Study of genotypic and phenotypic HIV-1 dynamics of integrase mutations during raltegravir treatment: a refined analysis by ultra-deep 454 pyrosequencing.

BACKGROUND: The dynamics of raltegravir-resistant variants and their impact on virologic response in 23 HIV-1-infected patients, who started a salvage raltegravir-containing regimen, were investigated. METHODS: Integrase population sequencing and Ultra-Deep-454 Pyrosequencing (UDPS) were performed on plasma samples at baseline and at raltegravir failure. All integrase mutations detected at a frequency ≥1% were considered to be reliable for the UDPS analyses. Phylogenetic and phenotypic resistance analyses were also performed. RESULTS: At baseline, primary resistance mutations were not detected by both population and UDPS genotypic assays; few secondary mutations (T97A-V151I-G163R) were rarely detected and did not show any statistically association either with virologic response at 24-weeks or with the development of resistant variants at failure. At UDPS, not all resistant variants appearing early during treatment evolved as major populations during failure; only specific resistance pathways (Y143R-Q148H/R-N155H) associated with an increased rate of fitness and phenotypic resistance were selected. CONCLUSIONS: Resistance to raltegravir in integrase strand transfer inhibitor-naive patients remains today a rare event, which might be changed by future extensive use of such drugs. In our study, pathways of resistance at failure were not predicted by baseline mutations, suggesting that evolution plus stochastic selection plays a major role in the appearance of integrase-resistance mutations, whereas fitness and resistance are dominant factors acting for the late selection of resistant quasispecies.

'Sentinel' mutations in standard population sequencing can predict the presence of HIV-1 reverse transcriptase major mutations detectable only by ultra-deep pyrosequencing.

OBJECTIVES: This proof-of-concept study aimed to identify whether mutations considered not yet relevant for drug resistance (but located at key drug-resistance positions) can act as 'sentinels' of minority resistant variants in HIV-1 drug-naive patients. METHODS: We focused our attention on three reverse transcriptase (RT) mutations (T69S, L210M and K103R) easily detected by standard population sequencing [i.e. the genotypic resistance test (GRT)]. Ultra-deep pyrosequencing (UDPS) of HIV-1 RT was performed using GS-FLX Roche, on plasma RNA from 40 drug-naive patients infected with HIV-1 subtype B without primary resistance detected by GRT. Only RT drug resistance mutations detected at >0.1% in both forward and reverse directions were considered. Associations between GRT sentinel mutations and UDPS drug resistance were assessed using Fisher's exact test. RESULTS: UDPS detected drug resistance mutations in 18/40 drug-naive patients. Patients carrying HIV-1 strains with T69S and L210M by GRT showed a trend to greater infection by minority drug-resistant variants than control patients infected by HIV-1 without these mutations (5/10 and 7/10 versus 3/10; P = not significant). No association was found for K103R by GRT. Notably, T69S and L210M (but not K103R or control viruses) were associated with GRT minority drug-resistant variants with a prevalence >1% (3/10 and 4/10 versus 0/20 in K103R and controls; P = 0.03 and P = 0.008, respectively). Moreover, the presence of L210M or T69S viruses by GRT significantly correlated with that of minority thymidine analogue mutations by UDPS (6/20 patients carrying HIV-1 strains with T69S/L210M versus 0/20 patients carrying HIV-1 having K103R or none of these mutations; P = 0.03). CONCLUSIONS: This proof-of-concept study suggests the existence of genetic markers, detectable by routine testing, potentially acting as sentinel mutations of minority drug resistance. Their identification may help in the selection of patients at high risk of resistance in reservoirs without the necessity of using UDPS.

Historical resistance profile helps to predict salvage failure.

BACKGROUND: This study compared the predictive value for treatment failure of extended resistance detected in the current genotype resistance test (GRT) versus those from GRT history in patients with multiple combination antiretroviral therapy (cART) failures. METHODS: Patients who underwent three GRT between 1999 and 2007 were included. Extended resistance at genotypic sensitivity score (GSS) using the Rega 7.1 interpretation system compared with a non-standard definition (defined as class-wide resistance [CWR] on the basis of International AIDS Society-USA mutations) was assessed both for current and historical GRTs (a combination of mutations was detected in all three tests). The predictive role of extended resistance for treatment failure was evaluated with an adjusted Cox proportional hazard model. RESULTS: Overall, 177 patients were included. The historical GRT increased the number of patients with extended resistance to all three major drug classes by 25% in comparison with the current GRT. Using the GSS method, the absence of detection of any active drug in any drug class was predictive of failure with both the current and historical GRTs. Similarly, the number of active drugs in the cART regimen after the third resistance test, used as continuous variable, was also predictive of failure. Using both GSS approaches, current genotype had a higher effect than historical genotype on risk of treatment failure. Using the non-standard definition (CWR), historical resistance predicted failure better than current resistance. CONCLUSIONS: Our results provide an epidemiological demonstration that analysis of a combined latest and historical GRT, which also considers archived mutations, might better identify of the more virologically impaired patients in order to assess the best salvage treatment.

Therapeutic drug monitoring in the management of HIV-infected patients.

The rate of HIV-positive patients that fails to reach or to maintain a durable virological suppression under anti-retroviral (ARV) therapy might be as high as 50%, therefore new tools to improve ARV drug efficacy are urgently needed. Among others, therapeutic drug monitoring (TDM) is a strategy by which the dosing regimen for a patient is guided by measurement of plasma drug levels, enabling physicians to optimize ARV drug efficacy and to avoid drug-related toxicity. The most used analytical methods to determine plasma levels of ARV drugs are HPLC-UV and HPLC-MS(/MS), recently MALDI-based methods and enzyme immunoassay (EIA) technologies have been also employed. The wide inter-patient variability in ARV drug pharmacokinetic supports the application of TDM to the clinical management of HIV-infected patients. Drug-drug and drug-food interactions, drug binding to plasma proteins, drug sequestering by erythrocytes, hepatic impairment, sex, age, pregnancy, and host genetic factors are sources of inter-patient variability affecting ARV drug pharmacokinetics. Combining the information of TDM and resistance tests in genotypic inhibitory quotient (GIQ) is likely to be of great clinical utility. Indeed, only two clinical trials on GIQ, both conducted using ARV drugs not more commonly in use, have shown clinical benefits. The design of new trials with long follow-up and sample size representative of the current HIV prevalence is urgently needed to give indications for GIQ as an early predictor of virological response. Here, the basic principles and the available methods for TDM in the management of HIV-infected patients are reviewed.

The V118I mutation as a marker of advanced HIV infection and disease progression.

BACKGROUND: The V118I mutation is included in the nucleoside analogue mutations (NAMs) set. It contributes to thymidine-analogue resistance and, consequently, to resistance to the whole nucleoside reverse transcriptase inhibitor (NRTI) class. We focused on the V1181 mutation in order to evaluate factors associated with its detection and its relationship with HIV progression. METHODS: Clinical and laboratory data at genotypic resistance test (GRT) of highly active antiretroviral therapy-failing patients were collected and their association with the V1181 mutation was analysed. Patients were also followed over time to determine factors related to progression to a new AIDS-related event or death. RESULTS: Of the 792 patients included, 114 (14.4%) carried the V118I mutation. In univariate analysis, the V118I mutation was significantly associated with a higher HIV RNA level, lower CD4+ T-cell count, Centers for Disease Control and Prevention (CDC) stage C, higher number of pre-GRT regimens and class-wide resistance (CWR) to NRTIs, protease inhibitors and nonnucleoside reverse transcriptase inhibitors. Higher numbers of pre-GRT regimens and NRTI CWR were also associated in the multivariable analysis. Within the post-GRT observation period of up to 6 years (median: 72 months; interquartile range: 33-109) 107 events (58 new AIDS-related diseases and 49 deaths) were observed. Using the Cox proportional hazard model and the major clinical, behavioural and laboratory data, the V118I mutation was found to be associated with the endpoint (hazard ratio: 1.93, 95% confidence interval: 1.06-3.50; P=0.031). Other factors associated with disease progression were CDC stage C and lower CD4+ T-cell count at GRT. CONCLUSIONS: The analysis of our observational database suggests that the onset of the V118I mutation after treatment failure is unfavourable for the patient and can be considered a strong marker of disease progression.

Drug-class-wide resistance to antiretrovirals in HIV-infected patients failing therapy: prevalence, risk factors and virological outcome.

BACKGROUND: Drug-class-wide resistance (DCWR) to antiretrovirals substantially reduces treatment options. METHODS: A database of 602 patients failing highly active antiretroviral therapy (HAART) undergoing genotypic resistance test (GRT) was analysed. DCWR was defined according to the International AIDS Society consensus. A multiple logistic regression model was built to define factors significantly associated with DCWR and to assess virological response to salvage regimens. RESULTS: NRTI DCWR was observed in 28.5% of 592 NRTI-exposed patients, NNRTI DCWR in 57.7% of 284 NNRTI exposed patients, PI DCWR in 19.9% of 412 PI exposed patients, and three-class resistance in 21.4% of 112 three-class-exposed patients. The prevalence of NRTI and PI DCWR increased significantly by year of exposure to the same class from 8.9% (< 1 year) to 35.3% (> 4 years) and from 1.2% (< 1 year) to 34.8% (> 4 years), respectively (P < 0.001, for trend). The risk of developing NRTI and PI DCWR increased by 25% (95% confidence interval [CI]: 1.6%-51.3%) and by 53% (20.5%-94.3%) for each year of treatment, and by 17% (95% CI: 5.6%-29.3%) and by 32% (17.7%-50.3%) for each previous failing NRTI- and PI-containing regimen, respectively. NRTI DCWR due to at least four nucleoside analogues mutations (NAMs) increased by year of NRTI exposure from 8.9% (< 1 year) to 32.6% (> 4 years; P < 0.001, for trend). After adjustment for confounding factors, the probability of achieving plasma viral load < 500 copies/ml was significantly reduced in patients with NRTI (OR: 0.750; 95% CI: 0.574-0.979), NNRTI (OR: 0.746; 95% CI: 0.572-0.975), PI (OR: 0.655; 95% CI: 0.456-0.941), three-class (OR: 0.220; 95% CI: 0.082-0.593) resistance. CONCLUSIONS: The probability of developing NRTI and PI DCWR increased with length of class exposure and with the number of previously failing regimens. By contrast, high levels of NNRTI DCWR were observed within 1 year in NNRTI-failing patients, with a steady prevalence over time. The increase in prevalence with time of NRTI DCWR was due to the accumulation of NAMs. DCWR to NRTIs, NNRTIs, PIs or all the three together was associated with an increased probability of virological failure to subsequent HAART regimens.

Antiviral efficacy and genotypic resistance patterns of combination therapy with stavudine/tenofovir in highly active antiretroviral therapy experienced patients.

OBJECTIVES: To evaluate antiviral efficacy of stavudine/tenofovir (d4T/TDF) backbone combination in late-line antiretroviral therapy, and to assess clinical and virological determinants of treatment success. DESIGN: Multicentric retrospective analysis on patients starting d4T/TDF after highly active antiretroviral therapy (HAART) failure. METHODS: The primary endpoint was the change in plasma HIV-1 RNA from the baseline (time of d4T/TDF initiation) to 6 months of therapy; secondary endpoint was the risk of virological failure. RESULTS: Among 172 patients included, a mean change in HIV-1 RNA of -1.69 (+1.23) and -1.53 (+1.43) log10 cp/ml was observed respectively at weeks 24 and 48 after starting d4T/TDF combination. Any single type-1 thymidine analogue mutation (TAM; M41L, L210W, T215Y) had a negative effort on the change in HIV RNA at 6 months, whereas among type-2 TAMs (D67N, K70R, K219Q), only D67N showed a trend for a negative effect. Presence of M184V mutation was related with a greater reduction in HIV RNA during d4T/TDF exposure. The risk of virological failure at 6 months after d4T/TDF starting was 22%. Type-1 TAMs were associated with a greater risk of failure (adjusted hazard ratio [HR]=1.65; 95% confidence interval [CI] 1.19-2.29). Conversely, M184V showed a protective effect. In 17 genotypic tests available at failure, no K65R mutation was detected, whereas a trend for an increasing prevalence of d4T-associated mutations was found. CONCLUSIONS: Combining TDF with a thymidine analogue as d4T may be effective as component of antiretroviral rescue regimens in HIV-infected patients with previous exposure to nucleoside analogue reverse transcriptase inhibitor. Previous selection of type-1 TAMs induces a detrimental effect over virological response.

Highly active antiretroviral therapy reduces the age-associated risk of dementia in a cohort of older HIV-1-infected patients.

Historically, older patients have shown a higher risk of HIV-1-associated dementia (HIVD). The objective of this study was to evaluate the association of aging with HIVD and minor cognitive motor disorders (MCMDs) during the late-highly active antiretroviral therapy (HAART) era and to analyze characteristics, predictive factors, and survival of older HIV-1-infected individuals affected by these disorders. A nested longitudinal study was designed for a cohort of HIV-1-infected individuals with neurological diseases. Multiple logistic regression and Cox regression for survival were employed. From 2000 to 2003, 195 patients with HIVD (53%) or MCMD (47%) were enrolled. The cumulative prevalence of these two disorders was 21%, with an increasing rate for calendar year (p < 0.001). Previous antiretroviral exposure occurred in 46% of patients. Mean CD4(+) cell count and plasma HIV-1 RNA were 144 cells/microl and 4.5 log10 copies/ml, respectively. The mean age was 44 years (SD, 9.9), with 35% of patients aged 20-39 years (I), 45% aged 40-49 years (II), and 20% aged >/=50 years (III). Among drug-naive patients, the prevalence of HIVD progressively increased in older subjects: 7.2% (I), 15.3% (II), and 27.3% (III) (p < 0.001), whereas no significant increase in HIVD with older age was observed in drug-treated subjects. Older age was independently associated with an increased risk of HIVD (odds ratio, 6.44; 95% confidence interval, 2.82-14.69) in naive but not in experienced individuals, but had no significant effect on survival. No significant effect of age was observed for MCMD. We conclude that in our cohort, HAART seems to alter the relationship between aging and HIVD, conferring a neuroprotective effect to older patients. These results may have significant implications for the clinical management of the older HIV population.

Temporal characterization of drug resistance associated mutations in HIV-1 protease and reverse transcriptase in patients failing antiretroviral therapy.

The aim of this study was to evaluate the prevalence of genotypic resistance for each drug-class, and of single resistance-mutations in 1075 HIV-1 infected multi-treated patients undergoing their first genotypic resistance-test (GRT) after virological failure, over the years 1999-2003. First GRT was requested in 2003 for patients at earlier stages of failure, with less advanced disease, higher CD4-cell-count, lower HIV-RNA, and lower drug-experience with respect to 1999. Prevalence of resistance to all three drug-classes decreased from 33.3% in 1999 to 14.8% in 2003 (p < 0.001). Patients with protease-inhibitor (PI) resistant viruses decreased from 68.1% in 1999 to 34.1% in 2003 (p < 0.001); patients with nucleoside reverse transcriptase-inhibitor (NRTI) resistant viruses remained unchanged (85.4% in 1999; 86.4% in 2003); patients with non-NRTI (NNRTI) resistant viruses increased from 36.1% in 1999 to 52.3% in 2003 (p = 0.005) (corresponding to an increased NNRTI-use and decreased PI-use). From 1999 to 2003, resistance-mutations to drugs with high genetic-barrier significantly decreased (L90M/V82A/M46I/I54V/G73S/I84V/G48V for PIs; M41L/D67N/L210W/V1181 for NRTIs, p < 0.05), while mutations to drugs with low genetic-barrier increased (D30N in protease, M184V/K103N/V108I in reverse transcriptase, p < 0.05). Taken together, earlier recruitment to first GRT in patients with less severe disease, and with lower prevalence of drug-resistant viruses may further improve therapeutic strategies aimed at longer and greater control of HIV-related disease progression.

Multiple drug class-wide resistance associated with poorer survival after treatment failure in a cohort of HIV-infected patients.

OBJECTIVE: To evaluate the effect of drug class-wide resistance (CWR) on survival in HIV-infected individuals who underwent genotypic resistance test after antiretroviral failure. DESIGN: Observational, longitudinal cohort study. METHODS: HIV-infected individuals experiencing treatment failure were enrolled at first genotypic resistance test. End-points were death for any cause, AIDS-related death and AIDS-defining event/death. CWR was defined according to the International AIDS Society consensus. Survival analysis was performed with Cox's model. RESULTS: Among 623 patients enrolled and followed for a median of 19 months (interquartile range, 12-29), Kaplan-Meier analyses for end-points at 48 months in patients with no CWR, one CWR, two CWR or three CWR were 8.9, 11.7, 13.4 and 27.1%, respectively, for death; 6.1, 9.9, 13.4 and 21.5%, respectively, for AIDS-related death; and 16.0, 17.7, 19.3 and 35.9%, respectively, for new AIDS event/death. In a multivariate Cox's model, higher HIV RNA level, previous AIDS and detection of three CWR (hazard ratio, 5.34; 95% confidence interval, 1.76-16.24) were all significantly associated with increased risk of death, while higher CD4 cell count and use of a new boosted protease inhibitor drug after identifying genotypic resistance were associated with reduced risk. Detection of three CWR was also significantly associated with higher risk of AIDS-related death and new AIDS event/death. CONCLUSIONS: Even in the late era of highly effective antiretroviral treatments, detection of CWR, particularly if extended to all three drug classes is related to poorer clinical outcome and represents a risk-marker of disease progression and death.

Neurocognitive impairment and survival in a cohort of HIV-infected patients treated with HAART.

Before the introduction of HAART, HIV-associated neurocognitive impairment (NCI) was recognized as an independent risk factor for death. Since 1996, we conducted a prospective study to assess whether NCI still represents a negative prognostic factor for mortality. Patients were administered measures of neurocognitive function (a battery of 17 neuropsychological tests), clinical and neurological evaluation, laboratory testing, and brain imaging studies. Among the 412 enrolled patients, 224 (54.4%) were neurocognitively impaired and 188 (45.6%) were neurocognitively unimpaired. A durable virological suppression under highly active antiretroviral therapy (HAART) was achieved by 63.3% of unimpaired patients and by 49.6% of impaired patients (p = 0.007). Overall, 47 deaths were recorded, 38 among impaired and 9 among unimpaired patients. At 84 months, the estimated survival proportions in impaired and unimpaired patients were 68.5% and 84.9%, respectively (p < 0.001). At univariate analysis the virological response to HAART was the variable most strongly associated with survival, since patients with virological failure had a nearly 10-fold increased risk of death than those with durable virological suppression (HR = 9.9, 95% CI: 3.9-25.0). After stratification for virological response to HAART, an increased risk of death for neurocognitively impaired patients was seen only among the 182 patients with virological failure (HR: 2.9, 95% CI: 1.2-7.1), while the survival probability of the 230 patients with durable virological suppression was not affected by neurocognitive impairment (p = 0.89). Our results highlight the clinical relevance of HIV-related central nervous system (CNS) involvement in the HAART era, and raise concerns regarding the clinical relevance of CNS involvement as potent antiretroviral therapies become less effective.

Factors influencing virological response to antiretroviral drugs in cerebrospinal fluid of advanced HIV-1-infected patients.

OBJECTIVE: To determine the effectiveness of antiretroviral therapy in controlling cerebrospinal fluid (CSF) HIV-1 replication and to assess factors related to virological response in advanced patients. DESIGN: A cross-sectional and longitudinal study. METHODS: Consecutive paired CSF and plasma samples from HIV-1-infected patients were collected before starting or changing highly active antiretroviral therapy (HAART). RESULTS: In the cross-sectional analysis 75 patients were included, 55 (73%) with neurological disease, 28 (37%) naive for antiretroviral agents. A significant correlation between plasma and CSF levels at baseline was observed only in antiretroviral-experienced patients. The absence of neurological disease, lower plasma HIV-1 load and a previous exposure to indinavir were all associated with a baseline CSF HIV-1-RNA level less than 80 copies/ml at multivariate analysis. In 29 patients included in the longitudinal study a significant reduction in CSF HIV-1 RNA was observed. Plasma HIV-1-RNA change, CSF HIV-1-RNA level at baseline, overall months of antiretroviral treatment and the magnitude of difference between plasma and CSF HIV-1-RNA levels were all correlated to CSF HIV-1-RNA change during treatment. A significant difference in the magnitude of CSF HIV-1-RNA reduction was observed according to naive status and to the use of three or more drugs penetrating the blood-brain barrier. CONCLUSION: HAART effectively reduces HIV-1 replication in CSF. A variable response to antiretroviral therapy was observed in CSF, reflecting a different compartmentalization of infection during treatment. Naive status and the use of CNS-penetrating drugs substantially enhance antiviral response. A negative interaction between virological response and the duration of antiretroviral treatment suggests long-term selection of drug-resistant CSF HIV-1 strains.

Q151M-mediated multinucleoside resistance: prevalence, risk factors, and response to salvage therapy.

Among 470 patients with acquired immune deficiency syndrome and/or human immunodeficiency virus infection (HIV/AIDS) who underwent genotype resistance testing (GRT) after the failure of therapy, 17 (3.6%) harbored the Q151M mutation. The Q151M mutation was associated with younger age, lower CD4(+) lymphocyte count, higher HIV RNA level, and treatment with >2 pre-GRT regimens. By contrast, the Q151M mutation was inversely associated with lamivudine administration. A full reversion of the Q151M mutation was observed in 5 of 5 patients who underwent treatment interruption after GRT. The reversion was followed by a response to salvage therapy in 4 (80%) of 5 patients.

The challenge of antiretroviral-drug-resistant HIV: is there any possible clinical advantage?

Resistance to antiretroviral drugs is associated with reduced treatment options and, therefore, increased risk of disease progression or death. Despite the main goal of antiretroviral therapy should be achievement of complete suppression of HIV replication, the accumulation of resistance mutations in patients with multiple treatment failure makes this objective often difficult, or even impossible to obtain. Thus, clinicians should be aware about the complex relationship between drug pressure and viral replication capacity and about some potential advantages related to antiretroviral drug resistance. The two main biological mechanisms that can be at the origin of these clinical benefits are: reduction of viral fitness and viral hypersusceptibility. The term "fitness" indicates the ability of HIV to maintain high rate of replication capacity in presence of antiretroviral drugs. Consequently, replication capacity, high in presence of wild type virus, tends to decrease when HIV must adapt its enzymes to work in presence of drugs. A reduction of viral fitness is observed in patients harbouring mutations conferring resistance to all the three classes of antiretroviral drugs currently in use. Particularly, the effects on reduction of replication capacity related to M184V mutation in reverse transcriptase are analyzed. Viral isolates with reduced susceptibility or resistance to some antiretroviral drugs may exhibit significant increased susceptibility to other drugs acting on the same enzyme. This phenomenon is known as hypersusceptibility and can be demonstrated in vitro by phenotypic assays. Phenotypic hypersusceptibility has been demonstrated for all three drug classes. Particularly, NNRTI hypersusceptibility, associated with NRTI mutations, is analyzed and discussed.

Using a database of HIV patients undergoing genotypic resistance test after HAART failure to understand the dynamics of M184V mutation.

OBJECTIVE: M184V/I mutation is associated with high-level phenotypic resistance to lamivudine (3TC). The aim of the present analysis was to correlate the time of appearance/disappearance of M184V/I with duration of 3TC treatment. METHODS: Overall, 211 patients were selected from a database of HIV patients undergoing genotypic resistance test after virological failure of HAART regimens in two major reference centres in Rome between 1999 and 2001. At the time of genotyping, 120 of them (56.9%) were failing a 3TC-including HAART, while 91 (43.1%) received 3TC only in previous HAART. Duration of the current 3TC-containing regimen and the time from the end of last 3TC treatment to genotypic resistance test (GRT) were analysed. RESULTS: Among patients currently undergoing 3TC-containing HAART, the prevalence of M184V/I was 82.5% (78.3/4.2%, respectively) and significantly associated to current 3TC use at GRT. Prevalence of M184V/I was associated to longer history of 3TC (from 47.1% in patients treated with 3TC for <6 months, to 84.0% among those treated for 7-12 months; 100.0% of patients with >42 months of current 3TC carried M184V. At logistic regression analysis, the rate of increase of M184V/I in 3TC-failing patients was statistically significant (OR: 1.066 per month of current 3TC therapy, 95% CI: 1.020-1.114, P<0.01), suggesting a 6.6% monthly increase of probability of M184V/I. Among patients who interrupted 3TC, overall prevalence of M184V/I was 23.1%: proportion of patients carrying the M184V/I dropped from 83.3% among those who interrupted 3TC from < or = 3 months, to 56.3, 20, 10.5 and 0% for those interrupting 3TC from 6, 12, 24 and > or = 24 months, respectively. At logistic regression, the rate of disappearance of M184V/I was also statistically significant (OR: 0.883 per month, 95% CI: 0.804-0.970, P=0.01), indicating a 11.7% monthly decrease of probability of M184V/I after 3TC interruption. CONCLUSIONS: Dynamics of appearance/disappearance of M184V/I mutation is rapid after 3TC failure/interruption, suggesting ease of development of such a mutation, but also suggesting a remarkable growth disadvantage for HIV. From the clinical perspective, recycling of drugs whose antiviral activity is affected by M184V mutation can be successful after appropriate drug wash-out, also in heavily pretreated patients.

The effect of number of mutations and of drug-class sparing on virological response to salvage genotype-guided antiretroviral therapy.

OBJECTIVE: To assess on longitudinal data the impact of number of drug-associated mutations at genotype resistance testing (GRT) and history of previous exposure to antiretrovirals on the virological response to genotype-guided antiretroviral therapy. METHODS: Subjects that failed HAART who underwent GRT between June 1999 and March 2002 were enrolled. GRT was performed by Viroseq-2 with expert advice offered to physicians. Main outcome was reaching undetectable (< 80 copies/ml) HIV-1 RNA level after GRT and maintaining undetectable viraemia for at least 6 months. The number of mutations conferring resistance to each class of antiretrovirals was categorized and their effect on virological outcome investigated. Mutations considered in the analysis were those reported by the IAS-USA in 2002. Multivariate analysis was performed by Cox proportional hazard model. RESULTS: Four-hundred-and-seventy consecutive subjects were enrolled and followed-up for a median of 14 (IQR 9-19) months after GRT. Sustained undetectable viraemia was reached by 80 of 449 subjects (18%). Using as end-point reaching and maintaining for at least 6 months < 400 copies/ml after GRT, 103 out of 447 subjects (23%) reached the outcome. For each single protease inhibitor (PI)-, nucleoside reverse transcriptase inhibitor (NRTI)-and non-nucleoside reverse transcriptase inhibitor (NNRTI)-associated mutation, there was a reduction of, respectively, 11% (P = 0.008), 12% (P = 0.001) and 39% (P = 0.005) in the likelihood of reaching virological outcome. Subjects carrying > or = 6 mutations to NRTIs, > or = 7 mutations to PIs and > or = 2 mutations to NNRTIs were less likely to reach the virological success compared with those carrying 0-1 (NRTI and PI) or 0 (NNRTI) mutations [HR = 0.25 (95% CI: 0.10-0.65); HR = 0.33 (950% CI: 0.16-0.67); HR = 0.33 (95% CI: 0.14-0.77)], respectively. However, at multivariate analysis the probability of reaching a favourable virological outcome in patients with > or = 7 mutations to PIs, if naive for NNRTIs [HR = 1.74 (0.69-4.36)], and in subjects with > or = 2 mutations for NNRTIs if naive for PIs [HR = 1.23 (0.22-6.80)], was comparable to those observed in patients with none or one mutation. CONCLUSIONS: Our data showed a non-linear association between resistance-conferring mutations and virological outcome. GRT-guided therapy still provided remarkable chances of durable virological success even in subjects with > or = 7 mutations to PIs and in subjects with > or = 2 mutations to NNRTIs, when the subjects did not have a three-class exposure or if GRT showed no evidence of mutations for a drug class. GRT and as-long-as-possible sparing of a drug class could be a convenient strategy for long-term management of drug-failing patients.

Neurocognitive performance and quality of life in patients with HIV infection.

We examined the relationship of HIV-related cognitive impairment and health-related quality of life (QoL). Subjects were administered measures of cognitive function (a battery of 17 neuropsychological tests) and of QoL (the MOS-HIV questionnaire). Study measures also included comprehensive clinical and neurological evaluation, laboratory testing, and brain imaging studies in patients with impaired neuropsychological evaluation. One-hundred and eleven subjects were examined. Cognitively impaired patients (33.3%) reported poorer QoL scores in all domains (p < 0.05): physical health summary score (PHS) (44.6 vs. 49.9), mental health summary score (MHS) (37.7 vs. 44.4), pain (67.6 vs. 79.4), physical functioning (75.9 vs. 87.7), role functioning (32.4 vs. 41.5), social functioning (70.3 vs. 83.5), mental health (48.2 vs. 61.0), energy (53.1 vs. 63.0), health distress (60.8 vs. 75.5), cognitive functioning (CF) (60.5 vs. 71.8), general health perceptions (29.2 vs. 43.4), and QoL (36.5 vs. 47.0). The number of altered neuropsychological tests correlated significantly with MHS (p < 0.001), PHS (p < 0.03), CF (p < 0.02), and QoL (p < 0.02) scores. A correlation between seven of seven neuropsychological measures exploring speed of mental processing, three of four exploring mental flexibility, four of six exploring memory, and two of two exploring fine motor functioning and MHS, PHS, CF, or QoL scores was also found. Poor performance on the Digit Symbol test was most strongly associated with poor MHS (OR 1.04, 95% CI 1.01-1.08, p < 0.009) and PHS (OR 1.04, 95% CI 1.01-1.08, p < 0.01) scores, controlling for CD4 count, previous AIDS diagnosis, receiving HAART, and drug abuse. Cognitive impairment is associated with poor QoL. People with more severe cognitive impairment have the highest probability of having a poor QoL. Cognitive impairment in any cognitive domain explored in our battery is also associated with poor QoL. Poor performance on the Digit Symbol Test is the strongest predictor of poor QoL.

Monophyletic HIV type 1 CRF02-AG in a nosocomial outbreak in Benghazi, Libya.

A cluster of HIV-1 infection has been identified in Libya in 1999, involving 402 children admitted to "El-Fath" Children's Hospital in Benghazi (BCH) during 1998 and 19 of their mothers. Nosocomial transmission has been indicated as responsible for the spread of infection. Out of this group, 104 children and 19 adult women have been followed at the National Institute for Infectious Diseases L. Spallanzani in Rome during 1 year. At BCH, all children had received intravenous infusions but not blood or blood products. A single child receiving a blood transfusion in 1997 and the 17 infected mothers were never hospitalized in Benghazi. In addition, two nurses were diagnosed as HIV-1 infected. In 40 subjects out of this group HIV-1 gag, env, and pol fragments were amplified and sequenced. The phylogenetic analyses showed that a monophyletic recombinant HIV-1 form CRF02-AG was infecting all of the HIV-1-seropositive patients admitted at BCH with no close similarities to the other CRF02-AG reported to GenBank. A different strain was found in the child infected by blood transfusion. The data thus suggest a highly contagious nosocomial spread of HIV-1 infection and possibly transmission of the virus from child to mother during breastfeeding in connection with primary HIV-1 infection.

APRI and FIB-4 scores are not associated with neurocognitive impairment in HIV-infected persons.

INTRODUCTION: Chronic liver disease leads to neurocognitive impairment (NCI) and more advanced liver fibrosis is associated with greater deficits. Further, cognitive performances do not differ significantly among patients affected by diverse types of chronic liver diseases. Thus, it would be useful to have a clinical tool associated with early cognitive change applicable to the HIV-infected population with high HCV prevalence. Aim of the analysis was to assess the association between NCI and aspartate aminotransferase-platelet ratio index (APRI) or Fibrosis-4, which are non-invasive scores used to assess liver fibrosis. MATERIALS AND METHODS: Single-centre, retrospective, cross-sectional analysis of cART-treated HIV-infected patients undergoing neuropsychological assessment (NPA) by a set of 14 standardized and comprehensive tests on five different domains: concentration and speed of mental processing; mental flexibility; memory, fine motor functioning; visual-spatial and constructional abilities. NPA obtained from the same patient were included, if collected while receiving different cART. Patients were classified as having NCI, if they scored >1 SD below the normative mean in at least two tests, or below >2 SD in one test. HIV-associated neurocognitive disorders (HAND) were classified according to Frascati's criteria, controlling for confounding comorbidities. Univariable analysis and multivariable logistic regression models were carried out. RESULTS: A total of 556 HIV-infected cART-treated patients from 2006 to 2013 were included: male 78%; IVDUs 14%; CDC stage C 31%; median CD4 nadir 200/mm(3); median current CD4 501/mm(3); undetectable HIV-RNA in 368 (67%); and HCV-positivity in 150 (29%). Frequency among score levels was for FIB-4: min-1.44=404 (73%), 1.45-3.25=118 (21%), 3.26-max=28 (5%); for APRI: min-0.5=414 (75%), 0.5-1.5=112 (20%), 1.5-max=24 (4%). Median FIB-4 and APRI were 0.98 and 0.27 in HIV+/HCV- and 1.40 and 0.50 in HIV+/HCV+ individuals, respectively. HAND was found in 176 (32%): 91 ANI, 73 MND, 12 HAD. Association of variables with NCI are shown in Table 1. CONCLUSIONS: In this large population, HAND was not associated with commonly used non-invasive liver fibrosis scores. As aetiology of cognitive dysfunction in HIV mono- and HCV co-infected patients is multifactorial and partially unknown, our results support the hypothesis of a direct or indirect effect on cognitive function of the viruses, rather than the consequence of alterations residing outside the brain.