Persistent low-level HIV-1 RNA between 20 and 50 copies/mL in antiretroviral-treated patients: associated factors and virological outcome

Enabling CAR T-cell therapies for HIV-positive lymphoma patients - A call for action

People living with HIV have a higher risk of developing lymphoma. Outcomes for people living with HIV with relapsed or refractory (r/r) lymphoma remain poor. For this group of patients, chimeric antigen receptor (CAR) T-cell therapy represents a new successful treatment strategy. However, people living with HIV were not included in pivotal trials, so data are limited to case reports. We searched the PubMed and Ovid technologies databases for literature until 1 November 2022 using the terms 'HIV and CAR-T', 'HIV and lymphoma' and 'HIV and CAR-T and lymphoma'. Six cases with sufficient information were included in the review. The mean CD4+ T-cell count before CAR T-cell therapy was 221 cells/μL (range 52-629). The viral load was below the limit of detection in four patients. All patients had diffuse large B-cell lymphoma (DLBCL) and were treated with gamma-retroviral-based axicabtagene ciloleucel. Four patients developed cytokine-release syndrome (CRS) grade 2 or less or immune effector-cell-associated neurotoxicity syndrome (ICANs) grade 3-4. Four of six patients responded to CAR T-cell therapy (three complete remissions, one partial remission). In summary, there are no clinical reasons to restrict the use of CAR T-cell therapy in people living with HIV with r/r DLBCL. According to the current data, CAR T-cell therapy was safe and effective. In people who meet the standard criteria for CAR T-cell therapy, this treatment approach could significantly improve the unmet need for more effective treatment options for people living with HIV with r/r lymphoma.

Influencing factors and adverse outcomes of different virologic rebound states in antiretroviral treated HIV/AIDS patients

Antiretroviral therapy (ART) aims to inhibit HIV replication, decrease CD4 T cell loss, and immune function recovery in order to reduce the morbidity and mortality associated with the infection. Treatment should also, improve quality of life and control HIV spread. However, incomplete viral suppression still occurs during ART. Viral suppression and virological failure (VF) thresholds vary between studies in terms of virological rebound (VR) states using different detection thresholds. Further understanding of influencing factors and adverse outcomes in various VR states should provide important guidance for HIV treatment.

HIV-1 Drug Resistance Profiles of Low-Level Viremia Patients and Factors Associated With the Treatment Effect of ART-Treated Patients: A Cross-Sectional Study in Jiangsu, China

Objectives

Evaluating the drug resistance (DR) profiles of LLV patients and the influencing factors of treatment effects in Jiangsu Province.

Method

The Pol gene (Reverse transcriptase and protease) was amplified and sequenced to identify the genotypes and DR profiles among LLV patients in 2021. Questionnaire survey was conducted among HIV/AIDS patients to investigate the potential influence factors of treatment effects.

Results

242 Pol genes were amplified from 345 specimens, and ten genotypes were detected. The DR rate was 40.5%, with 66, 86, and 14 being resistant to NRTIs, NNRTIs, and PIs, respectively. Patients treated with the 2NRTIs+PIs regimen were detected with more DR; and drug resistance was less detected in married or cohabiting patients than unmarried patients. Non-smokers were less likely to develop LLV at follow-up than smokers; patients with stage II clinical stage at diagnosis and using 2NRTIs+PIs regimen were also more likely to develop LLV at follow-up.

Conclusion

Drug resistance profiles in LLV patients are severe and differ in treatment regimens and marital statuses. Meanwhile, smoking history, clinical stage, and treatment regimen may influence the therapeutic effect. It is necessary to include LLV people in the free drug resistance testing program.

Factors associated with human immunodeficiency virus-1 low-level viremia and its impact on virological and immunological outcomes: A retrospective cohort study in Beijing, China

OBJECTIVES

We evaluated the impact of low-level viremia (LLV) on virological failure and immune reconstitution among people living with human immunodeficiency virus type 1 (HIV-1) treated with different antiretroviral regimens in Beijing, China.

METHODS

Human immunodeficiency virus type 1-positive adults who were registered at an infectious disease hospital in Beijing between January 1, 2005 and January 1, 2020 were administered antiretroviral therapy (ART) and whose viral load and CD4 counts were monitored were included in this retrospective cohort study. Univariate and multivariate logistic regression analyses were performed to identify risk factors associated with LLV in patients on different ART regimens. Cox proportional hazard model was employed to analyze the virological suppression and immune reconstitution cumulative probability in patients with LLV during follow-up.

RESULTS

A total of 10 124 HIV-1-infected participants was included. LLV occurred in 723 (8.2%), 204 (10.9%), 133 (8.6%), and 53 (14.4%) patients on first-line ART, second-line ART, third-line ART, and simplified regimens, respectively. Virological failure occurred in 514 (5.8%), 289 (15.5%), 86 (5.5%), and 34 (9.2%) patients on first-line ART, second-line ART, third-line ART, and simplified regimens, respectively. Earlier enrollment, lower baseline CD4 count, and higher baseline viral load were risk factors associated with LLV. LLV was related to increased hazards of virological failure compared to viral suppression of ≤50 copies/ml for those on first-line ART.

CONCLUSIONS

The risk of virological failure and poor immune reconstitution increases when LLV occurs. Targeted viral load and CD4 count monitoring are recommended for people living with HIV-1 with LLV to improve health-related outcomes.

Low-level viremia in treated HIV-1 infected patients: advances and challenges

Antiretroviral therapy (ART) can effectively suppress HIV-1 replication, improving quality of life and restoring the lifespan of persons living with HIV (PLWH) to near normal levels. However, after standardized ART, a low level of HIV-1 RNA, i.e., low-level viremia (LLV), may still be identified in 3% to 10% of the patients. LLV is capable of impacting the immunological and clinical outcome of patients and serves as a risk factor for transmission. The underlying mechanism of LLV is not yet certain, and the effects of LLV on patient outcomes remain under evaluation. Understanding LLV will allow effective prevention and control strategies to be designed for the benefit of PLWH.

Persistent low-Level viremia in persons living with HIV undertreatment: An unresolved status

Antiretroviral therapy (ART) allows suppressed viremia to reach less than 50 copies/mL in most treated persons living with HIV (PLWH). However, the existence of PLWH that show events of persistent low-level viremia (pLLV) between 50 and 1000 copies/mL and with different virological consequences have been observed. PLLV has been associated with higher virological failure (VF), viral genotype resistance, adherence difficulties and AIDS events. Moreover, some reports show that pLLV status can lead to residual immune activation and inflammation, with an increased risk of immunovirological failure and a pro-inflammatory cytokine level which can lead to a higher occurrence of non-AIDS defining events (NADEs) and other adverse clinical outcomes. Until now, however, published data have shown controversial results that hinder understanding of the true cause(s) and origin(s) of this phenomenon. Molecular mechanisms related to viral reservoir size and clonal expansion have been suggested as the possible origin of pLLV. This review aims to assess recent findings to provide a global view of the role of pLLV in PLWH and the impact this status may cause on the clinical progression of these patients.

The Evolution of Dendritic Cell Immunotherapy against HIV-1 Infection: Improvements and Outlook

Dendritic cells (DC) are key phagocytic cells that play crucial roles in both the innate and adaptive immune responses against the human immunodeficiency virus type 1 (HIV-1). By processing and presenting pathogen-derived antigens, dendritic cells initiate a directed response against infected cells. They activate the adaptive immune system upon recognition of pathogen-associated molecular patterns (PAMPs) on infected cells. During the course of HIV-1 infection, a successful adaptive (cytotoxic CD8⁺ T-cell) response is necessary for preventing the progression and spread of infection in a variety of cells. Dendritic cells have thus been recognized as a valuable tool in the development of immunotherapeutic approaches and vaccines effective against HIV-1. The advancements in dendritic cell vaccines in cancers have paved the way for applications of this form of immunotherapy to HIV-1 infection. Clinical trials with patients infected with HIV-1 who are well-suppressed by antiretroviral therapy (ART) were recently performed to assess the efficacy of DC vaccines, with the goal of mounting an HIV-1 antigen-specific T-cell response, ideally to clear infection and eliminate the need for long-term ART. This review summarizes and compares methods and efficacies of a number of DC vaccine trials utilizing autologous dendritic cells loaded with HIV-1 antigens. The potential for advancement and novel strategies of improving efficacy of this type of immunotherapy is also discussed.

Differences in HIV Markers between Infected Individuals Treated with Different ART Regimens: Implications for the Persistence of Viral Reservoirs

In adherent individuals, antiretroviral therapy (ART) suppresses HIV replication, restores immune function, and prevents the development of AIDS. However, ART is not curative and has to be followed lifelong. Persistence of viral reservoirs forms the major obstacle to an HIV cure. HIV latent reservoirs persist primarily by cell longevity and proliferation, but replenishment by residual virus replication despite ART has been proposed as another potential mechanism of HIV persistence. It is a matter of debate whether different ART regimens are equally potent in suppressing HIV replication. Here, we summarized the current knowledge on the role of ART regimens in HIV persistence, focusing on differences in residual plasma viremia and other virological markers of the HIV reservoir between infected individuals treated with combination ART composed of different antiretroviral drug classes.

Identifying causes of persistent HIV viremia in adult patients at an academic medical center

Objectives:

Despite many advances in medicine, not all individuals with HIV are able to achieve complete virologic suppression. This retrospective study identifies variables associated with persistent HIV viremia in an academic clinic.

Methods:

We studied 66 HIV-infected patients with a viral load of >200 copies/mL over 1 year, with controls matched 1:1 via a propensity score utilizing age at diagnosis, era of diagnosis, gender, and initial CD4 count. We collected data on multiple variables including medications, adherence, comorbidities, hospitalizations, and insurance status. Conditional logistic regression was used for unadjusted and adjusted analyses.

Results:

A total of 66 viremic cases/matched controls were included. Fewer viremic patients were on antiretroviral therapy for all 12 months (45% vs 77%; odds ratio: 0.33, p = .018) and fewer were of white race (52% vs 70%; odds ratio: 0.49, p = .053). Hospitalization (11% vs 3%; odds ratio: 10, p = .028), underinsurance (20% vs 1%; odds ratio: 5.87, p = .022), and conflicting personal beliefs about their disease (17% vs 3%; odds ratio: 5.5, p = .027) were more common in viremic patients. Psychiatric illness increased the odds of viremia in patients who had four or more visits (odds ratio: 1.63/6.64 with four/five clinic visits, respectively).

Conclusion:

Psychiatric illness is an important contributor to the presence of persistent viremia in HIV-infected patients and deserves further study.

Is HIV-1 viraemia below 20 copies/mL in antiretroviral-treated patients associated with virologic outcome?

BACKGROUND

We aimed to investigate whether very low-level HIV-1 viraemia (VLLV) <20 copies/mL in HIV-1-infected patients on antiretroviral therapy (ART) whose VL was <20 copies/mL, was associated with a subsequent VL > 20 copies/mL.

METHODS

VLLV was defined as VL <20 copies/mL and positive HIV-1-PCR. We compared patients with positive and negative HIV-1-PCRs <20 copies/mL at two time points, T0 and T1, after 21st of January 2016. Factors associated with a VLLV and subsequent VL >20 copies/mL were identified by logistic regression models.

RESULTS

Of 1341 participants at T0, 958 (71.4%) had a negative and 383 patients (28.6%) had positive HIV-RNA PCR signal during VL < 20 copies/mL. The negative relative to the positive signal at T0 was independently associated with dolutegravir (DTG) mono and/or DTG-lamivudine dual therapy (compared to nevirapine), a pre-ART-VL of 1000-9999 copies/mL (compared to ≥100,000 copies/mL), and each additional year of virologic suppression. Having a virolologic outcome at T1 of ≥ 20 copies/mL was independently associated with prior positive signal at T0. (OR = 2.291, 95% CI = 1.457-3.601, p value < .001), a past ART interruption, and a change in ART regimen during follow-up. Each additional year of virologic suppression was independently associated with a lower risk for a subsequent VL ≥ 20 copies/mL.

CONCLUSIONS

A positive HIV-1 RNA PCR <20 copies/mL at T0, was associated with a subsequent VL ≥ 20 copies/mL at T1. This was not a rare phenomenon among patients with VL <20 copies/mL. In most patients with a positive PCR signal, this was not followed by a clinically relevant HIV-1 viraemia, defined as ≥ 200 copies/mL.

Assessment of the 24th Week Success of Anti-Retroviral Therapy in the Action against HIV in Istanbul Database: Results from a Region with Increasing Incidence

We aimed to assess the 24-week virological and immunological success of the treatment of treatment-naive and treatment-experienced patients included in the Action against HIV in Istanbul (ACTHIV-IST) database. The ACTHIV-IST database was screened retrospectively from January 2012 to January 2014. The data for these patients such as age, sex, treatment-naive or treatment-experienced status, date of diagnosis, date of commencing antiretroviral therapy, antiretroviral therapy regimen, CD4+ cell count, and viral load before and after therapy were analyzed. In the 24th week of antiretroviral therapy, there were 40 (17.9%) and 29 (14.1%) virological and immunological failures, respectively. Virological failure (VF) was associated with a baseline viral load > 100,000 copies (p = 0.004). A CD4+ cell count lower than 200 cells/μl was not found to be associated with VF (p = 0.843). Immunological failure was substantially rare in patients with a baseline CD4+ cell count > 200 cells/μl (p = 0.005). Although an HIV-RNA ≤ 100,000 copies/ml was protective against VF in the 24th week, in individuals with an HIV-RNA > 100,000 copies/ml, VF was 3.2 times more likely to occur. Baseline VF was the most predictive parameter to estimate 24th week virological success and VF. VF is an important prognostic parameter resulting in CD4+ cell depletion, AIDS-related events, and increased mortality.

Incomplete viral suppression and mortality in HIV patients after antiretroviral therapy initiation

OBJECTIVE

To determine whether there is a threshold of detectable HIV RNA under 1000 copies/ml after antiretroviral therapy initiation associated with 10-year all-cause mortality.

DESIGN

This study included nearly 8000 patients from a US-based multicenter clinical cohort who started antiretroviral therapy between 1 January 1998 and 31 December 2013. Viral load was assessed 6 months after initiation of therapy. Patients were followed from 6 months after therapy initiation (between 1 July 1998 and 30 June 2014) until death, and data were administratively censored after 10 years or on 31 December 2014.

METHODS

We used nonparametric multiple imputation to account for left-censored viral load measurements, Cox proportional hazards models to estimate all-cause mortality hazard ratios, Nelson-Aalen cumulative hazard estimates to construct risk curves, and inverse probability of exposure weights to standardize estimated hazard ratios and risk curves to the total study population.

RESULTS

Plots of standardized hazard ratio estimates and 95% confidence intervals indicated there was no demonstrable viral load threshold between 30 and 500 copies/ml associated with a marked increase in 10-year mortality. The standardized 10-year risk of mortality among patients with viral loads between 400 and 999 copies/ml 6 months after starting treatment was comparable with the risk of mortality among patients with viral loads between 1000 and 4 million copies/ml (20 vs. 23%).

CONCLUSION

Incomplete suppression of plasma HIV RNA 6 months after starting therapy is associated with substantial 10-year all-cause mortality risk, highlighting the importance of rapid viral load suppression after therapy initiation.

Reduced adherence to antiretroviral therapy is associated with residual low-level viremia

The source and significance of residual low-level viremia (LLV) during combinational antiretroviral therapy (cART) remain a matter of controversy. It is unclear whether residual viremia depends on ongoing release of HIV from the latent reservoir or if viral replication contributes to LLV. We examined the relationship between adherence and LLV. Adherence was estimated by pharmacy refill and dichotomized as ≥95% or <95%. Plasma HIV-RNA was determined, with an ultrasensitive test having a limit of detection of 3 copies/mL at least 2 times over the follow-up period. Patients were grouped according to HIV-RNA over time as K<3: constantly <3 copies/mL; V<3: sometimes below or above the cutoff limit but always <50 copies/mL; K>3: constantly between 3 and 50 copies/mL; and V>50: a measure of >50 copies/mL minimum. Overall, 2789 patients were included. At each time point approximately 92% of the patients presented an HIV-RNA <50 copies/mL and two-thirds of those <3 copies/mL, 34.6% of patients had <3 copies/mL constantly, 32.7% sometimes below or above the cutoff limit but always <50 copies/mL, 9.5% constantly between 3 and 50 copies/mL, and 23.2% a measure of >50 copies/mL minimum. The mean adherence rate was 92.1% (95% confidence interval [CI] from 91.1% to 93.1%) in K<3 patients, similar in V<3 patients (91.9%), but lowered to 88.8% in K>3 patients and to 88.4% in V>50 patients (P<0.0001). Approximately 55% of patients in groups K<3 and V<3 showed an adherence rate ≥95%; this proportion lowered to ~51% in K>3 and to 48% in V>50. Moreover, 34% of patients with a steady adherence <95% were categorized as K>3, whereas 21.7% of those with a drug holiday (21.7%) were observed in the V>50 group (P=0.002). A steady viral suppression can occur despite moderate cART non-adherence, but reduced adherence is associated with low-level residual viremia, which could reflect new rounds of HIV replication. However, a detectable HIV-RNA could also be detected in patients with optimal cART adherence, indicating additional mechanisms favoring HIV persistence.

A European multicientre study on the comparison of HIV-1 viral loads between VERIS HIV-1 Assay and Roche COBAS® TAQMAN® HIV-1 test, Abbott RealTime HIV-1 Assay, and Siemens VERSANT HIV-1 Assay

BACKGROUND

Viral load monitoring is essential for patients under treatment for HIV. Beckman Coulter has developed the VERIS HIV-1 Assay for use on the novel, automated DxN VERIS Molecular Diagnostics System.^¥ OBJECTIVES: Evaluation of the clinical performance of the new quantitative VERIS HIV-1 Assay at multiple EU laboratories.

STUDY DESIGN

Method comparison with the VERIS HIV-1 Assay was performed with 415 specimens at 5 sites tested with COBAS^® AmpliPrep/COBAS^® TaqMan^® HIV-1 Test, v2.0, 169 specimens at 3 sites tested with RealTime HIV-1 Assay, and 202 specimens from 2 sites tested with VERSANT HIV-1 Assay. Patient monitoring sample results from 4 sites were also compared.

RESULTS

Bland-Altman analysis showed the average bias between VERIS HIV-1 Assay and COBAS HIV-1 Test, RealTime HIV-1 Assay, and VERSANT HIV-1 Assay to be 0.28, 0.39, and 0.61 log₁₀ cp/mL, respectively. Bias at low end levels below 1000cp/mL showed predicted bias to be <0.3 log₁₀ cp/mL for VERIS HIV-1 Assay versus COBAS HIV-1 Test and RealTime HIV-1 Assay, and <0.5 log₁₀cp/mL versus VERSANT HIV-1 Assay. Analysis on 174 specimens tested with the 0.175mL volume VERIS HIV-1 Assay and COBAS HIV-1 Test showed average bias of 0.39 log₁₀cp/mL. Patient monitoring results using VERIS HIV-1 Assay demonstrated similar viral load trends over time to all comparators.

CONCLUSIONS

The VERIS HIV-1 Assay for use on the DxN VERIS System demonstrated comparable clinical performance to COBAS^® HIV-1 Test, RealTime HIV-1 Assay, and VERSANT HIV-1 Assay.

European Multicenter Study on Analytical Performance of Veris HIV-1 Assay

The analytical performance of the Veris HIV-1 assay for use on the new, fully automated Beckman Coulter DxN Veris molecular diagnostics system was evaluated at 10 European virology laboratories. The precision, analytical sensitivity, performance with negative samples, linearity, and performance with HIV-1 groups/subtypes were evaluated. The precision for the 1-ml assay showed a standard deviation (SD) of 0.14 log₁₀ copies/ml or less and a coefficient of variation (CV) of ≤6.1% for each level tested. The 0.175-ml assay showed an SD of 0.17 log₁₀ copies/ml or less and a CV of ≤5.2% for each level tested. The analytical sensitivities determined by probit analysis were 19.3 copies/ml for the 1-ml assay and 126 copies/ml for the 0.175-ml assay. The performance with 1,357 negative samples demonstrated 99.2% with not detected results. Linearity using patient samples was shown from 1.54 to 6.93 log₁₀ copies/ml. The assay performed well, detecting and showing linearity with all HIV-1 genotypes tested. The Veris HIV-1 assay demonstrated analytical performance comparable to that of currently marketed HIV-1 assays. (DxN Veris products are Conformité Européenne [CE]-marked in vitro diagnostic products. The DxN Veris product line has not been submitted to the U.S. FDA and is not available in the U.S. market. The DxN Veris molecular diagnostics system is also known as the Veris MDx molecular diagnostics system and the Veris MDx system.).

Viral blips were infrequent in treatment-naive adults treated with rilpivirine/emtricitabine/tenofovir DF or efavirenz/emtricitabine/tenofovir DF through 96 weeks

BACKGROUND

The clinical impact of transient episodes of HIV viraemia (viral blips) on virological failure and resistance development is not fully understood. Here we investigated the blip frequency and virological outcomes of HIV-1-infected subjects experiencing viral blips among treatment-naive subjects initiating therapy on rilpivirine (RPV)/emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) or efavirenz (EFV)/FTC/TDF through 96 weeks of treatment.

METHODS

Subjects treated with at least one dose of study drug and with at least one post-baseline HIV-1 RNA value were included in this analysis. All on-drug HIV-1 RNA data points and FDA snapshot outcome data through week 96 were utilized. A viral blip was defined as after achieving confirmed suppression (two consecutive HIV-1 RNA values <50 copies/ml), any HIV-1 RNA value ≥50 copies/ml preceded and followed by HIV-1 RNA <50 copies/ml.

RESULTS

Of the 717 subjects with confirmed suppression, 67 (9.3%) experienced ≥1 blip through week 96 with similar blip frequencies occurring in both treatment arms (10.7% RPV/FTC/TDF versus 8.0% EFV/FTC/TDF; P=0.25). A significantly higher proportion of subjects with baseline HIV-1 RNA >100,000 copies/ml experienced blips compared to subjects with baseline HIV-1 RNA ≤100,000 copies/ml and this was observed in both arms. Of 72 total blip events, 61 (85%) were low-level (50-199 copies/ml). Overall, among subjects with blips, 79% were virological successes at week 96, similar to those subjects without blips (83%; P=0.50). More subjects with blips ≥200 copies/ml experienced virological failure compared to subjects with blips <200 copies/ml (36.4% versus 7.1%; P=0.02).

CONCLUSIONS

Viral blips were infrequent and similar among subjects treated with RPV/FTC/TDF or EFV/FTC/TDF. Most blips were low-level and most subjects with blips remained virologically suppressed through week 96 without experiencing virological failure.

Characterizing Patients with Very-Low-Level HIV Viremia: A Community-Based Study

OBJECTIVE

Very-low-level viremia (VLLV) is a relatively new concept in the realm of human immunodeficiency virus (HIV) care. Newer generation assays are now able to detect plasma HIV RNA Viral Load (VL) levels as low as 20 copies/mL. The authors characterized patients with VLLV (VL between 20 and 50 copies/mL) in order to identify possible risk factors associated with virologic failure and poor clinical outcomes.

METHODS

The authors reviewed 119 consecutive charts of patients with VLLV. Sociodemographic data were extracted and viral load and CD4 counts were trended over a 12 month period (February 2013-February 2014). Regression analysis was used to assess the role of different factors on virologic failure at 1 year.

RESULTS

Of the study participants with evaluable data (n = 100), the median age was 53 years (interquartile range: 43-57.5), 67% were nonwhite, 34% were women, 58% were smokers, 47% were alcoholics, 58% had a history of intravenous drug use, and 40% were coinfected with hepatitis C virus. More than half of the participants had 3 or more comorbidities and their HIV pill burden was high (more than 2 pills daily). After 12 months, 65 participants achieved undetectable viral load levels, whereas 15 experienced virologic failure (2 consecutive viral loads > 50 copies/mL) and the remaining 20 had persistent VLLV. In the virologic failure group, there was a predominance of white males (66%) with a significant number of comorbidities and pill burden. Univariate logistic regression suggested that there was a difference between the failure versus nonfailure groups in terms of race, ethnicity, and alcohol use. Multivariate regression with virological failure as the outcome suggested a trend only in terms of participant's alcohol use.

CONCLUSION

Most patients with initial VLLV (70%) achieved virologic suppression at 1 year with no antiretroviral therapy changes. Thus, VLLV does not necessarily predict virologic failure and should not prompt more frequent clinic visits or antiretroviral regimen changes. Further research is needed in order to determine the predictors of virologic failure in this subset of patients and the clinicians' attitude toward VLLV.

Very low level viraemia and risk of virological failure in treated HIV-1-infected patients

OBJECTIVES

The aim of the study was to investigate whether very low level viraemia (VLLV) (20-50 HIV-1 RNA copies/mL) was associated with increased risk of virological failure (VF) as compared with persistent full suppression (< 20 copies/mL).

METHODS

From the VACH Cohort database, we selected those patients who started antiretroviral therapy (ART) after January 1997 and who achieved effective viral suppression [two consecutive viral loads (VLs) < 50 copies/mL] followed by full suppression (at least one VL <20 copies/mL). We carried out survival analyses to investigate whether the occurrence of VLLV rather than maintaining full suppression at < 20 copies/mL was associated with virological failure (two consecutive VLs > 200 copies/mL or one VL > 200 copies/mL followed by a change of ART regimen, administrative censoring or loss to follow-up), adjusted for nadir CD4 cell count, sex, age, ethnicity, transmission group, type of ART and time on effective suppression at < 50 copies/mL.

RESULTS

Of 21 480 patients who started ART, 13 674 (63.7%) achieved effective suppression at < 50 copies/mL, of whom 4289 (31.4%) further achieved full suppression at < 20 copies/mL after May 2009. A total of 2623 patients (61.1%) remained fully suppressed thereafter, while 1666 had one or more episodes of VL detection > 20 copies/mL (excluding virological failure). A total of 824 patients had VLLV after suppression at < 20 copies/mL. VLLV was not associated with virological failure as compared with persistent full suppression [hazard ratio (HR) 0.67; 95% confidence interval (CI) 0.44-1.00], independently of the number of blips recorded (from one to 18).

CONCLUSIONS

In our population of HIV-infected patients on ART who achieved viral suppression at < 20 copies/mL, the risk of virological failure was no different for patients who remained fully suppressed compared with those who experienced subsequent episodes of VLLV.

A Single Quantifiable Viral Load Is Predictive of Virological Failure in Human Immunodeficiency Virus (HIV)-Infected Patients on Combination Antiretroviral Therapy: The Austrian HIV Cohort Study

Background.  Viral loads (VLs) detectable at low levels are not uncommon in patients on combination antiretroviral therapy (cART). We investigated whether a single quantifiable VL predicted virological failure (VF). Methods.  We analyzed patients receiving standard regimens with at least 1 VL measurement below the limit of quantification (BLQ) in their treatment history. The first VL measurement after 6 months of unmodified cART served as baseline VL for the subsequent analyses of the time to reach single VL levels of ≥200, ≥400, and ≥1000 copies/mL. Roche TaqMan 2.0 was used to quantify human immunodeficiency virus-1 ribonucleic acid. Factors associated with VF were determined by Cox proportional hazards models. Results.  Of 1614 patients included in the study, 68, 44, and 34 experienced VF ≥200, ≥400, and ≥1000 copies/mL, respectively. In multivariable analyses, compared with patients who were BLQ, a detectable VL ≤ 50 and VL 51-199 copies/mL predicted VF ≥ 200 copies/mL (hazards ratio [HR] = 2.19, 95% confidence interval [CI] = 1.06-4.55 and HR = 4.21, 95% CI = 2.15-8.22, respectively). In those with VL 51-199 copies/mL, a trend for an increased risk of VF ≥400 and VF ≥1000 copies/mL could be found (HR = 2.13, 95% CI = 0.84-5.39 and HR = 2.52, 95% CI = 0.96-6.60, respectively). Conclusions.  These findings support closer monitoring and adherence counseling for patients with a single measurement of quantifiable VL <200 copies/mL.

HIV Replication at Low Copy Number and its Correlation with the HIV Reservoir: A Clinical Perspective

The efficacy of combination therapy (antiretroviral therapy - ARV) is demonstrated by the high rates of viral suppression achieved in most treated HIV patients. Whereas contemporary treatments may continuously suppress HIV replication, they do not eliminate the latent reservoir, which can reactivate HIV infection if ARV is discontinued. The persistence of HIV proviral DNA and infectious viruses in CD4+ T cells and others cells has long been considered a major obstacle in eradicating the HIV virus in treated patients. Moreover, recent studies have demonstrated the persistence of HIV replication at low copies in most patients on suppressive ARV. The source of this ‘residual viraemia’ and whether it declines over years of therapy remain unknown. Similarly, little is known regarding the biological relationships between the HIV reservoir and viral replication at low copies. The question of whether this ‘residual viraemia’ represents active replication or the release of non-productive virus from the reservoir has not been adequately resolved.

From a clinical perspective, both the quantification of the HIV reservoir and the detection of low levels of replication in full-responder patients on prolonged ARV may provide important information regarding the effectiveness of treatment and the eradication of HIV. To date, the monitoring of these two parameters has been conducted only for research purposes; the routine use of standardised tests procedure is lacking. This review aims to assess the current data regarding the correlation between HIV replication at low copies and the HIV reservoir and to provide useful information for clinicians.

HIV-1 Very Low Level Viremia Is Associated with Virological Failure in Highly Active Antiretroviral Treatment-Treated Patients

The aim of this study was to evaluate the impact of HIV-1 very low-level viremia (<50 copies/ml) on the 2-year risk of virological failure. A retrospective analysis including HIV-positive patients presenting two consecutive HIV RNA below 50 copies/ml (outpatient clinic in Italy, first semester of 2010) was performed. HIV RNA was measured through real time polymerase chain reaction (PCR) assay CAP/CTM HIV-1 version 2.0 (detection limit: 20 copies/ml) and stratified as undetectable RNA ("Target Not Detected", TND), <20 copies/ml, 20-50 copies/ml. After 96 weeks virological failure was defined as two consecutive viral loads above 50 copies/ml. Log-rank tests and a multivariate Cox proportional hazard model were used for univariate and multivariate analysis. A total of 1,055 patients (71.4% male, 87.4% white, aged 46.7 years) were included: nadir and current CD4 cell counts were 203 cells/mm(3) (106-292) and 554 cells/mm(3) (413-713.5). HIV RNA was undetectable in 781 patients (74%), <20 copies/ml in 190 patients (18%) and 20-50 copies/ml in 84 patients (8%). Virological failure was observed in 81 patients (7.7%); at multivariate analysis detectable RNA at baseline (p=0.017), HCV infection (p=0.020), more than three pills in the regimen (p=0.003), and duration of HIV RNA <50 copies/ml below 2 years (p<0.001) were independently associated with virological failure. In 14 patients newly selected resistance-associated mutations were observed. Undetectable HIV RNA by real-time PCR is significantly associated with a lower 2-year risk of virological failure along with Ab HCV negativity, longer viral control, and lower pill burden. Studies investigating the management of residual viremia under antiretroviral treatment are warranted.

Comparing Abbott m2000 RealTime HIV test and Roche COBAS Ampliprep/COBAS Taqman HIV test, v2.0 in treated HIV-1 B and non-B subjects with low viraemia

Viral load testing is a valuable tool in HIV clinical care and research. Discrepancies among diverse viral load assays, especially with regard to non-B HIV-1 subtypes have been reported. Our study aimed to explore the impact of HIV subtype (B versus non-B) on the agreement between CAP/CTM, v2.0 and m2000 RealTime in treated HIV patients, focusing on low viral loads (<200 copies/ml). Our findings indicate that there is a significant difference in the performance of the compared assays in the low-viremic range and non-B subtypes, suggesting that a single assay should be used for follow-up.

Drug resistance is rarely the cause or consequence of long-term persistent low-level viraemia in HIV-1-infected patients on ART

BACKGROUND

The introduction of highly sensitive HIV-1 viral load assays with a lower quantification limit of 20 copies/ml uncovered that in a number of patients on ART, the viral load systematically fluctuates around or slightly above the detection limit of the assays. This study aimed to analyse the presence or occurrence of drug resistance mutations in HIV-1-infected patients during long-term persistent low-level viraemia (PLLV) under ART.

METHODS

A retrospective study was carried out in which baseline and on-therapy presence of drug resistance mutations in the HIV-1 protease and reverse transcriptase genes were analysed in patients with PLLV between 20 and 250 copies/ml. For all available plasma samples collected during PLLV, resistance analysis was attempted with an ultrasensitive amplification and sequencing protocol.

RESULTS

Resistance analysis was successful for 154 samples collected longitudinally from 23 patients over a median period of 4.7 years (IQR 3.3-5.7). Twenty of these patients were on a boosted protease inhibitor (PI)-based regimen (87%). Single drug resistance mutations were detected in isolated samples of 4 patients, 2 of the 3 patients who initiated a non-nucleoside reverse transcriptase inhibitor-based regimen and 2 of the 20 on a PI-based regimen. Only one of the detected mutations decreased susceptibility to the therapy regimen taken at the time of sample collection. Drug resistance mutations were not found in the three patients who developed virological failure (viral load >250 copies/ml) during the study.

CONCLUSIONS

Long episodes of PLLV in patients on boosted PI-based regimens rarely result in the selection of new drug-resistant variants.

Four days a week or less on appropriate anti-HIV drug combinations provided long-term optimal maintenance in 94 patients: the ICCARRE project

Short, intraweekly cycles of anti-HIV combinations have provided intermittent, effective therapy (on 48 patients) (1). The concept is now extended to 94 patients on treatment, 4 days per week or less, over a median of 2.7 discontinuous treatment years per patient. On suppressive combinations, 94 patients volunteered to treatment, 5 and 4 days per week, or reduced stepwise to 4, 3, 2, and 1 days per week in 94, 84, 66, and 12 patients, respectively, on various triple, standard, antiviral combinations, or nonregistered, quadruple, antiviral combinations. Ninety-four patients on treatment 4 days per week aggregated 165 intermittent treatment years; no viral breakthrough was observed over 87 average treatment weeks per patient, 63 of 94 having passed 2.5 intermittent treatment years on any of the antiviral combinations prescribed. On the hyperintermittent treatment of 3, 2, and 1 days per week, HIV RNA surged >50 copies, 4 weeks apart, in 18 instances (6.8 viral escapes/100 hyperdiscontinuous maintenance years). Viral escapes could have been a result of erratic adherence (EA) to regimen or follow-up (3 patients)--drug taken at half of the daily recommended dosage (8 patients) and/or overlooked archival-resistant HIVs from antecedent treatment failures (6 patients). Aside from the above circumstances, HIV unexpectedly rebounded in 3 patients on 2 days per week treatment and 1 patient on 1 day per week treatment, posting 2.2 intrinsic viral escapes/100 highly discontinuous treatment years. All 18 escapes were eventually reversed by 7 days per week salvage combinations, and 11 of 18 patients have been back for a second course of intermittent therapy, 4 days per week or less. Both cell-activation markers on the surface of T lymphocytes and cell-bound HIV DNA levels remained stable or declined. CD4/CD8 ratios rose to ≥1 in 35% of patients, whereas CD4 counts went ≥500/µl in 75%. These values were previously 7 and 40%, respectively, on 7 days per week therapy. In our aging, long, HIV-enduring, multitreated patient cohort, treatment 4 days per week and less over 421 intermittent treatment years reduced prescription medicines by 60%--equivalent to 3 drug-free/3 virus-free remission year per patient--actually sparing €3 million on just 94 patients at the cost of 2.2 intrinsic viral failure/100 hyperintermittent treatment years. At no risk of viral escape, maintenance therapy, 4 days per week, would quasiuniversally offer 40% cuts off of current overprescriptions.

Rate and determinants of residual viremia in multidrug-experienced patients successfully treated with raltegravir-based regimens

Residual HIV viremia, defined by low levels of plasma HIV RNA with enhanced-sensitivity assays, may persist even in the presence of successful antiretroviral therapy, but little is known about its determinants. Our objective was to evaluate the rate and determinants of residual viremia in patients who show stable undetectable plasma HIV-1 RNA with conventional assays. Forty-four multidrug-experienced patients with undetectable levels of HIV RNA for at least 2 years under raltegravir-based regimens were evaluated. An ultrasensitive (2.5 copies/ml) real-time PCR method was used to quantify plasma HIV RNA. After 12 months of salvage treatment, 48.3% of the patients had residual viremia between 2.5 and 37 copies/ml. The proportion of patients with plasma HIV RNA below 2.5 copies/ml decreased from 51.7% at 12 months to 30.8% at 24 months. The presence of residual viremia was not associated with levels of viremia before starting raltegravir. Considering CD4 counts, hepatitis B or C virus (HBV or HCV) coinfection, or other demographic characteristics, for the time interval between HIV diagnosis and initiation of antiretroviral therapy, patients with a longer interval (>1 year) were significant less likely to have RNA levels below 2.5 copies/ml at 12 months compared to patients who started therapy within 1 year of HIV diagnosis (28.6% vs. 73.3%, p=0.027). Half of the patients showing undetectable HIV viremia with conventional assays had low-level viremia with ultrasensitive assays, with no predictive role of viroimmunological status at the start of the regimen. The potential influence of the interval between HIV diagnosis and initiation of treatment should be confirmed in subjects with a known date of seroconversion.

Residual viremia is preceding viral blips and persistent low-level viremia in treated HIV-1 patients

BACKGROUND

It has been suggested that low-level viremia or blips in HIV-infected patients on antiretroviral treatment are related to assay variation and/or increased sensitivity of new commercial assays. The 50-copy cut-off for virologic failure is, therefore, under debate.

METHODS

Treated patients with low-level viremia (persistent viral loads (VL) of 50-1000 copies/mL, group A, N = 16) or a blip (single detectable VL, group B, N = 77) were compared to a control group (consistently suppressed viremia since start therapy (<50 copies/mL), N = 79). Residual viremia (detectable viral RNA <50 copies/ml) in the year preceding the first VL above 50 copies/mL (T0) was determined using Roche Cobas-Amplicor v1.5 or CAP-CTM v2.0. Subsequent virologic failure (2 consecutive VLs>500 or 1 VL>1000 copies/mL that was not followed by a VL<50 copies/mL; median follow up 34 months) was assessed.

RESULTS

Significantly more patients in groups A and B had residual viremia in the year preceding T0 compared to controls (50% and 19% vs 3% respectively; p<0.001). Residual viremia was associated with development of low-level viremia or blips (OR 10.9 (95% CI 2.9-40.6)). Subsequent virologic failure was seen more often in group A (3/16) and B (2/77) than in the control group (0/79).

CONCLUSION

Residual viremia is associated with development of blips and low-level viremia. Virologic failure occurred more often in patients with low-level viremia. These results suggest that low-level viremia results from viral production/replication rather than only assay variation.

Significance and clinical management of persistent low-level viremia and very-low-level viremia in HIV-1-infected patients

A goal of HIV therapy is to sustain suppression of the plasma viral load below the detection limits of clinical assays. However, widely followed treatment guidelines diverge in their interpretation and recommended management of persistent viremia of low magnitude, reflecting the limited evidence base for this common clinical finding. Here, we review the incidence, risk factors, and potential consequences of low-level HIV viremia (LLV; defined in this review as a viremia level of 50 to 500 copies/ml) and very-low-level viremia (VLLV; defined as a viremia level of <50 copies/ml detected by clinical assays that have quantification cutoffs of <50 copies/ml). Using this framework, we discuss practical issues related to the diagnosis and management of patients experiencing persistent LLV and VLLV. Compared to viral suppression at <50 or 40 copies/ml, persistent LLV is associated with increased risk of antiretroviral drug resistance and overt virologic failure. Higher immune activation and HIV transmission may be additional undesirable consequences in this population. It is uncertain whether LLV of <200 copies/ml confers independent risks, as this level of viremia may reflect assay-dependent artifacts or biologically meaningful events during suppression. Resistance genotyping should be considered in patients with persistent LLV when feasible, and treatment should be modified if resistance is detected. There is a dearth of clinical evidence to guide management when genotyping is not feasible. Increased availability of genotypic assays for samples with viral loads of <400 copies/ml is needed.

Virological outcome and management of persistent low-level viraemia in HIV-1-infected patients: 11 years of the Swiss HIV Cohort Study

BACKGROUND

Management of persistent low-level viraemia (pLLV) in patients on combined antiretroviral therapy (cART) with previously undetectable HIV viral loads (VLs) is challenging. We examined virological outcome and management among patients enrolled in the Swiss HIV Cohort Study (SHCS).

METHODS

In this retrospective study (2000-2011), pLLV was defined as a VL of 21-400 copies/ml on ≥ three consecutive plasma samples with ≥8 weeks between first and last analyses, in patients undetectable for ≥24 weeks on cART. Control patients had ≥ three consecutive undetectable VLs over ≥32 weeks. Virological failure (VF), analysed in the pLLV patient group, was defined as a VL>400 copies/ml.

RESULTS

Among 9,972 patients, 179 had pLLV and 5,389 were controls. Compared to controls, pLLV patients were more often on unboosted protease inhibitor (PI)-based (adjusted odds ratio [aOR; 95% CI] 3.2 [1.8, 5.9]) and nucleoside/nucleotide reverse transcriptase inhibitor (NRTI)-only combinations (aOR 2.1 [1.1, 4.2]) than on non-nucleoside reverse transcriptase inhibitor and boosted PI-based regimens. At 48 weeks, 102/155 pLLV patients (66%) still had pLLV, 19/155 (12%) developed VF and 34/155 (22%) had undetectable VLs. Predictors of VF were previous VF (aOR 35 [3.8, 315]), unboosted PI-based (aOR 12.8 [1.7, 96]) or NRTI-only combinations (aOR 115 [6.8, 1,952]), and VLs>200 during pLLV (aOR 3.7 [1.1, 12]). No VF occurred in patients with persistent very LLV (21-49 copies/ml; n=26). At 48 weeks, 29/39 patients (74%) who changed cART had undetectable VLs, compared with 19/74 (26%) without change (P<0.001).

CONCLUSIONS

Among patients with pLLV, VF was predicted by previous VF, cART regimen and VL≥200. Most patients who changed cART had undetectable VLs 48 weeks later. These findings support cART modification for pLLV>200 copies/ml.

Virological outcome at week 48 of three recommended first-line regimens using ultrasensitive viral load and plasma drug assay

OBJECTIVES

To describe the virological and pharmacological outcomes of three different recommended once-daily first-line regimens in a cross-sectional analysis within an observational cohort using ultra-sensitive HIV quantification.

PATIENTS AND METHODS

We enrolled all HIV-1-infected patients who initiated tenofovir/emtricitabine with efavirenz, darunavir/ritonavir or atazanavir/ritonavir as a first-line regimen between 1 November 2010 and 30 June 2012. An ultrasensitive viral load (VL) assay was performed and plasma drug concentrations at 24 h (C24) were determined at Week (W) 4, W12, W24, W36 and W48.

RESULTS

Sixty patients initiated efavirenz, 81 darunavir/ritonavir and 27 atazanavir/ritonavir. A higher proportion of patients with a VL >100 000 copies/mL received darunavir/ritonavir (P = 0.022). At W48, 89%, 85% and 88% of the patients had a VL <50 copies/mL, 69%, 73% and 79% had a VL <20 copies/mL and 45%, 48% and 54% had a VL <1 copy/mL using the ultrasensitive assay in the efavirenz, darunavir/ritonavir and atazanavir/ritonavir groups, respectively. Patients with a detectable VL signal at W48 had a higher baseline VL than those with no detectable VL signal (P = 0.0001). A total of 92%, 93% and 91% of the efavirenz, darunavir and atazanavir C24 values were above the respective effective cut-offs.

CONCLUSIONS

In this observational cohort, the choice of the regimen was related to the physicians' preferences and the patients' characteristics. The proportion of patients reaching VL <1 copy/mL at W48 was similar in the three regimens and was not associated with drug concentrations.

Association between discordant immunological response to highly active anti-retroviral therapy, regulatory T cell percentage, immune cell activation and very low-level viraemia in HIV-infected patients

The mechanisms sustaining the absence of complete immune recovery in HIV-infected patients upon long-term effective highly active anti-retroviral therapy (HAART) remain elusive. Immune activation, regulatory T cells (T(regs)) or very low-level viraemia (VLLV) have been alternatively suspected, but rarely investigated simultaneously. We performed a cross-sectional study in HIV-infected aviraemic subjects (mean duration of HAART: 12 years) to concomitantly assess parameters associated independently with inadequate immunological response. Patients were classified as complete immunological responders (cIR, n = 48) and inadequate immunological responders (iIR, n = 39), depending on the CD4(+) T cell count (> or < 500/mm(3)). Clinical and virological data (including very low-level viraemia) were collected. In parallel, immunophenotyping of CD4(+) lymphocytes, including T(reg) subsets, and CD8(+) T cells was performed. Percentages of activated CD4(+) T cells, T(regs), effector T(regs) and terminal effector T(regs) were found to be significantly elevated in iIR. Neither the percentage of activated CD8(+) T cells nor VLLV were found to be associated with iIR. In the multivariate analysis, nadir of CD4(+) T cell count and percentage of T(regs) were the only two parameters associated independently with iIR [odds ratio (OR) = 2·339, P = 0·001, and OR = 0·803, P = 0·041]. We present here the largest study investigating simultaneously the immune response to long-term HAART, activation of CD4(+) and CD8(+) T cells, T(reg) percentages and very low-level viraemia. Causative interactions between T(regs) and CD4(+) T cells should now be explored prospectively in a large patients cohort.

HIV drug resistance detected during low-level viraemia is associated with subsequent virologic failure

BACKGROUND

The clinical implications of emergent HIV drug resistance on samples with low-level viraemia (LLV <1000 copies/ml) remain unclear. We undertook the present analysis to evaluate the impact of emergent HIV drug resistance at LLV on the risk of subsequent virologic failure.

METHODS

One thousand, nine hundred and sixty-five patients had genotype results at LLV. Risk of virologic failure (≥1000 copies/ml) after LLV was evaluated by Kaplan-Meier analysis and Cox proportional hazards regression. Resistance was assessed using the Stanford algorithm or virtual phenotypes. Patients were grouped into four susceptibility categories ('GSS' or 'vPSS') during LLV, corresponding to the number of 'active' drugs prescribed: <1; 1-1.5; 2-2.5; and ≥3.

RESULTS

A total of 1702 patients with follow-up on constant therapy were eligible for analysis. Participants excluded due to changing therapy or loss to follow-up before their next observation had mostly similar characteristics to included participants. There was a 'dose-dependent' increase in the hazard ratio for virologic failure with susceptibility categories at LLV. Compared with a GSS of at least 3, hazard ratios for virologic failure were 1.4 for GSS 2-2.5; 2.0 for GSS 1-1.5; and 3.0 for GSS less than 1 (P < 0.001). Numerous sensitivity analyses confirmed these findings.

CONCLUSION

Our results demonstrate that emergent HIV drug resistance at LLV is strongly associated with subsequent virologic failure. Furthermore, we uncovered a 'dose-dependent' increase in the hazard ratio for virologic failure with decreasing GSS estimated at the time of LLV. On the basis of these findings, we propose that resistance genotyping be encouraged for HIV-infected individuals on antiretroviral therapy experiencing low-level viraemia.

Rate of and predicting factors for virologic failure in HIV-infected patients with persistent low-level viremia under antiretroviral therapy

To determine the rate of and predicting factors for virologic failure among HIV-infected patients with persistent low-level viremia (PLV) under antiretroviral therapy (ART), a retrospective cohort study was conducted among HIV-infected patients who experienced PLV under ART. Persistent low-level viremia was defined as HIV RNA level at 50 to 1000 copies/mL for at least 2 consecutive visits. Of 68 patients, mean ± standard deviation age was 35.2 ± 9.0 years and 64.7% were males. Median (interquartile range [IQR]) CD4 count was 94 (26-264) cells/mm(3) and baseline HIV RNA was 112 000 (1 090-461 500) copies/mL. During the median (IQR) follow-up period of 5.7 (3.4-10.3) years of ART, the rate of virologic failure was 38.2%. In multivariate analyses, only maximum amplitude of HIV RNA >400 copies/mL during PLV (hazard ratio = 5.668; 95% confidence interval, 1.888-17.014; P = .002) significantly predicted virologic failure. Patients with PLV >400 copies/mL are more likely to develop virologic failure and should be closely monitored. Interventional studies to prevent virologic failure in these patients are needed.

Comparing HIV viral load assays and frequency of low level virological rebound in clinical practice

Research suggests that some low-level virological rebound results occurring for no obvious clinical cause, in patients stable on antiretroviral therapy (ART), may be a consequence of the viral load assay used. We compared the relative frequency of clinically unexplained low-level virological rebound results when using the Roche HIV Taqman version-1 (CTM v1), the Roche HIV Taqman version-2 (CTM v2) and the Abbott RealTime (Abbott RT) assays in clinical practice. In all, 247 patients from our centre who had their viral loads measured by the three different assays over a period of 3 consecutive years (each assay used for a period of 1 year each) were included in the study. Low-level virological rebound was defined as <1000 copies/ml. Over similar time periods, there was significant discrepancy between the three assays when considering the proportion of clinically unexplained low-level virological rebound results in patients stable on ART: the CTM v2 assay produced the highest percentage (93%), CTM v1 much lower (65%) and Abbott RT even less (35%). There is further research required regarding what, if any, implications this has for patients who experience clinically unexplained low-level virological rebound on the more sensitive assays.

Markers associated with persisting low-level viraemia under antiretroviral therapy in HIV-1 infection

OBJECTIVES

To identify host and viral characteristics associated with long-term persisting low-level viraemia (PLLV) under antiretroviral therapy (ART).

PATIENTS AND METHODS

Seventy-one ART-treated patients with long-term PLLV (20-250 copies/mL) and 102 control patients with systematically undetectable viral load (VL) were selected retrospectively from ART-treated patients followed at the Ghent HIV reference centre. Host and viral characteristics were compared using univariate and multivariate analyses.

RESULTS

Higher plasma VL at therapy initiation (OR 3.52; 95% CI 1.86-6.65; P < 0.001), therapy re-initiation after an interruption (OR 3.94; 95% CI 1.70-9.16; P = 0.001), male gender (OR 4.28; 95% CI 1.40-13.00; P = 0.011), a protease inhibitor-based regimen (OR 2.90; 95% CI 1.20-6.97; P = 0.017) and predicted CCR5 co-receptor tropism (OR 2.53; 95% CI 1.05-6.11; P = 0.039) were independently associated with PLLV.

CONCLUSIONS

VL at ART initiation, therapy history, gender, ART regimen and co-receptor tropism were independently associated with PLLV. Gender, therapy history, co-receptor tropism and VL at ART initiation could be valuable predictive markers to identify patients at risk for PLLV.

Low-level viremia is associated with non-B subtypes in patients infected with HIV with virological success following HAART introduction

This prospective study aimed to determine factors associated with detection of very low-level viremia in patients infected with HIV-1 with virological success following HAART introduction. Fifty-seven patients, mostly (n = 51, 89%) treated with a protease inhibitor-based regimen, were included and followed for 2 years. Viral loads were monitored by Abbott m2000 RealTime HIV-1. Patients were classified as (i) HIV-RNA-negative if viral loads remained strictly undetectable (0 copies/ml), or (ii) HIV-RNA-positive if at least one HIV-1 RNA could be detected in 1-49 copies/ml during follow-up. At month 24, 44 patients (77%) were in the HIV-RNA-positive group, whereas 13 (23%) remained without very low-level viremia. Univariate analysis, Kaplan-Meier curves and the Cox proportional hazard model revealed that B subtype was the only predictor of belonging to the HIV-RNA-negative group (HR 3.98; 95% CI 1.08-14.7). This association needs to be confirmed. Further study of the reservoir and the mechanisms of viral latency according to HIV-subtype will also be necessary to develop new therapeutic strategies and eradicate HIV infection.

Disparities in engagement in care and viral suppression among persons with HIV

BACKGROUND

Engagement across the spectrum of HIV care can improve health outcomes and prevent HIV transmission. We used HIV surveillance data to examine these outcomes.

METHODS

San Francisco residents who were diagnosed with HIV between 2009 and 2010 were included. We measured the characteristics and proportion of persons linked to care within 6 months of diagnosis, retained in care for second and third visits, and virally suppressed within 12 months of diagnosis.

RESULTS

Of 862 persons included, 750 (87%) entered care within 6 months of diagnosis; of these, 72% had a second visit in the following 3-6 months; and of these, 80% had a third visit in the following 3-6 months. Viral suppression was achieved in 50% of the total population and in 76% of those retained for 3 visits. Lack of health insurance and unknown housing status were associated with not entering care (P < 0.01). Persons with unknown insurance status were less likely to be retained for a second visit; those younger than 30 years were less likely to be retained for a third visit. Independent predictors of failed viral suppression included age <40 years, homelessness, unknown housing status, and having a single or 2 medical visits compared with 3 visits.

CONCLUSIONS

Socioeconomic resources and age, not race or gender, are associated with disparities in engagement in HIV care in San Francisco.

Quantification of viral loads lower than 50 copies per milliliter by use of the Cobas AmpliPrep/Cobas TaqMan HIV-1 test, version 2.0, can predict the likelihood of subsequent virological rebound to >50 copies per milliliter

After 1 year of follow-up, patients on HAART with a baseline viral load (VL) of <20 copies/ml showed significantly lower odds of virological rebound to two consecutive VLs of >50 copies/ml than those with baseline VLs of 20 to 39 and 40 to 49 (P < 0.001). The time to virological rebound was also significantly shorter (P < 0.001) for the groups with baseline VLs of 20 to 39 and 40 to 49.

Increased risk of virologic rebound in patients on antiviral therapy with a detectable HIV load <48 copies/mL

We investigated the independent effects of HIV-1 "target not detected" measurements versus those that were detectable but below the limit of quantification by Taqman RT-PCR assay on subsequent viral rebound as there are conflicting data regarding the clinical implications of arbitrary or isolated low-level viremia. Cox proportional hazard regression modeling was used to investigate the independent effects of the first HIV-1 load measurement after introduction of the Taqman RT-PCR assay (time-point 0 [T0]), pre-T0 viral loads, CD4 T cell count, race/ethnicity, gender, age and NNRTI use on risk of a confirmed VL >50, >200, >400 and >1000 copies/mL at 22 months follow-up in analyses of all patients and propensity-matched baseline cohorts. 778 patients had a viral load that was either not detected by RT-PCR (N = 596) or detectable, but below the limit of quantification (N = 182) at T0. Detectable viremia, lower T0 CD4 count, decreased age, and having detectable or unknown VL within a year prior to T0 were each associated with viral rebound to >50, >200 and >400 copies/mL. Overall failure rates were low and <5.5% of all patients had confirmed VL >1000 copies/mL. A majority of patients with rebound >200 copies/mL subsequently re-suppressed (28 of 53). A detectable VL <48 copies/mL was independently and significantly associated with subsequent viral rebound, and is cause for clinical concern.