Long-term evaluation of triple nucleoside therapy administered from primary HIV-1 infection

Levels of HIV-1 in subgingival biofilm of HIV-infected patients

AIM

The aims of the current study were to compare the levels of HIV-1 in the subgingival biofilm (SHVL) between detectable and undetectable plasmatic HIV-1 viral load (PHVL) in HIV-infected patients as well as to determine the association of SHVL with PHVL and clinical periodontal parameters.

MATERIAL AND METHODS

Forty-one HIV-infected individuals were divided into two groups: detectable (21) and undetectable (20) PHVL. Subgingival biofilm samples were obtained for detection and quantification of HIV-1 by real-time RT-PCR. To estimate the effect of co-variables on the outcome undetectable SHVL, the Generalized Estimation Equation (GEE) was employed.

RESULTS

Detectable SHVL was observed only in the detectable PHVL group and the detection of the HIV-1 was observed in 40% of these individuals. In the bivariate analysis between co-variables from the individual level and the outcome SHVL, significant difference was observed only for the CD4+ T lymphocytes levels (p = 0.017). The multiple logistic model demonstrated that only CD4+ T lymphocytes levels had a significant effect on the outcome undetectable SHVL [OR 8.85 (CI 3.6-9.2), p = 0.002].

CONCLUSION

HIV-1 can be detected and quantified in the subgingival biofilm of HIV-infected individuals, but these findings are not associated with PHVL and periodontal clinical parameters.

The Development and Implementation of an Outreach Program to Identify Acute and Recent HIV Infections in New York City

Introduction:

Since 2004, the authors have been operating First Call NYU, an outreach program to identify acute and recent HIV infections, also called primary HIV infections, among targeted at-risk communities in the New York City (NYC) metropolitan area.

Materials and Methodology:

First Call NYU employed mass media advertising campaigns, outreach to healthcare providers in NYC, and Internet-based efforts including search engine optimization (SEO) and Internet-based advertising to achieve these goals.

Results:

Between October 2004 and October 2008, 571 individuals were screened through this program, leading to 446 unique, in-person screening visits. 47 primary HIV infections, including 14 acute and 33 recent HIV infections, were identified.

Discussion:

Internet and traditional recruitment methods can be used to increase self-referrals for screening following possible exposure to HIV.

Conclusion:

Community education of at-risk groups, with the goal of increased self-diagnosis of possible acute HIV infection, may be a useful addition to traditional efforts to identify such individuals.

LPS reduces HIV-1 replication in primary human macrophages partly through an endogenous production of type I interferons

It has been proposed that the systemic immune activation state seen in HIV-1-infected patients is caused by circulating microbial products such as lipopolysaccharide (LPS). Given that macrophages play a key role in HIV-1 pathogenesis, we investigated the LPS-mediated effect on HIV-1 replication in cells of the myeloid lineage. We demonstrate that LPS promotes virus gene expression in a monocytic cell line while it diminishes virus production in primary human monocyte-derived macrophages (MDM). The incapacity of LPS to drive HIV-1 production in MDM was not due to its inability to activate the ubiquitous transcription factor NF-kappaB even in virus-infected cells. Neutralization of type I interferons (IFN) with B18R, a soluble vaccinia virus-coded type I IFN receptor, significantly but not totally diminished the antiviral activity of LPS. Therefore, inhibition of HIV-1 replication in MDM treated with microbial-derived LPS resulted from the induction of type I interferons and a yet to be defined soluble factor.

Early infant human immunodeficiency virus type 1 detection suitable for resource-limited settings with multiple circulating subtypes by use of nested three-monoplex DNA PCR and dried blood spots

The early detection of human immunodeficiency virus type 1 (HIV-1) infection in infants is complicated by the persistence of maternal antibodies and by diverse HIV-1 subtypes. We developed a nested, three-monoplex HIV-1 DNA PCR (N3M-PCR) assay to detect diverse HIV-1 subtypes in infants born to infected mothers. We optimized the test for use with dried blood spot (DBS) samples for ease of storage and transport from rural China to central laboratories. Six pairs of primers were designed that targeted env, gag, and pol genes, and the test was run in three reactions with an analytical sensitivity of 10 copies DNA per reaction to cover nine HIV-1 subtypes, A, B, C, D, F, G, CRF01-AE, CRF08-BC, and CRF07-BC. The assay performance was evaluated on 347 DBS specimens from 151 exposed infants in four diverse provinces of China in which multiple subtypes were circulating. The results of this test were compared to those of HIV antibody enzyme immunoassay and Western blotting confirmation for the infants at > or =18 months of age or to convincing clinical and epidemiologic data for deceased infants. The sensitivity of the N3M-PCR assay was 30.0% (3/10) for infants at 48 h after birth, 91.7% (11/12) at 1 to 2 months of age, and 93.7% (15/16) at 3 to 6 months of age. The specificity was 100% (94/94) at all three time points. The PCR reproducibility in the three DNA regions was 100% for samples at 48 h after birth, 96.7% at 1 to 2 months, and 100% at 3 to 6 months of age. The HIV-1 DNA N3M-PCR assay on DBSs offers a simple and affordable approach for early infant HIV-1 diagnosis in regions with diverse HIV-1 circulating subtypes.

Probability of resistance evolution for exponentially growing virus in the host

Chemotherapy for tumor and pathogenic virus often faces an emergence of resistant mutants, which may lead to medication failure. Here we study the risk of resistance to evolve in a virus population which grows exponentially. We assume that infected cells experience a "proliferation event" of virus at a random time and that the number of newly infected cells from an infected cell follows a Poisson distribution. Virus starts from a single infected cell and the virus infection is detected when the number of infected cells reaches a detection size. Initially virus is sensitive to a drug but later acquires resistance by mutations. We ask the probability that one or more cells infected with drug-resistant virus exist at the time of detection. We derive a formula for the probability of resistance and confirm its accuracy by direct computer simulations. The probability of resistance increases with detection size and mutation rate but decreases with the population growth rate of sensitive virus. The risk of resistance is smaller when more cells are newly infected by viral particles from a single infected cell if the viral growth rate is the same.

Monocyte-derived macrophages and myeloid cell lines as targets of HIV-1 replication and persistence

HIV infection of mononuclear phagocytes (MP), mostly as tissue macrophages, is a dominant feature in the pathogenesis of HIV disease and its progression to AIDS. Although the general mechanism of infection is not dissimilar to that of CD4+ T lymphocytes occurring via interaction of the viral envelope with CD4 and a chemokine receptor (usually CCR5), other features are peculiar to MP infection. Among others, the long-term persistence of productive infection, sustained by the absence of substantial cell death, and the capacity of the virions to bud and accumulate in intracellular multivesicular bodies (MVB), has conferred to MP the role of "Trojan horses" perpetuating the chronic state of infection. Because the investigation of tissue macrophages is often very difficult for both ethical and practical reasons of accessibility, most studies of in vitro infection rely upon monocyte-derived macrophages (MDM), a methodology hampered by inter-patient variability and lack of uniformity of experimental protocols. A number of cell lines, mostly Mono Mac, THP-1, U937, HL-60, and their derivative chronically infected counterparts (such as U1 and OM-10.1 cell lines) have complemented the MDM system of infection providing useful information on the features of HIV replication in MP. This article describes and compares the most salient features of these different cellular models of MP infection by HIV.

Diminished Representation of HIV-1 Variants Containing Select Drug Resistance-Conferring Mutations in Primary HIV-1 Infection

This study compared the incidence of HIV-1 variants harboring mutations conferring resistance to thymidine analogues, ie, thymidine analogue mutations (TAMs), nonnucleoside reverse transcriptase (RT) inhibitors (NNMs), lamivudine (3TC) (ie, M184V), and protease inhibitors (PIs) acquired in primary HIV infection (PHI) (n = 59) to their observed prevalence in a corresponding potential transmitter (PT) population of persons harboring resistant infections (n = 380). Both of these populations in the context of this cohort analysis possessed similar demographics. Whereas the frequencies of observed TAMs, NNMs, M184V, and protease-associated mutations (PRAMs) were similar in the PT groups, the prevalence of M184V and major PI mutations were significantly lower in the PHI group (PHI/PT ratios of 0.14 and 0.39, respectively). There was a decreased prevalence in the PHI population of resistant viruses co-expressing NNMs or TAMs with M184V compared with viruses that harbored NNMs or TAMs in the absence of M184V (P < 0.0001). It was also observed that individuals in the PT subgroups who harbored RT mutations or PRAMs with M184V had lower levels of plasma viremia than individuals who lacked M184V (P < 0.05). These findings suggest that both decreased viremia and viral fitness in the case of M184V-containing HIV-1 variants may impact on viral transmissibility.

HIV-1 reservoirs

In most infected individuals, HIV-1 replicates high levels throughout the duration of infection, including the clinically quiescent phase of disease. The level of this active viral replication correlates directly with disease progression and survival. The advent of combination therapeutics for HIV-1 (i.e., highly active antiretroviral therapy [HAART]) has led to dramatic reductions in viral replication in vivo and morbidity and mortality, at least in the developed world.

Residual HIV-1 disease in seminal cells of HIV-1-infected men on suppressive HAART: latency without on-going cellular infections

BACKGROUND

HIV-1-infected men on suppressive highly active antiretroviral therapy (HAART) have a reduction of viral replication in vivo, but HIV-1 RNA is still detectable by certain ultrasensitive reverse transcriptase-PCR assays in blood plasma. Replication-competent virus can also be isolated from both peripheral blood mononuclear cells (PBMC) and seminal cells of these patients. Despite HAART, on-going in vivo infection of HIV-1-seropositive patients' PBMC was demonstrated by the detection of episomal HIV-1 moieties, known as HIV-1 two-long terminal repeat (2-LTR) DNA circles.

METHODS

The present study analyzes whether new cellular infections occur in vivo in seminal cells of HIV-1-infected men on suppressive HAART. PBMC and seminal cells were isolated from a cohort of HIV-1-seropositive men taking suppressive HAART (< 50 copies HIV RNA/ml blood plasma). Viral growth assays were performed in vitro, as well as semi-quantitative PCR to detect HIV-1 2-LTR circular DNA in PBMC and seminal mononuclear cells.

RESULTS

Viral growth in vitro was demonstrated in 16 out of 28 (57%) patients' PBMC, and in five patients' seminal cells (18%). Although 18 patients' PBMC were positive for HIV-1 2-LTR DNA circles, importantly, 2-LTR circular DNA was not detected in any semen sample, even when replication-competent HIV-1 virus had been recovered from a patient's seminal cells by viral co-culture assays.

CONCLUSIONS

The current study suggests that in HIV-1-infected men treated with suppressive HAART, new cellular infections occur in PBMC, but that new infections do not take place in seminal cells in vivo. Thus, these findings suggest that mainly latent HIV-1 occurs in seminal cells of men on suppressive HAART, which may be a compartment-specific mechanism of residual HIV-1 disease.

Decay of HIV type 1 DNA and development of drug-resistant mutants in patients with primary HIV type 1 infection receiving highly active antiretroviral therapy

The present study was aimed at describing the effect of highly active antiretroviral therapy (HAART) in 10 patients with primary HIV infection (PHI). Clearance rates of HIV RNA and HIV DNA in peripheral blood as well as the preexistence and the emergence of drug-resistant strains of HIV were determined over 52 weeks of treatment. The data indicate that HAART is able to induce a suppression of plasma viral load together with a significant decrease, but not a suppression, of peripheral blood mononuclear cell-associated proviral DNA in PHI subjects. Analysis of drug-resistant strains revealed that three PHI patients, showing a complete virologic response, developed mutations in the pol gene, thus suggesting that a persistent residual virus replication exists despite a sustained suppression of plasma viremia.

Current review and clinical management of patients with primary HIV-1 infection: limits and perspectives

Acute primary HIV-1 infection (PHI) remains underestimated or misdiagnosed in clinical practice. Meanwhile, it has been demonstrated that early therapeutic interventions with highly active antiretroviral therapy (HAART) may delay disease progression and possibly preserve and expand the most effective immune effector T-cells against HIV together with the humoral immune responses. Since long-life HAART is an unachievable goal due to long-term toxicity and risk of occurrence of resistant strains due to a decreased compliance or other still undefined host factors, preliminary data of programmed treatment interruption in patients treated for PHI suggest that a significant number (30-50%) could benefit from long periods off therapy. However, in more than half of them, the viral load will rebound, justifying that treatment be reinitiated. In order to reduce this proportion, new options are currently being investigated, including adjunctive immune therapy to HAART such as cytokines or vaccines, which could tackle the viral rebounds by increasing HIV-specific cellular responses. An update on the management of patients with PHI is reviewed and the limits of the current standard of care are discussed.

Proviral HIV-1 DNA in subjects followed since primary HIV-1 infection who suppress plasma viral load after one year of highly active antiretroviral therapy

OBJECTIVE

An assessment of the impact of one year potent antiretroviral treatment initiated during primary HIV infection on the cell-associated viral burden.

DESIGN AND METHODS

Proviral HIV-1 DNA was quantified in serial peripheral blood mononuclear cell (PBMC) samples from 19 patients enrolled in the French prospective PRIMO Cohort for whom plasma HIV RNA was suppressed to undetectable levels after one year of triple therapy; that is, plasma HIV-1 RNA was maintained below 200 copies/ml. Results were compared with those observed in 19 patients with chronic HIV-1 infection presenting the same degree of virus suppression after 12 months of treatment.

RESULTS

At study entry, PRIMO subjects presented heterogeneous levels of proviral HIV-1 DNA: 2-3.92 log10 copies/10(6) PBMC and plasma HIV RNA: 2.3-6.5 log10 copies/ml. One year of effective highly active antiretroviral therapy (HAART) resulted in a median diminution of proviral DNA of -0.78 log10/10(6) PBMC in PRIMO subjects. The median decline in chronic-phase patients was -0.32 for those who were pre-treated and -0.52 for those previously naive of treatment.

CONCLUSION

The decline in cell-associated HIV DNA observed throughout one year treatment indicated that HAART reduces the proviral HIV-DNA load more effectively when initiated during the primary rather than the chronic phase of HIV infection. These findings therefore tend to lend support to the early initiation of treatment. Nevertheless, heterogeneous baseline values observed for CD4 cell count, plasma HIV RNA and proviral HIV DNA in PRIMO subjects, raise the question of whether treatment should be delayed in some to spare early adverse effects of HAART.

Concentrations of human immunodeficiency virus type 1 (HIV-1) RNA in cerebrospinal fluid after antiretroviral treatment initiated during primary HIV-1 infection

In 6 patients with primary human immunodeficiency virus type 1 (HIV-1) infection, concentrations of HIV-1 RNA and beta(2)-microglobulin were monitored in cerebrospinal fluid (CSF) and in plasma during antiretroviral therapy. Four patients had neurological symptoms. At baseline, the CSF of 5 patients had detectable levels of HIV-1 RNA (median, 3.68 log(10) copies/mL; range, <2.60-5.67 log(10) copies/mL), and the CSF of 3 patients had elevated levels of beta(2)-microglobulin. After 8 weeks of treatment, the median concentrations of HIV-1 RNA in CSF had decreased to <2.60 log(10) copies/mL (range, <1.60-3.00 log(10) copies/mL; P=.04) and in plasma to 3.07 log(10) copies/mL (range, 2.57-3.79 log(10) copies/mL; P=.03). Median concentration of beta(2)-microglobulin in CSF had decreased to 1.2 mg/L (range, 0.9-1.7 mg/L; P=.06) and, in plasma, to 1.7 mg/L (range, 1.1-2.2 mg/L; P=.03). After 48 weeks, HIV-1 RNA concentrations in 1 patient were still 1.97 log(10) copies/mL in CSF and 1.51 log(10) copies/mL in plasma, although beta(2)-microglobulin concentrations in CSF and plasma had normalized after 8 weeks.

Quantification of human immunodeficiency virus type 1 proviral load by a TaqMan real-time PCR assay

Proviral human immunodeficiency virus type 1 (HIV-1) DNA could be a useful marker for exploring viral reservoirs and monitoring antiretroviral treatment, particularly when HIV-1 RNA is undetectable in plasma. A new technique was developed to quantify proviral HIV-1 using a TaqMan real-time PCR assay. One copy of proviral HIV-1 DNA could be detected with 100% sensitivity for five copies and the assay had a range of 6 log(10). Reproducibility was evaluated in intra- and interassays using independent extractions of the 8E5 cell line harboring the HIV-1 proviral genome (coefficients of variation [CV], 13 and 27%, respectively) and peripheral blood mononuclear cells (PBMC) from a patient with a mean proviral load of 26 copies per 10(6) PBMC (CV, 46 and 56%, respectively). The median PBMC proviral load of 21 patients, measured in a cross-sectional study, was determined to be 215 copies per 10(6) PBMC (range, <10 to 8,381). In a longitudinal study, the proviral load of 15 out of 16 patients with primary infection fell significantly during 1 year of antiretroviral therapy (P = 0.004). In the remaining patient, proviral HIV-1 DNA was detectable but not quantifiable due to a point mutation at the 5' end of the TaqMan probe. No correlation was observed between proviral load and levels of CD4(+) cells or HIV-1 RNA in plasma. TaqMan PCR is sensitive and adaptable to a large series of samples. The full interest of monitoring proviral HIV-1 DNA can now be ascertained by its application to the routine monitoring of patients.

Residual HIV-1 RNA in blood plasma of patients taking suppressive highly active antiretroviral therapy

Residual HIV-1 disease remains in the vast majority of patients treated with even the most intensive highly active antiretroviral therapy (HAART). There are at least two well-described molecular mechanisms for HIV-1 persistence in these patients. These include proviral latency in resting CD4+ T-cells, as well as 'cryptic' residual viral replication. As well, potential sanctuary sites, including the brain and testes, may be important areas which will hinder HIV-1 eradication attempts. It is not clear whether other sites of HIV-1 persistence, including tissue-bound infected monocytes/macrophages, may also be involved in residual HIV-1 disease during virally-suppressive HAART.

Cell-associated HIV-1-DNA quantitation after highly active antiretroviral therapy-treated primary infection in patients with persistently undetectable plasma HIV-1 RNA

OBJECTIVE

To determine the usefulness of cell-associated HIV-1-DNA quantification during the follow-up of highly active antiretroviral therapy (HAART)-treated primary-infected patients with persistently undetectable plasma RNA loads.

PATIENTS AND METHODS

In 27 patients given HAART within a median of 24 days after symptomatic primary HIV infection, plasma and peripheral blood mononuclear cell (PBMC) HIV-1 RNA were less than 50 copies/ml and less than 50 copies/10(6) cells after 18 months of treatment. HIV-1 RNA and DNA were quantified every 6 months in PBMC in these 27 patients, 14 of whom accepted excision lymph node biopsy after month 18 for HIV-1-RNA and -DNA quantification in lymph node mononuclear cells (LNMC).

RESULTS

The median decreases in plasma HIV-1 RNA, PBMC HIV-1 RNA and DNA over the 18 months of follow-up were 3.6 log (P< 0.005), 1.1 log (P< 0.05), and 1.0 log (P<0.001), respectively. HIV-1 DNA was detected in 92.3% of PBMC samples at baseline and at month 18. In LNMC, 100% of samples were detectable for HIV-1 DNA.

CONCLUSION

In this highly selected population of patients with excellent plasma virological response under HAART, HIV-1 DNA showed a progressive decrease but was still detectable in 92.3% of samples at month 18, whereas all LNMC samples tested scored positive for HIV-1 DNA. The utility of proviral HIV-1-DNA monitoring was not clearly demonstrated in this 18-month follow-up of HAART-treated primary-infected patients. However, this finding could be reconsidered when using other therapeutic strategies such as structured treatment interruptions, reinforced treatment or additive immunotherapy.

Comparison of clinical features of acute HIV-1 infection in patients infected sexually or through injection drug use. The Investigators of the Québec Primary HIV Infection Study

Acute HIV-1 infection (AHI) may present with a clinical picture that represents a diagnostic challenge. We tested the hypothesis that two different routes of infection, that is, sexual versus parenteral, might be associated with a difference in the clinical features of AHI. A prospective cohort of seroconvertors was established in Montréal in private medical clinics and hospitals from February 1996 to May 1999. The prevalence of the symptomatic presentation was almost overlapping within the two groups of newly infected individuals 69% (42 of 61) for men having sex with men (MSM) and 69% (18 of 26) for injection drug users (IDUs; p =.98). Comparison of all types of symptoms and signs as well as their duration was also similar in both groups. Of particular interest, the site of lymph node enlargement was not different despite the estimated sites of intravenous inoculation. Oral and anal ulcers were more frequently observed in MSM than in IDUs (6 versus 0 and 4 versus 1, respectively). Neither the mean CD4+ count (514.8 and 414.7 cells/mm3; p =.14) nor the mean viral load (4.45 and 4.70 log copies/ml; p =.40) were different between the two groups at the time of the first study visit. Our study results clearly indicate that health care workers can expect similar clinical presentation of AHI in MSM and in IDUs despite the different routes of infection.