memory count (r = -0.21, P = 0.0002). In a multivariable model, week 48 CD4 increase (DeltaCD448) was associated with lower CD4BL memory count and higher CD4BL-naive percent (P = 0.004, P = 0.015, respectively). The interaction between CD4BL and RCBL was significant (P = 0.018), with a positive association between RCBL and DeltaCD448 in subjects with higher CD4BL and a negative association at lower absCD4BL.

CONCLUSIONS

At baseline, higher RC was significantly associated with higher HIV-1 RNA, higher CD4 cell activation, lower CD4 cell count, and lower CD4 memory cell count. These factors may interact, directly or indirectly, to modify the extent to which CD4 recovery occurs in patients starting antiretroviral therapy at different CD4BL counts.

Incomplete reconstitution of T cell subsets on combination antiretroviral therapy in the AIDS Clinical Trials Group protocol 384

BACKGROUND

Initiation of combination antiretroviral therapy (ART) results in higher total CD4 cell counts, a surrogate for immune reconstitution. Whether the baseline CD4 cell count affects reconstitution of immune cell subsets has not been well characterized.

METHODS

Using data from 978 patients (621 with comprehensive immunological assessments) from the AIDS [Acquired Immunodeficiency Syndrome] Clinical Trials Group protocol 384, a randomized trial of initial ART, we compared reconstitution of CD4(+), CD4(+) naive and memory, CD4(+) activation, CD8(+), CD8(+) activation, B, and natural killer cells among patients in different baseline CD4(+) strata. Reference ranges for T cell populations in control patients negative for human immunodeficiency virus (HIV) infection were calculated using data from AIDS Clinical Trials Group protocol A5113.

RESULTS

Patients in the lower baseline CD4(+) strata did not achieve total CD4(+) cell counts similar to those of patients in the higher strata during 144 weeks of ART, although CD4(+) cell count increases were similar. Ratios of CD4(+) naive-memory cell counts and CD4(+):CD8(+) cell counts remained significantly reduced in patients with lower baseline CD4(+) cell counts (

CONCLUSIONS

After nearly 3 years of ART, T cell subsets in patients with baseline CD4(+) cell counts >350 cells/mm(3) achieved or approached the reference range those of control individuals without HIV infection. In contrast, patients who began ART with Collapse

Key Words Collapse

MESH Headings

• Acquired Immunodeficiency Syndrome/drug therapy
• Acquired Immunodeficiency Syndrome/immunology
• Adult
• Antiretroviral Therapy, Highly Active
• B-Lymphocytes/immunology
• CD4 Lymphocyte Count
• CD4-CD8 Ratio
• Female
• Humans
• Killer Cells, Natural/immunology
• Male
• Middle Aged
• T-Lymphocyte Subsets/immunology

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Grants

• AI25879 NIAID NIH HHS
• AI066992 NIAID NIH HHS
• K01 AI062435-02 NIAID NIH HHS
• R01 AI066992 NIAID NIH HHS
• U01 AI038858 NIAID NIH HHS
• AI27659 NIAID NIH HHS
• AI38855 NIAID NIH HHS
• IP30AI060354 NIAID NIH HHS
• U01 AI025879 NIAID NIH HHS
• K01 AI062435 NIAID NIH HHS
• AI27666 NIAID NIH HHS
• AI38858 NIAID NIH HHS
• K01 AI062435-04 NIAID NIH HHS
• U01 AI038855 NIAID NIH HHS
• K01 AI062435-03 NIAID NIH HHS
• K01AI062435 NIAID NIH HHS
• U01 AI027666 NIAID NIH HHS
• K01 AI062435-01A1 NIAID NIH HHS
• U01 AI027659 NIAID NIH HHS
• P30 AI060354 NIAID NIH HHS

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Affiliation(s)

Gregory K Robbins Infectious Diseases Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
John G Spritzler
Ellen S Chan
David M Asmuth
Rajesh T Gandhi
Benigno A Rodriguez
Gail Skowron
Paul R Skolnik
Robert W Shafer
Richard B Pollard

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Continuous improvement in the immune system of HIV-infected children on prolonged antiretroviral therapy

BACKGROUND

The goal of HAART is to promote reconstitution of CD4+ T cells and other immune responses. We evaluated the extent and the kinetics of immune reconstitution in HIV-infected children over 144 weeks of successful HAART.

METHODS

Thirty-seven children receiving their first HAART regimen had plasma HIV RNA; T cells and subpopulations; T-cell rearrangement excision circles (TREC) DNA; candida, HIVCD4 and HIVCD8 enzyme-linked immunospot measured at regular intervals.

RESULTS

Plasma HIV RNA became undetectable in 81% of patients at 24 weeks and remained undetectable in 77% at 144 weeks. In contrast, CD4+% continuously increased. Distribution of T-cell subpopulations changed rapidly during the first 48 weeks of HAART and more slowly thereafter. At 144 weeks, total, naive and activated CD4+% and naive CD8+% of HIV-infected children were not significantly different from those of healthy age-matched controls, whereas total and activated CD8+% remained elevated. CD4 and CD8 TREC content increased only during the first 48 weeks of HAART. They positively correlated with each other and with total CD4+%, naive CD4+% and naive CD8+%. Candida and HIVCD4 enzyme-linked immunospot increased over time reaching peak values at 48 weeks and 144 weeks, respectively. HIVCD8 enzyme-linked immunospot decreased in magnitude over 144 weeks of HAART but retained its breadth. Baseline CD4+% positively correlated with CD4+% and with functional immune reconstitution at week 144, whereas baseline TREC correlated with TREC at week 144.

CONCLUSION

HIV-infected children acquired normal distribution of CD4 T cells and other subpopulations and recovered CD4-mediated HIV immunity after 144 weeks of HAART.

Efavirenz-based regimens in treatment-naive patients with a range of pretreatment HIV-1 RNA levels and CD4 cell counts

The potency of 2 nucleoside reverse transcriptase inhibitors (NRTIs) and efavirenz in patients with higher viral loads (VLs) or low CD4 cell counts remains uncertain. Virologic failure and changes in CD4 count in relation to pretreatment VL and CD4 count were evaluated in treatment-naive patients randomized to treatment groups that received 2 or 3 NRTIs with efavirenz. Over 3 years, the risk of virologic failure was not significantly different among subgroups categorized according to pretreatment VL or CD4 count. No significant differences among subgroups were observed for CD4 count changes, except in patients with high pretreatment VL. There were no significant differences among subgroups with respect to treatment responses. These results demonstrate the potency of efavirenz-containing regimens across a spectrum of pretreatment VLs and CD4 counts.

Potential risks and benefits of HIV treatment simplification: a simulation model of a proposed clinical trial

BACKGROUND

In recent studies, subjects who had achieved suppression of the human immunodeficiency virus (HIV) RNA level while receiving an initial 3-drug antiretroviral regimen successfully maintained suppression while receiving treatment with a "boosted" protease inhibitor (PI) alone. We projected the long-term outcomes of this treatment simplification strategy to inform the design of a proposed multicenter, randomized clinical trial.

METHODS

We used published studies to estimate the efficacy, adverse effects, and cost of a sequence of HIV drug regimens for the simplification strategy, compared with those outcomes for the current standard-of-care (SOC) strategy. Using a published simulation model of HIV disease, we projected life expectancy, discounted quality-adjusted life expectancy (QALE), and discounted lifetime medical costs for each strategy.

RESULTS

Subjects who have not developed PI-resistant HIV infection at the time of failure of the simplification regimen have a greater life expectancy (27.9 vs. 27.1 years) and QALE (14.9 vs. 14.7 years), compared with SOC subjects, because they receive an additional line of therapy without negative consequences for future treatment options. The QALE for the simplification strategy remains higher than that for the SOC, unless a large proportion of patients experiencing virologic failure while receiving the simplification regimen develop PI resistance. Depending on the probability of simplification regimen failure, the advantage is maintained even if HIV develops PI resistance in 42%-70% of subjects. Projected lifetime costs are $26,500-$72,400 per person lower for the simplification strategy than for the SOC strategy.

CONCLUSIONS

An HIV treatment simplification strategy involving use of a boosted PI alone may lead to longer survival overall at lower cost, compared with the SOC combination therapy, because the simplification strategy potentially adds an additional line of therapy. The risk of emergence of PI resistance during treatment with a simplified regimen is a critical determinant of the viability of this strategy.

Optimal Timing and Best Antiretroviral Regimen in Treatment-naive HIV-Infected Individuals with Advanced Disease

The introduction of highly active antiretroviral therapy (HAART) in developed countries has achieved a good control of HIV infection. Despite this, a delayed HIV diagnosis makes it necessary to start antiretroviral treatment in individuals with severe impairment of their immunological function. Very often, this is accompanied by an opportunistic infection that needs to be treated, with a consequent complication of management because of overlapping toxicities and pharmacokinetic interactions with antiretroviral drugs, and a greater pill burden. All this could impair adherence and reconstitution of the immune function with a paradoxical clinical worsening in some patients, especially if the CD4 cell count is below 50 cells/microl. The best antiretroviral regimen and the best timing for starting antiretroviral therapy in treatment-naive patients with advanced infection have not yet been established. Recommendations for the clinical management of advanced HIV disease come from panels of experts in the therapy of opportunistic infections and antiretroviral treatment, and they advise starting combined antiretroviral therapy 2-4 weeks after initiating treatment of the opportunistic infection. Many patients have been successfully treated with a pharmacologically enhanced (boosted) protease inhibitor (mainly lopinavir/ritonavir)-based regimens. The efficacy of non-nucleoside reverse transcriptase inhibitor-based regimens for the treatment of very immunosuppressed patients has been tested in few clinical trials during the HAART era. Some cohort studies and randomized clinical trials support the use of efavirenz-based antiretroviral therapy for the treatment of advanced HIV-1-infected patients; however, recent randomized controlled data suggest, in a moderately advanced HIV population, a better CD4 cell recovery for lopinavir-ritonavir than for efavirenz-treated patients, but a greater virological suppression in the efavirenz arm. Further randomized clinical trials are needed in order to determine whether the efficacy, tolerability and the immunological reconstitution of efavirenz-based therapy can match that achieved with lopinavir/ritonavir or other current boosted protease inhibitor regimens in advanced patients.