Week 48 Resistance Analyses of the Once-Daily, Single-Tablet Regimen Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (D/C/F/TAF) in Adults Living with HIV-1 from the Phase III Randomized AMBER and EMERALD Trials

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg is being investigated in two Phase III trials, AMBER (NCT02431247; treatment-naive adults) and EMERALD (NCT02269917; treatment-experienced, virologically suppressed adults). Week 48 AMBER and EMERALD resistance analyses are presented. Postbaseline samples for genotyping/phenotyping were analyzed from protocol-defined virologic failures (PDVFs) with viral load (VL) ≥400 copies/mL at failure/later time points. Post hoc analyses were deep sequencing in AMBER, and HIV-1 proviral DNA from baseline samples (VL <50 copies/mL) in EMERALD. Through week 48 across both studies, no darunavir, primary PI, or tenofovir resistance-associated mutations (RAMs) were observed in HIV-1 viruses of 1,125 participants receiving D/C/F/TAF or 629 receiving boosted darunavir plus emtricitabine/tenofovir-disoproxil-fumarate. In AMBER, the nucleos(t)ide analog reverse transcriptase inhibitor (N(t)RTI) RAM M184I/V was identified in HIV-1 of one participant during D/C/F/TAF treatment. M184V was detected pretreatment as a minority variant (9%). In EMERALD, in participants with prior VF and genoarchive data (N = 140; 98 D/C/F/TAF and 42 control), 4% had viruses with darunavir RAMs, 38% with emtricitabine RAMs, mainly at position 184 (41% not fully susceptible to emtricitabine), 4% with tenofovir RAMs, and 21% ≥ 3 thymidine analog-associated mutations (24% not fully susceptible to tenofovir) detected at screening. All achieved VL <50 copies/mL at week 48 or prior discontinuation. D/C/F/TAF has a high genetic barrier to resistance; no darunavir, primary PI, or tenofovir RAMs were observed through 48 weeks in AMBER and EMERALD. Only one postbaseline M184I/V RAM was observed in HIV-1 of an AMBER participant. In EMERALD, baseline archived RAMs to darunavir, emtricitabine, and tenofovir in participants with prior VF did not preclude virologic response.

Persistent Ulceration of the Anal Margin in Homosexuals with Hiv Infection

A study of the outcome of surgical treatment of ulceration of the anal margin occurring in male homosexuals with HIV infection was undertaken. Ten patients with acquired immunodeficiency syndrome and three patients with symptomatic HIV infection were referred to the Department of Surgery with painful anal ulceration which had not responded to medical treatment. The medical treatments given prior to surgical referral included high dose oral acyclovir, intravenous foscarnet and broad spectrum antibiotics. Excision biopsy was performed in 12 patients and in 11 cases was followed by healing of the ulcers within 10 weeks. One patient died 2 weeks postoperatively from Pneumocystis carinii pneumonia without healing. The response to excision biopsy was unexpected but suggests that surgical excision may be beneficial for lesions which have failed to respond to aggressive medical treatment.

Abnormalities of Liver Function during HIV Seroconversion Illness

In 6 patients with a severe human immunodeficiency virus (HIV) seroconversion illness distinct abnormalities of liver transaminases were observed; in addition there was marked hepatomegaly in 5 patients.

Meningococcal infection in patients with the human immunodeficiency virus and acquired immunodeficency syndrome

Meningococcal infection is believed to be rare in HIV-positive individuals. We present 2 cases from our reference caseload within the last 10 years.

Pancreatic insufficiency in patients with HIV infection: role of didanosine questioned

OBJECTIVES

The aim of the study was to identify possible causes of pancreatic insufficiency in patients with HIV infection.

METHODS

A retrospective analysis of 233 HIV-positive patients for whom faecal elastase measurement was available was performed to investigate potential associations with core demographic data, HIV infection characteristics, degree of immunosuppresion, exposure to antiretroviral therapy (ART), alcohol misuse, diabetes, hepatitis C virus (HCV) infection, triglyceride and cholesterol levels and symptomatology. The response to pancreatic enzyme replacement for patients with evidence of insufficiency was also evaluated.

RESULTS

Of 233 patients, 104 (45%) had evidence of pancreatic exocrine insufficiency (faecal elastase < 200 mcg/g). A positive association with exocrine pancreatic insufficiency was found for HCV infection (P = 0.007), previous or current HCV treatment (P = 0.003), alcohol misuse history (P = 0.006) and the presence of steatorrhoea (P = 0.03). There was no demonstrated association between exocrine pancreatic insufficiency and didanosine (ddI) exposure (P = 0.43) or stavudine (d4T) exposure (P = 0.62). Seventy-seven per cent of patients who were treated with pancreatic enzymatic supplementation reported a subjective improvement in symptoms.

CONCLUSIONS

Faecal elastase sampling should form part of the routine work-up for HIV-positive patients with chronic diarrhoea even in the absence of 'traditional' risk factors such as ddI exposure. In particular, if the patient has steatorrhoea, a history of alcohol exposure or their HCV serology is positive, they should be considered for investigation. Treatment with pancreatic enzyme supplementation appears to be effective in the treatment of chronic diarrhoea caused by pancreatic insufficiency in the majority of patients.

Charcoal haemoperfusion for paracetamol overdose

1 A controlled trial of charcoal haemoperfusion as an early treatment for paracetamol overdose showed no benefit. 2 The plasma clearances of paracetamol by the charcoal column were variable and disappointingly small (range 4-119 ml/minute). The cumulative amounts removed were also low, mean 1.4 g (range 0.2-5.2 g). 3 No clinical problems were encountered with the technique of haemoperfusion and in particular the drop in blood platelet counts was small (mean fall 16%).

British HIV Association and Children's HIV Association position statement on infant feeding in the UK 2011

To prevent the transmission of HIV infection during the postpartum period, the British HIV Association and Children's HIV Association (BHIVA/CHIVA) continue to recommend the complete avoidance of breast feeding for infants born to HIV-infected mothers, regardless of maternal disease status, viral load or treatment.

Increased proportion of CD16(+) NK cells in the colonic lamina propria of inflammatory bowel disease patients, but not after azathioprine treatment

BACKGROUND

Distinct functional subsets of natural killer cells potentially contribute to the pathology of inflammatory bowel disease (IBD).

AIM

To report the phenotypic and functional characteristics of natural killer cells in blood and lamina propria of IBD patients, and the effect of azathioprine.

METHODS

Natural killer cells from blood and lamina propria of healthy controls or patients with Crohn's disease, or ulcerative colitis were studied by flow cytometry. Activation, cytokine production, proliferation and apoptosis of natural killer cell subsets were studied in vitro.

RESULTS

CD16(+) natural killer cells are increased in frequency in the lamina propria comparing Crohn's disease or ulcerative colitis with healthy controls. Azathioprine therapy was associated with a reduction in total natural killer cells in blood and lamina propria, preferentially of the CD16(+) subset. Azathioprine therapy did not impair natural killer degranulation, but reduced natural and cytokine-activated cytotoxicity and interferon-gamma (IFN-γ) production. Culture of resting peripheral blood mononuclear cells with azathioprine resulted in loss of natural killer cells and inhibition of activation and IFN-γ production. Azathioprine preferentially inhibited proliferation of CD16(+) natural killer cells and induced apoptosis in resting but not in pre-activated natural killer cells.

CONCLUSIONS

Natural killer cells with cytolytic potential are enriched in the colonic lamina propria of individuals with IBD. Azathioprine is associated with a reduction in these cells and a normalization of natural killer cell populations.

CD38 expression on CD8 T cells has a weak association with CD4 T-cell recovery and is a poor marker of viral replication in HIV-1-infected patients on antiretroviral therapy

OBJECTIVE

The aim of the study was to determine whether the expression of CD38 on CD8 T cells can identify patients with virological failure on antiretroviral therapy (ART).

DESIGN

This was a cross-sectional study of patients attending a single HIV clinic in London.

METHODS

The expression of CD38 on CD8 T cells was assessed using a biologically calibrated flow cytometry protocol. Patients were characterized by lymphocyte subset and viral load measurements. Characteristics including historical CD4 T cell counts, therapeutic history, co-infections and demographics were obtained from medical records.

RESULTS

Elevated levels of CD8 CD38(high) T cells were found in HIV-1-infected patients who failed to suppress viral replication with ART; however, this parameter lacked sufficient sensitivity and specificity to replace viral load testing in assessing the efficacy of ART. Increased levels of CD8 CD38(high) cells were associated with reduced CD4 T cell counts in HIV-1-infected patients on ART after correcting for known determinants of CD4 T-cell recovery.

CONCLUSIONS

The expression of CD38 on CD8 T cells lacks sufficient sensitivity and specificity to be used as a surrogate marker for viral load to monitor HIV-1 infection. T-cell activation is associated with reduced CD4 T-cell reconstitution in patients receiving ART.

Switching from twice-daily abacavir and lamivudine to the once-daily fixed-dose combination tablet of abacavir and lamivudine improves patient adherence and satisfaction with therapy

BACKGROUND

Patients prefer fewer pills and once-daily (qd) dosing without food restrictions. We assessed the impact on adherence [by Medication Event Monitoring System (MEMS) cap monitoring] of switching from abacavir (ABC) and lamivudine (3TC) twice daily (bid) to ABC/3TC fixed-dose formulation (FDC, Kivexa) qd to achieve a qd regimen.

METHODS

A randomized, open-label, 8-week study comparing adherence, efficacy and safety of immediate vs. delayed switching from ABC/3TC to FDC qd.

RESULTS

Ninety-four patients were dosed. Significantly improved adherence was observed at week 4 with qd ABC/3TC across all three adherence variables: taking compliance 99.2% (90.7-100%) vs. 96.6% (60.0-100%) (P=0.017); dosing compliance 97.1% (64.3-100%) vs. 91.9% (33.3-100%) (P=0.016); and timing compliance 95.5% (53.8-100%) vs. 86.3% (4.3-100%) (P=0.006). Treatment satisfaction increased significantly at week 4 with ABC/3TC qd [92% (82-99%) vs. 85% (75-93%) (P=0.004)]. Two patients were withdrawn from the study because of intolerance to ABC/3TC.

CONCLUSIONS

Switching from ABC and 3TC bid to ABC/3TC FDC qd significantly improved adherence by MEMS cap monitoring at week 4 and improved patient satisfaction with therapy. The results remain to be confirmed over a longer follow-up. Use of qd regimens supports adherence and improves treatment satisfaction relative to bid regimens.

Pulmonary Kaposi sarcoma in the era of highly active antiretroviral therapy

OBJECTIVE

Since the introduction of highly active antiretroviral therapy (HAART) there has been a dramatic reduction in the incidence of Kaposi sarcoma (KS) and an improvement in survival. We wished to examine whether the outcome in pulmonary KS (pKS) has also altered.

METHODS

In a single-institution cohort of 1140 HIV-positive patients with KS, 305 patients were diagnosed in the HAART era (1996-2004). We examined the clinicopathological features and outcomes of these patients, of whom 25 had pKS and 280 did not.

RESULTS

Patients with pKS had lower CD4 cell counts at the time of KS diagnosis (Mann-Whitney U-test P=0.005). The incidence of pKS was higher in African patients than in non-African patients in this sample (Fisher's test, P=0.001). There were no significant differences in age, gender, plasma HIV-1 viral load or prior HAART treatment at the time of KS diagnosis. Five-year overall survival in the pKS group was 49% [95% confidence interval (CI) 26-73%] as compared with 82% (95% CI 76-87%) for the non-pKS group (log rank, P<0.0001).

CONCLUSION

PKS remains an ominous diagnosis in the era of HAART, with a median survival of just 1.6 years.

Impact of antiretroviral choice on hypercholesterolaemia events: the role of the nucleoside reverse transcriptase inhibitor backbone

BACKGROUND

The use of highly active antiretroviral therapy (HAART) has profoundly altered the life expectancy of individuals infected with HIV. Metabolic abnormalities associated with antiretrovirals and cumulative exposure to combination antiretroviral therapy, including dyslipidaemia and insulin resistance, have been linked to an increased risk of myocardial infarction.

METHODS

Longitudinal data from a large prospectively collected clinical database were analysed. All patients who commenced first antiretroviral therapy (ART) [two nucleoside reverse transcriptase inhibitors (NRTIs)+one nonnucleoside reverse transcriptase inhibitor (NNRTI) or one active protease inhibitor (PI)] since 1996 were identified. Patients with elevated cholesterol levels [>5.5 mmol/L (215 mg/dL)] prior to therapy initiation were excluded. Quantitative data were categorized into quartiles and presented stratified by individuals developing abnormal levels of cholesterol during first-line HAART. Event time was defined as time from commencing first-line ART to either development of cholesterol level >6.5 mmol/L (254 mg/dL) or switch of first-line therapy. The Kaplan-Meier product limit survival method was used to estimate time to abnormal cholesterol level, and the chi2 test was used for comparisons between drug classes. Cox's proportional hazards regression analysis was used to identify factors predicting a likelihood of raised cholesterol level.

RESULTS

A total of 1664 patients were included in the study: 57.1% on two NRTIs+one NNRTI, 38.4% on two NRTIs+one PI, and 4.4% on two NRTIs+a boosted PI regimen. Regimens containing stavudine or PIs were associated with a significantly higher event risk and earlier time to event. No differences between efavirenz and nevirapine or between didanosine and lamivudine were observed. In 28 patients exposed to the combination of tenofovir+lamivudine+efavirenz, there were no episodes of elevated cholesterol level.

CONCLUSION

Dyslipidaemia has emerged as an important issue in HIV-infected individuals receiving antiretroviral therapy. This study demonstrates that age at start of therapy, baseline cholesterol level, stavudine use and PI use are all associated with increased risk of hypercholesterolemia on initial therapy. Both NRTI and NNRTI/PI choice influence risk of hypercholesterolaemia.

Immunological and virological consequences of patient-directed antiretroviral therapy interruption during chronic HIV-1 infection

Increasing numbers of patients are choosing to interrupt highly active antiretroviral therapy (HAART). We describe the effect of patient-directed treatment interruption (PDTI) on plasma viral loads (pVL), proviral DNA (pDNA), lymphocyte subsets and immune responses in 24 chronically HIV-1 infected individuals. Patients were divided into group A with pVL > 50 copies/ml and group B with pVL < 50 copies/ml, prior to the PDTI. pVL rose significantly in group B during the first month off HAART and was associated with a significant decrease in CD4 T-cell count. At baseline there was a significant difference in HIV-1 pDNA levels between groups A and B, however, levels significantly increased in group B, but not in group A during PDTI becoming equivalent after 1 month PDTI. We have previously shown no increase in pDNA over the time of substitution in patients switching HAART regimens despite a small rebound in pVL. These observations indicate that to protect low pDNA levels PDTI should be discouraged and that changing regimen at the first sign of failure should be advised where possible. Only transient, no longer than 4 week, HIV-1-specific responses were observed during PDTI in 5/24 patients, 2 from group A and 3 from group B. The low numbers of responders and the transient nature of the anti-HIV-1 immune responses do not favour the auto-vaccination hypothesis.

Immune Reconstitution Inflammatory Syndrome Associated With Kaposi's Sarcoma

Purpose

A proportion of patients with HIV infection who subsequently receive highly active antiretroviral therapy (HAART) exhibit a deterioration in their clinical status, despite control of virologic and immunologic parameters. This clinical response, known as the immune reconstitution inflammatory syndrome (IRIS), occurs secondary to an immune response against previously diagnosed pathogens.

Patients and Methods

From our cohort of 5,832 patients treated in the HAART era, we identified 150 therapy-naive patients with a first presentation of Kaposi's sarcoma (KS). Their clinicopathologic features and progress were recorded prospectively.

Results

After commencing HAART, ten patients (6.6%) developed progressive KS, which we identify as IRIS-associated KS. In a comparison of these individuals with those whose KS did not progress, we found that IRIS-KS occurred in patients with higher CD4 counts (P = .03), KS-associated edema (P = .01), and therapy with both protease inhibitors and non-nucleosides together (P = .03). Time to treatment failure was similar for both groups, although the CD4 count declined more rapidly at first, in those patients with IRIS-associated KS. Despite this initial decline, in our clinical experience HAART could be successfully continued in those with IRIS-associated KS.

Conclusion

We have identified IRIS-KS in a cohort of HIV patients with KS who start HAART.

The value of anal cytology and human papillomavirus typing in the detection of anal intraepithelial neoplasia: a review of cases from an anoscopy clinic

BACKGROUND

Previous studies have reached differing conclusions about the utility of anal cytology as a screening tool for anal intraepithelial neoplasia (AIN). There is a need also to establish whether HPV typing offers a useful adjunct to screening.

METHODS

We analysed data from 99 consecutive homosexual/bisexual male patients (89 HIV-1 positive) who underwent high resolution anoscopy. Follow up visits for these patients were also included, giving a total of 160 anoscopic procedures. Comparison was made between results of anal cytology using the sampling method of Palefsky, and histological findings of biopsies taken from abnormal areas seen on high resolution anoscopic examination of the anal canal. Swabs taken concurrently with the cytology were analysed for the presence of human papillomavirus (HPV) DNA and compared with the cytological and histological findings.

RESULTS

The sensitivity of the cytology was 83%, and the specificity 38% when compared with histology. At screening of 34 asymptomatic men, 83% had anal cytological dysplasia and 78% had AIN. There were no significant differences in the prevalence of hrHPV genotypes between different cytological or histological grades of abnormalities.

CONCLUSION

Anal cytology by the Palefsky method is simple to undertake, has a sensitivity and specificity comparable with cervical cytology, and can therefore be used as the basis of a pilot screening project in centres with large cohorts of HIV positive homosexual men who have a high risk of developing anal carcinoma. HPV genotyping is not a useful adjunct to cytological screening.

Better maintained adherence on switching from twice-daily to once-daily therapy for HIV: a 24-week randomized trial of treatment simplification using stavudine prolonged-release capsules

BACKGROUND

Adherence to antiretroviral therapy is critical to treatment outcomes. Adherence studies in other therapeutic areas of medicine suggest that once-daily regimens support improved adherence when compared to twice-daily therapy. An expansion in the range of once-daily antiretrovirals is making once-daily therapy possible for persons with HIV infection.

METHODS

A 24-week randomized open-label simplification study of twice-daily regimens based on stavudine immediate release or zidovudine to an all once-daily regimen based on the stavudine prolonged-release capsule (PRC), in persons with complete virological suppression on regimens also including efavirenz and lamivudine, was carried out. Subjects were assessed for adherence [using the Medication Event Monitoring System (MEMS) cap; Aardex Corporation, Union City, CA, USA], quality of life, tolerability and efficacy.

RESULTS

Forty-three patients were randomly assigned: 21 remained on their original regimen and 22 switched to once-daily therapy with stavudine PRC. Although high levels of adherence and good quality of life were present at study enrollment, adherence declined to a significantly lesser extent at week 24 in the group that switched to once-daily therapy. Efficacy was maintained in both groups and there were no differences in tolerability or toxicity.

CONCLUSIONS

Subjects switching from twice-daily therapy to once-daily therapy demonstrate less of a decline in adherence over 24 weeks. A once-daily regimen including stavudine PRC is as effective and tolerable as a regimen containing the twice-daily formulation.

Fever in the recently returned HIV infected traveller

A 41 year old HIV infected man with an extensive travel history developed intermittent fever and weight loss shortly after returning from abroad. Extensive and prolonged investigation identified the cause.

Paclitaxel for anthracycline-resistant AIDS-related Kaposi's sarcoma: clinical and angiogenic correlations

BACKGROUND

Murine data indicate that angiogenesis is central to the aetiopathogenesis of Kaposi's sarcoma (KS). Therefore, we measured angiogenic cytokines and growth factors in patients with AIDS-related KS during treatment with both antiretrovirals and second-line paclitaxel chemotherapy. Cytokines measured included tumour necrosis factor-alpha (TNF-alpha), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and the interleukins IL-2, -6 and -12.

PATIENTS AND METHODS

Enzyme-linked immunosorbent assays (ELISAs) were carried out to measure plasma cytokine levels in 17 patients with AIDS-related KS who had progressed within 6 months of receiving liposomal anthracyclines and were treated with paclitaxel 100 mg/m(2) every 2 weeks. Measurements were carried out before progression, at commencement and at the completion of paclitaxel.

RESULTS

The objective response rate to paclitaxel was 71% (95% confidence interval 60% to 81%). In 17 patients with AIDS-related KS, we observed eight partial responses and four complete responses. Patients with AIDS Clinical Trial Group stage T1 disease had higher plasma VEGF (P = 0.05) and lower plasma TNF-alpha levels (P = 0.05) than patients with earlier stage T0 KS. There were no correlations between plasma cytokines (bFGF, VEGF, TNF-alpha, and IL-2,-6 and -12) and the CD4 and CD8 cell counts or HIV-1 RNA viral load. Response to paclitaxel was associated with a fall in plasma IL-6 levels (P = 0.04) but no change in other cytokines. There were no significant changes in CD4, CD8, CD16/56, CD19 cell counts and HIV-1 viral loads during chemotherapy.

CONCLUSIONS

Angiogenic cytokines may correlate with KS disease extent but not with cellular immune function or HIV viraemia. Response to paclitaxel therapy correlates with a fall in plasma IL-6 levels and recent data indicate this may be a surrogate marker of KS-associated herpesvirus viral load. Overall, clinical response in KS correlates poorly with known angiogenic cytokines.

Treatment of primary HIV-1 infection with nonnucleoside reverse transcriptase inhibitor-based therapy is effective and well tolerated

OBJECTIVES

Highly active antiretroviral therapy (HAART) has been advocated for the management of primary HIV-1 infection. We investigated the use of a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen in this setting.

METHODS

Twenty-one antiretroviral-naïve individuals with early HIV-1 disease were treated with a combination of efavirenz and Combivir (GlaxoSmithKline, Uxbridge, Middlesex, UK). They were evaluated for immune and lymphocyte function by standard immunological assays.

RESULTS

The median time to an undetectable HIV-1 viral load was 12 weeks (range 4-36 weeks). CD4 and CD16/56 counts increased during treatment and CD8 counts decreased minimally. The main side-effects observed were transient sleep disturbances (five patients). In addition, we observed a decrease in lymphocyte activation as assessed by CD38 surface expression.

CONCLUSIONS

This study demonstrates that primary HIV-1 infection can be treated with NNRTI-based HAART.

The prevalence of reduced zidovudine susceptibility in zidovudine-naive, antiretroviral-experienced HIV-1-infected patients

OBJECTIVES

There is increasing in vitro and in vivo evidence that reduced zidovudine (ZDV) susceptibility is generated by the selective pressure conferred by other nucleoside reverse transcriptase inhibitors (NRTIs). However, the degree to which this occurs in clinical practice remains unclear. We assessed phenotypic and genotypic resistance in ZDV-naive patients with virological failure on stavudine (d4T)-containing regimens, with particular reference to potential cross-resistance between d4T and ZDV.

METHODS

Patients were identified from a clinical database. Treatment history was confirmed by case note evaluation and discussion with patients. Genotypic and phenotypic analyses were undertaken by Virco (Virco BVBA, Mechelen, Belgium).

RESULTS

Sixty-seven drug-experienced, ZDV-naive patients who underwent a resistance test while failing a d4T-containing regimen were identified. Of these patients, 23% had received three or more NRTIs and 42% at least one non-nucleoside reverse transcriptase (RT) inhibitor; 22% had viruses with reduced d4T susceptibility (>1.8-fold resistance), and 25% had viruses with reduced ZDV susceptibility (>4-fold). The most frequently observed RT mutations were identified. A significant correlation was found between susceptibility to d4T and susceptibility to ZDV (r=0.36; P=0.003), and also between virtual resistance to d4T and that to ZDV (r=0.38; P=0.002).

CONCLUSIONS

A significant minority of d4T-treated, ZDV-naive patients were found to have viruses with reduced ZDV susceptibility, with a variable association with classical ZDV resistance mutations. These data suggest that cross-resistance between d4T and ZDV may involve novel constellations of mutations. Correlations between d4T and ZDV susceptibilities and resistances further support cross-resistance between NRTIs.

Reconstitution of CD4+ T cell responses in HIV-1 infected individuals initiating highly active antiretroviral therapy (HAART) is associated with renewed interleukin-2 production and responsiveness

Reconstitution of functional CD4(+) T cell responsiveness to in vitro stimuli is associated with continuous highly active antiretroviral therapy (HAART). Thirty-six antiretroviral naive patients received HAART over 16 weeks. Antigen-specific, mitogen and interleukin (IL)-2 induced lymphocyte proliferative responses and specific IL-2 and IL-4 production were assessed at each time-point, together with quantification of HIV-1 RNA load and lymphocyte populations. Reconstitution of recall responses was limited largely to persistent antigens such as Herpes simplex virus and Candida, rather than to HIV-1 or neo-antigens. Recall antigens, mitogens and IL-2-induced renewed responses were associated with in-vitro production of IL-2, but not IL-4. Differential responsiveness to low versus high concentration IL-2 stimulus increases in a stepwise manner, suggesting normalization of IL-2 receptor expression and improved functionality. These increases in in-vitro proliferative responses thus probably reflect short lived effector clones, driven by ongoing antigenic stimulus associated with persisting long-term organisms. In this context non-responsiveness to HIV-1 antigens suggests ongoing HIV-1 specific clonal T cell anergy.

Restoration of human immunodeficiency virus-1-specific responses in patients changing from protease to non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy

The effect of altering antiretroviral therapy (ART) on responses to viral, recall and human immunodeficiency virus (HIV)-1-specific recombinant antigens and interleukin-2 (IL-2) in HIV-1-infected patients was assessed. A longitudinal cohort study in eight HIV-1 infected individuals following a clinically indicated therapy change (seven for drug intolerance and one for virological failure) from protease inhibitor (PI) to non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral regimens was performed. CD4 T-cell counts, viral loads, lymphoproliferative responses, cytokine production and latent proviral deoxyribonucleic acid (DNA) were measured at baseline and at weeks 12 and 24 after therapy substitution. Following therapy-switch there was a 33% proportional increase in mitogen response (95% confidence interval (CI), 3-33%) and a 31% increase (95% CI, 15-48%) in viral and recall-antigen responses. Six patients developed proliferative responses to low concentration IL-2 stimulation. All patients demonstrated an increase in median HIV-1-specific responses, as three had detectable virus at baseline (two being viral rebound); this may reflect an autovaccination effect. Proviral DNA changes largely reflected plasma HIV-1 ribonucleic acid (RNA). In conclusion, NNRTI substitution for a PI may favour immune reconstitution with an improvement in HIV-1-specific responses, which may reflect differential effects on antigen processing and presentation, an autovaccination effect or alternatively a potential suppressive effect of the PI.

A 48-week, randomized, open-label comparison of three abacavir-based substitution approaches in the management of dyslipidemia and peripheral lipoatrophy

BACKGROUND

The mechanisms by which dyslipidemia and lipoatrophy develop during antiretroviral therapy are not clear. No treatment of lipoatrophy is currently established.

METHODS

This was an open-label randomized study of HIV-positive individuals on a first-line therapy containing stavudine (d4T) with either a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI) and with hypercholesterolemia (defined as total cholesterol >5.2 mmol/L or >180 mg/dL) and/or lipoatrophy and with a viral load of <50 copies/mL. Patients switched d4T to abacavir (ABC) (group 1), a PI or NNRTI to ABC (group 2), or d4T and PI or NNRTI to ABC plus AZT (group 3). Patients were followed-up with fasting blood levels, dual-energy X-ray absorptiometry (DXA), and computed tomography (CT) scans for 48 weeks.

RESULTS

Thirty patients were included, with 27 completing 48 weeks of therapy. One ABC hypersensitivity reaction was the only serious adverse event. All patients' viral loads remained at <50 copies/mL. CD4 cell counts rose in groups 2 and 3 but fell modestly in group 1. Total and low-density lipoprotein cholesterol improved significantly in groups 2 and 3. Triglycerides fell significantly in group 2. In contrast, total, arm, and leg fat mass (by DXA) rose significantly in group 1 but fell modestly in groups 2 and 3. Visceral adiposity (by CT scan) was unaffected in all groups.

CONCLUSIONS

Abacavir represents a virologically effective replacement for d4T, PI, or NNRTI in persons on successful first-line therapy. Replacement of a PI or NNRTI with ABC leads to modest improvement in both cholesterol and triglycerides. Replacement of d4T with ABC leads to modest improvements in fat mass.

Sequencing to NRTI plus NNRTI-only combinations after virological failure of protease inhibitor-based combination HIV-1 therapy

PURPOSE

To examine the success of sequencing to nucleoside reverse transcriptase inhibitor (NRTI) plus nonnucleoside reverse transcriptase inhibitor (NNRTI)-only combinations after virological failure of protease inhibitor (PI)-based combinations in NNRTI-naïve individuals.

METHOD

This was an observational cohort study.

RESULTS

171 patients were identified. The group was highly antiretroviral therapy-experienced with median cumulative NRTI and PI durations prior to change of 53 months and 21 months, respectively. The median CD4 count and viral load (VL) prior to change were 228 cells/mm(3) and 24500 copies/mL. Overall, 37.4% had a VL below the limit of detection (50 copies/mL) at 12 months (intention-to-treat analysis). Markers associated with success at 12 months were efavirenz (EFV) use, the use of three NRTI+NNRTI combinations, and abacavir (ABC) use. In multivariate analysis, use of EFV remained highly significant (relative hazard of virological success of nevirapine [NVP] vs. EFV = 0.39; p =.003), while ABC use became nonsignificant. A benefit from the use of three NRTI + NNRTI regimens was observed.

CONCLUSION

NRTI plus NNRTI-only combinations performed poorly, however the superior outcomes of patients treated with EFV are consistent with findings in cohort studies. The suggestion of benefit in patients receiving three NRTIs in addition to either NVP or EFV deserves further study in randomized trials.

The paradox of improved antiretroviral therapy in HIV: potential for nutritional modulation?

Chronic infection with HIV type 1 is associated with alterations in macronutrient metabolism, specifically elevated plasma lipids, glucose and reduced insulin sensitivity. These alterations are most severe in patients at the later stages of AIDS, indicating a relationship with disease progression. Recently, a metabolic syndrome, termed lipodystrophy, has been described in successfully-treated HIV patients in whom the altered macronutrient metabolism of HIV infection appears to be amplified markedly, with concurrent alterations in adipose tissue patterning. This syndrome presents a paradox, as before the development of highly-active antiretroviral therapy (HAART) the most severe perturbations in metabolism were observed in the sickest patients. Now, the patients that respond well to therapy are showing metabolic perturbations much greater than those seen before. The implications of this syndrome are that, whilst life expectancy may be increased by reducing viral load, there are concomitant increases in the risk of cardiovascular disease, diabetes and pancreatitis within this patient population. The aetiology of the syndrome remains unclear. In a collaborative trial with the Chelsea and Westminster Hospital in London we have used stable-isotope-labelled fatty acids to examine the hypothesis that treatment with HAART causes a delayed clearance of dietary lipid from the circulation, resulting in the retention of lipid within plasma and the downstream changes in insulin and glucose homeostasis. This hypothesis would indicate a role for low-fat diets, exercise and drugs that reduce plasma lipid or insulin resistance, in modulating the response to antiretroviral therapy in HIV infection.

Low prevalence of antiretroviral drug resistance among HIV-1 seroconverters in London, 1984-1991

OBJECTIVES

To examine the prevalence of resistance mutations and natural polymorphisms to reverse transcriptase (RT) and protease inhibitors in a cohort of patients with defined seroconversion dates.

METHODS

Eligible patients were those attending an HIV centre in North London who seroconverted from HIV negative to positive status between 01/01/85 and 31/12/91 (n=104). Genotypic resistance analysis was performed on the first positive serum sample after seroconversion and before use of antiretroviral therapy using population-based sequencing of RT-PCR fragments and rule-based sequence interpretation (Vircogen).

RESULTS

Protease and RT sequences were successfully amplified from only 37 (35.6%) of the 104 seroconverters. Only one patient who seroconverted in August 1991 showed any evidence of significant mutations in the RT region, and this was associated with resistance to zidovudine (ZDV) (215Y and 210W). An additional patient who seroconverted in July 1991 had a TOR mutation and was classified as having intermediate resistance to ZDV. No spontaneous mutations were detected in the protease region.

CONCLUSIONS

Overall only 2 (5%) of these treatment-naïve individuals were infected with HIV variants resistant to ZDV. Although the data at present do not support the need for pretreatment genotyping, there is a need for continued surveillance of the frequency of resistance mutations in antiretroviral naïve patients since the introduction of highly active antiretroviral therapy.

Effect of octreotide on small intestinal motility in HIV-infected patients with chronic refractory diarrhea

Octreotide has been used to treat HIV-associated diarrhea. We aimed to assess the effect of octreotide on small intestinal motility in a group of HIV infected individuals with chronic diarrhea. Small intestinal motility was measured continuously for 48 hr by ambulatory strain gauge manometry in 12 HIV seropositive subjects with chronic diarrhea. During the second 24-hr period, intravenous octreotide was administered (100 microg every 8 hr). Postprandial and nocturnal fasting motility data were compared before and during administration of octreotide. Octreotide was associated with increased numbers of migrating motor complexes (MMCs) (7.25 vs 4.92, P = 0.03), and a relative decrease in the duration of phase II (22% vs 49.8, P = 0.03) during nocturnal fasting activity. Postprandial activity was absent in half of the subjects and the duration significantly reduced in the remainder. In conclusion, octreotide has a significant effect on small intestinal motility in HIV-infected individuals with diarrhea, which may influence intestinal transit.

Reasons for non-adherence to antiretroviral therapy: patients' perspectives provide evidence of multiple causes

The objective of the study was to define common reasons for non-adherence (NA) to highly active antiretroviral therapy (HAART) and the number of reasons reported by non-adherent individuals. A confidential questionnaire was administered to HIV-seropositive patients taking proteinase inhibitor based HAART. Median self-reported adherence was 95% (n = 178, range = 60-100%). The most frequent reasons for at least 'sometimes' missing a dose were eating a meal at the wrong time (38.2%), oversleeping (36.3%), forgetting (35.0%) and being in a social situation (30.5%). The mean number of reasons occurring at least 'sometimes' was 3.2; 20% of patients gave six or more reasons; those reporting the lowest adherence reported a significantly greater numbers of reasons (rho = - 0.59; p < 0.001). Three factors were derived from the data by principal component analysis reflecting 'negative experiences of HAART', 'having a low priority for taking medication' and 'unintentionally missing doses', accounting for 53.8% of the variance. On multivariate analysis only the latter two factors were significantly related to NA (odds ratios 0.845 and 0.849, respectively). There was a wide spectrum of reasons for NA in our population. The number of reasons in an individual increased as adherence became less. A variety of modalities individualized for each patient are required to support patients with the lowest adherence.

The potential place of tenofovir in antiretroviral treatment regimens

Advice from the Food & Drug Administration and the European Medicines Commission indicates that tenofovir is likely to be licensed shortly for use in patients failing antiretroviral therapy as part of a regimen constructed by the clinician. Tenofovir is a nucleotide (NtRTI) that acts in a similar way to nucleoside analogues by inhibiting reverse transcriptase, producing similar HIV plasma viral load fall. In use up to 48 weeks it appears to be safe without evident toxicity. It has particular value because it has activity against many HIV viruses with mutations which render them insensitive to other nucleoside analogues. Its eventual optimal role in treatment, particularly whether it should be part of a first line regimen, awaits the outcome of further studies.

PCR-ELISA: a new simplified tool for tracing the source of cryptosporidiosis in HIV-positive patients

Cryptosporidium parvum is a major parasitic cause of death in end-stage AIDS patients that results from both zoonotic and person-to-person transmission. Recent studies have provided evidence that parasites causing zoonotic disease and those causing anthroponotic infection are genetically distinct. Isolates carrying "animal"-type genetic markers were presumed to be the result of zoonotic spread, either directly or through contaminated food and water. The need for a genotype-specific diagnostic tool that can provide clues as to the origin and possible modes of spread of C. parvum strains has been recognised. Here, we report the development of such a tool for C. parvum based on polymerase chain reaction-enzyme linked immunosorbent assay that enables the accurate typing of isolates from HIV-seropositive and HIV-negative patients presenting with diarrhoea from the United Kingdom and Canada. This study also showed that zoonotic transmission might be predominant in the HIV-positive patient group in the United Kingdom.

Incidence and risk factors for the development of indinavir-associated renal complications

OBJECTIVES

To describe the incidence and risk factors for the development of indinavir-associated renal complications (IRC), and subsequent clinical outcome.

PATIENTS AND METHODS

This was a retrospective cohort study based on two large HIV centres in London. Eligible patients received indinavir for at least 1 week between 1 December 1995 and 28 February 1999. Development of IRC was ascertained by case-note review. Multivariate logistic regression and Cox Proportional Hazard's model analysis were used to determine independent risk factors for the development of IRC.

RESULTS

781 patients were eligible. Median CD4 count and viral load at indinavir initiation were 117 x 10(6) cells/L and 47 332 copies/mL, respectively. Median indinavir exposure was 53 weeks (IQR: 20-83). Many patients received other potentially nephrotoxic drugs during indinavir treatment: co-trimoxazole (46%), aciclovir (33%) or both (20%). Overall IRC incidence was 7.3% (6.7 per 100 person-years indinavir exposure). Cases presented with loin pain (58%), renal colic (42%) or dysuria (19%). Identified precipitating events (26%) included fluid depletion or altered indinavir regimen. In the majority of cases indinavir therapy was continued and there was no progressive rise in creatinine levels. In the multivariate analysis, for indinavir treatment >74 weeks there was a reduced risk of developing IRC (OR = 0.23, 95% CI 0.09-0.57, P = 0.001). Concomitant aciclovir increased the IRC risk (OR = 1.99, 95% CI 1.14-3.51, P = 0.016). Factors not associated with outcome were age, gender, ethnicity, baseline CD4 count and viral load, concomitant co-trimoxazole, or use of specific antiretrovirals.

CONCLUSION

An overall IRC incidence of 7.3% was identified. Concomitant aciclovir doubled the risk of IRC and we therefore recommend careful monitoring when prescribing aciclovir with indinavir. A precipitating event was identified in 26% of IRC cases, many of which could have been avoided.

Dietary advice with or without pravastatin for the management of hypercholesterolaemia associated with protease inhibitor therapy

BACKGROUND

Therapy with a HIV protease inhibitor is associated with elevations in cholesterol and triglycerides. HMG-CoA reductase inhibitors ('statins') are the established therapy for persons with primary hypercholesterolaemia. Because of drug interactions, pravastatin may represent the preferred choice in those taking HIV protease inhibitors.

DESIGN

A randomized, open-label comparative 24 week trial of dietary advice alone or with pravastatin in 31 male patients established on protease inhibitor-based regimens for greater than 12 weeks with viral load < 500 copies/ml and cholesterol > 6.5 mmol/l.

RESULTS

There were no significant clinical or laboratory events and no patient discontinuation secondary to adverse effects. Viral rebound did not occur. Relative to baseline, total cholesterol at week 24 fell significantly in the pravastatin (1.2 mmol/l; 17.3%) (P < 0.05) but not in the dietary advice (0.3 mmol/l; 4%) group. The difference between the two groups approached significance at week 24 (P = 0.051). This fall was accounted for entirely by a reduction in low density lipoprotein [calculated change 1.24 mmol/l (19%) and 0.07 mmol (5.5%) in pravastatin and dietary advice groups, respectively] as high density lipoprotein rose non-significantly by 0.6 mmol/l in both groups. Weight, basal metabolic rate, fasting glucose and triglycerides did not change significantly in either group.

CONCLUSIONS

Dietary advice plus pravastatin significantly reduced total cholesterol in HIV-positive individuals taking protease inhibitors, without significant adverse effects. The inclusion of pravastatin substantially increases the magnitude of the change, which is comparable with changes achieved in endogenous hyperlipidaemia.

Comparison of virologic, immunologic, and clinical response to five different initial protease inhibitor-containing and nevirapine-containing regimens

CONTEXT

The effectiveness of different protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors outside the setting of clinical trials has not been well described.

OBJECTIVES

To compare five different PI-and nevirapine (NVP)-containing regimens on virologic, immunologic, and clinical outcomes and treatment discontinuation.

DESIGN AND SETTING

Observational cohort study based on an HIV clinic in London.

PATIENTS

A total of 690 patients who received either saquinavir hard gel (SQV HG) (n = 183), indinavir (IDV) (n = 189), nelfinavir (NFV) (n = 109), ritonavir (RTV) (n = 42), ritonavir with saquinavir hard gel (RTV/SQV HG) (n = 45), or NVP (n = 122) as part of an initial PI-or NVP-containing treatment regimen between November 1994 and December 1998. A total of 351 (51%) patients had prior exposure to nucleoside reverse transcriptase inhibitors (NRTIs).

MAIN OUTCOME MEASURES

The main outcome measures were virologic undetectability, subsequent virologic rebound, CD4 cell count rise, development of AIDS, and treatment discontinuation. All analyses were stratified for year of initiation of the PI-or NVP-containing regimen.

RESULTS

Overall, 63% of patients attained an undetectable viral load (VL) within 6 months of starting their PI or NVP regimen. The adjusted relative hazard (95% confidence interval [CI]) for an undetectable VL relative to SQV HG was (in rank order): 2.77 (CI: 1.84-4.17) for NFV, 2.54 (CI: 1.81-3.57) for IDV, 2.43 (CI: 1.52-3.87) for RTV, 2.08 (CI: 1.28-3.37) for RTV/SQV HG, and 1.96 (CI: 1.35-2.85) for NVP. Forty-nine percent of patients experienced VL rebound within 12 months of initial attainment of undetectability, but relative to SQV HG, this did not differ significantly across the different PI and NVP regimens. The CD4 cell count response and rate of AIDS events were also similar across the different regimens. No independent predictors of VL undetectability were identified, but prior NRTI exposure was associated with VL rebound, and a lower baseline VL and CD4 cell count were associated with a reduced CD4 count response. The frequency (95% CI) of treatment discontinuation differed across the regimens; at 6 months, it was lowest for NFV (18% [CI: 13%-24%]), IDV (25% [CI: 22%-29%]), and NVP (28% [CI: 22%-34%]) and highest for RTV (41% [CI: 31%-52%]) and SQV HG (52% [CI: 48%-57%]).

CONCLUSIONS

Although PI- and NVP-containing regimens were similar in their CD4 cell count response and rates of subsequent VL rebound, differences were observed in time to VL undetectability and discontinuation rates relative to SQV HG. SQV HG was consistently inferior to the other PIs and NVP. The use of NFV and IDV was associated with the highest rates of undetectability, and together with NVP, the lowest rates of discontinuation.

Cessation of secondary prophylaxis in patients with cryptococcosis

Cryptococcal disease in HIV-positive individuals is usually a consequence of advanced immunosuppression. Treatment consists of long period of induction therapy followed by long-term secondary prophylaxis, usually with fluconazole. The introduction of highly active antiretroviral therapy has resulted in improvements in immunological function such that the cessation of primary and secondary prophylaxis against several opportunistic infections has become possible. We report our experience of the cessation of secondary antifungal prophylaxis in patients responding to highly active antiretroviral therapy.

Distribution of K103N and/or Y181C HIV-1 mutations by exposure to zidovudine and non-nucleoside reverse transcriptase inhibitors

Our aim was to identify whether zidovudine has a role in the emergence of the K103N resistance mutation in the HIV-1 reverse transcriptase gene on non-nucleoside reverse transcriptase inhibitors (NNRTIs). No difference was found in the exposure to zidovudine or major zidovudine mutations between the resistance patterns K103N-/Y181C+, K103N+/Y181C- and K103N+/ Y181C+, either in group A (patients on nevirapine and previously NNRTI naive) or in group B (on any NNRTI and experience of two or more NNRTIs including nevirapine). Group B patients had the highest prevalence of K103N+/Y181C+. In conclusion, zidovudine seems not to determine the emergence of K103N; however, there appears to be an accumulation of NNRTI resistance mutations with sequential use of NNRTIs.