Acute human immunodeficiency virus type 1 infection

Pathogenesis of infections in HIV-infected individuals: insights from primary immunodeficiencies

Following infection with almost any given microorganism other than an emerging pathogen, only a minority of individuals develop life-threatening clinical disease, implying that these individuals have some form of immunodeficiency. A growing number of inherited and acquired immunodeficiencies have been deciphered over the last 50 years. HIV infection is probably the best-known acquired immunodeficiency. It emerged about 40 years ago and precipitates various severe infections, the occurrence of which is associated with a fall in circulating CD4⁺ T cells. However, despite the strength of this correlation, infection rates differ between patients with similar levels and durations of CD4⁺ T lymphopenia in the presence or absence of antiretroviral treatment. Moreover, a few infections seem to be less dependent on total CD4⁺ T-cell levels. The fine detail of the mechanisms underlying these infections is unknown. We discuss here how studies of the human genetics and immunology of some of these infections in patients with primary immunodeficiencies (PIDs) have provided unique insights into their molecular and cellular basis. Defects of specific CD4⁺ Th-cell subsets account for some of these infections, as best exemplified by Th1* for mycobacteriosis and Th17 for candidiasis. PIDs are individually rare, but collectively much more common than initially thought, with new disorders being discovered at an ever-increasing pace and a global prevalence worldwide approaching that of HIV infection. Studies of known and new PIDs should make it possible to dissect the pathogenesis of most human infections at an unprecedented level of molecular and cellular precision. The predictive, preventive, and therapeutic implications of studies of immunity to infection in PIDs may extend to HIV-infected patients and patients with infectious diseases in other settings.

Potential Role of Vδ2+ γδ T Cells in Regulation of Immune Activation in Primary HIV Infection

Although conventional regulatory T cells (Tregs) are sufficient in controlling low residual T-cell activation in ART-treated patients, they are not efficient in controlling exaggerated immune activation associated with high levels of HIV replication in primary HIV infection (PHI). Our previous data suggested that double negative (DN) T cells including mainly γδ DN T cells play a role in the control of immune activation in PHI. Since γδ T cells are capable of exerting regulatory functions, we investigated their implication as Tregs in PHI as well as chronic HIV infection (CHI). In a cross-sectional study of 58 HIV-infected patients, in the primary and the chronic phase either ART-treated or untreated (UT), we analyzed phenotype and cytokine production of γδ T cells using flow cytometry. Cytokine production was assessed following in vitro stimulation with isopentenyl pyrophosphate or plate-bound anti-CD3/anti-CD28 monoclonal antibodies. We found that the proportion of γδ T cells negatively correlated with CD8 T-cell activation in PHI patients. Furthermore, we found that in these patients, the Vδ2 receptor bearing (Vδ2⁺) γδ T cells were strongly activated, exhibited low terminal differentiation, and produced the anti-inflammatory cytokine, TGF-β. In contrast, in UT-CHI, we observed a remarkable expansion of γδ T cells, where the Vδ2⁺ γδ T cells comprised of an elevated proportion of terminally differentiated cells producing high levels of IFN-γ but very low levels of TGF-β. We also found that this loss of regulatory feature of γδ T cells in CHI was a lasting impairment as we did not find recovery of TGF-β production even in ART-CHI patients successfully treated for more than 5 years. Our data therefore suggest that during the primary HIV infection, Vδ2⁺ γδ T cells may act as Tregs controlling immune activation through production of TGF-β. However, in CHI, γδ T cells transform from an anti-inflammatory into pro-inflammatory cytokine profile and participate in sustenance of immune activation.

In vitro inhibition of HIV-1 replication in autologous CD4+ T cells indicates viral containment by multifactorial mechanisms

HIV-1-specific cytotoxic T lymphocytes (CTLs) and neutralizing antibodies (NAbs) are present during chronic infection, but the relative contributions of these effector mechanisms to viral containment remain unclear. Here, using an in vitro model involving autologous CD4⁺ T cells, primary HIV-1 isolates, HIV-1-specific CTLs, and neutralizing monoclonal antibodies, we show that b12, a potent and broadly neutralizing monoclonal antibody to HIV-1, was able to block viral infection when preincubated with virus prior to infection, but was much less effective than CTLs at limiting virus replication when added to infected cell cultures. However, the same neutralizing antibody was able to contain viruses by antibody-dependent cell-mediated virus inhibition in vitro, which was mediated by natural killer cells (NKs) and dependent on an Fc-Fc receptor interaction. Meanwhile, bulk CTLs from HIV-1 controllers were more effective in suppression of virus replication than those from progressors. These findings indicate that control of HIV-1 replication in activated CD4⁺ T cells is ineffectively mediated by neutralizing antibodies alone, but that both CTLs and antibody-dependent NK-mediated immune mechanisms contribute to viral containment. Our study systemically compared three major players in controlling HIV-1 infection, CTLs, NAbs, and NKs, in an autologous system and highlighted the multifactorial mechanisms for viral containment and vaccine success.

Management of Newly Diagnosed HIV Infection

No field in medicine has moved as swiftly as HIV/AIDS over the past 35 years. Because of the rapid turnover of key information, this In the Clinic focuses on essential principles of care for newly diagnosed adults with HIV-1 infection and how to prevent infection in persons at risk. To ensure continued usefulness, future directions in therapy and how to access updated information on a continuous basis are emphasized.

Assessment of provider-initiated HIV screening in Nigeria with sub-Saharan African comparison

Background

Despite Nigeria’s high HIV prevalence, voluntary testing and counselling rates remain low. UNAIDS/WHO/CDC recommends provider-initiated testing and counselling (PITC) for HIV in settings with high HIV prevalence. We aimed to assess the acceptability and logistical feasibility of the PITC strategy among adolescents and adults in a secondary health care centre in Idekpa Benue state, Nigeria.

Method

All patients (aged ≥ 13 years) who visited the out-patient department and antenatal care unit of General Hospital Idekpa, Benue state, Nigeria were offered PITC for HIV. The intervention was implemented by trained health professionals for the period spanning (June to December 2010).

Results

Among the 212 patients who were offered PITC for HIV, 199 (94%) accepted HIV testing, 10 patients (4.7%) opted out and 3 patients (1.4%) were undecided. Of the 199 participants who were tested for HIV, 9% were HIV seropositive. The PITC strategy was highly acceptable and feasible, and increased the number of patients who tested for HIV by 5% compared to voluntary counselling and testing. Findings from this assessment were consistent with those from other sub-Saharan African countries (such as Uganda and South Africa).

Conclusion

PITC for HIV was highly acceptable and logistically feasible, and resulted in an increased rate of HIV testing among patients. Public health initiatives (such as the PITC strategy) that facilitate early detection of HIV and referral for early treatment should be encouraged for broader HIV control and prevention in Nigerian communities.

The importance of registration of sexual orientation and recognition of indicator conditions for an adequate HIV risk-assessment

Background

HIV testing among risk groups and guided by HIV indicator conditions (IC) is widely recommended by European guidelines. In this study we investigated how these strategies are used by general practitioners (GP) and in other healthcare settings. The objectives of our study were to describe: 1) the proportion of consultations in primary care and other healthcare settings in the five years prior to diagnosis; 2) patient and GP perspectives on the primary healthcare providers’ awareness and registration of sexual orientation and ethnicity in the electronic medical record (EMR); and 3) the proportion of HIV-infected patients who had been diagnosed with an IC prior to HIV diagnosis.

Methods

A survey study (2014–2016) was conducted among newly diagnosed HIV-infected patients presenting at two HIV outpatient clinics in Amsterdam. We collected information on the number of consultations and extent of HIV testing in healthcare settings in the 5 years prior to HIV diagnosis; on patient and GP perspectives on the primary healthcare providers’ awareness of sexual orientation and ethnicity; and on preselected ICs and symptoms of acute HIV infection prior to diagnosis. GPs were also approached for further information.

Results

In the 5 years prior to HIV diagnosis, 82.9% of the 111 patients had one or more consultations with their GP, but only 34.8% had one or more HIV tests performed in general practice during this period. In more than 50% of cases the patients took the initiative for the positive HIV test. GPs stated that they were aware of the sexual orientation of 59.6% of their patients who were men who have sex with men (MSM); however, sexual orientation was only documented in the EMR in 34.0% of these cases. GPs also reported that they were aware that a patient was from an HIV endemic country in more than half of the cases. GPs diagnosed 48.3% of all ICs and 39.5% of this group was offered an HIV test at that time.

Conclusions

Documentation of sexual orientation and ethnicity, and IC-guided testing by GPs could be the starting point for more proactive provider-initiated HIV testing.

The investigation of patients with HIV infection: 10 years of progress

The past decade has seen great advances in the management of patients with HIV infection. The introduction of highly active antiretroviral therapy (HAART) has resulted in a decrease in opportunistic infections but the development of new clinical entities such as lipodystrophy and immune reconstitution illnesses. The use of investigations such as lipid profiles and dual energy X-ray absorptiometry (DEXA) scanning to assess lipodystrophy have been necessitated by these changes in the epidemic. Technological advances have resulted in new techniques such as viral resistance assays and single photon emission computed tomography (SPECT) scanning. The appropriate use of these investigations is subject to ongoing assessment.

Mechanisms of HIV persistence in HIV reservoirs

The establishment and maintenance of HIV reservoirs that lead to persistent viremia in patients on antiretroviral drugs remains the greatest challenge of the highly active antiretroviral therapy era. Cellular reservoirs include resting memory CD4+ T lymphocytes, implicated as the major HIV reservoir, having a half-life of approximately 44 months while this is less than 6 hours for HIV in plasma. In some individuals, persistent viremia consists of invariant HIV clones not detected in circulating resting CD4+ T lymphocytes suggesting other possible sources of residual viremia. Some anatomical reservoirs that may harbor such cells include the brain and the central nervous system, the gastrointestinal tract and the gut-associated lymphoid tissue and other lymphoid organs, and the genital tract. The presence of immune cells and other HIV susceptible cells, occurring in differing compositions in anatomical reservoirs, coupled with variable and poor drug penetration that results in suboptimal drug concentrations in some sites, are all likely factors that fuel the continued low-level replication and persistent viremia during treatment. Latently, HIV-infected CD4+ T cells harboring replication-competent virus, HIV cell-to-cell spread, and HIV-infected T cell homeostatic proliferation due to chronic immune activation represent further drivers of this persistent HIV viremia during highly active antiretroviral therapy.

Human Immunodeficiency Virus, Other Sexually Transmitted Infections, and Sexual and Reproductive Health in Lesbian, Gay, Bisexual, Transgender Youth

Lesbian, gay, bisexual, transgender (LGBT), and questioning youth represent a diverse population who are affected by many sexual health inequities, including increased risk for human immunodeficiency virus (HIV) and sexually transmitted infections (STIs). To provide comprehensive sexual health care for LGBT youth, providers should set the stage with a nonjudgmental, respectful tone. Providers should be competent in recognizing symptoms of STIs and HIV and aware of the most up-to-date screening guidelines for LGBT youth. Sexual health visits should also focus on prevention, including safer sex practices, HIV pre-exposure and post-exposure prophylaxis, family planning, and immunization for hepatitis and human papillomavirus.

Potent and Broad Inhibition of HIV-1 by a Peptide from the gp41 Heptad Repeat-2 Domain Conjugated to the CXCR4 Amino Terminus

HIV-1 entry can be inhibited by soluble peptides from the gp41 heptad repeat-2 (HR2) domain that interfere with formation of the 6-helix bundle during fusion. Inhibition has also been seen when these peptides are conjugated to anchoring molecules and over-expressed on the cell surface. We hypothesized that potent anti-HIV activity could be achieved if a 34 amino acid peptide from HR2 (C34) were brought to the site of virus-cell interactions by conjugation to the amino termini of HIV-1 coreceptors CCR5 or CXCR4. C34-conjugated coreceptors were expressed on the surface of T cell lines and primary CD4 T cells, retained the ability to mediate chemotaxis in response to cognate chemokines, and were highly resistant to HIV-1 utilization for entry. Notably, C34-conjugated CCR5 and CXCR4 each exhibited potent and broad inhibition of HIV-1 isolates from diverse clades irrespective of tropism (i.e., each could inhibit R5, X4 and dual-tropic isolates). This inhibition was highly specific and dependent on positioning of the peptide, as HIV-1 infection was poorly inhibited when C34 was conjugated to the amino terminus of CD4. C34-conjugated coreceptors could also inhibit HIV-1 isolates that were resistant to the soluble HR2 peptide inhibitor, enfuvirtide. When introduced into primary cells, CD4 T cells expressing C34-conjugated coreceptors exhibited physiologic responses to T cell activation while inhibiting diverse HIV-1 isolates, and cells containing C34-conjugated CXCR4 expanded during HIV-1 infection in vitro and in a humanized mouse model. Notably, the C34-conjugated peptide exerted greater HIV-1 inhibition when conjugated to CXCR4 than to CCR5. Thus, antiviral effects of HR2 peptides can be specifically directed to the site of viral entry where they provide potent and broad inhibition of HIV-1. This approach to engineer HIV-1 resistance in functional CD4 T cells may provide a novel cell-based therapeutic for controlling HIV infection in humans.

Time Until Emergence of HIV Test Reactivity Following Infection With HIV-1: Implications for Interpreting Test Results and Retesting After Exposure

BACKGROUND

 Understanding the period of time between an exposure resulting in infection with human immunodeficiency virus (HIV) and when a test can reliably detect the presence of that infection, that is, the test window period, may benefit testing programs and clinicians in counseling patients about when the clinician and the patient can be confident a suspected exposure did not result in HIV infection.

METHODS

 We evaluated the intervals between reactivity of the Aptima HIV-1 RNA test (Aptima) and 20 US Food and Drug Administration-approved HIV immunoassays using 222 longitudinally collected plasma specimens from HIV-1 seroconverters from the United States. Using interval-censored survival and binomial regression approaches a multi-model framework was implemented to estimate the relative emergence of test reactivity, referred to here as an inter-test reactivity interval (ITRI). We then combined ITRI results with simulated data for the eclipse period, the time between exposure and detection of HIV virus by Aptima, to estimate the window period for each test.

RESULTS

 The estimated ITRIs were shorter with each new class of HIV tests, ranging from 5.9 to 24.8 days. The 99^th percentiles of the window period probability distribution ranged from 44 days for laboratory screening tests that detect both antigen and antibody to 65 days for the Western blot test.

CONCLUSIONS

 Our directly comparable estimates of the emergence of reactivity for 20 immunoassays are valuable to testing providers for interpreting negative HIV test results obtained shortly after exposure, and for counseling individuals on when to retest after an exposure.

Oral preexposure prophylaxis to prevent HIV infection: clinical and public health implications

This article reviews the use of combination emtricitabine (FTC)/tenofovir as preexposure prophylaxis (PrEP) for HIV-negative patients at high risk of acquiring HIV, including heterosexual men and women, men who have sex with men, and IV drug users. When used with classic prevention strategies such as condoms, PrEP has been found effective in reducing the risk of HIV transmission.

Prevalence of and progression to abnormal noninvasive markers of liver disease (aspartate aminotransferase-to-platelet ratio index and Fibrosis-4) among US HIV-infected youth

OBJECTIVE

To longitudinally characterize noninvasive markers of liver disease in HIV-infected youth.

DESIGN

HIV infection, without viral hepatitis coinfection, may contribute to liver disease. Noninvasive markers of liver disease [FIB-4 (Fibrosis-4) and APRI (aspartate aminotransferase-to-platelet ratio index)] have been evaluated in adults with concomitant HIV and hepatitis C, but are less studied in children.

METHODS

In prospective cohorts of HIV-infected and HIV-uninfected youth, we used linear regression models to compare log-transformed FIB-4 and APRI measures by HIV status based on a single visit at ages 15-20 years. We also longitudinally modeled trends in these measures in HIV-infected youth with two or more visits to compare those with behavioral vs. perinatal HIV infection (PHIV) using mixed effect linear regression, adjusting for age, sex, body mass index, and race/ethnicity.

RESULTS

Of 1785 participants, 41% were men, 57% black non-Hispanic, and 27% Hispanic. More HIV-infected than uninfected youth had an APRI score more than 0.5 (13 vs. 3%, P < 0.001). Among 1307 HIV-infected participants with longitudinal measures, FIB-4 scores increased 6% per year (P < 0.001) among all HIV-infected youth, whereas APRI scores increased 2% per year (P = 0.007) only among PHIV youth. The incidence rates (95% confidence interval) of progression of APRI to more than 0.5 and more than 1.5 were 7.5 (6.5-8.7) and 1.4 (1.0-1.9) cases per 100 person-years of follow-up, respectively. The incidence of progression of FIB-4 to more than 1.5 and more than 3.25 were 1.6 (1.2-2.2) and 0.3 (0.2-0.6) cases per 100 person-years, respectively.

CONCLUSION

APRI and FIB-4 scores were higher among HIV-infected youth. Progression to scores suggesting subclinical fibrosis or worse was common.

Colorectal Disorders in Acute Human Immunodeficiency Virus Infection: A Case Series

Background.  The gastrointestinal (GI) tract is important in the pathogenesis of human immunodeficiency virus (HIV) infection. We report a case series of lower GI endoscopic and histopathologic findings of HIV-infected individuals after presentation with acute infection. Methods.  We performed a retrospective case review of individuals infected with HIV who enrolled between August 2010 and April 2013 in a primary infection treatment trial. All participants started the trial during acute infection and underwent colonoscopy with biopsies at baseline and after the start of antiretroviral treatment. Results.  Twenty acutely infected individuals were included in the study (mean age, 33 years; range, 20-54 years). All participants were male who reported having receptive anal sex as an HIV risk factor. Nine individuals (45%) had at least 1 finding by colorectal pathology; 1 person had 2 diagnoses (diverticulosis and focal active proctitis). The histopathological findings revealed anal dysplasia in 3 cases: 2 had high-grade anal intraepithelial neoplasia (AIN) and 1 had low-grade AIN. Two persons had a colorectal polyp, 1 hyperplastic and 1 adenomatous. Three persons were diagnosed with diverticulosis, and 2 persons were diagnosed with proctitis, including 1 with focal active proctitis and 1 with cytomegalovirus proctitis. Conclusions.  To our knowledge, this is the first case series report of lower GI disorders in acute HIV-infected individuals. Although the causal relationship remains uncertain, we describe the endoscopic findings that were observed during acute HIV infection among men who have sex with men. Understanding the prevalence of these pathologies may likely shed light on how acute HIV infection damages the lower GI tract.

Neutralization breadth and potency of serum derived from recently human immunodeficiency virus type 1-infected Thai individuals

Neutralizing antibody responses play important roles in controlling several viral infections including human immunodeficiency virus type 1 (HIV-1). Potent and broad neutralizing antibody responses have been reported in some HIV-1-infected individuals; therefore, elucidating the mechanisms underlying neutralizing antibody responses will provide important information for the development of anti-HIV-1 vaccines. We herein performed a comparative study on the neutralization breadth and potency of serum samples collected from Thai individuals recently and chronically infected with HIV-1. Neutralization tests using a series of envelope glycoproteins (Env)-recombinant viruses revealed that although several serum samples derived from recently infected individuals did not show any HIV-1-specific neutralizing activity, the remaining serum samples exhibited neutralizing activity not only for recombinant viruses with CRF01_AE Env, but also for viruses with subtypes B and C Env. Furthermore, some serum samples derived from recently infected individuals showed the neutralization potency. Our results may provide a deeper insight into the characteristics of neutralizing antibody responses that develop during the course of HIV-1 infection among individuals in Thailand.

Differences in the variability of cerebral proton magnetic resonance spectroscopy (1H-MRS) measurements within three HIV-infected cohorts

INTRODUCTION

Cerebral functional impairment remains prevalent in effectively treated HIV-infected subjects. As the results of formal cognitive testing are highly variable, surrogate markers to accurately measure cerebral function parameters are needed. Such markers include measurement of cerebral metabolite ratios (CMR) using proton magnetic resonance spectroscopy (1H-MRS). However, data on the inter-subject variability of CMR are sparse. Our aim was to assess inter-subject variability in CMRs within three different HIV-infected cohorts.

METHODS

Cerebral 1H-MRS was performed using a Phillips Achieva™ 1.5 Tesla magnetic resonance scanner in HIV-infected subjects as follows: 12 subjects before (group 1) and after intensification of antiretroviral therapy with maraviroc (group 2) and 13 subjects with acute viral hepatitis C (HCV) co-infection (group 3). The coefficients of variation (CV) for CMRs in each group were determined and compared using non-parametric tests to determine whether the inter-subject variability differed significantly. All baseline characteristics between the groups were similar.

RESULTS

Overall CVs for all CMRs in groups 1, 2 and 3 were 32.3%, 33.2% and 23.4%, respectively (group 1 vs. 2, p=0.863; group 1 vs. 3, p=0.076). On testing for differences in variability between individual CMRs, two metabolites in the right basal ganglia (RBG) had statistically significantly different CVs when comparing group 1 with group 3: N-acetyl aspartate/creatine (NAA/Cr), p=0.029 and myo-Inositol/creatine (mI/Cr), p=0.016.

CONCLUSION

The variability of 1H MRS-measurable CMRs in HIV-infected individuals was lower in those with acute HCV co-infection (group 3).We can conclude that the use of these CMRs in 1H MRS imaging in patients with HIV/acute HCV co-infection is more reliable to assess cerebral function than in patients with HIV infection alone. This has implications for future sample size estimations.

Effect of Aerobic Exercise on CD4 Cell Count and Lipid Profile of HIV Infected Persons in North Eastern Nigeria

Background:

Literature consistently shows dearth of published data from developing countries on effect of exercise on HIV infected persons.

Objective:

The study was aimed at determining effect of aerobic exercise on CD4 cell counts and lipid profile of HIV infected persons in Northeastern Nigeria.

Methods:

Sample of convenience was employed to enroll volunteer and willing 91 HIV infected persons attending antiretroviral clinic at a tertiary hospital in Northeastern Nigeria. Eighty two met the inclusion criteria and participated in the study. Participants were randomly assigned to experimental and control groups. Baseline values of the variables were determined. Experimental group participated in moderate intensity treadmill aerobic exercise for 12 weeks. Control group participated in weekly lectures on nutrition, adherence to therapy among others. At the end, the study recorded 22% attrition rate, leaving 32 participants in each group (64 participants in both). After the 12 weeks, the variables were re-evaluated. Descriptive statistic summarized the socio-demographic characteristics of the participants. Paired and unpaired Student t-tests analyzed the significant difference in mean values of the variables.

Results:

Mean ages in years of the 64 participants, the control and experimental groups were 39.57 ± 10.13, 39.38 ± 10.03 and 40.84 ± 10.05 respectively. There was significant improvement (p < 0.05) in the variables between pre- and post-tests in the experimental group. In the control group, there was either no significant change (p > 0.05) or significant deterioration (p < 0.05) in lipid profile between pre- and post-tests, while in CD4 cell counts, significant improvement was observed. Significant difference (p < 0.05) existed in the variables at the end of the study between both groups.

Conclusion:

CD4 cell counts and lipid profile of HIV infected persons who participated in the 12 weeks moderate intensity treadmill aerobic exercise significantly improved. Proper nutrition and adherence to antiretroviral therapy may enhance immune function in HIV population.

Differences in Clinical Manifestations of Acute and Early HIV-1 Infection between HIV-1 Subtypes in African Women

Little is known about the differences in clinical manifestations between women with various HIV-1 subtypes during acute (AI) and early (EI) HIV infection. In a longitudinal cohort study, clinical signs and symptoms among Uganda and Zimbabwe women with AI and EI were compared with HIV-negative controls; symptoms were assessed quarterly for 15 to 24 months. Early HIV infection was defined as the first visit during which a woman tested HIV antibody positive. Women who were HIV negative serologically but DNA polymerase chain reaction positive were considered AI. In all, 26 women were classified AI and 192 EI, with 654 HIV-negative controls. Primary HIV infection (AI and EI) was associated with unexplained fever (P <.01), weight loss (P <.01), fatigue (P <.01), inguinal adenopathy (P <.01), and cervical friability (P =.01). More women with subtype C infection had unexplained fever, fatigue, and abnormal vaginal discharge compared to subtype A or D infection. Inguinal adenopathy occurred less often in women with subtype A infection than those with subtype C or D infection.

How can we better identify early HIV infections?

PURPOSE OF REVIEW

Detection of early HIV infections (EHIs), including acute HIV infection (AHI), is important for individual health, prevention of HIV transmission, and measurement of HIV incidence. We describe markers of EHI, diagnostic strategies for detecting these markers, and ways to incorporate these strategies into diagnostic and HIV incidence algorithms.

RECENT FINDINGS

For individual diagnosis in the USA and Europe, laboratory-based diagnostic algorithms increasingly incorporate fourth-generation HIV antigen tests, allowing for earlier detection. In some sub-Saharan African settings, symptom-based screening is being explored to identify subsets of persons at high risk for AHI. Point-of-care diagnostics designed for AHI detection are in the pipeline and, if validated, represent an opportunity for real-time AHI diagnosis. At the population level, multiassay algorithms are promising new strategies for estimating HIV incidence on the basis of several assays applied to cross-sectional samples. These algorithms can be developed to optimize performance, in addition to cost and logistical considerations.

SUMMARY

There are important recent advances in detection of EHIs at the individual and population levels. Applying optimal combinations of tests in diagnostic and HIV incidence algorithms is urgently needed to support the multiple goals derived from enhanced detection and discrimination of EHIs.

Preserving HIV-specific T cell responses: does timing of antiretroviral therapy help?

PURPOSE OF REVIEW

HIV-specific T cell responses are likely to have an important role in HIV cure strategies that aim for long-lasting viral control without antiretroviral therapy (ART). An important issue in enhancing virus-specific T cell responses is whether timing of ART can influence their magnitude and breadth.

RECENT FINDINGS

Early ART is associated with lower T cell activation, preservation of T cell numbers, smaller DNA and RNA reservoir size, and, in a single study (VISCONTI), control of plasma viremia after treatment interruption. The prevention of T cell destruction by early ART is associated with relatively low anti-HIV CD8⁺ T cell responses but stronger CD4⁺ T helper function. The relatively lower CD8⁺T cell response, which is presumably due to rapid lowering of HIV antigen burden after early ART, appears sufficient to control residual viral replication as well as viral rebound upon treatment interruption.

SUMMARY

Available evidence of starting ART during acute or early HIV infection has shown benefit in both virologic and immunologic parameters despite the lower HIV-specific CD8⁺ T cell responses observed. Encouraging as this is, more extensive data are necessary to evaluate its role in combination with immunotherapeutic and latency activation strategies that are being assessed in various HIV cure-related studies.

In vitro affinity maturation and characterization of anti-P24 antibody for HIV diagnostic assay

P24 antigen is the main structural protein of HIV-1, its detection provide a means to aid the early diagnosis of HIV-1 infection. The aim of this study was to improve the selectivity and sensitivity of the HIV P24 diagnostic assay by developing a cohort of 9E8 affinity-matured antibodies through in vitro phage affinity maturation which was performed by complementarity determining region (CDR)-hot spot mutagenesis strategy. Antibody 9E8-491 had an affinity constant of 5.64 × 10(-11) M, which was 5.7-fold higher than that of the parent antibody (9E8). Furthermore, the affinity, sensitivity and specificity of 9E8-491 were higher than those of 9E8, which indicate that 9E8-491 is a good candidate detection antibody for HIV P24 assay. Structure analysis of matured variants revealed that most hydrogen bonds resided in HCDR3. Among the antibody-antigen predicted binding residues, Tyr(100A/100B) was the original conserved residue that was commonly present in HCDR3 of 9E8 and variants. Arg(100)/Asp(100C) was the major variant substitution that most likely influenced the binding differences among variants and 9E8 monoclonal antibody. Both efficient library panning and predicted structural data were in agreement that the binding residues were mostly located in HCDR3 and enabled identification of key residues that influence antibody affinity.

Disease progression of HIV-1 infection in symptomatic and asymptomatic seroconverters in Osaka, Japan: a retrospective observational study

Background

Estimates of the interval from HIV-1 infection to disease progression may be affected by selection bias, and data concerning asymptomatic early seroconverters are limited. We examined the interval until disease progression in HIV-1 seroconverters in whom the timing of infection could be estimated within 1 year before diagnosis.

Methods

Subjects included newly diagnosed patients at Osaka National Hospital between 2003 and 2010 who had either (1) symptomatic acute HIV-1 infection with a negative or intermediate reaction on Western blotting and a positive reaction on an HIV RNA test (symptomatic acute group) or (2) a positive reaction on Western blotting at diagnosis and a <1-year interval from the last negative HIV test until the first positive test. The latter was divided into symptomatic recent or asymptomatic recent groups based on the presence or absence, respectively, of any transient fever between the last negative and first positive tests. Disease progression was defined as a fall in the CD4 count to <350 cells/microL on 2 consecutive tests, the start of anti-HIV therapy, or the onset of AIDS-indicator diseases. Information was retrospectively collected from medical records.

Results

Subjects included 210 patients: 91 in the symptomatic acute group, 72 in the symptomatic recent group, and 47 in the asymptomatic recent group. In the symptomatic acute (0.8 years) and symptomatic recent (2.2 years) groups, the Kaplan-Meier estimate of median interval until disease progression was significantly shorter than that in the asymptomatic recent group (2.9 years). Multivariate analysis by Cox’s proportional hazards test showed that the symptomatic acute group (vs. asymptomatic recent group: hazard ratio: 1.93; 95% confidence interval: 1.14–3.36; p = 0.0140) and a baseline CD4 count of <400 cells/microL (hazard ratio: 3.88; 95% confidence interval: 2.57–5.96; p < 0.0001) were independent prognostic factors associated with early disease progression.

Conclusions

Symptomatic seroconversion was associated with early disease progression. Furthermore, the estimated median interval until the CD4 count was <350 cells/microL was only 2.9 years even in patients with asymptomatic seroconversion. These results suggest the importance of early diagnosis in early seroconverters.

Common sexually transmitted infections in adolescents

Adolescents are often at higher risk for acquiring sexually transmitted infections (STIs). Medical providers should be alert for both asymptomatic and symptomatic STIs, and follow appropriate screening guidelines. Moreover, providers need to know how to best administer adolescent-friendly confidential care, treatment, and health education in the primary care setting. This article addresses the most common adolescent STIs and pertinent recommendations for screening, diagnosis, and management of infections, in addition to a brief focused discussion on human immunodeficiency virus and adolescents.

An evolutionary role for HIV latency in enhancing viral transmission

HIV latency is the chief obstacle to eradicating HIV but is widely believed to be an evolutionary accident providing no lentiviral fitness advantage. However, findings of latency being "hardwired" into HIV's gene-regulatory circuitry appear inconsistent with latency being an evolutionary accident, given HIV's rapid mutation rate. Here, we propose that latency is an evolutionary "bet-hedging" strategy whose frequency has been optimized to maximize lentiviral transmission by reducing viral extinction during mucosal infections. The model quantitatively fits the available patient data, matches observations of high-frequency latency establishment in cell culture and primates, and generates two counterintuitive but testable predictions. The first prediction is that conventional CD8-depletion experiments in SIV-infected macaques increase latent cells more than viremia. The second prediction is that strains engineered to have higher replicative fitness—via reduced latency—will exhibit lower infectivity in animal-model mucosal inoculations. Therapeutically, the theory predicts treatment approaches that may substantially enhance "activate-and-kill" HIV-cure strategies.

Analysis of protein kinase C theta inhibitors for the control of HIV-1 replication in human CD4+ T cells reveals an effect on retrotranscription in addition to viral transcription

HIV-1 infection cannot be cured due to reservoirs formed early after infection. Decreasing the massive CD4+ T cell activation that occurs at the beginning of the disease would delay reservoir seeding, providing a better prognosis for patients. CD4+ T cell activation is mediated by protein kinase C (PKC) theta (θ), which is involved in T-cell proliferation, as well as NF-κB, NF-AT, and AP-1 activation. We found that PKCθ activity increased viral replication, but also that HIV-1 induced higher activation of PKCθ in infected CD4+ T cells, creating a feedback loop. Therefore, specific inhibition of PKCθ activity could contribute to control HIV-1 replication. We tested the efficacy of seven PKCθ specific inhibitors to control HIV-1 replication in CD4+ T cells and selected two of the more potent and safer: CGX1079 and CGX0471. They reduced PKCθ phosphorylation at T538 and its translocation to the plasma membrane, which correlated with decreased HIV-1 retrotranscription through partial inhibition of SAMHD1 antiviral activity, rendering lower proviral integration. CGX1079 and CGX0471 also interfered with viral transcription, which would reduce the production of new virions, as well as the subsequent spread and infection of new targets that would increase the reservoir size. CGX1079 and CGX0471 did not completely abrogate T-cell functions such as proliferation and CD8-mediated release of IFN-γ in PBMCs from HIV-infected patients, thereby avoiding general immunosuppresion. Consequently, using PKCθ inhibitors as adjuvant of antiretroviral therapy in recently infected patients would decrease the pool of activated CD4+ T cells, thwarting proviral integration and reducing the reservoir size.

Drug resistance and plasma viral RNA level after ineffective use of oral pre-exposure prophylaxis in women

BACKGROUND

Pre-exposure prophylaxis (PrEP) with daily oral emtricitabine (FTC)/tenofovir disoproxil fumarate may select for drug resistance if there is low adherence.

METHODS

Plasma viral HIV-1 RNA level, CD4+ T-cell counts, and drug resistance were evaluated among seroconverting women in the FEM-PrEP trial (clinicaltrials.gov NCT00625404) using standard clinical tests, allele-specific PCR (ASPCR), and by deep sequencing. Tenofovir, FTC, and their intracellular metabolites were measured in plasma and cells.

RESULTS

There was no difference in plasma HIV-1 RNA level or CD4+ cell count among seroconverters in the active arm versus those receiving placebo. Tenofovir resistance was not observed. FTC resistance was detected using clinical assays in five seroconverters (four in the active arm and one in the placebo arm); two in the active arm occurred among women having moderate concentrations of PrEP drugs in the blood. The first evidence of infection occurred at the first postenrollment visit in three of the four with FTC resistance, although none had detectable viral nucleic acids at enrollment. FTC-resistant minor variants were detected in an additional four seroconverters (one in the active arm and three in the placebo arm).

CONCLUSIONS

Drug resistance detected during ineffective PrEP use had characteristics suggesting transmitted infection or incubating infection prior to starting PrEP.

Evaluation of a HIV voluntary opt-out screening program in a Singapore hospital

Background

Early diagnosis of human immunodeficiency virus (HIV) allows for appropriately timed interventions with improved outcomes, but HIV screening among asymptomatic persons and the general population in Singapore remains low. In 2008, Singapore’s Ministry of Health implemented HIV voluntary opt-out screening (VOS) for hospitalised adults. We evaluated the outcome of VOS and surveyed reasons for its low uptake in our institution.

Methods

We assessed the outcomes of the VOS programme from January 2010 to December 2013 at National University Hospital, a 1081-bed tertiary hospital in Singapore. We also examined reasons for opting-in and opting-out using an interviewer–administered structured questionnaire in a representative sample in January 2013.

Results

107,523 patients fulfilled VOS criteria and were offered HIV screening, of which 5215 (4.9%) agreed to testing. 4850 (93.1%) of those who opted-in had an HIV test done. Three (0.06%) tested positive for HIV. 238 patients (14.2%) were surveyed regarding reasons for opting-in or out of VOS. 21 (8.8%) had opted-in. Patients who opted-in were likely to be younger, more educated and reported having more regular sexual partners. Type of housing, number of casual sexual partners, sexual orientation, intravenous drug use, condom use and previous sexually transmitted infection were not associated with deciding to opt-in/out. Patients’ most common reasons for opting-out were: belief that they were at low risk (50.2%), belief that they were too old (26.8%), cost (6.9%) and aversion to venepuncture (6.5%). The most common reason for opting-in was desire to know their HIV status (47.6%).

Conclusion

The success of an HIV-VOS program is largely determined by test uptake. Our study showed that the majority of eligible VOS patients opted-out of HIV screening. Given the considerable cost and low yield of this programme, more needs to be done to better equip patients in self-risk assessment and opting in to testing.

Contingency management facilitates the use of postexposure prophylaxis among stimulant-using men who have sex with men

Compared to a control behavioral intervention, Contingency Management, an escalating voucher-based incentive system to reinforce stimulant abstinence, better supported MSM stimulant users in PEP course completion, decreased stimulant use, and a trend toward fewer condomless sexual acts.

Background. Stimulant-using men who have sex with men (MSM) are at high risk of human immunodeficiency virus (HIV) acquisition. Contingency Management (CM) is a robust substance abuse intervention that provides voucher-based incentives for stimulant-use abstinence.

Methods. We conducted a randomized controlled trial of CM with postexposure prophylaxis (PEP) among stimulant-using MSM. Participants were randomized to CM or a noncontingent “yoked” control (NCYC) intervention and observed prospectively. Generalized linear models were used to estimate the effect of CM on PEP course completion, medication adherence, stimulant use, and sexual risk behaviors.

Results. At a single site in Los Angeles, 140 MSM were randomized to CM (n = 70) or NCYC (n = 70). Participants were 37% Caucasian, 37% African American, and 18% Latino. Mean age was 36.8 (standard deviation = 10.2) years. Forty participants (29%) initiated PEP after a high-risk sexual exposure, with a mean exposure-to-PEP time of 32.9 hours. PEP course completion was greater in the CM group vs the NCYC group (adjusted odds ratio [AOR] 7.2; 95% confidence interval {CI}, 1.1–47.9), with a trend towards improved medication adherence in the CM group (AOR, 4.3; 95% CI, 0.9–21.9).

Conclusions. CM facilitated reduced stimulant use and increased rates of PEP course completion, and we observed a trend toward improved adherence. Participants in the CM group reported greater reductions in stimulant use and fewer acts of condomless anal intercourse than the control group. This novel application of CM indicated the usefulness of combining a CM intervention with PEP to produce a synergistic HIV prevention strategy that may reduce substance use and sexual risk behaviors while improving PEP parameters.

High-density lipoprotein-mediated cholesterol efflux capacity is improved by treatment with antiretroviral therapy in acute human immunodeficiency virus infection

Background

 Individuals infected with human immunodeficiency virus (HIV) have decreased high-density lipoprotein (HDL)-cholesterol and increased cardiovascular disease (CVD). Reverse cholesterol transport from macrophages may be inhibited by HIV and contribute to increased CVD. Human studies have not investigated longitudinal effects of HIV and antiretroviral therapy (ART) on cholesterol efflux.

Methods

 Subjects with acute HIV infection were randomized to ART or not. Cholesterol efflux capacity was determined ex vivo after exposure of murine macrophages to apolipoprotein B-depleted patient sera obtained at baseline and after 12 weeks.

Results

 After 12 weeks, HIV RNA decreased most in subjects randomized to ART. Available data on cholesterol demonstrated that efflux capacity from Abca1^+/+ macrophages was increased most by sera obtained from ART-treated subjects (20.5% ± 5.0% to 24.3 % ± 6.9%, baseline to 12 weeks, P = .007; ART group [n = 6] vs 18.0 % ± 3.9% to 19.1 % ± 2.9%, baseline to 12 weeks, P = .30; untreated group [n = 6] [P = .04 ART vs untreated group]). Change in HIV RNA was negatively associated with change in Abca1^+/+ macrophage cholesterol efflux (r = − 0.62, P = .03), and this finding remained significant (P = .03) after controlling for changes in HDL-cholesterol, CD4⁺ cells, and markers of monocyte or macrophage activation.

Conclusions

 In subjects acutely infected with HIV, ATP-binding cassette transporter A1-mediated cholesterol efflux was stimulated to a greater degree over time by apolipoprotein B-depleted serum from subjects randomized to ART. The improvement in cholesterol efflux capacity is independently related to reduction in viral load.

Understanding HIV infection for the design of a therapeutic vaccine. Part I: Epidemiology and pathogenesis of HIV infection

HIV infection leads to a gradual loss CD4+ T lymphocytes comprising immune competence and progression to AIDS. Effective treatment with combined antiretroviral drugs (cART) decreases viral load below detectable levels but is not able to eliminate the virus from the body. The success of cART is frustrated by the requirement of expensive life-long adherence, accumulating drug toxicities and chronic immune activation resulting in increased risk of several non-AIDS disorders, even when viral replication is suppressed. Therefore there is a strong need for therapeutic strategies as an alternative to cART. Immunotherapy, or therapeutic vaccination, aims to increase existing immune responses against HIV or induce de novo immune responses. These immune responses should provide a functional cure by controlling viral replication and preventing disease progression in the absence of cART. The key difficulty in the development of an HIV vaccine is our ignorance of the immune responses that control of viral replication, and thus how these responses can be elicited and how they can be monitored. Part one of this review provides an extensive overview of the (patho-) physiology of HIV infection. It describes the structure and replication cycle of HIV, the epidemiology and pathogenesis of HIV infection and the innate and adaptive immune responses against HIV. Part two of this review discusses therapeutic options for HIV. Prevention modalities and antiretroviral therapy are briefly touched upon, after which an extensive overview on vaccination strategies for HIV is provided, including the choice of immunogens and delivery strategies.

Performances of fourth generation HIV antigen/antibody assays on filter paper for detection of early HIV infections

BACKGROUND

Point-of-care testing and diagnosis of HIV acute infections play important roles in preventing transmission, but HIV rapid diagnosis tests have poor capacity to detect early infections. Filter paper can be used for capillary blood collection and HIV testing using 4th generation immunoassays.

OBJECTIVES

Antigen/antibody combined immunoassays were evaluated for their capacity to identify early HIV infections using filter paper in comparison with rapid test.

STUDY DESIGN

Thirty nine serum samples collected from HIV seroconverters were spotted onto filter paper and tested by the Roche Elecsys(®) HIV Combi PT test and the DiaSorin Liaison XL Murex HIV Ab/Ag assay.

RESULTS

Fourth generation immunoassays identified 34 out of 39 HIV early infections using dried serum spot, whereas the Determine™ HIV-1/2 rapid test detected 24 out of 39 HIV positive serum (87.2% vs 61.5% respectively, p = 0.009). p24 antigen was detected by the Liaison XL in 19 dried serum samples (48.7%). In the group characterized by a negative western blot, 7 out of 8 (87.5%) and 6 out of 8 (75.0%) samples were found positive for HIV using the Elecsys and the Liaison XL, respectively. None of these eight samples classified in this group of early acute infections were found positive by the rapid test.

CONCLUSION

Fourth generation Ag/Ab immunoassays performed on dried serum spot had good performance for HIV testing during the early phases of HIV infection. This method may be useful to detect HIV early infections in hard-to-reach populations and individuals living in remote areas before rapid tests become positive.

A severe manifestation of primary HIV-1 infection in an adolescent

Primary HIV infection (PHI) is symptomatic in 50-90% of patients with symptoms resembling infectious mononucleosis. The diagnosis, however, is seldom made at first presentation. Clinically severe presentations during primary HIV type 1 infection are considered to occur infrequently. We report a case of a severe manifestation of PHI with meningoencephalitis in the setting of HIV seroconversion in an adolescent girl.

Characterization of human immunodeficiency virus type 1 CRF01_AE env genes derived from recently infected Thai individuals

Transmitted/founder virus is responsible for the establishment of human immunodeficiency virus type 1 (HIV-1) infection and induces primary anti-HIV-1 immune responses; therefore, it is important to study the viral population to understand the early events of HIV-1 infection. We amplified HIV-1 env genes from sera derived from recently infected Thai individuals, and established envelope glycoproteins (Env)-recombinant viruses. Generated Env-recombinant viruses were tested for their neutralization susceptibility to neutralizing human monoclonal antibodies (NHMAbs) and entry inhibitors, as well as being subjected to genotypic analysis. Most recombinant viruses were susceptible to neutralization by NHMAbs to Env gp41, whereas approximately one-third of the recombinant viruses were susceptible to a NHMAb against the CD4 binding site of gp120. In addition, all env genes were classified into CRF01_AE genes and showed low genetic divergence. Taken together with our previous studies on CRF01_AE env genes derived from chronically infected Thai individuals, these results suggested that the immunological and genetic characteristics of CRF01_AE Env derived from recently infected Thai individuals were different from those derived from chronically infected individuals.

Periradicular lesions in HIV-infected patients attending the faculty of dentistry: clinical findings, socio-demographics status, habits and laboratory data - seeking an association

OBJECTIVE

The purpose of this study was to estimate the prevalence of periradicular lesions in HIV-infected Brazilian patients and to assess the correlation of several factors with the periradicular status.

METHOD

One hundred full-mouth periapical radiographs were evaluated. A total of 2,214 teeth were evaluated for the presence of periradicular lesions, caries lesions, coronal restorations, pulp cavity exposure and endodontic treatment.

RESULTS

The prevalence of periradicular lesions was 46%. There were no significant differences between individuals with or without periradicular lesions with respect to their socio-demographic status, habits, laboratory data and route of HIV infection. However, the presence of a periradicular lesion was statistically correlated with the number of teeth with endodontic treatment (p = 0.018), inadequate endodontic treatment (p = 0.025), images suggesting pulp cavity exposure (p = 0.002) and caries lesions (p = 0.001).

CONCLUSIONS

The prevalence of periradicular lesions in HIV-infected individuals was 46% and was not related to HIV infection.

Microdevices for examining immunological responses of single cells to HIV

More than 60 million people in the world have been diagnosed with HIV infections since the virus was recognized as the causative agent of AIDS in the 1980s. Even though more than half of the infected patients have died, effective disease treatment and prevention measures have not been established. ART (antiretroviral therapy) is the only proven HIV treatment that sustains the suppression of patient viraemia. Current routine approaches to treat HIV infections are targeted at developing vaccines that will induce humoral or cell memory immune responses. However, developing an effective vaccine has been challenging because the HIV mutates rapidly, which allows the virus to evade immune surveillances established against the previous strain. In addition, the virus is able to quickly establish a reservoir and treatment is difficult because of the general lack of knowledge about HIV immune response mechanisms. This review introduces common disease symptoms and the progression of HIV infection with a brief summary of the current treatment approaches. Different cellular immune responses against HIV are also discussed, with emphasis on a nanotechnology research that has focused on probing T-cell response to HIV infection. Furthermore, we discuss recent noteworthy nanotechnology updates on T-cell response screening that is focused on HIV infection. Finally, we review potential future treatment strategies based on the correlations between T-cell response and HIV infection.