Undergoing Treatment Interruption Research Articles

Implications of therapy interruption on monthly migraine days and modified migraine disability assessment in patients treated with erenumab for chronic and episodic migraine: SQUARE study interim results

BackgroundThere are limited real-world data in Switzerland examining the impact of erenumab, a fully human IgG2 monoclonal antibody targeting the calcitonin gene-related peptide (CGRP) receptor, on migraine-related quality of life.ObjectiveThis 18-month interim analysis of 172 patients with episodic or chronic migraine from the SQUARE study provides first prospective insights on the impact of mandatory erenumab treatment interruption, following Swiss-reimbursement requirements, in a real-world clinical setting in Switzerland.FindingsRecruited patients receiving 70 or 140 mg erenumab underwent treatment interruption on average 11.2 months after therapy onset with a mean duration of 4 months. There were sustained improvements in mean monthly migraine days (MMD) and migraine disability (mMIDAS) during initial treatment with erenumab. Treatment interruption was associated with a temporary worsening of condition. Symptoms ameliorated upon therapy reuptake reaching improvements similar to pre-break within 3 months.ConclusionsTreatment interruption was associated with a temporary worsening of condition, which improved again after therapy restart.

Autologous CD4 T Lymphocytes Modified with a Tat-Dependent, Virus-Specific Endoribonuclease Gene in HIV-Infected Individuals

MazF is an Escherichia coli-derived endoribonuclease that selectively cleaves ACA sequences of mRNA prevalent in HIV. We administered a single infusion of autologous CD4T lymphocytes modified to express a Tat-dependent MazF transgene to 10 HIV-infected individuals (six remaining on antiretroviral therapy [ART]; four undergoing treatment interruption post-infusion) in order to provide a population of HIV-resistant immune cells. In participants who remained on ART, increases in CD4 and CD8 Tcell counts of ~200 cells/mm3 each occurred within 2weeks of infusion and persisted for at least 6months. Modified cells were detectable for several months in the blood and trafficked to gastrointestinal lymph tissue. HIV-1 Tat introduced exvivo to the modified CD4+ Tcells induced MazF expression in both pre- and post-infusion samples, and MazF expression was detected invivo post-viral-rebound during ATI. One participant experienced mild cytokine release syndrome. In sum, this study of a single infusion of MazF-modified CD4T lymphocytes demonstrated safety of these cells, distribution to lymph tissue and maintenance of Tat-inducible MazF endoribonuclease activity, as well as sustained elevation of blood CD4 and CD8 Tcell counts. Future studies to assess effects on viremia and latent proviral reservoir are warranted.

Use and Outcomes of Antiretroviral Monotherapy and Treatment Interruption in Adolescents With Perinatal HIV Infection in Asia

PurposeAntiretroviral monotherapy and treatment interruption are potential strategies for perinatally HIV-infected adolescents (PHIVA) who face challenges maintaining effective combination antiretroviral therapy (ART). We assessed the use and outcomes for adolescents receiving monotherapy or undergoing treatment interruption in a regional Asian cohort. MethodsRegional Asian data (2001–2016) were analyzed to describe PHIVA who experienced ≥2 weeks of lamivudine or emtricitabine monotherapy or treatment interruption and trends in CD4 count and HIV viral load during and after episodes. Survival analyses were used for World Health Organization (WHO) stage III/IV clinical and immunologic event-free survival during monotherapy or treatment interruption, and a Poisson regression to determine factors associated with monotherapy or treatment interruption. ResultsOf 3,448 PHIVA, 84 (2.4%) experienced 94 monotherapy episodes, and 147 (4.3%) experienced 174 treatment interruptions. Monotherapy was associated with older age, HIV RNA >400 copies/mL, younger age at ART initiation, and exposure to ≥2 combination ART regimens. Treatment interruption was associated with CD4 count <350 cells/μL, HIV RNA ≥1,000 copies/mL, ART adverse event, and commencing ART age ≥10 years compared with age <3 years. WHO clinical stage III/IV 1-year event-free survival was 96% and 85% for monotherapy and treatment interruption cohorts, respectively. WHO immunologic stage III/IV 1-year event-free survival was 52% for both cohorts. Those who experienced monotherapy or treatment interruption for more than 6 months had worse immunologic and virologic outcomes. ConclusionsUntil challenges of treatment adherence, engagement in care, and combination ART durability/tolerability are met, monotherapy and treatment interruption will lead to poor long-term outcomes.

Safety and efficacy of VRC01 broadly neutralising antibodies in adults with acutely treated HIV (RV397): a phase 2, randomised, double-blind, placebo-controlled trial

HIV-1-specific broadly neutralising antibodies such as VRC01 could promote HIV remission by halting viral replication and clearing infected cells. We investigated whether VRC01 could promote sustained viral control off antiretroviral therapy (ART) in adults who initiated ART during acute HIV infection. We did a randomised, double-blind, placebo-controlled trial at the Thai Red Cross AIDS Research Centre in Bangkok, Thailand. Eligible participants were aged 20-50 years, had initiated ART during acute infection (ie, Fiebig stages I-III), had been taking ART for more than 24 months, had fewer than 50 HIV-1 RNA copies per mL on three consecutive measurements, had more than 400 CD4 cells per μL, had fewer than ten copies of integrated HIV-1 DNA per 106 peripheral blood mononuclear cells, and were in generally good health. Eligible participants were randomly assigned (3:1) based on computer-generated lists with a blocking factor of 4 to receive VRC01 (40 mg/kg) or placebo (saline) intravenously every 3 weeks for up to 24 weeks during analytic interruption of ART, followed by continued observation off all therapies. Randomisation was stratified by Fiebig stage (I vs II vs III) at HIV diagnosis. Participants were monitored closely and resumed ART if 1000 or more HIV-1 RNA copies were detected per mL of plasma. The primary outcomes were the frequency of serious adverse events and the proportion of participants with fewer than 50 HIV-1 RNA copies per mL 24 weeks after treatment interruption. Efficacy analyses included all participants who received at least one full dose of study product, and safety analyses included all participants exposed to any study product. The trial was registered with ClinicalTrials.gov, number NCT02664415. This trial is completed. Between Aug 8, 2016, and Jan 9, 2017, 19 men were randomly assigned, 14 to the VRC01 group and five to the placebo group. One participant in the VRC01 group received a partial infusion without undergoing treatment interruption. The other 18 participants all received at least one full study infusion and underwent ART interruption. No serious adverse events were reported in either group. Only one participant in the VRC01 group achieved the primary efficacy endpoint of viral suppression 24 weeks after ART interruption. The other 17 restarted ART because of a confirmed recording of 1000 or more HIV-1 RNA copies per mL before 24 weeks. VRC01 monotherapy in individuals who initiated ART during acute HIV infection was well tolerated but did not significantly increase the number of participants with viral suppression 24 weeks after ART interruption. Further development of VRC01 and other immunotherapies for HIV will probably occur as part of combination regimens that include several treatments directed against unique therapeutic targets. US Department of the Army, US National Institutes of Health, and the Thai Red Cross AIDS Research Centre.

The Control of HIV After Antiretroviral Medication Pause (CHAMP) Study: Posttreatment Controllers Identified From 14 Clinical Studies.

HIV posttreatment controllers are rare individuals who start antiretroviral therapy (ART), but maintain HIV suppression after treatment interruption. The frequency of posttreatment control and posttreatment interruption viral dynamics have not been well characterized. Posttreatment controllers were identified from 14 studies and defined as individuals who underwent treatment interruption with viral loads ≤400 copies/mL at two-thirds or more of time points for ≥24 weeks. Viral load and CD4+ cell dynamics were compared between posttreatment controllers and noncontrollers. Of the 67 posttreatment controllers identified, 38 initiated ART during early HIV infection. Posttreatment controllers were more frequently identified in those treated during early versus chronic infection (13% vs 4%, P < .001). In posttreatment controllers with weekly viral load monitoring, 45% had a peak posttreatment interruption viral load of ≥1000 copies/mL and 33% had a peak viral load ≥10000 copies/mL. Of posttreatment controllers, 55% maintained HIV control for 2 years, with approximately 20% maintaining control for ≥5 years. Posttreatment control was more commonly identified amongst early treated individuals, frequently characterized by early transient viral rebound and heterogeneous durability of HIV remission. These results may provide mechanistic insights and have implications for the design of trials aimed at achieving HIV remission.

Local failure and acute radiodermatological toxicity in patients undergoing radiation therapy with and without postmastectomy chest wall bolus: Is bolus ever necessary?

PurposePostmastectomy chest wall radiation therapy has historically used bolus to increase dose at the skin surface. Despite the theoretical benefits of bolus, the clinical implications of locoregional tumor control, cosmesis, and the incidence of radiodermatitis are less well characterized. We hypothesized that treatment in the presence or absence of bolus results in equivalent chest wall recurrence rates, but its presence results in more severe acute dermatologic toxicity. Methods and materialsLocally advanced breast cancer patients undergoing chest wall radiation therapy were retrospectively reviewed from 2005 to 2015 (n = 106; 53 with bolus, 53 without). Outcomes including local failure, acute skin toxicity, and treatment interruptions were recorded. Median age was 59 years (range, 28-91) and median follow-up was 34 months. Histology was invasive ductal carcinoma (73%), invasive lobular carcinoma (20%), inflammatory (6%), and neuroendocrine (1%). Fifty-nine percent were T3/T4 primary tumors and 29.2% had clinical/pathologic skin involvement. Node-positive patients accounted for 80.2%. Chemotherapy was administered in 84.0%. All patients had 3-dimensional conformal radiation therapy and received a median dose of 61Gy (range, 50-63 Gy). ResultsLocal failure was 6.6% (n = 7) overall, with 4 failures in the bolus group and 3 in the no bolus group. No pathological factors were associated with local failure. Acute grade 2 and 3 skin toxicities (37 vs 22) and treatment interruptions (20 vs 3) were more common in the bolus group (P < .05). Mean treatment interruption (14.5 vs 5 days) was longer for patients receiving bolus. Patients undergoing treatment interruption were more likely to fail locally than patients not requiring a treatment interruption (17.4% vs 3.6%, P = .0322). ConclusionsBolus omission in adjuvant chest wall radiation therapy may be a reasonable approach to avoid acute skin toxicity and treatment interruptions while preserving local control; however, further study will be needed to reach a definitive conclusion.

Treatment interruption in chronically HIV-infected patients with an ultralow HIV reservoir

To investigate the potential for combination antiretroviral therapy (cART)-free remission following analytic treatment interruption (ATI) in chronically HIV-infected patients with ultralow cell-associated DNA. Pilot study of patients (pts) with plasma viral load (pVL) less than 50 copies/ml for more than 2 years on cART, CD4 above 500 cells/μl, CD4/CD8 above 0.9, CD4 nadir above 300 cells/μl and HIV-DNA below 100 copies/10 peripheral blood mononuclear cells (PBMCs), undergoing treatment interruption. Ultrasensitive pVL, CD4 cell count, triplicate HIV-DNA were measured at D0, W2, W4, and every 4 weeks off-ART until W48 and at W4, W12 and W24 after ART resumption (RxR). RxR occurred in case of pVL rebound above 400 copies/ml or CD4 above 400 cells or HIV-related clinical event. The primary endpoint was the percentage of patients who did not reach RxR criteria at W24. Individuals were to be enrolled in three cohorts of five. Enrolment in cohort 2 began if at least one of five patients from cohort 1 remained in success at W8. Cohort 3 did not start. Ten patients were enrolled, with median (range) CD4 1118 cells/μl (608-1494), CD4/CD8 2.1 (1.4-2.6), HIV-DNA 66 copies/10 PBMC (<66-66) at screening, viral suppression of 4.9 years (2.9-8.3), CD4 nadir 495 cells/μl (330-739). One patient remained off-ART up to W48. Viral rebound occurred in nine of 10 patients at W2 (2 patients), W4 (6 patients) and W12 (one patient). pVL was resuppressed on cART at W4 (8 patients) and W12 (one patient). HIV DNA returned to baseline values within a median of 12 weeks following RxR. In a highly selected population of 10 patients with chronic HIV infection, an excellent immune status, durable virological suppression and ultralow reservoir, the success rate of ATI was 10% (95% confidence interval 0.3-44.5%) and nine of 10 patients had prompt rebound of plasma viremia. Resumption of ART led to return to baseline cell-associated total DNA.

Origin of Rebound Plasma HIV Includes Cells with Identical Proviruses That Are Transcriptionally Active before Stopping of Antiretroviral Therapy.

Understanding the origin of HIV variants during viral rebound may provide insight into the composition of the HIV reservoir and has implications for the design of curative interventions. HIV single-genome sequences were obtained from 10 AIDS Clinical Trials Group participants who underwent analytic antiretroviral therapy (ART) interruption (ATI). Rebounding variants were compared with those in pre-ART plasma in all 10 participants and with on-ART peripheral blood mononuclear cell (PBMC)-associated DNA and RNA (CA-RNA) in 7/10 participants. The highest viral diversities were found in the DNA and CA-RNA populations. In 3 of 7 participants, we detected multiple, identical DNA and CA-RNA sequences during suppression on ART that exactly matched plasma HIV sequences. Hypermutated DNA and CA-RNA were detected in four participants, contributing to diversities in these compartments that were higher than in the pre-ART and post-ATI plasma. Shifts in the viral rebound populations could be detected in some participants over the 2- to 3-month observation period. These findings suggest that a source of initial rebound viremia could be populations of infected cells that clonally expanded prior to and/or during ART, some of which were already expressing HIV RNA before treatment was interrupted. These clonally expanding populations of HIV-infected cells may represent an important target for strategies aimed at achieving reservoir reduction and sustained virologic remission. Antiretroviral therapy alone cannot eradicate the HIV reservoir, and viral rebound is generally rapid after treatment interruption. It has been suggested that clonal expansion of HIV-infected cells is an important mechanism of HIV reservoir persistence, but the contribution of these clonally proliferating cells to the rebounding virus is unknown. We report a study of AIDS Clinical Trials Group participants who underwent treatment interruption and compared rebounding plasma virus with that found within cells prior to treatment interruption. We found several incidences in which plasma HIV variants exactly matched that of multiple proviral DNA copies from infected blood cells sampled before treatment interruption. In addition, we found that these cells were not dormant but were generating unspliced RNA transcripts before treatment was interrupted. Identification of the HIV reservoir and determining its mechanisms for persistence may aid in the development of strategies toward a cure for HIV. (This study was presented in part at the Conference on Retroviruses and Opportunistic Infections, Seattle, WA, February 23 to 26 2015.).

HIV Reactivation from Latency after Treatment Interruption Occurs on Average Every 5-8 Days--Implications for HIV Remission.

HIV infection can be effectively controlled by anti-retroviral therapy (ART) in most patients. However therapy must be continued for life, because interruption of ART leads to rapid recrudescence of infection from long-lived latently infected cells. A number of approaches are currently being developed to ‘purge’ the reservoir of latently infected cells in order to either eliminate infection completely, or significantly delay the time to viral recrudescence after therapy interruption. A fundamental question in HIV research is how frequently the virus reactivates from latency, and thus how much the reservoir might need to be reduced to produce a prolonged antiretroviral-free HIV remission. Here we provide the first direct estimates of the frequency of viral recrudescence after ART interruption, combining data from four independent cohorts of patients undergoing treatment interruption, comprising 100 patients in total. We estimate that viral replication is initiated on average once every ≈6 days (range 5.1- 7.6 days). This rate is around 24 times lower than previous thought, and is very similar across the cohorts. In addition, we analyse data on the ratios of different ‘reactivation founder’ viruses in a separate cohort of patients undergoing ART-interruption, and estimate the frequency of successful reactivation to be once every 3.6 days. This suggests that a reduction in the reservoir size of around 50-70-fold would be required to increase the average time-to-recrudescence to about one year, and thus achieve at least a short period of anti-retroviral free HIV remission. Our analyses suggests that time-to-recrudescence studies will need to be large in order to detect modest changes in the reservoir, and that macaque models of SIV latency may have much higher frequencies of viral recrudescence after ART interruption than seen in human HIV infection. Understanding the mean frequency of recrudescence from latency is an important first step in approaches to prolong antiretroviral-free viral remission in HIV.

Added Value of Deep Sequencing Relative to Population Sequencing in Heavily Pre-Treated HIV-1-Infected Subjects

ObjectiveTo explore the potential of deep HIV-1 sequencing for adding clinically relevant information relative to viral population sequencing in heavily pre-treated HIV-1-infected subjects.MethodsIn a proof-of-concept study, deep sequencing was compared to population sequencing in HIV-1-infected individuals with previous triple-class virological failure who also developed virologic failure to deep salvage therapy including, at least, darunavir, tipranavir, etravirine or raltegravir. Viral susceptibility was inferred before salvage therapy initiation and at virological failure using deep and population sequencing genotypes interpreted with the HIVdb, Rega and ANRS algorithms. The threshold level for mutant detection with deep sequencing was 1%.Results7 subjects with previous exposure to a median of 15 antiretrovirals during a median of 13 years were included. Deep salvage therapy included darunavir, tipranavir, etravirine or raltegravir in 4, 2, 2 and 5 subjects, respectively. Self-reported treatment adherence was adequate in 4 and partial in 2; one individual underwent treatment interruption during follow-up. Deep sequencing detected all mutations found by population sequencing and identified additional resistance mutations in all but one individual, predominantly after virological failure to deep salvage therapy. Additional genotypic information led to consistent decreases in predicted susceptibility to etravirine, efavirenz, nucleoside reverse transcriptase inhibitors and indinavir in 2, 1, 2 and 1 subject, respectively. Deep sequencing data did not consistently modify the susceptibility predictions achieved with population sequencing for darunavir, tipranavir or raltegravir.ConclusionsIn this subset of heavily pre-treated individuals, deep sequencing improved the assessment of genotypic resistance to etravirine, but did not consistently provide additional information on darunavir, tipranavir or raltegravir susceptibility. These data may inform the design of future studies addressing the clinical value of minority drug-resistant variants in treatment-experienced subjects.

Immune correlates of CD4 decline in HIV-infected patients experiencing virologic failure before undergoing treatment interruption

BackgroundThe advantage of treatment interruptions (TIs) in salvage therapy remains controversial. Regardless, characterizations of the correlates of CD4 count fall during TI are important to identify since patients with virologic failure commonly stop antiretroviral (ARV) therapy. The objective of this study was to determine the predictive value of pre-TI proliferative capacity and cell surface markers for CD4 count change in HIV-infected patients experiencing virologic failure before undergoing TI.MethodsPeripheral blood mononuclear cells (PBMCs) from 13 HIV-infected patients experiencing virologic failure at baseline time points before the TI were tested for proliferation using the 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution assay and a Gag p55 peptide pool, staphylococcus enterotoxin B (SEB), cytomegalovirus (CMV) recall antigen, and anti-CD3 antibody as stimuli. CD28 and CD57 expression on CD4+ and CD8+ T-cells was measured.ResultsThe median changes in the CD4+ T-cell count and viral load from baseline to the TI time point corresponding to the CD4 count nadir were -44 cells/mm3 {Interquartile range (IQR) -17, -104} and +85,332 copies/mL (IQR +11,198, +283,327), respectively. CD4+ T-cell proliferation to CMV, pre-TI CD4+ T-cell count, and percent CD4+CD57+ cells correlated negatively with CD4 count change during TI (r = -0.59, p = 0.045, r = -0.61, p = 0.030 and r = -0.69, p = 0.0095, respectively; Spearman correlation). The presence of HIV-specific proliferative responses was not associated with a reduced decline in CD4 count during TI.ConclusionThe use of pre-TI immune proliferative responses and cell surface markers may have predictive value for CD4 count decline during TI.

HIV‐1 replication capacity and genotype changes in patients undergoing treatment interruption or lamivudine monotherapy

The objective of this study was to investigate the mechanisms underlying the virological and immunological changes occurring in failing HIV-1 infected patients undergoing treatment interruption or lamivudine monotherapy (the E-184V Study). Associations were sought between the de-selection of individual reverse transcriptase and protease resistance mutations and replication capacity recovery, HIV-RNA changes, and immunological changes. The replication capacity recovery was defined as the ratio between the replication capacity at weeks 24 or 48, and that measured at baseline. The replication capacity recovery, which was evaluable in 21 patients at week 24 and in 18 at week 48, was significantly higher in the treatment interruption than in the lamivudine group at week 24 (P = 0.002). Forty-eight week replication capacity recovery was greater when the 184V (P = 0.023), the 41L (P = 0.02), or the 215Y mutation (P = 0.037) were deselected at week 12. A greater reduction in the CD4+/CD8+ ratio at week 48 (P = 0.038) was observed as the 184V mutation was deselected and the de-selection of the 184V mutation at week 12 was the only independent predictor of the change of the CD4+/CD8+ ratio at week 48 from baseline at multivariable analysis (F-value = 6.72, P = 0.021). In conclusion, among patients undergoing treatment interruption or lamivudine monotherapy, the recovery of HIV-1 replication capacity was associated with the de-selection of reverse transcriptase mutations. The de-selection of the 184V mutation predicts independently a reduction in the CD4+/CD8+ ratio.

Favorable outcome of ex‐vivo purging of monocytes after the reintroduction of treatment after interruption in patients infected with multidrug resistant HIV‐1

In multidrug resistant patients treatment interruptions allow the selection of archived wild-type drug-susceptible viruses that compete for the less fit drug-resistant strains. However, the selection of viruses with increased replicative capacity is often followed by a loss of CD4+ T cells. In addition, drug resistant variants later re-emerge limiting the overall clinical benefit of treatment interruption. Blood monocytes are a key component of the HIV reservoir and can be partially removed by a system for purging of myeloid cells (MYP). This study tested the safety and efficacy of MYP on multidrug resistant patients who underwent treatment interruption. Twelve patients were randomized to receive or not six cycles of MYP during treatment interruption. An optimized antiretroviral regimen was reintroduced after the reappearance of a drug susceptible genotype. Following therapy reintroduction, a long lasting increase in CD4+ T cell counts was observed only in the treatment interruption + MYP patients but not in the control patients. Five/six treatment interruption + MYP patients never experienced virological rebound during a median follow up period of 98 weeks. In contrast, 4/6 patients who did not receive MYP never reached complete viral suppression and had a virological rebound after a median of 16.5 weeks after treatment reintroduction. The difference between the two groups in the time to virological rebound was statistically significant (P = 0.021). A consistent decrease of HIV DNA load in CD14+ purified cells was observed only in treatment interruption + MYP patients. These data suggest that MYP can improve the immunological and virological response to treatment interruption.

Risk of selecting resistance mutations during treatment interruption

To describe the evolution of drug-resistant mutations in patients undergoing treatment interruption strategies. We discuss potential predictors for selecting resistant mutations during treatment interruption. Current studies on the evolution of drug-resistant mutations during treatment interruption show a low selection frequency for de-novo and archived mutations. The de-novo selection of resistant mutations increases when lamivudine or non-nucleoside reverse transcriptase inhibitor-containing regimens are withdrawn. Although treatment interruption in the context of failing antiretroviral therapy induces the selection of more drug-susceptible strains, resistant virus remains archived and re-emerges once therapy is re-administered, thus thwarting long-term clinical benefits. Alternatively, partial treatment interruption data support the evaluation of treatment strategies aimed at maintaining the benefit of therapy while reducing drug exposure. The safety and efficiency of treatment interruption strategies remain controversial. The selection of new drug-resistance mutations during treatment interruption is not a key factor in accelerating disease progression when compared with continuous therapy. Conversely, reversion towards more drug-susceptible virus after treatment interruption in heavily treated patients may be accompanied by increased viral pathogenicity, and provides little clinical benefit in subsequent HIV-1 chemotherapy. Partial treatment interruption may be valuable in this context, but larger randomized clinical trials are needed.

Evolution of HIV resistance during treatment interruption in experienced patients and after restarting a new therapy

Background To analyse the evolution of resistance patterns in patients undergoing treatment interruption (TI) and reinitiating highly active anti-retroviral therapy (HAART). Methods HIV- RT and - PR gene-sequences were analysed in 14 patients (>5 failing prior drugs) before and during TI and under a new HAART. Genotypes were interpreted using two bioinformatics systems. Additionally, virus load (VL) and CD4 +-T-cell counts were measured. Results Six patients (42%) achieved sustained undetectable VL up to one year after TI (responders), while 8 (57%) maintained VL of more than 2000 copies/mL (non-responders). Different patterns of resistance-mutations evolution were detected. During TI loss of all mutations was observed in three patients, a reduction of mutations was detected in seven patients, and no alteration was seen in four patients. In the responders, 87.5% of protease inhibitor (PI)-resistance mutations waned during TI and remained undetectable under the new treatment. In contrast, in the non-responder group most PI-resistance mutations continued noticeable under the new therapy. Loss of primary PI-resistance mutations and the presence of one fully active PI in the new regimen significantly correlated with success of subsequent treatment ( p = 0.028). In two patients new reverse transcriptase associated mutations were detected during TI, G190A (NNRTI mutation) and K70R (NRTI mutation). Appearance of K70R could be explained by a reverse direction of a previously described pathway of thymidin analogues mutation resistance development, while G190A could be due to prolonged subinhibitory drug levels after cessation of NNRTIs. Conclusion In the evolution of HAART-resistance, different patterns were observed in responders and non-responders during but not before TI. Absence of PI-resistance associated mutations during and after TI and administration of a predicted fully active PI for the new therapy correlated with success. Newly detected mutations during TI may indicate reversibility of previously described mutational pathways.

Comprehensive analysis of human immunodeficiency virus type 1-specific CD4 responses reveals marked immunodominance of gag and nef and the presence of broadly recognized peptides.

Increasing evidence suggests that human immunodeficiency virus type 1 (HIV-1)-specific CD4 T-cell responses contribute to effective immune control of HIV-1 infection. However, the breadths and specificities of these responses have not been defined. We screened fresh CD8-depleted peripheral blood mononuclear cells (PBMC) from 36 subjects at different stages of HIV-1 infection for virus-specific CD4 responses by gamma interferon enzyme-linked immunospot assay, using 410 overlapping peptides spanning all HIV-1 proteins (based on the clade B consensus sequence). HIV-1-specific CD4 responses were identified in 30 of the 36 individuals studied, with the strongest and broadest responses detected in persons treated in acute infection who underwent treatment interruption. In individuals with identified responses, the total number of recognized HIV-1 peptides ranged from 1 to 36 (median, 7) and the total magnitude of responses ranged from 80 to >14,600 (median, 990) spot-forming cells/10(6) CD8-depleted PBMC. Neither the total magnitude nor the number of responses correlated with viremia. The most frequent and robust responses were directed against epitopes within the Gag and Nef proteins. Peptides targeted by >/=25% of individuals were then tested for binding to a panel of common HLA-DR molecules. All bound broadly to at least four of the eight alleles tested, and two bound to all of the HLA-DR molecules studied. Fine mapping and HLA restriction of the responses against four of these peptides showed a combination of clustering of epitopes and promiscuous presentation of the same epitopes by different HLA class II alleles. These findings have implications for the design of immunotherapeutic strategies and for testing candidate HIV vaccines.

Q151M-mediated multinucleoside resistance: prevalence, risk factors, and response to salvage therapy.

Among 470 patients with acquired immune deficiency syndrome and/or human immunodeficiency virus infection (HIV/AIDS) who underwent genotype resistance testing (GRT) after the failure of therapy, 17 (3.6%) harbored the Q151M mutation. The Q151M mutation was associated with younger age, lower CD4(+) lymphocyte count, higher HIV RNA level, and treatment with >2 pre-GRT regimens. By contrast, the Q151M mutation was inversely associated with lamivudine administration. A full reversion of the Q151M mutation was observed in 5 of 5 patients who underwent treatment interruption after GRT. The reversion was followed by a response to salvage therapy in 4 (80%) of 5 patients.