Effective Highly Active Antiretroviral Therapy Research Articles

Contribution of metabolic and anthropometric abnormalities to cardiovascular disease risk factors.

Patients with human immunodeficiency virus (HIV) infection have sustained alterations in metabolism (lipids and insulin/glucose homeostasis) and body composition (fat distribution) that are proatherogenic (the Figure). HIV infection itself and/or its therapies may contribute to these alterations (the Table); although most effects are reversible, there are some possibly irreversible consequences of treatment. With the relative restoration to health seen in the era of highly active antiretroviral therapy (HAART), many traditional risk factors and promoters of dyslipidemia and diabetes also are present; they interact with HIV-specific inducers to worsen dyslipidemia and to increase the prevalence of insulin resistance and diabetes. Figure. Overview of the effects of HIV and its therapies on CVD risk. The contribution of traditional risk factors must be kept in mind, and they may occur with increased prevalence in people with HIV infection (eg, smoking). HIV, likely through the inflammatory response, and antiretroviral therapies independently affect many of the mediators of CVD risk. The effects on lipids are a prominent but complex example; HIV infection lowers LDL levels, but antiretroviral therapy raises LDL back up to normal levels. The bidirectional arrows indicate associations, but there is not yet adequate proof of causality. The dotted arrow between body composition and CVD indicates that body fat is known to affect the mediators such as dyslipidemia and insulin resistance but may also have a direct effect. FFA indicates free fatty acids; ARV, antiretroviral. View this table: Table. Effects of HIV Treatment These disturbances in lipid and glucose metabolism and renal disease may contribute, at least in part, to the excess cardiovascular disease (CVD) morbidity and mortality observed in HIV-infected individuals (the Figure). However, the relative contribution to excess CVD risk of traditional CVD risk factors, especially smoking, compared with these infection- and treatment-specific complications requires clarification. More prospective data with multivariable modeling are needed. …

Case Report: Highly Active Antiretroviral Therapy as the Sole Treatment for AIDS-Related Primary Central Nervous System Lymphoma: A Case Report with Implications for Treatment

A 40-year-old male presented to medical attention with Pneumocystis jiroveci pneumonia and HIV infection. His CD4+ count was 18 cells per microliter and his HIV viral load (VL) was more than 400,000 copies milliliter. After 3 weeks of antibiotic therapy, he continued to have global cognitive deficits. A brain imaging study showed a right temporal mass, which on biopsy proved to be primary central nervous system lymphoma (PCNSL). He began highly active antiretroviral therapy (HAART) but declined palliative whole-brain radiotherapy (WBRT). Four months later, his CD4+ count had improved to 153 cells per microliter and his HIV VL was less than 75 copies per milliliter. At 36 months follow-up, he remained in complete remission (CR). Through a literature review, we identified 4 additional PCNSL patients who achieved prolonged remission after the initiation of HAART. One patient required WBRT and ventriculo-peritoneal shunting for signs and symptoms of obstructive hydrocephalus. The other 3 patients presented with stable neurologic findings and were treated with HAART alone. The median initial CD4+ count for these patients was 50 cells per microliter (range, 2 to 220 cells per microliter). All 5 remained in CR with a median follow-up of 23.5 (range, 13 to 36) months. For patients who present with PCNSL as their initial AIDS-defining event, stable neurologic findings, and effective HAART options, initial treatment with HAART alone may be possible, reserving WBRT and corticosteroids for those who show signs of impending neurologic demise. Chemotherapy and other novel approaches could also be considered for selected patients with lesser degrees of immune suppression and high baseline functional status.

Declining incidence of intestinal microsporidiosis and reduction in AIDS-related mortality following introduction of HAART in Sydney, Australia

Limited data exist regarding the incidence of intestinal microsporidiosis following the introduction of highly active antiretroviral therapy (HAART) in Australia. At St Vincent's Hospital, Sydney, all faecal samples submitted for diarrhoea from HIV-infected patients between 1995 and 2006 underwent screening for microsporidiosis. A total of 3564 patients (7366 faecal specimens) was examined, resulting in 159 patients identified with microsporidiosis. The incidence of microsporidiosis declined from 11% in 1995 to 0% from 2004 onwards. At presentation the majority of patients were severely immunocompromised (median CD4 105 cells/mm(3)), with only 16% of patients on effective HAART. Twenty-four patients (24/76, 32%) died within a median of 22 months following microsporidiosis diagnosis. Significant predictors of AIDS-related mortality at presentation included the level of immunodeficiency and receiving no or ineffective HAART (P<0.05). Patients presenting after 1998 had a significant reduction in the risk of AIDS-related mortality compared with patients presenting before 1998 (hazard ratio 0.27, 95% CI 0.79-0.92). All 52 (68%) surviving patients were on effective HAART, with a median CD4 count 382 cells/mm(3) and HIV RNA of < 50 copies/ml at follow-up (median 4 years). The dramatic decline of intestinal microsporidiosis in our study reconfirms the importance of effective HAART in preventing advanced immunodeficiency, opportunistic infections and associated AIDS-related deaths.

Short Communication: Decreasing Soluble CD30 and Increasing IFN-γ Plasma Levels Are Indicators of Effective Highly Active Antiretroviral Therapy

It was previously reported that without highly active antiretroviral therapy (HAART), secretion of Th1 cytokines and antiviral IFN-gamma in HIV-infected patients is decreased, whereas the production of Th2 cytokines, proinflammatory cytokines, and TNF-alpha is increased. We studied the effect of HAART on Th1-, Th2-, and monocyte-derived cytokines, and on the Th2-type immune response marker soluble (s)CD30 in HIV-1-infected hemophilia patients. Viral Load (VL), CD4+ lymphocyte counts, and plasma levels of sIL-1RA, IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-7, IL-10, TNF-alpha, TGF-beta2, IFN-gamma, and sCD30 were measured in 18 patients who received HAART. Nine patients were initially treatment-naive and were monitored after the initiation of HAART. sCD30 median levels were significantly higher in treatment-naive patients than in patients who were on HAART (77 vs. 30 U/ml, p = 0.005). A strong association was observed between sCD30 and VL (r = 0.85, p = 0.004). After the initiation of HAART, sCD30 levels decreased and remained low (at 1 year, 38; at 2 years, 41 U/ml; p = 0.012 and p = 0.021, respectively, as compared to baseline level) and this was accompanied by a decrease in VL and monocyte-derived IL-6 and an increase in CD4+ lymphocyte counts and Th1-derived IFN-gamma. One year after the initiation of HAART a strong inverse correlation was observed between IFN-gamma and VL (r = -0.83, p = 0.006). In contrast to sCD30 and IFN-gamma, CD4 counts and plasma IL-6 did not correlate with VL at any time. Our data suggest that decreasing sCD30 and increasing IFN-gamma plasma levels are indicators of effective HAART treatment and CD4 Th1 cell recovery in HIV-infected patients.

Pregnancy Rates and Birth Outcomes Among Women on Efavirenz-Containing Highly Active Antiretroviral Therapy in Botswana

Millions of HIV-infected women in developing countries are in need of safe and highly effective antiretroviral therapy. Pregnancy rates are usually high in developing countries, and efavirenz (EFV) use in women of childbearing age is of concern because of its potential teratogenicity. As part of a prospective study comparing 6 initial highly active antiretroviral therapy (HAART) regimens, 3 of which contained EFV, pregnancy and birth outcomes were evaluated among female participants enrolled in a randomized clinical trial in Botswana. Before enrollment, all female participants indicated a willingness to avoid pregnancy for the 3-year duration of the study. Monthly urine pregnancy testing and regular contraceptive education and counseling were given to all women on study. Four hundred fifty-one (69.4%) of 650 enrolled study participants were female and experienced 71 pregnancies, for a rate of 7.9 per 100 person-years during the study. The mean time from HAART initiation to time of first pregnancy was 385 days. The median birth weight of babies was 2950 g (interquartile range: 2700-3250 g); the gender of babies (24 female and 15 male) and occurrence of early pregnancy loss (42%) and stillbirths (3%) did not differ between EFV- and non-EFV-exposed pregnancies (P=0.7). First-trimester EFV exposure occurred in 38 (53.5%) of the 71 pregnancies; 22 (57.9%) of these 38 pregnancies resulted in live births. One infant (4.5%) of the 22 EFV-exposed live births had a congenital abnormality with right limb shortening that was assessed to be unrelated to EFV exposure. The restoration of health and longevity in many HAART-treated women is often accompanied by childbearing, as evidenced by the large fraction of women in our cohort who became pregnant despite their initial statements of intent to avoid pregnancy. Of 22 first-trimester EFV-exposed live births, 1 neonate was found to have a major congenital abnormality; however, this defect was unrelated to EFV exposure. The small sample size is insufficient to estimate accurately the underlying risk of congenital malformation after exposure to EFV in early pregnancy, underscoring the importance of reporting to the existing international Antiretroviral Pregnancy Registry. In addition to accessing safe and effective HAART regimens, HIV-infected women require access to comprehensive family planning services, including contraception and procreation counseling.

Lack of Evidence for Prolonged Double-Long Terminal Repeat Episomal HIV DNA Stability In Vivo

Lack of Evidence for Prolonged Double-Long Terminal Repeat Episomal HIV DNA Stability In Vivo

Hepatitis C virus genetic variability in patients undergoing antiviral therapy

Hepatitis C virus (HCV) has been the subject of intense research and clinical investigations due to its worldwide prevalence and major role in chronic liver disease. Like most RNA viruses, HCV circulates in vivo as a complex population of different but closely related viral variants, commonly referred to as a quasispecies. Recent studies suggest that ribavirin might exert an antiviral effect against HCV through both mutageneic effect and an impairment of RNA replication. The introduction of alpha interferon (IFN-α) plus ribavirin combination therapy was an important breakthrough in the treatment of chronic HCV infection. However, the rate of sustained virological response is still unsatisfactory, particularly in patients infected with HCV genotype 1. Viral persistence, a hallmark of HCV, may result from a dynamic control of the host response by the virus. In children with chronic HCV infection, the viral population is initially highly homogeneous, but diversifies during prolongend infection which seems to be a common event during chronic hepatitis C in childhood. Coinfection of human immunodeficiency virus 1 (HIV-1) patients by HCV can complicate the treatment of these patients with highly active antiretroviral therapy (HAART). HIV coinfection is associated with a decrease of HCV quasispecies variability, which appears to be reversed by effective HAART.

Individual, Interpersonal, and Structural Correlates of Effective HAART Use Among Urban Active Injection Drug Users

Among individuals receiving highly active antiretroviral therapy (HAART), injection drug users (IDUs) are less likely to achieve HIV suppression. The present study examined individual-level, interpersonal, and structural factors associated with achieving undetectable plasma viral load (UVL) among US IDUs receiving recommended HAART. Data were from baseline assessments of the INSPIRE (Interventions for Seropositive Injectors-Research and Evaluation) study, a 4-site, secondary HIV prevention intervention for heterosexually active IDUs. Of 1113 study participants at baseline, 42% (n = 466) were currently taking recommended HAART (34% were female, 69% non-Hispanic black, 26% recently homeless; median age was 43 years), of whom 132 (28%) had a UVL. Logistic regression revealed that among those on recommended HAART, adjusted odds of UVL were at least 3 times higher among those with high social support, stable housing, and CD4 > 200; UVL was approximately 60% higher among those reporting better patient-provider communication. Outpatient drug treatment and non-Hispanic black race and an interaction between current drug use and social support were marginally negatively significant. Among those with high perceived support, noncurrent drug users compared with current drug users had a greater likelihood of UVL; current drug use was not associated with UVL among those with low support. Depressive symptoms (Brief Symptom Inventory) were not significant. Results suggest the major role of social support in facilitating effective HAART use in this population and suggest that active drug use may interfere with HAART use by adversely affecting social support. Interventions promoting social support functioning, patient-provider communication, stable housing, and drug abuse treatment may facilitate effective HAART use in this vulnerable population.

HIV Infection and Antiretroviral Therapy: Effect on Hepatitis C Virus Quasispecies Variability

Hepatitis C virus (HCV) quasispecies variability has been associated with liver disease progression. The effects of human immunodeficiency virus (HIV) coinfection and highly active antiretroviral therapy (HAART) on HCV quasispecies variability have not been firmly established. We determined HCV quasispecies complexity and diversity in 69 subjects, 28 of whom were HIV infected, using clonal frequency analysis via heteroduplex mobility analysis of the second envelope gene hypervariable region. Nucleotide sequencing was performed for a small subset of subjects. HIV-positive, HAART-naive subjects had significantly lower HCV quasispecies complexity and diversity than did both HIV-negative and HIV-positive HAART-treated subjects. In multivariate analysis, HIV infection predicted decreased complexity (P < .0001) and diversity (P = .001) of HCV quasispecies, whereas HAART predicted increased complexity (P = .013) and diversity (P = .026). For 4 of 6 patients, sequence analysis yielded data supporting the model that positive host pressure drives HCV quasispecies heterogeneity, although data favoring the hypothesis of selective outgrowth of the most fit variants were also observed. HIV coinfection is associated with decreased HCV quasispecies variability, which appears to be reversed by effective HAART. Although HIV- and HAART-related effects on host immune pressure are likely to play a role in the observed differences in HCV genetic heterogeneity, other mechanisms may be operative.

Cerebrospinal Fluid Viral Loads Reach Less than 2 Copies/ML in HIV-1-Infected Patients with Effective Antiretroviral Therapy

A low-grade persisting viraemia despite long-term treatment with highly active antiretroviral therapy (HAART) has previously been demonstrated in HIV-1-infected patients. Whether ongoing viral replication also could be detected in cerebrospinal fluid (CSF) in those circumstances has not been studied before. Paired CSF and blood samples from 13 neurologically asymptomatic HIV-1-infected patients on stable HAART were analysed regarding HIV-1 RNA, by using a PCR assay with a detection limit of 2 copies/ml. All 13 patients had HIV-1 RNA < 2 copies/ml in CSF, compared with 8/13 in plasma. We could not demonstrate any persistent viral replication in the CSF of neurologically asymptomatic HIV-1-infected patients on effective HAART, rendering it unlikely that CSF acts as a viral reservoir in this category of patients.

Evidence that Low-Level Viremias during Effective Highly Active Antiretroviral Therapy Result from Two Processes: Expression of Archival Virus and Replication of Virus

Episodes of low-level viremia (LLV), with plasma human immunodeficiency virus type 1 (HIV-1) RNA levels ranging from 50 to 400 copies (c)/ml, occur commonly during highly active antiretroviral therapy (HAART). LLV has been associated with virologic failure of HAART in some studies, while in others LLV did not appear to affect the clinical outcome. To understand the processes leading to LLV, genetic analyses were used to determine whether plasma virions emanated from archived or from newly evolved viral genomes. Episodes of LLV (plasma HIV-1 RNA, 50 to 379 [median, 77] c/ml) were detected in 21/37 (57%) HIV-1-infected children with median plasma HIV-1 RNA levels of <50 c/ml during 79 patient years of HAART. Viral sequences were derived by direct sequencing of PCR products from 21 plasma specimens diluted to end point. In phylogenetic analysis, LLV viral sequences grouped with virus from early in the course of infection in 8/11 subjects. Six specimens had multiple identical viral sequences, suggesting origin from clonally expanded infected cells. LLV plasma virus evolved over time, indicating viral replication, in 3/11 subjects. Two of these had frequent LLV, including the selection of drug-resistant mutants. In summary, plasma virus from episodes of LLV during effective HAART appeared to originate from two distinct processes, (i) clonal outgrowth from long-lived HIV-1-infected cells, presumably following activation and proliferation of these cells, and (ii) ongoing viral replication that included the selection of new drug-resistant mutants. These observations provide a plausible explanation for the divergent clinical outcomes previously associated with LLV.

Switch strategies in patients on effective HAART

To provide the best possible long-term outcomes for patients, a number of strategies have been proposed based on the possibility to switch from a successful protease inhibitor (PI)-based highly active antiretroviral therapy (HAART) to another antiretroviral regimen. The available evidence from clinical trials in virologically controlled patients demonstrates that switching the PI-based HAART to a simplified regimen is safe. However, abacavir-based simplified therapies should be limited to patients with a known drug history who have not undergone prior mono or dual nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) therapy. Triple NRTI regimens that do not include a thymidine analogue have not been adequately tested so far and are not recommended. The switch strategy may enhance long-term adherence and induce a moderate reduction in cholesterol or amelioration of the total/high-density lipoprotein (HDL) cholesterol ratio that might be particularly relevant for patients presenting other risks for coronary heart disease. Simplified regimens are not associated with a clinically relevant improvement in the redistribution of body fat. Thus, if such a therapeutic strategy is considered, it should be preferably implemented to prevent or delay lipodystrophy. As the therapeutic scenario is significantly changing, in the future, convenience and metabolic alterations will be less of an issue in the decision to use a PI-switch strategy. Future switch strategies may involve NRTIs. Among NRTIs, thymidine analogues and particularly stavudine appear to be most associated with lipoatrophy. NRTI switches may also be beneficial in reducing the risk of lactate level elevation, mitochondrial toxicity, insufficient immunological response to HAART and of selecting class-inducing resistance mutations.

The Role Of Human Papillomavirus (HPV) And The Increasing Incidence Of Oral Pathology In The Era Of Highly Active Antiretroviral Therapy (HAART)

Oral HPV infection and disease results from increases in oral-based immune suppression in the HIV co-infected individual that cannot be restored and is possibly compromised further by HAART. This review provides greater insight into the rate of oral HPV infection in the HIV individual, the effect of HAART on oral HPV infection, it's role in oral pathology, and the host's immune response against HPV under immune compromised (HIV without effective HAART) and potentially immune restored (effective HAART) conditions.

Administration of HDAC inhibitors to reactivate HIV-1 expression in latent cellular reservoirs: implications for the development of therapeutic strategies

The discovery of powerful antiviral compounds in the 90’s raised the hope that the human immunodeficiency virus type 1 (HIV-1) might be eradicated. However, if these drugs succeed in decreasing and controlling viral replication, complete eradication of the virus is nowadays impossible. The persistence of virus even after long periods of highly active antiretroviral therapy (HAART) mainly results from the presence of cellular reservoirs that contain transcriptionally competent latent viruses capable of producing infectious particles after cellular activation. These latently infected cells are a permanent source for virus reactivation and lead to a rebound of the viral load after interruption of HAART. Activation of HIV gene expression in these cells combined with an effective HAART has been proposed as an adjuvant therapy that could lead to the elimination of the latently infected cells and then to the eradication of the infection. In this context, we have previously demonstrated that deacetylase inhibitors (HDACi) synergize with TNF-induced NF-κB to activate the HIV-1 promoter. The physiological relevance of the TNF/HDACi synergism was shown on HIV-1 replication in both acutely and latently HIV-infected cell lines. Based on these results, we propose the administration of deacetylase inhibitor(s) together with continuous HAART as a new potential therapeutic perspective to decrease the pool of latent HIV reservoirs by forcing viral expression.

Long‐term suppression of plasma viremia with highly active antiretroviral therapy despite virus evolution and very limited selection of drug‐resistant genotypes

HIV-1 evolution and the possible emergence of mutations associated with resistance to antiretroviral inhibitors have been evaluated in a cohort of sixty-three patients successfully treated with highly active antiretroviral therapy (HAART). The patients under effective HAART were recruited in three different hospitals in Spain, and none of them had been treated (naïve) before entering this study. HIV-1 RNA levels, CD4+, and CD8+ T-cell counts were determined, and nucleotide sequences of proviral regions encoding protease and reverse transcriptase (RT) were obtained for longitudinal blood samples spanning a mean follow-up period of 88 weeks. Phylogenetic reconstructions and calculations of genetic distances among the different sequences of each patient were performed. All except one of the patients under study showed an early and sustained decrease in plasma HIV-1 RNA to levels that were below 200 copies/ml. The plasma viral decline paralleled a significant increase in the CD4+ T-lymphocyte counts. Amino acid sequence analyses revealed the occurrence of mutations associated with antiretroviral resistance in nine patients (14.3%) during HAART treatment, that in some cases could be attributed to excess G to A transitions. In six of the nine patients, the mutations conferred resistance to inhibitors administered in the treatment regime, although the mutations did not result in treatment failure. Sequence comparisons revealed viral evolution during the period of treatment in 47.5% of the patients. The results indicate successful suppression of HIV-1 under HAART for extended time periods, indistinguishable for patients in which evidence of virus evolution could or could not be documented.

High-dose therapy and autologous peripheral-blood stem-cell transplantation as salvage treatment for HIV-associated lymphoma in patients receiving highly active antiretroviral therapy.

High-dose therapy (HDT) and peripheral-blood stem-cell transplantation (PBSCT) in HIV-associated lymphoma (HIV-Ly) has been recently reported in selected patients. We describe the results of a multi-institutional program of HDT and PBSCT as salvage therapy in HIV-Ly responsive to highly active antiretroviral therapy (HAART) in unselected patients. Patients with resistant or relapsed HIV-Ly after first-line chemotherapy (CT) underwent PBSC collection after a course of second-line CT or cyclophosphamide and granulocyte colony-stimulating factor. Patients with chemotherapy-sensitive disease received carmustine, etoposide, cytarabine, and melphalan (BEAM regimen) and PBSC reinfusion. Effective HAART was maintained during the entire program. Sixteen consecutive patients entered the program. Adequate collection of PBSC was obtained in 80% of patients (median CD34+ cells 6.8 x 106/kg). Three patients had early progression. Ten patients (62%) received PBSCT with prompt engraftment in all patients (neutrophils and platelet engraftment after a median of 10 days [range, 8 to 10 days] and 13 days [range, 8 to 18 days], respectively). No patients died as a result of opportunistic or other infections or treatment-related complications. Eight of nine assessable patients achieved complete remission (one patient after radiotherapy for residual disease) and one patient achieved partial remission. Two patients experienced relapse and died at +10 and +14 months. Six patients are alive and disease free at a median of 8 months after transplantation. Our data confirm that HDT plus PBSCT is feasible and active as salvage therapy in HIV-Ly on a multi-institutional basis and in unselected HAART-responding patients. HIV infection should no longer preclude the opportunity of HDT in patients with lymphoma.

Sustained viremia during highly active antiretroviral therapy with accelerated proviral DNA decay in the setting of infection with syphilis

Highly active antiretroviral therapy (HAART) suppresses viral replication to undetectable levels in most adherent HIV-1-infected individuals. Although intermittent isolated episodes of detectable viremia are common and not necessarily associated with treatment failure [1], persistently detectable viremia is generally regarded as such and often results in a change in regimen [2]. Although sustained viremia during therapy is probably a result of the emergence of a drug-resistant variant [3], non-adherence [4,5] or superinfection with a drug-resistant virus [6] could also lead to viremia during therapy. Measurable HIV-1-RNA levels in the plasma may also reflect the release of particles from recently activated, previously infected cells harboring provirus, including resting lymphocytes and macrophages. We detail the course of a 28-year-old Caucasian gay man, who was found to be viremic on three consecutive monthly visits after 18 months of effective HAART. The viremia resolved without a change in treatment and no viremia has been detectable for the past 17 months. The patient was self-referred to the Aaron Diamond AIDS Research Center on 4 February 2000. The subject had participated in a recombinant envelope vaccine trial, was negative serologically on 13 December 1999 and was newly HIV-1 positive on 26 January 2000. On 8 February 2000 a regimen of abacavir 600 mg, lamivudine 300 mg, indinavir 2400 mg and amprenavir 900 mg a day was initiated. After 16 weeks, indinavir was discontinued and substituted with amprenavir 1200 mg/ritonavir 200 mg a day. On 30 October 2001 the patient presented with complaints of lymphadenopathy in the inguinal region. He described two brief episodes of low-grade fevers in August and September of 2001, and concomitantly reported multiple anal-receptive sexual encounters without the use of condoms. Examination revealed bilateral non-tender lymphadenopathy. A serological test for syphilis was newly positive at a 1 : 64 dilution. The patient was treated with three injections of 2.4 million units of benzathine penicillin. Low-level viremia was detected at 4-week intervals beginning at week 68 (3 July 2001), and continued until week 84 (14 September 2001) of HAART (Fig. 1a). To investigate whether the viremia resulted from superinfection, we compared the V3 region of the envelope gene from plasma virus at baseline and week 84. The V3 region was amplified using a modified nested reverse transcriptase–polymerase chain reaction as previously described [7]. The consensus sequences of the two timepoints were 100% homologous, providing conclusive evidence that the virus that initially infected this patient was the same as that being detected in the patient's plasma during rebound.Fig. 1.: (a) Longitudinal determination of plasma viremia (HIV-1-RNA copies/ml in log 10 ) and CD4 T-cell count (cells/mm 3 ) while on antiretroviral therapy. Viral load (□) is plotted on a semi-log scale, whereas CD4 cell count (●) is on a linear scale. The viral load values at the times of ‘blip’ are denoted as VL. The dotted line indicates the lower limit of detection of HIV-1 RNA (< 50 copies/ml). (b) Proviral DNA (▴) and HIV-1 RNA (□) (copies/ml) of patient from weeks 55 to 110 of highly active antiretroviral therapy. A fivefold drop in proviral DNA is noted immediately before increased viremia. The dotted line indicates the lower limit of detection of HIV-1 RNA (< 50 copies/ml). HAART, Highly active antiretroviral therapy.Having ruled out superinfection, we then asked whether resistance to the antiviral agent was emerging. Clonal sequencing of the HIV-1 protease and reverse transcriptase regions was performed. Six clones at baseline and 10 clones at week 84 were studied. Reverse transcriptase–polymerase chain reaction, cloning and sequencing of pol were performed as described elsewhere [8,9]. No resistance-conferring mutations in protease or reverse transcriptase were detected. We then asked whether the detectable viremia was a result of low-level replication from a sequestered site. We performed longitudinal assessments of the levels of proviral DNA in patient peripheral blood mononuclear cells. We hypothesized that the proviral DNA levels would remain stable or increase slightly if there was ongoing viral replication during HAART. Conversely, if viremia resulted from the expression of HIV-1 proviral DNA without replication, the proviral DNA levels would decrease. Proviral DNA was measured using the Amplicor HIV-DNA Monitor Test (Roche, Alameda, CA, USA) with modifications as published [10]. Proviral DNA levels decreased sharply between weeks 68 and 76 (Fig. 1b). These data suggest that the measurable HIV-1-RNA levels may have originated from activated reservoirs. We hypothesize that this activation is a result of immune stimulation caused by infection with syphilis. This observation suggests that efforts should be made to study apparent virological failure carefully before a particular regimen is abandoned.

Delayed motor learning and psychomotor slowing in HIV-infected children.

To find out whether HIV-associated subclinical psychomotor slowing is present in HIV-infected children despite effective highly active antiretroviral therapy (HAART). An electrophysiological motor test battery shown to sensitively describe HIV-associated CNS disease in adults (tremor peak frequency []TPF], most rapid alternating movements [MRAM], reaction time [RT] and contraction time [CT]) was performed in 17 HIV seropositive (+) right-handed children. Results were compared to 16 HIV seronegative (-) children. HIV (-) children showed slower frequencies (TPF, MRAM) and longer RT and CT than (-) adults. They showed a significant correlation (p = 0.0263) between RT (right = dominant hand) and age. HIV (+) children showed significant prolongations of RT (right hand) and CT (both hands) compared to HIV (-) children. RT right hand did not accelerate with age in HIV (+) children. CT were significantly prolonged in 10 children with detectable HIV plasma viral burden and normal in 7 children with no detectable HIV plasma viral load. There was no correlation between CT and CD 4 cell counts. Despite effective HAART, electrophysiological motor testing in HIV (+) children reveals significant subclinical CNS dysfunction, especially in children with insufficient viral load suppression.

Nucleoside analogues and HIV: the combined cost to mitochondria.

Highly active antiretroviral therapy (HAART) has revolu- tionized human immunodeficiency virus (HIV) care in the developed world. Since the introduction of HAART the morbidity and mortality associated with HIV infection have decreased dramatically, 1 but this benefit has been associated with the emergence of a diverse range of antiretroviral toxici- ties. Nucleoside reverse transcriptase inhibitors (NRTIs) are central to effective HAART, with current antiretroviral guidelines recommending the inclusion of at least two of these agents in each regimen. However, NRTIs also con- tribute significantly to the toxicities of HAART. Here we review the known mechanism of action of NRTIs, the pro- posed mechanism by which they may cause toxicities through mitochondrial damage, the evidence that HIV infection may predispose individuals to overt mitochondrial dysfunction, and potential future methods of monitoring and preventing these problems. Nucleoside analogues act as alternative substrates for DNA polymerases. Because NRTIs lack a hydroxyl group in the 3'-position (required for the addition of the next nucleo- tide onto the primer) their incorporation causes termination of the growing DNA strand. Their intended therapeutic action is to prevent the formation of HIV DNA by inhibiting HIV reverse transcriptase. However, NRTIs have the potential to cause serious cellular toxicities by interacting in a similar manner with human DNA polymerases. 2 The enzymes responsible for the replication of human nuclear DNA are polymerase α and δ. Polymerase β and e play roles in DNA repair, and polymerase γ is responsible for replication of mitochondrial DNA (mtDNA). The NRTIs currently used in the treatment of HIV infection (zidovudine, stavudine, lamivudine, didanosine, zalcitabine and abacavir) all inhibit DNA polymerases β and γ. The inhibition of poly- merase β has not been shown to be of clinical significance, but

Persistence of replication-competent HIV in both memory and naive CD4 T cell subsets in patients on prolonged and effective HAART

To investigate the phenotypic features of infected lymphocytes in patients on prolonged and effective highly active antiretroviral therapy (HAART). We examined highly purified subsets of memory and naive CD4 T lymphocytes for the presence of replication-competent virus. In 11 highly selected HAART-treated patients, we isolated highly purified CD45RO CD45RA CD4 T cells using a magnetic bead-based procedure. In some patients, a subsequent cell separation according to CD62L expression was performed. We quantified total viral DNA in freshly isolated T-cell subsets. To verify whether the virus was replication-competent, HIV RNA was measured in supernatants following cell activation. HIV DNA was detectable in the CD45RO and CD45RA CD4 T-cell subsets in 100% and 90% of the patients tested, respectively. In central memory CD45ROCD62L, effector memory CD45RO+CD62L-, truly naive CD45RACD62L, and CD45RA+CD62L- CD4 T cells, HIV DNA was found in 100%, 55%, 88%, and 50% of the patients tested respectively. HIV DNA was significantly higher in the CD45RO fraction than in the CD45RA subset and in the CD45ROCD62L fraction than in the three other CD45RA/ROCD62L+/- subsets. Detectable HIV RNA was found in the culture supernatants of CD45RO and CD45RA CD4 T-cell subsets in 80% and 66% of the patients tested respectively, and in CD45ROCD62L, CD45RO+CD62L-, CD45RACD62L, and CD45RA+CD62L- CD4 T cells in 100%, 100%, 100% and 50% of the patients tested respectively. In patients on prolonged and effective HAART, the pool of infected CD4 T lymphocytes consists predominantly of memory cells but also contains naive cells.