British HIV Association (BHIVA) guidelines for the treatment of HIV-infected adults with antiretroviral therapy (2005)

Virological measures and factors associated with outcomes, and missing outcome data in HIV clinical trials: a methodological study

BACKGROUND

To evaluate the definition of HIV virological outcomes in the literature and factors associated with outcomes and missing outcome data.

METHODS

We conducted a methodological review of HIV RCTs using a search (2009-2019) of PubMed, Embase and the Cochrane Central Register of Controlled Trials.Only full-text, peer-reviewed, randomised controlled trials (RCTs) that measured virological outcomes in people living with HIV, and published in English were included.We extracted study details and outcomes. We used logistic regression to identify factors associated with a viral threshold ≤50 copies/mL and linear regression to identify factors associated with missing outcome data.

RESULTS

Our search yielded 5847 articles; 180 were included. A virological outcome was the primary outcome in 73.5% of studies. 89 studies (49.4%) used virological success. The remaining used change in viral load (VL) (33 studies, 18.3%); virological failure (59 studies, 32.8%); or virological rebound (9 studies, 5.0%). 96 studies (53.3%) set the threshold at ≤50 copies/mL; and 33.1% used multiple measures.Compared with government and privately funded studies, RCTs with industry funding (adjusted OR 6.39; 95% CI 2.15 to 19.00; p<0.01) were significantly associated with higher odds of using a VL threshold of ≤50 copies/mL. Publication year, intervention type, income level and number of patients were not associated with a threshold of ≤50 copies/mL. Trials with pharmacological interventions had less missing data (β=-11.04; 95% CI -20.02 to -1.87; p=0.02).

DISCUSSION

Country source of funding was associated with VL threshold choice and studies with pharmacological interventions had less missing data, which may in part explain heterogeneous virological outcomes across studies. Multiple measures of VL were not associated with missing data. The development of formal guidelines on virological outcome reporting in RCTs is needed.

A packaged intervention to improve viral load monitoring within a deeply rural health district of South Africa

BACKGROUND

The KwaZulu-Natal (KZN) province of South Africa has the highest prevalence of HIV infection in the world. Viral load (VL) testing is a crucial tool for clinical and programmatic monitoring. Within uMkhanyakude district, VL suppression rates were 91% among patients with VL data; however, VL performance rates averaged only 38·7%. The objective of this study was to determine if enhanced clinic processes and community outreach could improve VL monitoring within this district.

METHODS

A packaged intervention was implemented at three rural clinics in the setting of the KZN HIV AIDS Drug Resistance Surveillance Study. This included file hygiene, outreach, a VL register and documentation revisions. Chart audits were used to assess fidelity. Outcome measures included percentage VL performed and suppressed. Each rural clinic was matched with a peri-urban clinic for comparison before and after the start of each phase of the intervention. Monthly sample proportions were modelled using quasi-likelihood regression methods for over-dispersed binomial data.

RESULTS

Mkuze and Jozini clinics increased VL performance overall from 33·9% and 35·3% to 75·8% and 72·4%, respectively which was significantly greater than the increases in the comparison clinics (RR 1·86 and 1·68, p < 0·01). VL suppression rates similarly increased overall by 39·3% and 36·2% (RR 1·84 and 1·70, p < 0·01). The Chart Intervention phase showed significant increases in fidelity 16 months after implementation.

CONCLUSIONS

The packaged intervention improved VL performance and suppression rates overall but was significant in Mkuze and Jozini. Larger sustained efforts will be needed to have a similar impact throughout the province.

First-line HIV treatment outcomes following the introduction of integrase inhibitors in UK guidelines

Objective:

To investigate the characteristics and outcomes of people who initiated different antiretroviral therapy (ART) regimens during the era of integrase strand transfer inhibitors (INSTIs).

Design:

UK-based observational cohort study.

Methods:

UK Collaborative HIV Cohort study participants were included if they had started ART between 1 January 2012 and 30 June 2017. Virological failure was defined as the first of two consecutive plasma HIV RNA more than 50 copies/ml, at least 6 months after starting ART. Follow-up was censored at ART discontinuation, class switch or death. The risk of virological failure among those on INSTI, protease inhibitor or nonnucleoside reverse transcriptase inhibitor (NNRTI) regimens was compared using Kaplan–Meier and Cox regression methods.

Results:

Of 12 585 participants, 45.6% started a NNRTI, 29.0% a protease inhibitor and 25.4% an INSTI regimen. Over a median follow-up of 20.3 months (interquartile range 7.9–38.9), 7.5% of participants experienced virological failure. Compared with those starting an NNRTI regimen, people receiving INSTIs or protease inhibitors were more likely to experience virological failure: INSTI group adjusted hazard ratio 1.52, 95% confidence interval 1.19–1.95, P = 0.0009; protease inhibitor group adjusted hazard ratio 2.70, 95% confidence interval 2.27–3.21, P less than 0.0001, likelihood ratio test P less than 0.0001.

Conclusion:

First-line INSTI regimens were associated with a lower risk of virological failure than protease inhibitor regimens but both groups were more likely to experience virological failure than those initiating treatment with a NNRTI. There is likely to be residual channelling bias resulting from selected use of INSTIs and protease inhibitors in specific clinical contexts, including in those with a perceived risk of poor adherence.

New Crystal Forms for Biologically Active Compounds. Part 1: Noncovalent Interactions in Adducts of Nevirapine with XB Donors

Stabilization of specific crystal polymorphs of an active pharmaceutical ingredient is crucial for preventing uncontrollable interconversion of various crystalline forms, which affects physicochemical properties as well as physiological activity. Co-crystallization with various excipients is an emerging productive way of achieving such stabilization in the solid state. In this work, we identified an opportunity for co-crystallization of antiviral drug nevirapine (NVP) with a classical XB donor, 1,2,4,5-tetrafluoro-3,6-diiodobenzene (1,4-FIB), as well as 1,3-diiodobenzene (1,3-DIB), which has been seldom employed as an XB donor to date. In the X-ray structures of NVP·1,4-FIB and NVP·1,3-DIB co-crystals, different hydrogen and halogen bonding modes were detected and further investigated via DFT calculations as well as topological analysis of the electron density distribution within the framework of the QTAIM method at the M06/DZP-DKH level of theory. Estimated energies of these supramolecular contacts vary from 0.6 to 5.7 kcal/mol.

Non-covalent interactions observed in nevirapinium pentaiodide hydrate which include the rare I4–I−···O=C halogen bonding

In the course of screening for novel crystalline forms of antiviral drug nevirapine, co-crystallization of the latter with molecular iodine was attempted. This resulted in the formation of a hydrate salt form composed of the protonated nevirapinium cation and pentaiodide anion. In the X-ray structure of NVPH+I5 −·H2O, halogen and hydrogen bonding interactions were identified and studied by DFT calculations and topological analysis of the electron density distribution within the framework of QTAIM method at the B3LYP/DZP-DKH and M06/DZP-DKH levels of theory. Estimated energies of these contacts are 1.3–9.4 kcal/mol.

A tale of two countries: all-cause mortality among people living with HIV and receiving combination antiretroviral therapy in the UK and Canada

OBJECTIVES

We sought to compare all-cause mortality of people living with HIV and accessing care in Canada and the UK.

METHODS

Individuals from the Canadian Observational Cohort (CANOC) collaboration and UK Collaborative HIV Cohort (UK CHIC) study who were aged ≥ 18 years, had initiated antiretroviral therapy (ART) for the first time between 2000 and 2012 and who had acquired HIV through sexual transmission were included in the analysis. Cox regression was used to investigate the difference in mortality risk between the two cohort collaborations, accounting for loss to follow-up as a competing risk.

RESULTS

A total of 19 960 participants were included in the analysis (CANOC, 4137; UK CHIC, 15 823). CANOC participants were more likely to be older [median age 39 years (interquartile range (IQR): 33, 46 years) vs. 36 years (IQR: 31, 43 years) for UK CHIC participants], to be male (86 vs. 73%, respectively), and to report men who have sex with men (MSM) sexual transmission risk (72 vs. 56%, respectively) (all P < 0.001). Overall, 762 deaths occurred during 98 798 person-years (PY) of follow-up, giving a crude mortality rate of 7.7 per 1000 PY [95% confidence interval (CI): 7.1, 8.3 per 1000 PY]. The crude mortality rates were 8.6 (95% CI: 7.4, 10.0) and 7.5 (95% CI: 6.9, 8.1) per 1000 PY among CANOC and UK CHIC study participants, respectively. No statistically significant difference in mortality risk was observed between the cohort collaborations in Cox regression accounting for loss to follow-up as a competing risk (adjusted hazard ratio 0.86; 95% CI: 0.72-1.03).

CONCLUSIONS

Despite differences in national HIV care provision and treatment guidelines, mortality risk did not differ between CANOC and UK CHIC study participants who acquired HIV through sexual transmission.

High Rate Multiple Drug Resistances in HIV-Infected Patients Failing Nonnucleoside Reverse Transcriptase Inhibitor Regimens in Thailand, Where Subtype A/E is Predominant

The prevalence of drug resistance was determined among 64 HIV-infected Thai patients who were failed while receiving nonnucleoside reverse transcriptase inhibitor (NNRTI)–based regimens. Eighty-nine percent of patients had 1 or more NNRTI mutation resistances. Almost all patients had resistance to at least 1 nucleoside reverse transcriptase inhibitor (NRTI), and 42% had multiple-NRTI resistance.

Apricitabine: A Novel Deoxycytidine Analogue Nucleoside Reverse Transcriptase Inhibitor for the Treatment of Nucleoside-Resistant HIV Infection

Existing nucleoside reverse transcriptase inhibitors for HIV disease are limited by problems of resistance and, in some cases, long-term toxicity. Apricitabine (ATC; formerly BCH10618, SPD754 and AVX754) is a deoxycytidine analogue nucleoside reverse transcriptase inhibitor in clinical development. ATC retains substantial in vitro activity against HIV-1 containing many mutations associated with nucleoside reverse transcriptase inhibitor resistance, showing a less than twofold reduction in susceptibility in the presence of either up to five thymidine analogue mutations or the M184V mutation. ATC showed a low potential for cellular or mitochondrial toxicity in vitro. ATC is well absorbed orally, with a bioavailability of 65–80%. Its plasma elimination half-life (approximately 3 h), and the intracellular half-life of its triphosphate (TP) metabolite (6–7 h) support twice-daily dosing. Intracellular ATC-TP levels are markedly reduced in the presence of lamivudine or emtricitabine, indicating that clinical co-administration of ATC together with these agents will not be possible. The drug is renally eliminated, giving a low potential for hepatic drug interactions. In a double-blind, randomized, placebo-controlled Phase II monotherapy trial in antiretroviral-naive patients, ATC doses of 1,200 and 1,600 mg/day reduced plasma viral load levels by 1.65 and 1.58 log10 HIV RNA copies/ml, respectively, after 10 days of treatment ( P<0.0001 versus placebo). ATC showed a low propensity to select for resistance mutants in vitro and during clinical monotherapy. ATC was well tolerated in volunteers and in HIV-infected patients. This promising profile suggests that ATC may be useful in treating patients who have failed previous lamivudine- or emtricitabine-containing regimens. Further studies to evaluate the long-term efficacy and tolerability of ATC are underway.

Comparison of Two Once-Daily Regimens with a Regimen Consisting of Nelfinavir, Didanosine, and Stavudine in Antiretroviral Therapy-Naïve Adults: 48-Week Results from the Antiretroviral Regimen Evaluation Study (ARES)

BACKGROUND

To improve the dosing frequency and pill burden of antiretroviral therapy, we compared two once-daily dosed regimens to a twice-daily dosed regimen.

METHOD

HIV-1-infected, antiretroviral drug-naïve adults were randomized to either twice-daily nelfinavir and stavudine and once-daily didanosine (regimen A) or simplified once-daily dosed antiretroviral regimens consisting of nevirapine, didanosine, and lamivudine (regimen B) or saquinavir, ritonavir, didanosine, and lamivudine (regimen C).

RESULTS

At 48 weeks of therapy, the proportion of patients with a blood plasma HIV-1 RNA concentration (pVL) <50 copies/mL by intention-to treat analysis was 42.3%, 50.0%, and 56.5% for regimens A (n = 26), B (n = 22), and C (n = 23), respectively. The time to a pVL <50 copies/mL for the first time was significantly shorter in regimen C, and there was significantly more progression to CDC events in regimen B. These differences are possibly due to differences in baseline characteristics. Adverse events were lowest for regimen C; more signs associated with mitochondrial toxicity occurred in regimen A. Increase in CD4 count was comparable between arms.

CONCLUSION

No statistically significant difference in efficacy was found between the two investigated once-daily dosed treatment regimens (B and C) and the reference (A). Regimen C possibly had a better virological response and less toxicity than regimens A and B.

A robust HIV-1 viral load detection assay optimized for Indian sub type C specific strains and resource limiting setting

BACKGROUND

Human Immunodeficiency Virus Type 1 (HIV-1) viral load testing at regular intervals is an integral component of disease management in Acquired Immunodeficiency Syndrome (AIDS) patients. The need in countries like India is therefore an assay that is not only economical but efficient and highly specific for HIV-1 sub type C virus. This study reports a SYBR Green-based HIV-1 real time PCR assay for viral load testing and is designed for enhanced specificity towards HIV-1 sub type C viruses prevalent in India.

RESULTS

Linear regression of the observed and reference concentration of standards used in this study generated a correlation coefficient of 0.998 (p<0.001). Lower limit of detection of the test protocol was 50 copies/ml of plasma. The assay demonstrated 100% specificity when tested with negative control sera. The Spearman coefficient of the reported assay with an US-FDA approved, Taqman probe-based commercial kit was found to be 0.997. No significant difference in viral load was detected when the SYBR Green based assay was used to test infected plasma stored at -20°C and room temperature for 7 days respectively (Wilcoxon signed rank test, p=0.105). In a comparative study on 90 pretested HIV-1 positive samples with viral loads ranging from 5,000-25,000 HIV-1 RNA copies/ml and between two commercial assays it was found that the later failed to amplify in 13.33% and 10% samples respectively while in 7.77% and 4.44% samples the copy number values were reduced by >0.5 log value, a figure that is considered clinically significant by physicians.

CONCLUSION

The HIV-1 viral load assay reported in this study was found to be robust, reliable, economical and effective in resource limited settings such as those existing in India. PCR probes specially designed from HIV-1 Subtype C-specific nucleotide sequences originating from India imparted specificity towards such isolates and demonstrated superior results when compared to two similar commercial assays widely used in India.

The increasing genetic diversity of HIV-1 in the UK, 2002-2010

Objective:

HIV-1 is typically categorized by genetically distinct viral subtypes. Viral subtypes are usually compartmentalized by ethnicity and transmission group and, thus, convey important epidemiological information, as well as possibly influencing the rate of disease progression. We aim to describe the prevalence and time trends of subtypes observed among key populations living with HIV-1 in the UK.

Design:

Analyses of reverse transcriptase and protease sequences generated from HIV-1-positive antiretroviral-naive patients as part of routine resistance testing between 2002 and 2010 in all public health and NHS laboratories in the UK.

Methods:

Subtype was assigned centrally using the SCUEAL algorithm. Subtyping results were combined with data from the UK Collaborative HIV Cohort Study and the UK HIV and AIDS Reporting System. Analyses adjusted for the number of national HIV-1 diagnoses made each year within demographic subgroups. Viral subtypes were described overall, over time and by demographic subgroup.

Results:

Subtype B diagnoses (39.9%) have remained stable since 2005, whereas subtype C diagnoses (34.3%) were found to decline in prevalence from 2004. Across most demographic subgroups, the prevalence of non-B non-C subtypes has increased over time, in particular novel recombinant forms (9.9%), subtype G (2.7%), and CRF01 AE (2.0%).

Conclusion:

HIV-1 subtypes are increasingly represented across all demographic subgroups and this could be evidence of sexual mixing. Between 2002 and 2010, the prevalence of novel recombinant forms has increased in all demographic subgroups. This increasing genetic diversity and the effect of subtype on disease progression may impact future HIV-1 treatment and prevention.

Didanosine, lamivudine-emtricitabine and efavirenz as initial therapy in naive patients

There are currently several suitable and different antiretroviral regimens to start highly active antiretroviral therapy (HAART), and many clinicians and patients prefer once-daily therapy. The efficacy and potency of efavirenz (EFV) has been established in many clinical trials and cohort studies; its pharmacokinetics, allowing for a convenient once-daily administration, make EFV one of the first agents to be included in once-daily regimens in naive patients. The two nucleoside reverse transcriptase inhibitors (NRTIs) accompanying the third drug have become the central skeleton, or the 'backbone' of the therapeutic scheme. Among the different NRTI pairs, a didanosine-lamivudine (3TC) or emtricitabine backbone for combination antiretroviral therapy may be a good option compared with any current NRTI-combinations due to its security, tolerance and once-daily dose. In this article, we review the advantages and drawbacks of didanosine-XTC-EFV as the initial regimen of HAART in HIV-infected patients.

A review of the use of complementary and alternative medicine and HIV: issues for patient care

HIV/AIDS is a chronic illness, with a range of physical symptoms and psychosocial issues. The complex health and social issues associated with living with HIV mean that people living with HIV/AIDS (PLWHA) have historically often turned to complementary and alternative medicine (CAM). This article provides an overview of the literature on HIV and CAM. Databases were searched using keywords for CAM and HIV from inception to December 2012. Articles in English and in Western countries were included; letters, commentaries, news articles, articles on specific therapies and basic science studies were excluded. Of the 282 articles identified, 94 were included. Over half reported prevalence and determinants of CAM use. Lifetime use of CAM by PLWHA ranged from 30% to 90%, with national studies suggesting CAM is used by around 55% of PLWHA, practitioner-based CAM by 15%. Vitamins, herbs, and supplements were most common, followed by prayer, meditation, and spiritual approaches. CAM use was predicted by length of time since HIV diagnosis, and a greater number of medications/symptoms, with CAM often used to address limitations or problems with antiretroviral therapy. CAM users rarely rejected conventional medicine, but a number of CAM can have potentially serious side effects or interactions with ART. CAM was used as a self-management approach, providing PLWHA with an active role in their healthcare and sense of control. Clinicians, particularly nurses, should consider discussing CAM with patients as part of patient-centered care, to encourage valuable self-management and ensure patient safety.

Incidence and risk factors of immune reconstitution inflammatory syndrome in HIV-TB coinfected patients

Tuberculosis is one of the leading causes of development of Immune reconstitution inflammatory syndrome (IRIS) in HIV patients receiving antiretroviral therapy (ART).

OBJECTIVE

To determine the incidence of IRIS in HIV-TB coinfected patients, and to find out the possible risk factors associated with IRIS.

MATERIALS AND METHODS

Study commenced with 96 patients adhered to standard antitubercular therapy (ATT) and ART without defaulting, and followed up for six months.

RESULT

The mean (± SD) CD4 count and CD4 percentage at baseline was 59.16 (± 24.63) per mm³ and 4.59% (± 1.73) respectively. Only 18.75% developed IRIS after 57.05 (± 14.12) days of initiation of ART. Extrapulmonary tuberculosis was the most significant factor associated with IRIS (83.33%) than those without IRIS (44.87%) (p = 0.0032). Specifically, tubercular lymphadenitis (38.88%, p = 0.0364) and disseminated tuberculosis (33.33%, p = 0.0217) were significantly associated with IRIS. The other risk factors associated with appearance of IRIS were higher CD4 count (p = 0.0212) at three months after initiation of ART and increment of CD4 count (p = 0.0063) and CD4 percentage (p = 0.0016) during this period. The major manifestations of IRIS were fever (40%), followed by lymphadenitis (38%). The mortality rate in IRIS was not higher than those without IRIS.

CONCLUSION

Patients with extrapulmonary tuberculosis, especially tubercular lymphadenitis, were more likely to develop IRIS and fever was associated in most of them. Higher increment of CD4 count may indicate development of IRIS in presence of new or worsening tuberculosis lesion.

Prospective long-term outcomes of a cohort of Ugandan children with laboratory monitoring during antiretroviral therapy

BACKGROUND

Treatment of HIV-1 infected Ugandan children with antiretroviral therapy (ART) is increasing, but few prospective long-term studies evaluating the treatment process have been reported. In this study, we sought to determine prospectively how consistent monitoring of HIV-1 RNA levels affects the ART treatment process.

METHODS

One hundred eight children initiating ART were enrolled into this study. These children had comprehensive laboratory monitoring, including HIV-1 RNA level determination and genotype analysis (where appropriate), CD4% plus absolute counts and safety laboratory measurements performed before starting therapy and at regular intervals after receiving ART. Kaplan-Meier statistics were used to examine predictors of survival and virologic failure. Viral genotype analysis was performed on samples obtained from children having virologic failure to determine the emergence of mutations.

RESULTS

Clinically, there was no difference in the 3-year survival between our cohort receiving consistent laboratory monitoring and a matched historical clinic cohort not routinely receiving laboratory monitoring. However, 34% of children receiving ART demonstrated virologic failure. Eleven of these children received second-line ART, and all responded with an undetectable HIV-1 RNA level and an increase in CD4 count. Children remaining on a failing antiretroviral regimen accumulated resistance mutations.

CONCLUSIONS

Our prospective long-term findings support the general use of monitoring HIV-1 RNA levels for the management of children on ART and the adoption of a clearer definition for virologic failure and better guidelines for managing children with unsuppressed HIV-1 RNA levels.

Surgical management of bilateral parotid lipomatosis in a patient with HIV

BACKGROUND

The long-term use of highly active antiretroviral therapy (HAART) in patients with human immunodeficiency virus (HIV) has led to sequelae including lipodystrophy syndrome (LDS). We present the first published case of surgical management of bilateral parotid lipomatosis in a patient with HIV on long-term HAART.

METHODS

We undertook review of the case notes from the time of diagnosis with HIV and literature review of this topic.

RESULTS

A 45-year-old man with HIV on HAART presented with a 4-year history of increasing bilateral facial swelling. He was asymptomatic apart from the stigmatizing cosmetic deformity. MRI revealed the parotid glands had been replaced by fat. He elected for surgery and parotid lipomatosis was diagnosed on histopathological examination.

CONCLUSION

Lipohypertrophy in LDS is rare in the literature and this presentation of bilateral parotid lipomatosis secondary to HAART is only the third reported case, and the first to undergo surgical resection.

Outcomes in the first year after initiation of first-line HAART among heterosexual men and women in the UK CHIC Study

BACKGROUND

We analysed the influence of gender on use and outcomes of first-line HAART in a UK cohort.

METHODS

Analyses included heterosexuals starting HAART from 1998-2007 with pre-treatment CD4(+) T-cell count<350 cells/mm(3) and viral load (VL)>500 copies/ml. Virological suppression (<50 copies/ml), virological rebound (>500 copies/ml), CD4(+) T-cell counts at 6 and 12 months, clinical events and treatment discontinuation/switch in the first year of HAART were compared using linear, logistic and Cox regression.

RESULTS

Compared with women (n=2,179), men (n=1,487) were older and had lower CD4(+) T-cell count and higher VL at start of HAART. Median follow-up was 3.8 years (IQR 2.0-6.2). At 6 and 12 months, 72.7% and 75.3% had VL≤50 copies/ml, with no large differences between genders at either time after adjustment for confounders (6 months, OR 0.92 [95% CI 0.76-1.13]; 12 months, OR 1.06 [95% CI 0.85-1.31]). Overall, 79.4% patients achieved virological suppression and 19.2% experienced virological rebound, without gender differences, although men had an increased risk of rebound after excluding pregnant women (adjusted relative hazard [RH] 1.33 [95% CI 1.04-1.71]). Mean CD4(+) T-cell count increases at 6 and 12 months were, respectively, 112 and 156 cells/mm(3) overall, with mean differences between men and women of -14.6 cells/mm(3) (95% CI -24.6--4.5) and -12.1 cells/mm(3) (95% CI -24.4-0.2) at 6 and 12 months, respectively. Clinical progression was similar in men and women, but men were less likely to experience treatment discontinuation/switch (adjusted RH 0.72 [95% CI 0.63-0.83]).

CONCLUSIONS

Despite higher discontinuation rates among women, men had an increased risk of virological rebound and slightly poorer CD4(+) T-cell count responses. Identifying the reasons underlying treatment discontinuation/switch may help optimize treatment strategies for both genders.

Non-uptake of highly active antiretroviral therapy among patients with a CD4 count < 350 cells/μL in the UK

OBJECTIVES

Current British HIV Association (BHIVA) guidelines recommend that all patients with a CD4 count <350 cells/μL are offered highly active antiretroviral therapy (HAART). We identified risk factors for delayed initiation of HAART following a CD4 count <350 cells/μL.

METHODS

All adults under follow-up in 2008 who had a first confirmed CD4 count <350 cells/μL from 2004 to 2008, who had not initiated treatment and who had >6 months of follow-up were included in the study. Characteristics at the time of the low CD4 cell count and over follow-up were compared to identify factors associated with delayed HAART uptake. Analyses used proportional hazards regression with fixed (sex/risk group, age, ethnicity, AIDS, baseline CD4 cell count and calendar year) and time-updated (frequency of CD4 cell count measurement, proportion of CD4 counts <350 cells/μL, latest CD4 cell count, CD4 percentage and viral load) covariates.

RESULTS

Of 4871 patients with a confirmed low CD4 cell count, 436 (8.9%) remained untreated. In multivariable analyses, those starting HAART were older [adjusted relative hazard (aRH)/10  years 1.15], were more likely to be female heterosexual (aRH 1.13), were more likely to have had AIDS (aRH 1.14), had a greater number of CD4 measurements < 350 cells/μL (aRH/additional count 1.18), had a lower CD4 count over follow-up (aRH/50 cells/μL higher 0.57), had a lower CD4 percentage (aRH/5% higher 0.90) and had a higher viral load (aRH/log(10) HIV-1 RNA copies/ml higher 1.06). Injecting drug users (aRH 0.53), women infected with HIV via nonsexual or injecting drug use routes (aRH 0.75) and those of unknown ethnicity (aRH 0.69) were less likely to commence HAART.

CONCLUSION

A substantial minority of patients with a CD4 count < 350 cells/μL remain untreated despite its indication.

HIV type-1 drug resistance in antiretroviral treatment-naive adults infected with non-B subtype virus in the United Kingdom

BACKGROUND

There is an increasing prevalence of non-B subtype HIV type-1 (HIV-1) infections in Europe, reflecting patterns of migration. We examined the characteristics of HIV-1 drug resistance in antiretroviral treatment (ART)-naive individuals migrating to the UK.

METHODS

Resistance tests reported to the UK HIV Drug Resistance Database between 2001 and 2006 were included. Demographic data were obtained via linkage to national databases. Resistance was defined as ≥ 1 drug resistance mutation. Non-B HIV-1 subtype was used as a surrogate marker of infection acquired outside the UK. Logistic regression was used to examine the association between demographics and the prevalence of resistance.

RESULTS

Overall, 196/4,291 (4.6%) samples with non-B subtype showed resistance compared with 745/6,435 (11.6%) samples for subtype B. Among non-B subtypes, the prevalence of resistance decreased over time (6.0% in 2001-2003 to 3.2% in 2006) and was independently associated with later calendar year of sampling (P=0.001). Resistance was confined mainly to one ART class (85%); non-nucleoside reverse transcriptase inhibitor resistance was more common in subtype C (47%) compared with non-B non-C subtypes (29%; P=0.02). M184V was more common in non-B subtypes (non-B 30% versus B 5%; P<0.001) and T215 variants were more common in subtype B (non-B 10% versus B 49%; P<0.001).

CONCLUSIONS

In ART-naive individuals living in the UK, but who are likely to have acquired HIV-1 abroad, we observed a downward trend in resistance over time, which is surprising in light of ART roll-out in resource-limited settings. Reassuringly, resistance was mainly confined to one drug class; however, patterns of resistance differed by subtype, with some evidence of possible undisclosed prior therapy in non-B subtypes.

Cost effectiveness of darunavir/ritonavir 600/100 mg bid in protease inhibitor-experienced, HIV-1-infected adults in Belgium, Italy, Sweden and the UK

BACKGROUND

Two phase II trials (POWER 1 and 2) have demonstrated that darunavir co-administered with low-dose ritonavir (DRV/r) provides significant clinical benefit compared with control protease inhibitors (PIs) in highly treatment-experienced, HIV-1-infected adults, when co-administered with optimized background therapy (OBR).

OBJECTIVE

To determine whether DRV/r is cost effective compared with control PIs, from the perspective of Belgian, Italian, Swedish and UK reimbursement authorities, when used in treatment-experienced patients similar to those included in the POWER 1 and 2 trials.

METHODS

An existing Markov model containing health states defined by CD4 cell count ranges (> 500, 351-500, 201-350, 101-200, 51-100 and 0-50 cells/mm³) and death was adapted for use in four European healthcare settings. Baseline demographics, CD4 cell count distribution and antiretroviral drug usage reflected those reported in the POWER 1 and 2 trials. Virological/immunological response rates and matching transition probabilities over the patient's lifetime were based on results from the POWER trials and published data. After treatment failure, patients were assumed to switch to a tipranavir-containing regimen plus OBR. For each CD4 cell count range, utility values and HIV-related mortality rates were obtained from the published literature. National all-cause mortality data and published data on the increased risk of non HIV-related mortality in HIV-infected individuals were taken into account in the model. Data from observational studies conducted in each healthcare setting were used to determine resource-use patterns and costs associated with each CD4 cell count range. Unit costs were derived from official local sources; a lifetime horizon was taken and discount rates were selected based on local guidelines.

RESULTS

In the base-case analysis, quality-adjusted life-year (QALY) gains of up to 1.397 in Belgium, over 1.171 in Italy, 1.142 in Sweden and 1.091 in the UK were predicted when DRV/r-based therapy was used instead of control PI-based treatment. The base-case analyses predicted an incremental cost-effectiveness ratio (ICER) of €11,438/QALY in Belgium, €12,122/QALY in Italy,€10,942/QALY in Sweden and €16,438/QALY in the UK. Assuming an acceptability threshold of €30,000/QALY, DRV/r-based therapy remained cost effective over all parameter ranges tested in extensive one-way sensitivity analyses. Probabilistic sensitivity analysis revealed a 95% (Belgium), 97% (Italy), 92% (Sweden) or 78% (UK) probability of attaining an ICER below this threshold.

CONCLUSION

From four European payer perspectives, DRV/r-based antiretroviral therapy is predicted to be cost effective compared with currently available control PIs, when both are used with an OBR in treatment-experienced, HIV-1-infected adults who failed to respond to more than one PI-containing regimen.

Inhibitory quotient in HIV pharmacology

PURPOSE OF REVIEW

This review discusses the use of the inhibitory quotient in light of therapeutic drug monitoring of antiretroviral drugs. The inhibitory quotient is a parameter that combines viral resistance data with drug exposure data, and has its main role in therapeutic drug monitoring of protease inhibitors in experienced patients. Data from recent clinical studies investigating inhibitory quotient cutoffs to be used in therapeutic drug monitoring will be reviewed. In addition points for discussion regarding the use and study of inhibitory quotients will be presented.

RECENT FINDINGS

A number of studies generated data on the use of the inhibitory quotient in general and the genotypic inhibitory quotient in particular. Most of these studies define a cutoff inhibitory quotient value, above which the virological response rate is higher. These cutoff values can be used in therapeutic drug monitoring and give guidance to the clinician on dose adjustments. Genotypic inhibitory quotient cutoff values are available for amprenavir, atazanavir, darunavir, lopinavir, saquinavir and tipranavir.

SUMMARY

The inhibitory quotient is becoming a valuable tool in therapeutic drug monitoring. At this moment most data are available for the genotypic inhibitory quotient. Nevertheless, a consensus needs to be reached on a number of items, including the methods to study inhibitory quotient as well as the mathematical and virological background.

Reduced glomerular filtration rate but sustained virologic response in HIV/hepatitis B co-infected individuals on long-term tenofovir

Reports have described a decrease in glomerular filtration rate (eGFR) associated with tenofovir disoproxil fumarate (TDF) use in HIV positive individuals. However, no study has examined renal function over a prolonged period in HIV/hepatitis B virus (HBV) co-infected patients. We assessed the long-term durability and toxicity of TDF in a cohort of 39 e antigen (eAg) positive co-infected patients commenced on TDF 245 mg daily either in addition to or as part of standard antiretroviral therapy. Immunological and virological parameters were followed to 260 weeks, with the median follow-up period being 251 weeks (range 69-290 weeks). eGFR was calculated using the Modification in Diet in Renal Disease equation. On treatment at 260 weeks, 88% (14/16) had HIV viral load <50 copies/mL, median CD4 count rose from 318 to 532 cells/mm(3), median alanine aminotransferase (ALT) fell from 61 IU/L to 42 IU/L, with 35% (7/20) having a normal ALT, median HBV DNA fell from 69 x 10(6) copies/mL to 500 copies/mL, with 75% (12/16) having an undetectable HBV DNA level and 55% (6/11) becoming eAg negative. Of those with detectable HBV DNA, none had TDF resistance mutations. The eGFR declined by 22.19 mL/min/1.73 mm(2) from baseline (P = 0.023) over this period, which was unaffected by protease inhibitor use, baseline CD4 count, ALT or HBV DNA level. Three patients discontinued TDF therapy due to renal dysfunction. In conclusion, TDF has sustained efficacy but is associated with a significant decline in eGFR. Further larger studies are required to clarify this observation.

British HIV Association (BHIVA) national cohort outcomes audit of patients commencing antiretrovirals from naïve

OBJECTIVES

The aim of this work was to audit the extent to which routine HIV care in the UK conforms with British HIV Association (BHIVA) guidelines and specifically the proportion of patients starting highly active antiretroviral therapy (HAART) who achieve the outcome of virological suppression below 50 HIV-1 RNA copies/mL within 6 months.

METHODS

A prospective cohort review of adults with HIV infection who started antiretroviral therapy (ART) for the first time between April and September 2006 was carried out using structured questionnaire forms.

RESULTS

A total of 1170 adults from 122 clinical sites participated in the review. Of these patients, 699 (59.7%) started ART at CD4 counts <200 cells/microL and 193 (16.5%) had not been tested for HIV drug resistance. Excluding patients with valid reasons for stopping short-term ART, 795 (73.5%) of 1081 patients had an undetectable viral load (VL) at follow-up. Detectable VL was strongly associated with pretreatment CD4 count below 50 cells/microL and pretreatment VL above 100 000 copies/mL, and was not associated with clinic location or case load. About a quarter of patients did not have a VL measurement during the first 6 weeks after starting ART.

CONCLUSIONS

The majority of patients who initiated ART at sites participating in this UK national audit were managed within the BHIVA guidelines and achieved virological suppression below 50 copies/mL around 6 months after commencing treatment. Poor VL outcomes were associated with very low CD4 cell count and/or high VL at baseline but not with clinic case load or location. There is an urgent need to diagnose patients at an earlier stage of their HIV disease.

Prescribing and using self-injectable antiretrovirals: how concordant are physician and patient perspectives?

Background

The selection of agents for any treatment regimen is in part influenced by physician and patient attitudes. This study investigated attitudinal motivators and barriers to the use of self-injectable antiretroviral agents among physicians and patients and measured the degree of concordance between physician and patient perspectives.

Methods

Attitudes toward prescribing and usage of self-injectable antiretroviral therapy (SIAT) were assessed by structured interview in 2 cohorts sampled from the European Union and the USA: 499 HIV-treating physicians and 603 treatment-experienced HIV-infected patients. Motivators and barriers to prescribing SIAT were identified from statistical analysis of the associations between physicians' ratings of enfuvirtide-based therapy compared to standard oral-based therapy and 2 indicators of enfuvirtide prescribing behavior. Patients' attitudes were assessed by their responses to a written profile of enfuvirtide and their ratings of the likelihood of accepting a treatment offer.

Results

Both indicators of SIAT prescribing behavior were predicted by the same pattern of physician beliefs. Nonprescribing was associated with: (1) the belief that offering enfuvirtide would be perceived negatively by patients, leading to treatment refusal and nonadherence; (2) the belief that prescribing enfuvirtide is harder to justify in terms of time/resources; and (3) a lack of confidence in the efficacy and use of enfuvirtide in practice (all p < 0.05). However, physicians' beliefs were not in concordance with patients' views. After reading a profile of enfuvirtide, 76% patients said that they would be moderately or highly likely to accept a treatment offer, although most (72%) had not discussed enfuvirtide with their doctor. Patients' beliefs predicted the likelihood of accepting enfuvirtide.

Conclusion

Physician and patient beliefs about SIAT influence prescribing behavior and compliance yet may not be concordant, with patients having more positive attitudes towards SIAT than anticipated by physicians.

Markov modelling of HIV infection evolution in the HAART era

The aim was to investigate the impact of the main prognostic factors on HIV evolution. A multi-state Markov model was applied in a cohort of 2126 patients to estimate impact of these factors on patients' clinical and immunological evolutions. Clinical progression and immunological deterioration shared most of their prognostic factors: male gender, intravenous drug use, weight loss, low haemoglobin level (<110 g/l), CD8 cell count (<500/mm(3)) and HIV viral load (>5 log(10) copies/ml). Highly active retroviral therapy reduced the risks of clinical progression and immune deterioration whatever patients' CD4 cell count. Risk reductions were 41-60% for protease inhibitor-based and 27-68% for non-nucleoside reverse transcriptase inhibitor-based regimens. Three-year transition probabilities showed that only patients with a CD4 cell count >or=350 CD4/mm(3) could in most cases maintain their immunity. This model provides 'real life' transition probabilities from one immunological stage to another, allowing decision analyses that could help determine the beneficial therapeutic strategies for HIV-infected patients.

An audit of baseline HIV-1 genotypic resistance testing in a UK provincial city

Baseline HIV-1 resistance testing is recommended in the 2005 BHIVA treatment guidelines. We compared the practice in our clinic with these guidelines. The aim of this study was to assess the prevalence of transmitted resistance in all antiretroviral therapy-naïve patients identified from our virology resistance test database. In 2006, 93% of all newly diagnosed patients had a baseline HIV-1 genotypic resistance test performed. The estimated prevalence of transmitted resistance was 8% in newly diagnosed patients and 7% overall with the majority in subtype B. These findings are in keeping with nationally reported data. It was of concern that we also identified a number of patients who had tested negative in the previous year.

Does less frequent routine monitoring of patients on a stable, fully suppressed cART regimen lead to an increased risk of treatment failure?

OBJECTIVE

To investigate whether HIV-infected patients on a stable and fully suppressive combination antiretroviral therapy (cART) regimen could safely be monitored less often than the current recommendations of every 3 months.

DESIGN

Two thousand two hundred and forty patients from the EuroSIDA study who maintained a stable and fully suppressed cART regimen for 1 year were included in the analysis.

METHODS

Risk of treatment failure, defined by viral rebound, fall in CD4 cell count, development of new AIDS-defining illness, serious opportunistic infection or death, in the 12 months following a year of a stable and fully suppressed regimen was assessed.

RESULTS

One hundred thirty-one (6%) patients experienced treatment failure in the 12 months following a year of stable therapy, viral rebound occurred in 99 (4.6%) patients. After 3, 6 and 12 months, patients had a 0.3% [95% confidence interval (CI) 0.1-0.5], 2.2% (95% CI 1.6-2.8) and 6.0% (95% CI 5.0-7.0) risk of treatment failure, respectively. Patients who spent more than 80% of their time on cART with fully suppressed viraemia prior to baseline had a 38% reduced risk of treatment failure, hazard ratio 0.62 (95% CI 0.42-0.90, P = 0.01).

CONCLUSION

Patients who have responded well to cART and are on a well tolerated and durably fully suppressive cART regimen have a low chance of experiencing treatment failure in the next 3-6 months. Therefore, in this subgroup of otherwise healthy patients, it maybe reasonable to extend visit intervals to 6 months, with cost and time savings to both the treating clinics and the patients.

Treatment switches after viral rebound in HIV-infected adults starting antiretroviral therapy: multicentre cohort study

OBJECTIVE

To describe the time from first viral rebound on highly active antiretroviral therapy to first treatment change, identify factors associated with more rapid switching, and investigate whether treatment changes are in line with treatment guidelines.

DESIGN AND SETTING

A multicentre cohort study.

METHODS

We described the time to first treatment switch among individuals experiencing confirmed virological rebound after initiating highly active antiretroviral therapy; factors associated with more rapid switching were identified using proportional hazards regression and predictors of a switch in line with guidelines were identified using logistic regression.

RESULTS

Thirty-four percent of the 694 patients experiencing virological rebound remained on a failing regimen for more than 6 months. Factors associated with more rapid switching were lower CD4 cell count (hazard ratio, 0.84 /100 cells/mul higher, P < 0.001), higher viral load (1.29 /log10 copies/ml higher, P < 0.001), older age (1.06 /5 years older, P = 0.07), and changing/adding drugs to the regimen prior to rebound (1.16, P = 0.16). Two hundred and eighteen of the 394 treatment changes (55%) were in line with guidelines; those receiving nonnucleoside reverse transcriptase inhibitor-containing regimens were more likely to make changes in line with guidelines (adjusted odds ratio, 2.80, P < 0.001), whereas those who had previously added drugs to their regimen were less likely to make changes in line with guidelines (0.15, P = 0.001).

CONCLUSION

A substantial minority of patients remain on a failing highly active antiretroviral therapy regimen for periods of 6 months or longer without adding new drugs. Changes made are often not in line with treatment guidelines, raising concerns about the development of resistance and long-term clinical outcomes in these individuals.

A national review of assessment and monitoring of HIV-infected patients

OBJECTIVES

The British HIV Association (BHIVA) audit subcommittee aimed to survey UK clinic policy and practice regarding baseline assessment and immunization of newly diagnosed HIV-positive patients, and frequency of follow-up and testing in established patients in the UK.

METHODS

UK centres providing HIV care were requested to complete an online survey between October 2006 and March 2007.

RESULTS

111 centres participated in the survey. 89.2% of centres routinely performed baseline HIV resistance testing. 99% of centres had a policy of routine screening for hepatitis B. Only 91% of centres were routinely offering a sexual health screen at diagnosis. Frequency of routine follow-up for patients not requiring antiretroviral therapy (ART) and stable on ART varied between three and six months.

DISCUSSION

This review showed variations in practice regarding the post diagnosis assessment and routine monitoring of HIV patients. It is of concern that not all centres perform baseline HIV resistance testing. It has also been noted that hepatitis B vaccination is not being offered to non-immune patients at diagnosis. Less frequent follw-up of stable patients (both on and off ART) should allow resources to be focussed on those with specific clinical needs.

Restoration of anti-tetanus toxoid responses in patients initiating highly active antiretroviral therapy with or without a boost immunization: an INITIO substudy

INITIO is an open-labelled randomized trial evaluating first-line therapeutic strategies for human immunodeficiency virus-1 (HIV-1) infection. In an immunology substudy a tetanus toxoid booster (TTB) immunization was planned for 24 weeks after initiation of highly active antiretroviral therapy (HAART). All patients had received tetanus toxoid immunization in childhood. Generation of proliferative responses to tetanus toxoid was compared in two groups of patients, those receiving a protease inhibitor (PI)-sparing regimen (n = 21) and those receiving a PI-containing (n = 54) regimen. Fifty-two participants received a TTB immunization [PI-sparing (n = 15), PI-containing (n = 37)] and 23 participants did not [PI-sparing (n = 6) or PI-containing (n = 17)]. Cellular responses to tetanus antigen were monitored by lymphoproliferation at time of immunization and every 24 weeks to week 156. Proportions with a positive response (defined as stimulation index > or = 3 and Delta counts per minute > or = 3000) were compared at weeks 96 and 156. All analyses were intent-to-treat. Fifty-two participants had a TTB immunization at median 25 weeks; 23 patients did not. At weeks 96 and 156 there was no evidence of a difference in tetanus-specific responses, between those with or without TTB immunization (P = 0.2, P = 0.4). There was no difference in the proportion with response between those with PI-sparing or PI-containing regimens at both time-points (P = 0.8, P = 0.7). The proliferative response to tetanus toxoid was unaffected by initial HAART regimen. Anti-tetanus responses appear to reconstitute eventually in most patients over 156 weeks when treated successfully with HAART, irrespective of whether or not a TTB immunization has been administered.

Audit of the management of antiretroviral treatment-naïve HIV patients in Greater Manchester, UK

Summary:

We evaluated the management of antiretroviral treatment (ART)-naïve HIV-positive patients in Greater Manchester against the 2005 British HIV association (BHIVA) guidelines. Fifty-seven HIV patients (median age 36 years, 61% males, 53% black Africans) commenced their first ART regimen between 1 October and 31 December 2005. Most of them presented with advanced HIV disease (74% had CD4 lymphocytes <200 and 33% were Centers for Disease Control and Prevention stage C) and 51% commenced ART within three months of their HIV diagnosis. Ninety-six percent had baseline laboratory investigations performed but only 53% had baseline blood pressure estimation. Only 25% had urinalysis performed. A combination of two nucleoside reverse transcriptase inhibitors (NRTI) and one non-NRTI was chosen in 76% of patients. Eighty-two percent of patients had a clinical review and blood tests within five weeks of starting treatment.

Seven-year efficacy of a lopinavir/ritonavir-based regimen in antiretroviral-naïve HIV-1-infected patients

OBJECTIVE

Evaluate efficacy and tolerability of lopinavir/ritonavir (LPV/r) plus stavudine and lamivudine long term in antiretroviral-naïve patients.

DESIGN

Open-label follow-up of prospective, randomized, multicenter trial.

METHOD

Antiretroviral-naïve HIV-infected subjects (N = 00) received of 3 doses of LPV/r plus stavudine and lamivudine for 48 weeks then received LPV/r soft-gel capsules 400/00 mg plus stavudine and lamivudine. After 6 years, subjects replaced stavudine with tenofovir.

RESULTS

At 7 years, by intent-to-treat analysis, 61 % had plasma HIV-RNA <400 copies/mL and 59% had < 50 copies/mL. Thirty-nine subjects discontinued treatment due to adverse events (n = 6), personal/other reasons (0), loss to follow-up (9), and noncompliance (4). Among 28 subjects qualifying for drug resistance testing, no protease inhibitor or stavudine resistance was observed and 4 showed lamivudine resistance. Most common drug-related moderate or severe adverse events were diarrhea (28%), nausea (6%), and abdominal pain (11 %). Subjects who received stavudine (median 6.6 years) and switched to tenofovir demonstrated significant improvements in total cholesterol (p = .009), triglycerides (p = .023), apolipoprotein C-III (p < .001 ), adiponectin (p = .008), fasting insulin (p = .04), and leptin (p = .03).

CONCLUSION

LPV/r-based therapy demonstrated sustained efficacy with no protease inhibitor or stavudine resistance through 7 years in antiretroviral-naïve patients. Switching from stavudine to tenofovir resulted in significant improvements in multiple metabolic parameters.

The impact of monitoring HIV patients prior to treatment in resource-poor settings: insights from mathematical modelling

BACKGROUND

The roll-out of antiretroviral treatment (ART) in developing countries concentrates on finding patients currently in need, but over time many HIV-infected individuals will be identified who will require treatment in the future. We investigated the potential influence of alternative patient management and ART initiation strategies on the impact of ART programmes in sub-Saharan Africa.

METHODS AND FINDINGS

We developed a stochastic mathematical model representing disease progression, diagnosis, clinical monitoring, and survival in a cohort of 1,000 hypothetical HIV-infected individuals in Africa. If individuals primarily enter ART programmes when symptomatic, the model predicts that only 25% will start treatment and, on average, 6 life-years will be saved per person treated. If individuals are recruited to programmes while still healthy and are frequently monitored, and CD4(+) cell counts are used to help decide when to initiate ART, three times as many are expected to be treated, and average life-years saved among those treated increases to 15. The impact of programmes can be improved further by performing a second CD4(+) cell count when the initial value is close to the threshold for starting treatment, maintaining high patient follow-up rates, and prioritising monitoring the oldest (> or = 35 y) and most immune-suppressed patients (CD4(+) cell count < or = 350). Initiating ART at higher CD4(+) cell counts than WHO recommends leads to more life-years saved, but disproportionately more years spent on ART.

CONCLUSIONS

The overall impact of ART programmes will be limited if rates of diagnosis are low and individuals enter care too late. Frequently monitoring individuals at all stages of HIV infection and using CD4 cell count information to determine when to start treatment can maximise the impact of ART.

Maraviroc: a CCR5 antagonist

HIV requires binding to both the CD4 molecule and a coreceptor to enable entry into the cell. CCR5 is a chemokine receptor that is utilized as a coreceptor by the majority of virus in early asymptomatic HIV infection. Maraviroc is a novel small molecule CCR5 antagonist which, in Phase IIb/III clinical trials up to 48 weeks, has been shown to be efficacious as part of an optimized antiretroviral regimen against CCR5 tropic HIV-1 in treatment-experienced patients. A further trial has demonstrated its noninferiority to efavirenz in achieving a HIV viral load less than 400 copies/ml as part of highly active antiretroviral therapy in treatment-naive individuals. It has recently received regulatory approval for use in North America and Europe in treatment-experienced patients. With increasing use, the role of maraviroc in the treatment of HIV-infected patients will be more clearly defined.

Impact of transmission of drug-resistant HIV on the course of infection and the treatment success. Data from the German HIV-1 Seroconverter Study

BACKGROUND

Data on the clinical course of infection in patients with transmitted drug-resistant HIV before and after initiation of treatment are scarce.

PATIENTS AND METHODS

Genotypic resistance was analysed in 504 therapy-naïve individuals with a known date of infection. Resistance was predicted using the Stanford algorithm. Clinical parameters for 80 individuals with transmitted drug-resistant HIV and for 424 patients with susceptible virus were analysed.

RESULTS

In 16% of the individuals transmitted drug-resistant HIV was found. Detection of drug-resistant HIV was more likely in individuals with acute primary HIV infection [odds ratio (OR)=1.529; 95% confidence interval (95% CI) 1.001; 2.236]. At the time of infection patients with an acute infection with resistant HIV had lower viral loads. CD4 cell counts tended to be higher and the CD4 cell loss more pronounced in the group with resistant HIV. Suppression of the viral load below the detection limit was achieved in 64% of the group with resistant HIV and in 85% of the group with susceptible HIV 6 months after initiation of therapy (P=0.199). The majority of the group with resistant HIV (74%) received at least one compromised drug.

CONCLUSION

First-line treatment including drugs with predicted resistance can impair virological success in some patients. Factors influencing the decision to include compromised drugs need to be investigated.

CD4 cell count and initiation of antiretroviral therapy: trends in seven UK centres, 1997-2003

OBJECTIVES

We examined whether the timing of initiation of antiretroviral therapy (ART) in routine clinical practice reflected treatment guidelines, which have evolved towards recommending starting therapy at lower CD4 cell counts.

METHODS

We analysed longitudinal data on 10,820 patients enrolled in the UK Collaborative HIV Cohort (UK CHIC) Study, which includes seven large clinical centres in south-east England. CD4 cell and viral load measurements performed in the period between 1 January 1997 and 31 December 2003 were classified according to whether ART was subsequently initiated or deferred, to estimate the probability of ART initiation by CD4 count and viral load over time. The effect of nonclinical factors (age, sex, ethnicity, and exposure category) was analysed by logistic regression. Kaplan-Meier analysis was used to estimate the proportion of patients who had initiated ART by a particular CD4 count among 'early' presenters (initial CD4 cell count >500 cells/microL).

RESULTS

There was a tendency to initiate ART at lower CD4 cell counts over time in the years 1997-2000, especially in the range 200-500 cells/microL, with little change thereafter. An estimated 34% of HIV-infected individuals having presented early initiated ART at a CD4 count <200 cells/microL. We also found an independent influence of viral load, which was particularly pronounced for CD4 <350 cells/microL. Use of injection drugs was the only nonclinical factor associated with initiation of ART at lower CD4 cell counts.

CONCLUSIONS

The initiation of ART in the clinics included in this analysis reflected evolving treatment guidelines. However, an unexpectedly high proportion of patients started ART at lower CD4 counts than recommended, which is only partly explained by late presentation.

Setting a minimum threshold CD4 count for initiation of highly active antiretroviral therapy in HIV-infected patients

The aim of our study was to determine a minimum threshold CD4 count for highly active antiretroviral therapy (HAART) initiation in HIV-infected patients. A schema using longitudinal data from a clinical cohort was designed. The presenting CD4 counts of asymptomatic HIV-infected patients in Hong Kong were evaluated in relation to their progression to AIDS within 1 year of diagnosis of HIV infection. A graph was generated to depict the changes in the percentage of cumulative AIDS diagnoses for every 10 cell/microL increase in presenting CD4 count. Of 181 patients, 24 had developed AIDS within 1 year of diagnosis of HIV infection. Setting the CD4 count threshold at 150 cells/microL gave a good balance between the number of preventable AIDS-defining events and the number of non-AIDS patients initiating HAART. No extra AIDS-defining events occurred when the CD4 count threshold was reduced from 200 to 150 cells/microL, despite the addition of 13 more patients. In multivariate Cox regression analysis, presenting CD4 count was a significant predictor for AIDS occurrence. The relative hazard for AIDS occurrence of patients with presenting CD4 counts <or=150 cells/microL was 27-fold greater. We suggest a CD4 count of 150 cells/microL as the minimum threshold for HAART initiation in a cohort of Chinese HIV-infected patients. At this level, 20.8% of the AIDS-defining events could be prevented. While a cut-off of 200 cells/microL remains a standard for considering HAART initiation, the minimum threshold signifies a critical moment for timely intervention to be introduced.

National review of first treatment change after starting highly active antiretroviral therapy in antiretroviral-naïve patients

OBJECTIVES

The aim of the study was to explore the factors surrounding modification of the first antiretroviral (ARV) regimen where drug switch occurred 3 months or more after initiation. Reference was made to the British HIV Association (BHIVA) guidelines on HIV management.

METHODS

A case note and questionnaire-based audit was carried out.

RESULTS

Toxicity was the single most important reason for ARV change and was the only, or a contributory, cause in over half the patients. Virological failure, adherence issues, requirement for treatment simplification, and patient request were other significant reasons cited. In one-third of those with virological failure, six or more months had elapsed between first detection and the time of switching to a new ARV regimen.

CONCLUSIONS

This audit demonstrated broad adherence to the BHIVA guidelines, although the long time before switching ARVs in the setting of virological failure was of some concern, particularly given the continuing and significant occurrence of primary ARV resistance in the UK.

A cluster-randomised trial to compare home-based with health facility-based antiretroviral treatment in Uganda: study design and baseline findings

The scale-up of antiretroviral therapy is progressing rapidly in Africa but with a limited evidence-base. We report the baseline results from a large pragmatic cluster-randomised trial comparing different strategies of ART delivery. The trial is integrated in normal health service delivery. 1453 subjects were recruited into the study. Significantly more women (71%) than men (29%) were recruited. The WHO HIV clinical stage at presentation did not differ significantly between men and women: 58% and 53% respectively were at WHO stage III or IV (p=0.9). Median CD4 counts (IQR) x 106cells/l were 98 (28, 160) among men and 111 (36, 166) among women. Sixty-four percent of women and 61% men had plasma viral load ≥100,000 copies. Baseline characteristics did not change over time. Considerably fewer men than women presented for treatment. Both men and women presented at an advanced stage with very low median CD4 count and high plasma viral load.

A Randomized Controlled Trial of Therapeutic Drug Monitoring in Treatment-Naive and -Experienced HIV-1-Infected Patients

OBJECTIVE

To improve the utility of therapeutic drug monitoring (TDM) by defining the proportion of patients with and predictors of above or below target protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI) concentrations.

METHODS

This 48-week, multicenter, open-label clinical trial randomized patients to TDM versus standard of care (SOC). Serial pharmacokinetics, including a week-2 3-sample sparse collection, and expert committee TDM recommendations were given to TDM-arm patients' providers.

RESULTS

Seventy-four (39%) of 190 patients had week-2 concentrations outside of targets and 122 (64%) of 190 had nontarget exposure at least once over 48 weeks. Providers accepted 75% of TDM recommendations. Among patients with below-target concentrations, more TDM-arm than SOC-arm patients achieved targets (65% vs. 45%; P = 0.09). Increased body weight and efavirenz or lopinavir/ritonavir use were significant predictors of nontarget concentrations. Patients at target and patients who achieved targets after TDM-directed dose modifications trended toward greater viral load reductions at week 48 than patients with below-target exposures (HIV RNA reductions: 2.4, 2.3, and 1.9 log10 copies/mL, respectively; P = 0.09).

CONCLUSIONS

Most patients had nontarget PI and/or NNRTI concentrations over 48 weeks. TDM recommendations were well accepted and improved exposure. Patients below TDM targets trended toward worse virologic response.

Response to efavirenz-containing regimens in previously antiretroviral-naive HIV-positive patients: the role of gender

BACKGROUND

We investigated the role of gender on response to efavirenz (EFV)-containing regimens in previously antiretroviral-naive patients.

METHODS

All previously antiretroviral-naive individuals from the Royal Free Hospital in London starting EFV from 1996 onward were included. Treatment failure was defined as the first of 2 consecutive viral load measurements >500 copies/mL more than 24 weeks after starting EFV. Standard survival methods were used to assess time to discontinuation and to treatment failure.

RESULTS

Ninety-six women and 337 men were included. Women were mostly of black African ethnicity (64.6%) with a heterosexual risk (94.8%), whereas men were mostly white (66.8%; P < 0.0001) with a homosexual risk (71.2%; P < 0.0001). Women had lower CD4 counts when starting EFV (median [interquartile range [IQR] = 126 [36, 220] cells/mm for women vs. 190 [109, 268] cells/mm for men; P = 0.0003). After 48 and 96 weeks, 38.8% (95% confidence interval [CI]: 28.8% to 48.7%) and 56.3% (95% CI: 45.8% to 66.9%) of women had discontinued EFV compared with 28.3% (95% CI: 23.4% to 33.2%) and 41.8% (95% CI: 36.3% to 47.3%) of men (P = 0.005). The percentage experiencing failure by 48 and 96 weeks when ignoring treatment changes but censoring at the date of discontinuing all treatment was 1.3% (0.0%, 3.9%) and 4.4% (0.0%, 9.3%) for women compared with 3.8% (1.6%, 6.0%; P = 0.49) and 5.8% (3.0%, 8.6%) for men. Median (IQR) CD4 count increases at 48 weeks were +166 (+89, +239) cells/mm for women and +176 (+93, +263) cells/mm for men.

CONCLUSIONS

Women seem to have comparable virologic and immunologic outcomes to first-line EFV-containing regimens compared with men, although they are more likely to discontinue the drug.