Risk Factors For Virological Failure Research Articles

Virological and Social Outcomes of HIV-Infected Adolescents and Young Adults in The Netherlands Before and After Transition to Adult Care.

As a result of effective combination antiretroviral therapy (cART) and advanced supportive healthcare, a growing number of human immunodeficiency virus (HIV)-infected children survive into adulthood. The period of transition to adult care is often associated with impaired adherence to treatment and discontinuity of care. We aimed to evaluate virological and social outcomes of HIV-infected adolescents and young adults (AYAs) before and after transition, and explore which factors are associated with virological failure. We included 59 HIV-infected AYAs from the Netherlands who had entered into pediatric care and transitioned from pediatric to adult healthcare. We used HIV RNA load and cART data from the Dutch Stichting HIV Monitoring database (1996-2014), and collected social and treatment data from patients' medical records from all Dutch pediatric HIV treatment centers and 14 Dutch adult treatment centers involved. We evaluated risk factors for virological failure (VF) in a logistic regression model adjusted for repeated measurements. HIV VF occurred frequently during the study period (14%-36%). During the transition period (from 18 to 19 years of age) there was a significant increase in VF compared with the reference group of children aged 12-13 years (odds ratio, 4.26 [95% confidence interval, 1.12-16.28]; P = .03). Characteristics significantly associated with VF were low educational attainment and lack of autonomy regarding medication adherence at transition. HIV-infected AYAs are vulnerable to VF, especially during the transition period. Identification of HIV-infected adolescents at high risk for VF might help to improve treatment success in this group.

Factors associated with the failure of first and second-line antiretroviral therapies therapy, a case control study in Cambodian HIV-1 infected children.

BackgroundLittle is known about the efficacy of first and and second-line antiretroviral therapies (ART) for HIV-1 infected children in resource limited Southeast Asian settings. Previous studies have shown that orphans are at a higher risk for virological failure (VF) in Cambodia. Consequently most of them required transfer to second-line ART. We assessed the factors associated with VF among HIV-1 infected children who were either under first-line (mostly 3TC + D4T + NVP) or under second-line (mostly ABC + DDI + LPV) therapies at a referral hospital in Cambodia.MethodsA case-control study was conducted from February to July 2013 at the National Pediatric Hospital among HIV-1 infected children (aged 1–15 years) under second-line ART (cases) or first-line (matched controls at a ratio of 1:3) regimens. Children were included if a HIV-1 RNA plasma viral load (VL) result was available for the preceding 12 months. A standardized questionnaire explored family sociodemographics, HIV history, and adherence to ART. Associations between VF (HIV-1 RNA levels ≥1000 copies/ml) and the children’s characteristics were assessed using bivariate and multivariate analyses.ResultsA total of 232 children, 175 (75.4 %) under first-line and 57 (24.6 %) under second-line ART, for a median of 72.0 (IQR: 68.0–76.0) months, were enrolled. Of them, 94 (40.5 %) were double orphans and 51 (22.0 %) single orphans, and 77 (33.2 %) were living in orphanages. A total of 222 children (95.6 %) were deemed adherent to ART. Overall, 18 (7.7 %; 95 % CI 4.6–11.9) showed a VF, 14 (8.6 %; 95 % CI 4.8–14.0) under first-line and 4 (7.0 %; 95 % CI 1.9–17.0) under second-line ART (p = 0.5). Their median CD4 percentage was 8 % (IQR 2.9–12.9) at ART initiation. Children under second-line ART were older; more often double orphans, and had lower CD4 cell counts at the last control.In the multivariate analysis, having the last CD4 percentage below 15 % was the only factor associated with VF for ART regimen separately or when combined (OR 40.4; 95 % CI 11–134).ConclusionsThe pattern of risk factors for VF in children is changing in Cambodia. Improved adherence evaluation and intensified monitoring of children with low CD4 counts is needed to decrease the risk of VF.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-016-1884-y) contains supplementary material, which is available to authorized users.

The Cologne-Bonn cohort: lessons learned.

Much of our knowledge about HIV infection has been obtained from cohort studies, including description of the natural history of infection, identification of CD4 count and viral load as good surrogate markers of clinical progression, identification of co-factors [including older age and viral infections (CMV, HCV)] for progression of HIV-related disease and assessment of impact of highly active antiretroviral therapy on clinical outcomes. The Cologne-Bonn cohort was founded by Gerd Fätkenheuer and Bernd Salzberger after introduction of combination antiretroviral therapy in 1996 and has delivered important findings which have helped to improve treatment strategies as well as quality of overall care in HIV infection in these two cities. Indeed, the first pivotal paper from the cohort reported on an unexpectedly high rate of virological treatment failure of protease inhibitor therapy in an unselected cohort of HIV-infected patients. The subsequent analysis of risk factors for virological failure initiated the development of more potent HIV combination therapy. This review summarizes some of the major findings and contributions from the Cologne-Bonn cohort since 1996.

Short term adherence tool predicts failure on second line protease inhibitor-based antiretroviral therapy: an observational cohort study.

BackgroundMost patients who experience virologic failure (VF) on second line antiretroviral therapy (ART) in low-middle income countries fail due to poor adherence rather than antiretroviral resistance. A simple adherence tool designed to detect VF would conserve resources by rationally limiting need for viral load (VL) testing and, in those countries with access to third line ART, the need for resistance testing.MethodsWe conducted an observational cohort study of patients who initiated second line ART at a clinic in Kwazulu-Natal, South Africa. Using clinical and pharmacy refill data extracted from the clinic’s electronic database, we determined risk factors for VF. Three different methods of calculating short term pharmacy refill adherence were evaluated and compared with long term adherence since second line initiation. We also explored the ability of differing durations of short term pharmacy refill to predict VF on second line ART.ResultsWe included 274 patients with a median follow up of 27 months on second line ART. VF ranged between 3% and 16% within each six month interval after initiating second line ART. 243 patients with at least one VL after 4 months on second line were analysed in the statistical analysis. Pharmacy refill adherence assessed over shorter periods (4 to 6 months) predicted virologic suppression as well as pharmacy refill assessed over longer periods. The risk of VF fell 73% with each 10% increase in adherence measured from pharmacy refills over a 4 month period. Low CD4 count at second line ART initiation was a significant independent risk factor for VF.ConclusionPatients identified as poorly adherent by short term pharmacy refill are at risk for VF on second line ART. This pragmatic adherence tool could assist in identifying patients who require adherence interventions, and help rationalize use of VL monitoring and resistance testing among patients on second line ART.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0664-3) contains supplementary material, which is available to authorized users.

Virological failure after 1 year of first-line ART is not associated with HIV minority drug resistance in rural Cameroon .

The aim of this study was to describe clinical and virological outcomes in therapy-naive HIV-1-positive patients treated in a routine ART programme in rural Cameroon. In a prospective cohort, 300 consecutive patients starting first-line ART were enrolled and followed for 12 months. Among 238 patients with available viral load data at Month 12, logistic regression was used to analyse risk factors for virological failure (≥1000 HIV RNA copies/mL) including clinical, immunological and virological parameters, as well as data on drug adherence. Population sequencing was performed to detect the presence of drug-resistance mutations in patients with virological failure at Month 12; minority drug-resistance mutations at baseline were analysed using next-generation sequencing in these patients and matched controls. At Month 12, 38/238 (16%) patients experienced virological failure (≥1000 HIV RNA copies/mL). Patients with virological failure were younger, had lower CD4 cell counts and were more often WHO stage 3 or 4 at baseline. Sixty-three percent of patients with virological failure developed at least one drug-resistance mutation. The M184V (n = 18) and K103N (n = 10) mutations were most common. At baseline, 6/30 patients (20%) experiencing virological failure and 6/35 (17%) matched controls had evidence of minority drug-resistance mutations using next-generation sequencing (P = 0.77). Lower CD4 count at baseline (OR per 100 cells/mm(3) lower 1.41, 95% CI 1.02-1.96, P = 0.04) and poorer adherence (OR per 1% lower 1.05, 95% CI 1.02-1.08, P < 0.001) were associated with a higher risk of virological failure. Unavailability of ART at the treatment centre was the single most common cause for incomplete adherence. Virological failure after 1 year of ART was not associated with minority drug resistance at baseline but with incomplete adherence. Strategies to assure adherence and uninterrupted drug supplies are pivotal factors for therapy success.

Clinical and socio-demographic predictors for virologic failure in rural Southern Africa: preliminary findings from CART-1.

IntroductionIn 2013, the World Health Organization (WHO) recommended scaling up of routine viral load (VL) monitoring for patients on antiretroviral therapy (ART) in resource-limited settings [1]. During the transition phase from no VL-testing at all to routine VL-monitoring, targeted VL for groups at particular risk of virologic failure (VF) may be an option [2]. We present socio-demographic and clinical risk factors for VF in a cohort in rural Lesotho with no access to VL prior to the study.Materials and MethodsData derive from a cross-sectional study providing multi-disease screening as well as VL testing to adult patients (≥16 years old) on first-line ART ≥6 months [3]. VF was defined as VL≥1000 copies/mL. Assessed potential predictors of VF were: (1) socio-demographic (sex, age, wealth-quintile, education, employment status, disclosure of HIV status to environment, travel-time to facility); (2) treatment history (history of treatment interruption >2 days, previous drug substitution within first-line ART, time on ART, ART-base and -backbone); (3) adherence (pill count) and (4) clinical (clinical or immunological failure as defined by WHO guidelines [1], presence of papular pruritic eruption (PPE)). All variables with association to VF in univariate analysis were included in a multivariate logistic regression reporting adjusted Odds ratios (aOR).ResultsData from 1,488 patients were analyzed. Overall VF-prevalence was 6.9% (95% CI 5.7–8.3). In univariate analysis, the following were associated with VF: age <30, lower wealth-quintile, no primary education, history of treatment interruption, nevirapine-base, zidovudine-backbone, history of drug substitution, travel-time to clinic ≥2 hours, disclosure of HIV status to <5 persons, clinical failure, presence of PPE and immunological failure. In multivariate analysis, 6 out of the above 12 variables were independent predictors: age <30 years (aOR: 2.4; 95% CI 1.1–5.3, p=0.029), history of treatment interruption (2.5; 1.3–4.7, p=0.005), PPE (6.9; 2.5–18.9, p<0.001), immunological failure (11.5; 5.7–23.2, p<0.001), history of drug substitution (1.9; 1.0–3.7, p=0.043), disclosure of HIV status to <5 persons (1.8; 1.1–3.1, p=0.03).ConclusionIn this cohort in rural Lesotho, several socio-demographic and clinical predictors were associated with VF. Particularly age <30 years, history of treatment interruption, PPE and immunological failure were strongly associated with VF. These patients may be prioritized for targeted VL-testing.

Gender-Specific Risk Factors for Virologic Failure in KwaZulu-Natal: Automobile Ownership and Financial Insecurity

We sought to examine which socioeconomic indicators are risk factors for virologic failure among HIV-1 infected patients receiving antiretroviral therapy (ART) in KwaZulu-Natal, South Africa. A case-control study of virologic failure was conducted among patients recruited from the outpatient clinic at McCord Hospital in Durban, South Africa between October 1, 2010 and June 30, 2012. Cases were those failing first-line ART, defined as viral load >1,000 copies/mL. Univariate logistic regression was performed on sociodemographic data for the outcome of virologic failure. Variables found significant (p<0.05) were used in multivariate models and all models were stratified by gender. Of 158 cases and 300 controls, 35% were male and median age was 40years. Gender stratification of models revealed automobile ownership was a risk factor among males, while variables of financial insecurity (unemployment, non-spouse family paying for care, staying with family) were risk factors for women. In this cohort, financial insecurity among women and automobile ownership among men were risk factors for virologic failure. Risk factor differences between genders demonstrate limitations of generalized risk factor analysis.

Abstract supplement: HIV Drug Therapy in the Americas Congress 13–15 June 2013, São Paulo, Brazil

Abstract supplement: HIV Drug Therapy in the Americas Congress 13–15 June 2013, São Paulo, Brazil

Efficacy and safety of a switch to unboosted atazanavir in combination with nucleoside analogues in HIV-1-infected patients with virological suppression under antiretroviral therapy

Limited data are available on the use of unboosted atazanavir in combination with nucleoside reverse transcriptase inhibitors (NRTIs) in treatment-experienced HIV-infected patients. We conducted a multicentre, retrospective study among patients with plasma HIV-1 RNA levels <50 copies/mL under antiretroviral therapy who switched to unboosted atazanavir + NRTIs between January 2002 and December 2008. Virological failure during follow-up was defined as a confirmed plasma HIV-1 RNA level >50 copies/mL. Baseline risk factors for virological failure were identified using Cox proportional hazards models. A total of 886 patients were analysed. At baseline, median age was 44 years, 71.5% were males and median CD4 cell count was 490 cells/mm(3). NRTIs used in combination with atazanavir were tenofovir, abacavir and emtricitabine/lamivudine in 36.9%, 44.1% and 94.4% of patients, respectively. Median follow-up was 21 months. The 3 year probability of virological failure was 20.1%. Only a history of virological failure under NRTIs [hazard ratio (HR) 1.63, P = 0.049] and under protease inhibitors (HR 2.04, P = 0.006) were significantly associated with the risk of virological failure. Among the 431 patients without a prior history of virological failure, the 3 year probability of virological failure was 11.3%, and only hepatitis C virus co-infection (HR 2.25, P = 0.026) and abacavir use (HR 0.43, P = 0.04) were associated with the risk of virological failure. Safety of the switch was satisfactory, with improvement of the lipid profile. In patients with virological suppression and no prior history of virological failure, a switch to unboosted atazanavir in combination with NRTIs is associated with a low probability of virological failure and a good safety profile.

Adherence to drug-refill is a useful early warning indicator of virologic and immunologic failure among HIV patients on first-line ART in South Africa.

BackgroundAffordable strategies to prevent treatment failure on first-line regimens among HIV patients are essential for the long-term success of antiretroviral therapy (ART) in sub-Saharan Africa. WHO recommends using routinely collected data such as adherence to drug-refill visits as early warning indicators. We examined the association between adherence to drug-refill visits and long-term virologic and immunologic failure among non-nucleoside reverse transcriptase inhibitor (NNRTI) recipients in South Africa.MethodsIn 2008, 456 patients on NNRTI-based ART for a median of 44 months (range 12–99 months; 1,510 person-years) were enrolled in a retrospective cohort study in Soweto. Charts were reviewed for clinical characteristics before and during ART. Multivariable logistic regression and Kaplan-Meier survival analysis assessed associations with virologic (two repeated VL>50 copies/ml) and immunologic failure (as defined by WHO).ResultsAfter a median of 15 months on ART, 19% (n = 88) and 19% (n = 87) had failed virologically and immunologically respectively. A cumulative adherence of <95% to drug-refill visits was significantly associated with both virologic and immunologic failure (p<0.01). In the final multivariable model, risk factors for virologic failure were incomplete adherence (OR 2.8, 95%CI 1.2–6.7), and previous exposure to single-dose nevirapine or any other antiretrovirals (adj. OR 2.1, 95%CI 1.2–3.9), adjusted for age and sex. In Kaplan-Meier analysis, the virologic failure rate by month 48 was 19% vs. 37% among adherent and non-adherent patients respectively (logrank p value = 0.02).ConclusionOne in five failed virologically after a median of 15 months on ART. Adherence to drug-refill visits works as an early warning indicator for both virologic and immunologic failure.

Efficacy, tolerability and risk factors for virological failure of darunavir-based therapy for treatment-experienced HIV-infected patients: the Swiss HIV Cohort Study

Darunavir was designed for activity against HIV resistant to other protease inhibitors (PIs). We assessed the efficacy, tolerability and risk factors for virological failure of darunavir for treatment-experienced patients seen in clinical practice. We included all patients in the Swiss HIV Cohort Study starting darunavir after recording a viral load above 1000 HIV-1 RNA copies/mL given prior exposure to both PIs and nonnucleoside reverse transcriptase inhibitors. We followed these patients for up to 72 weeks, assessed virological failure using different loss of virological response algorithms and evaluated risk factors for virological failure using a Bayesian method to fit discrete Cox proportional hazard models. Among 130 treatment-experienced patients starting darunavir, the median age was 47 years, the median duration of HIV infection was 16 years, and 82% received mono or dual antiretroviral therapy before starting highly active antiretroviral therapy. During a median patient follow-up period of 45 weeks, 17% of patients stopped taking darunavir after a median exposure of 20 weeks. In patients followed beyond 48 weeks, the rate of virological failure at 48 weeks was at most 20%. Virological failure was more likely where patients had previously failed on both amprenavir and saquinavir and as the number of previously failed PI regimens increased. As a component of therapy for treatment-experienced patients, darunavir can achieve a similar efficacy and tolerability in clinical practice to that seen in clinical trials. Clinicians should consider whether a patient has failed on both amprenavir and saquinavir and the number of failed PI regimens before prescribing darunavir.

Impact of Previous Virological Treatment Failures and Adherence on the Outcome of Antiretroviral Therapy in 2007

BackgroundCombination antiretroviral treatment (cART) has been very successful, especially among selected patients in clinical trials. The aim of this study was to describe outcomes of cART on the population level in a large national cohort.MethodsCharacteristics of participants of the Swiss HIV Cohort Study on stable cART at two semiannual visits in 2007 were analyzed with respect to era of treatment initiation, number of previous virologically failed regimens and self reported adherence. Starting ART in the mono/dual era before HIV-1 RNA assays became available was counted as one failed regimen. Logistic regression was used to identify risk factors for virological failure between the two consecutive visits.ResultsOf 4541 patients 31.2% and 68.8% had initiated therapy in the mono/dual and cART era, respectively, and been on treatment for a median of 11.7 vs. 5.7 years. At visit 1 in 2007, the mean number of previous failed regimens was 3.2 vs. 0.5 and the viral load was undetectable (<50 copies/ml) in 84.6% vs. 89.1% of the participants, respectively. Adjusted odds ratios of a detectable viral load at visit 2 for participants from the mono/dual era with a history of 2 and 3, 4, >4 previous failures compared to 1 were 0.9 (95% CI 0.4–1.7), 0.8 (0.4–1.6), 1.6 (0.8–3.2), 3.3 (1.7–6.6) respectively, and 2.3 (1.1–4.8) for >2 missed cART doses during the last month, compared to perfect adherence. From the cART era, odds ratios with a history of 1, 2 and >2 previous failures compared to none were 1.8 (95% CI 1.3–2.5), 2.8 (1.7–4.5) and 7.8 (4.5–13.5), respectively, and 2.8 (1.6–4.8) for >2 missed cART doses during the last month, compared to perfect adherence.ConclusionsA higher number of previous virologically failed regimens, and imperfect adherence to therapy were independent predictors of imminent virological failure.

Safety and Efficacy of Once-Daily Nevirapine Dosing: A Multicohort Study

Nevirapine (NVP) is often prescribed once daily in clinical practice in combination with a once daily nucleoside backbone. We investigated the relationship of NVP dosing with safety and efficacy. Patients from the Dutch AIDS Therapy Evaluation in the Netherlands (ATHENA) cohort study, Canadian HAART Observational Medical Evaluation and Research (HOMER) cohort and Swiss HIV Cohort Study (SHCS) using NVP-based combination therapy either once daily or twice daily were included. Risk factors for discontinuing NVP because of hypersensitivity reactions (HSRs) were investigated using multivariate logistic regression. Risk factors for virological failure 96 weeks after NVP initiation were identified using logistic regression and Cox models. Of 5,636 patients (774 once daily and 4,862 twice daily), 268 (4.8%) discontinued NVP because of HSR between 2 and 18 weeks. Logistic regression showed that, compared with patients with detectable HIV type-1 (HIV-1) RNA starting twice-daily NVP, there was a significantly higher risk of discontinuation of once-daily NVP because of HSR in patients with detectable HIV-1 RNA at the start of NVP (odds ratio [OR] 1.52; P=0.04), whereas the risk was actually significantly lower in patients starting once-daily NVP with undetectable HIV-1 RNA (OR 0.44; P=0.04). Cox models showed that risk of virological failure was not different for twice- versus once-daily NVP in treatment-naive patients (twice-daily versus once-daily hazard ratio [HR] 1.01; P=0.95), treatment-experienced patients experiencing treatment failure (twice-daily versus once-daily HR 1.22; P=0.30) or patients with undetectable HIV-1 RNA simplifying treatment with NVP (twice-daily versus once-daily HR 1.29; P=0.30). Initiation of a once-daily NVP-based regimen in patients with suppressed viraemia carries a low risk of treatment-limiting HSR. Once- or twice-daily NVP-based regimens appear to have similar antiretroviral efficacy.

Risk factors for virological failure and subtherapeutic antiretroviral drug concentrations in HIV-positive adults treated in rural northwestern Uganda

BackgroundLittle is known about immunovirological treatment outcomes and adherence in HIV/AIDS patients on antiretroviral therapy (ART) treated using a simplified management approach in rural areas of developing countries, or about the main factors influencing those outcomes in clinical practice.MethodsCross-sectional immunovirological, pharmacological, and adherence outcomes were evaluated in all patients alive and on fixed-dose ART combinations for 24 months, and in a random sample of those treated for 12 months. Risk factors for virological failure (>1,000 copies/ml) and subtherapeutic antiretroviral (ARV) concentrations were investigated with multiple logistic regression.ResultsAt 12 and 24 months of ART, 72% (n = 701) and 70% (n = 369) of patients, respectively, were alive and in care. About 8% and 38% of patients, respectively, were diagnosed with immunological failure; and 75% and 72% of patients, respectively, had undetectable HIV RNA (<400 copies/ml). Risk factors for virological failure (>1,000 copies/ml) were poor adherence, tuberculosis diagnosed after ART initiation, subtherapeutic NNRTI concentrations, general clinical symptoms, and lower weight than at baseline. About 14% of patients had low ARV plasma concentrations. Digestive symptoms and poor adherence to ART were risk factors for low ARV plasma concentrations.ConclusionEfforts to improve both access to care and patient management to achieve better immunological and virological outcomes on ART are necessary to maximize the duration of first-line therapy.

199 Risk factors for Virologic Failure and Adverse Reactions among Patients on Triple Antiretroviral therapy

Introduction: Adverse effects from antiretroviral (ARV) drugs can result in poor compliance and which may results in treatment failure. Recognition and management of adverse effects are important issues in improving quality of lives of HIV positive patients. This study examined the prevalence of adverse effects and the risk factors associated with adverse effects and virologic failure. Methods: Retrospective chart review of 146 naive patients on antiretroviral therapy between January 2007 and December 2007 was done in Lagos Nigeria. The following information was obtained: time of first diagnosis, demographical information, missing clinic, CD4 count, weight, tuberculosis/opportunistic infections, viral loads (at least one in 6 months after starting ARV), and partner/family notification. Results: Female 93 (64%), male 53 (36%); mean age: 33.4 years; 234 person-years of follow-up with a mean of follow-up of 1.6 ± 0.7 years; 126 (86%) had undetectable viral load at 6 months of ARV; mean weight change from 56 kg to 62 kg; and 53 (36%) experienced adverse effects. Adverse effects were peripheral neuropathy 35 (24%); gynecomasia 6 (4%) lactic acidosis 10 (7%); diarrhea 18 (12%); nausea and vomiting 4 (3%); hepatitis 6 (4%); Stevens-Johnson syndrome 3 (2%); rash 20 (14%); insomnia 12 (8%); lipodystrophy/lipoatrophy 9 (6%). CD4 count and Viral load at initiation were 2 significant predictors of virologic failure, with CD4 < 100 cells/mm3 (OR 1.6, 95% CI 1.2 to 1.9) and viral load at initiation ≥100,000 copies/mL (OR 2.1, 95% CI 1.5-2.7). For the adverse effects: patients with weight <60 kg (OR: 3.2, 95% CI 1.9 to 4.2) and with age >40 years OR 2.4 (1.2 to 3.9) are more likely to experience adverse effects. Mean change of regimen was 13.5 ± 6.2 months. Conclusion: Despite increasing access to ARV, good drug toxicity monitoring system should be put in place so that life threatening adverse effect is adequately screened for and proper managed. However, care should be taken with D4T associated peripheral neuropathy. More surveillance studies on HIV drug toxicity are needed to enhance safety and effectiveness of the therapy in Nigeria.

Highly active antiretroviral therapy in a large urban clinic: risk factors for virologic failure and adverse drug reactions.

In clinical trials, highly active antiretroviral therapy (HAART) reduces plasma HIV-1 RNA levels to less than 500 copies/mL in 60% to 90% of patients with HIV-1 infection. The performance of such therapy outside of the clinical trial setting is unclear. To determine factors associated with failure to suppress HIV-1 RNA levels and adverse drug reactions in a cohort of patients in whom protease inhibitor-containing therapy was begun in a large urban clinic. Retrospective cohort study. Johns Hopkins HIV Clinic in Baltimore, Maryland. 273 protease inhibitor-naive patients began taking a protease inhibitor regimen containing at least one other antiretroviral drug to which the patients had not previously been exposed. Demographic variables, plasma HIV-1 RNA levels, CD4+ lymphocyte counts, and adverse drug reactions. Levels of HIV-1 RNA were undetectable in 42% of the cohort at 1 to 90 days, in 44% at 3 to 7 months, and in 37% at 7 to 14 months. Factors associated with failure to suppress viral load at two or more time points included higher rates of missed clinic appointments, nonwhite ethnicity, age 40 years or younger, injection drug use, lower baseline CD4+ lymphocyte count, and higher baseline viral load. In a multivariate model, only higher rates of missed clinic appointments were independently associated with viral suppression at 1 year. Ritonavir was associated with adverse drug reactions about twice as frequently as indinavir or nelfinavir, and women experienced significantly more adverse effects than men. Unselected patients in whom HAART is started in a clinic setting achieve viral suppression substantially less frequently than do patients in controlled clinical trials. Missed clinic visits were the most important risk factor for failure to suppress HIV-1 RNA levels. Studies are needed to identify interventions that maximize the performance of HAART in inner-city clinics.

Virological treatment failure of protease inhibitor therapy in an unselected cohort of HIV-infected patients.

To determine the rate of virological treatment failure with protease inhibitor therapy in unselected patients and to assess underlying risk factors. Retrospective study in two German tertiary care treatment centres. A total of 198 HIV-infected patients treated with protease inhibitors in 1996. Levels of HIV RNA 1-6 months after start of treatment; definition of treatment failure of < 1 log10 reduction in plasma HIV RNA within 6 months after starting protease inhibitor therapy; multivariate analysis of risk factors for treatment failures. A total of 226 treatment episodes with protease inhibitors were evaluable (saquinavir, 83; ritonavir, 47; indinavir, 96). The rate of virological treatment failure was 44% (saquinavir, 64%; ritonavir, 38%; indinavir, 30%). In a multivariate analysis, the following independent risk factors for virological failure were found: CD4 cell count, pretreatment with antiretroviral drugs (number), and protease inhibitor (compound). The relative risk reduction for each CD4 cell count increase was 0.997 (P = 0.012), 2.64 for pretreatment with one or two drugs versus no drug (P = 0.05), 2.97 for pretreatment with more than two drugs versus no drug (P = 0.05), and 4.62 for treatment with saquinavir versus indinavir (P = 0.001). An unexpectedly high rate of virological treatment failure of protease inhibitor therapy was found in an unselected cohort of HIV-infected patients. Response to antiretroviral combination therapy in normal clinical practice may considerably differ from results of randomized clinical trials. Further studies are warranted to find optimal treatment strategies for both initial and salvage therapy.