Novel human immunodeficiency virus type 1 protease mutations potentially involved in resistance to protease inhibitors

Plasma-derived sequences of human immunodeficiency virus type 1 (HIV-1) protease from 1,162 patients (457 drug-naive patients and 705 patients receiving protease inhibitor [PI]-containing antiretroviral regimens) led to the identification and characterization of 17 novel protease mutations potentially associated with resistance to PIs. Fourteen mutations were positively associated with PIs and significantly correlated in pairs and/or clusters with known PI resistance mutations, suggesting their contribution to PI resistance. In particular, E34Q, K43T, and K55R, which were associated with lopinavir treatment, correlated with mutations associated with lopinavir resistance (E34Q with either L33F or F53L, or K43T with I54A) or clustered with multi-PI resistance mutations (K43T with V82A and I54V or V82A, V32I, and I47V, or K55R with V82A, I54V, and M46I). On the other hand, C95F, which was associated with treatment with saquinavir and indinavir, was highly expressed in clusters with either L90M and I93L or V82A and G48V. K45R and K20T, which were associated with nelfinavir treatment, were specifically associated with D30N and N88D and with L90M, respectively. Structural analysis showed that several correlated positions were within 8 A of each other, confirming the role of the local environment for interactions among mutations. We also identified three protease mutations (T12A, L63Q, and H69N) whose frequencies significantly decreased in PI-treated patients compared with that in drug-naive patients. They never showed positive correlations with PI resistance mutations; if anything, H69N showed a negative correlation with the compensatory mutations M36I and L10I. These mutations may prevent the appearance of PI resistance mutations, thus increasing the genetic barrier to PI resistance. Overall, our study contributes to a better definition of protease mutational patterns that regulate PI resistance and strongly suggests that other (novel) mutations beyond those currently known to confer resistance should be taken into account to better predict resistance to antiretroviral drugs

Prognostic importance of anaemia in HIV type-1-infected patients starting antiretroviral therapy: collaborative analysis of prospective cohort studies

Background: In HIV type-1-infected patients starting highly active antiretroviral therapy (HAART), the prognostic value of haemoglobin when starting HAART, and of changes in haemoglobin levels, are not well defined. Methods: We combined data from 10 prospective studies of 12,100 previously untreated individuals (25% women). A total of 4,222 patients (35%) were anaemic: 131 patients (1.1%) had severe (<8.0 g/dl), 1,120 (9%) had moderate (male 8.0-<11.0 g/dl and female 8.0-<10.0g/dl) and 2,971 (25%) had mild (male 11.0-<13.0g/dl and female 10.0-<12.0 g/dl) anaemia. We separately analysed progression to AIDS or death from baseline and from 6 months using Weibull models, adjusting for CD4+ T-cell count, age, sex and other variables. Results: During 48,420 person-years of follow-up 1,448 patients developed at least one AIDS event and 857 patients died. Anaemia at baseline was independently associated with higher mortality: the adjusted hazard ratio (95% confidence interval) for mild anaemia was 1.42 (1.17-1.73), for moderate anaemia 2.56 (2.07-3.18) and for severe anaemia 5.26 (3.55-7.81). Corresponding figures for progression to AIDS were 1.60 (1.37-1.86), 2.00 (1.66-2.40) and 2.24 (1.46-3.42). At 6 months the prevalence of anaemia declined to 26%. Baseline anaemia continued to predict mortality (and to a lesser extent progression to AIDS) in patients with normal haemoglobin or mild anaemia at 6 months. Conclusions: Anaemia at the start of HAART is an important factor for short- and long-term prognosis, including in patients whose haemoglobin levels improved or normalized during the first 6 months of HAART

Medical and societal consequences of late presentation

Patients presenting late with HIV infection are at a higher risk of clinical events, are difficult to treat and have a higher mortality compared with those who present earlier. Indeed, being diagnosed too late for effective treatment has been shown to be a common scenario leading to death. The increased risk for opportunistic diseases and increased mortality are associated with low CD4+ T-cell counts. In addition to the detrimental effect on the health of the individual, late presentation also creates a significant societal burden because it is associated with increased risk of HIV transmission and increased resource use. All of these factors highlight the benefit of earlier testing, diagnosis and treatment of HIV

Late diagnosis of HIV infection : epidemiological features, consequences and strategies to encourage earlier testing

A substantial proportion of HIV-infected individuals do not present for HIV testing until late in infection; these individuals are often ill, have a high mortality risk, and are less likely to respond to treatment when initiated. Furthermore, late presentation means that opportunities to reduce onward transmission, either by reducing high-risk behaviours or by reducing an individual's infectivity, are missed. The proportion of HIV-infected individuals who present late has remained relatively stable over the past decade, despite several attempts to encourage earlier diagnosis. Late presenters tend to be those at lower perceived risk of infection, those who are not routinely offered HIV testing, and are often from marginalized groups. Strategies that encourage earlier testing, including routine HIV testing in healthcare settings where high-risk individuals attend frequently, the availability of HIV testing services in non-medical settings, and partner notification schemes or peer-led projects to encourage high-risk individuals to attend for testing, may all increase the proportion of HIV-infected individuals who are aware of their HIV status, thus helping to control the spread of the epidemic. This review summarizes recent evidence on the epidemiology of late presentation and its impact on clinical progression, and describes several key strategies that may encourage earlier diagnosi

Treatment interruptions in HIV-infected subjects

Despite a high antiviral efficacy, the use of highly active antiretroviral therapy (HAART) in clinical practice is often impaired by the long-term toxicity of antiretroviral treatment, the increased rate of human immunodeficiency virus-1 (HIV-1) drug resistance in treated patients and the cost of therapies, so that possible interruption of HAART has to be considered as part of the current clinical practice. However, this strategy is usually followed by a rapid viral rebound with a substantial loss of CD4 T lymphocytes because the HIV suppression with HAART does not result in reconstitution of the HIV-specific immune response. Structured treatment interruption (STI) has already been investigated in HIV-infected subjects with well-controlled viral replication (initiating treatment during primary or chronic HIV infection) and in those with multiple treatment failures. A clear benefit of STI in patients with chronic infection remains controversial and these benefits are more often observed in patients starting treatment during primary HIV infection

Indicator disease guided testing for HIV- the next step for Europe?

HIV should preferably be diagnosed in its earlier stages. To optimize the chances of doing so, HIV testing in patients presenting with one of several indicator diseases and conditions is recommended. Patients presenting with tuberculosis and other AIDS-defining conditions should be tested. Patients with sexually transmitted diseases should be offered an HIV test, as should patients with certain types of cancers and laboratory abnormalities. Governments should consider adopting opt-out testing for pregnant women. These recommendations should be considered for implementation by all types of health professionals across Europe, and audits to study the extent of their being followed, conducted and reported to the European AIDS Clinical Society webpage (http://www.eacs.eu)