AIDS Research and Therapy - Latest articles

A feasibility study of immediate versus deferred antiretroviral therapy in children with HIV infection

2008-10-28

ObjectiveTo evaluate the feasibility of a large immediate versus deferred antiretroviral therapy (ART) study in children. Methods: We conducted an open-label pilot randomized clinical trial study in 43 Thai children with CD4 15 to 24% of starting generic AZT/3TC/NVP immediately (Arm 1) or deferring until CD4 < 15% or CDC C (Arm 2). Primary endpoints were recruitment rate, adherence to randomized treatment and retention in trial. Secondary endpoints were % with CDC C or CD4 < 15%. Children were in the trial until the last child reached 108 weeks. Intention to treat and on treatment analyses were performed. Results: Recruitment took 15 months. Twenty-six of 69 (37.7%) were not eligible due mainly to low CD4%. Twenty four and 19 were randomized to arms 1 and 2 respectively. All accepted the randomized arm; however, 3 in arm 1 stopped ART and 1 in arm 2 refused to start ART. Ten/19 (53%) in arm 2 started ART. At baseline, median age was 4.8 yrs, CDC A:B were 36:7, median CD4 was 19% and viral load was 4.8 log. All in arm 1 and 17/19 in arm 2 completed the study (median of 134 weeks). No one had AIDS or death. Four in immediate arm had tuberculosis. Once started on ART, deferred arm children achieved similar CD4 and viral load response as the immediate arm. Adverse events were similar between arms. The deferred arm had a 26% ART saving. Conclusion: Almost 40% of children were not eligible due mainly to low CD4% but adherence to randomized treatment and retention in trial were excellent. A larger study to evaluate when to start ART is feasible.

Sub-optimal CD4 reconstitution despite viral suppression in an urban cohort on Antiretroviral Therapy (ART) in sub-Saharan Africa: Frequency and clinical significance

2008-10-28

Background: A proportion of individuals who start antiretroviral therapy (ART) fail to achieve adequate CD4 cell reconstitution despite sustained viral suppression. We determined the frequency and clinical significance of suboptimal CD4 reconstitution despite viral suppression (SO-CD4) in an urban HIV research cohort in Kampala, Uganda Methods: We analyzed data from a prospective research cohort of 559 patients initiating ART between 04/04-04/05. We described the patterns of SO-CD4 both in terms of:- I) magnitude of CD4 cell increase (a CD4 count increase < 50 CD4 cells/ ul at 6 months, <100 cells/ul at 12 months; and <200 cells/ ul at 24 months of ART) and II) failure to achieve a CD4 cell count above 200 cells/ul at 6,12 and 24 months of ART. Using criteria I) we used logistic regression to determine the predictors of SO-CD4. We compared the cumulative risk of clinical events (death and/or recurrent or new AIDS-defining illnesses) among patients with and without SO-CD4. Results: Of 559 patients initiating ART, 386 (69%) were female. Median (IQR) age and baseline CD4 counts were 38 yrs (33-44) and 98 cells/ul (21-163) respectively; 414 (74%) started a d4T-based regimen (D4T+3TC+NVP) and 145 (26%) a ZDV-based regimen (ZDV+3TC+EFV). After 6, 12 and 24 months of ART, 380 (68%), 339 (61%) and 309 (55%) had attained and sustained HIV-RNA viral suppression. Of these, 78 (21%), 151 (45%) and 166 (54%) respectively had SO-CD4 based on criteria I), and 165(43%), 143(42%) and 58(19%) respectively based on criteria II). With both criteria combined, 56 (15%) and 129 (38%) had SO-CD4 at 6 and 12 months respectively. A high proportion (82% and 58%) of those that had SO-CD4 at 6 months (using criteria I) maintained SO-CD4 at 12 and 24 months respectively. There were no statistically significant differences in the incidence of clinical events among patients with [19/100PYO (12-29)] and without SO-CD4 [23/100PYO (19-28)]. Conclusion: Using criteria I), the frequency of SO-CD4 was 21% at 6 months. Majority of patients with SO-CD4 at 6 months maintained SO-CD4 up to 2 years. We recommend studies of CD4 T-cell functional recovery among patients with SO-CD4.

The intracellular detection of MIP-1beta enhances the capacity to detect IFN-gamma mediated HIV-1-specific CD8 T-cell responses in a flow cytometric setting providing a sensitive alternative to the ELISPOT

2008-10-06

Background: T-cell mediated immunity likely plays an important role in controlling HIV-1 infection and progression to AIDS. Several candidate vaccines against HIV-1 aim at stimulating cellular immune responses, either alone or together with the induction of neutralizing antibodies, and assays able to measure CD8 and CD4 T-cell responses need to be implemented. At present, the IFN-γ-based ELISPOT assay is considered the gold standard and it is broadly preferred as primary assay for detection of antigen-specific T-cell responses in vaccine trials. However, in spite of its high sensitivity, the measurement of the sole IFN-γ production provides limited information on the quality of the immune response. On the other hand, the introduction of polychromatic flow-cytometry-based assays such as the intracellular cytokine staining (ICS) strongly improved the capacity to detect several markers on a single cell level. Results: The cumulative analysis of 275 samples from 31 different HIV-1 infected individuals using an ICS staining procedure optimized by our laboratories revealed that, following antigenic stimulation, IFN-γ producing T-cells were also producing MIP-1β whereas T-cells characterized by the sole production of IFN-γ were rare. Since the analysis of the combination of two functions decreases the background and the measurement of the IFN-γ+ MIP-1β+ T-cells was equivalent to the measurement of the total IFN-γ+ T-cells, we adopted the IFN-γ+ MIP-1β+ data analysis system to evaluate IFN-γ-based, antigen-specific T-cell responses. Comparison of our ICS assay with ELISPOT assays performed in two different experienced laboratories demonstrated that the IFN-γ+ MIP-1β+ data analysis system increased the sensitivity of the ICS up to levels comparable to the sensitivity of the ELISPOT assay. Conclusion: The IFN-γ+ MIP-1β+ data evaluation system provides a clear advantage for the detection of low magnitude HIV-1-specific responses. These results are important to guide the choice for suitable highly sensitive immune assays and to build reagent panels able to accurately characterize the phenotype and function of responding T-cells. More importantly, the ICS assay can be used as primary assay to evaluate HIV-1-specific responses without losing sensitivity in comparison to the ELISPOT assay.

Significant improvements in self-reported gastrointestinal tolerability, quality of life, patient satisfaction, and adherence with lopinavir/ritonavir tablet formulation compared with soft gel capsules

2008-09-17

Background: The tablet formulation of ritonavir-boosted lopinavir (LPV/r; Kaletra®) has many advantages over the soft gel capsule (SGC) formulation, including lower pill count, no refrigeration requirement, and no dietary restrictions. These advantages may help improve patient compliance and therefore increase adherence to treatment. However, there are limited data regarding patient preferences and only recently was the comparative efficacy and tolerability data of LPV/r SGC versus tablet formulation presented at an international conference. To address this deficit, we conducted a market research survey to assess potential tolerability benefits, patient satisfaction, changes in adherence, and formulation preference in patients switching from SGCs to the tablet formulation. Data from 332 patients who switched from LPV/r SGCs twice-daily (BID) to tablets BID and 41 patients who switched from LPV/r SGCs BID or once daily (QD) to tablets QD were analyzed. Results: Switching from SGCs to a tablet formulation of LPV/r was associated with increased patient satisfaction, tolerability and self-reported adherence to treatment; gastrointestinal side effects were reduced. In addition, respondents indicated that they preferred the tablet formulation to the SGC. Conclusion: The LPV/r tablet formulation provides HIV-infected patients with multiple benefits over the SGC in terms of tolerability and convenience. Additional assessments to further define the tolerability profile of the LPV/r tablet, including studies using once-daily dosing, are warranted.

Predictive validity of a brief antiretroviral adherence index: Retrospective cohort analysis under conditions of repetitive administration

2008-08-29

Background: Newer antiretroviral (ARV) agents have improved pharmacokinetics, potency, and tolerability and have enabled the design of regimens with improved virologic outcomes. Successful antiretroviral therapy is dependent on patient adherence. In previous research, we validated a subset of items from the ACTG adherence battery as prognostic of virologic suppression at 6 months and correlated with adherence estimates from the Medication Event Monitoring System (MEMS). The objective of the current study was to validate the longitudinal use of the Owen Clinic adherence index in analyses of time to initial virologic suppression and maintenance of suppression. Results: 278 patients (naïve n = 168, experienced n = 110) met inclusion criteria. Median [range] time on the first regimen during the study period was 286 (30 – 1221) days. 217 patients (78%) achieved an undetectable plasma viral load (pVL) at median 63 days. 8.3% (18/217) of patients experienced viral rebound (pVL > 400) after initial suppression. Adherence scores varied from 0 – 25 (mean 1.06, median 0). The lowest detectable adherence score cut point using this instrument was ≥ 5 for both initial suppression and maintenance of suppression. In the final Cox model of time to first undetectable pVL, controlling for prior treatment experience and baseline viral load, the adjusted hazard ratio for time updated adherence score was 0.36score ≥ 5 (95% CI: 0.19–0.69) [reference: <5]. In the final generalized estimating equations (GEE) logistic regression model the adjusted odds ratio for time-updated adherence score was 0.17score ≥ 5 (0.05–0.66) [reference: <5]. Conclusion: A brief, longitudinally administered self report adherence instrument predicted both initial virologic suppression and maintenance of suppression in patients using contemporary ARV regimens. The survey can be used for identification of sub-optimal adherence with subsequent appropriate intervention.

Microbicides 2008 conference: From discovery to advocacy

2008-08-15

Recently revised statistics show the number of individuals living with HIV at over 33 million worldwide, with 68% being in sub-Saharan Africa. Current HIV prevention methods, such as condom use, monogamy and abstinence, are not always feasible. The need for improved HIV preventative technologies remains urgent. Of these, microbicides represent a promising female-initiated preventative method. Microbicides are designed to be applied vaginally to prevent HIV and STI acquisition. Research is also being undertaken to assess the safety of the product during rectal application.The biannual Microbicides conference took place in New Delhi, India from 24–27 February 2008. The conference was open to delegates from the scientific and medical fields, as well as communities and advocates. In addition to microbicide research and development, the conference afforded the opportunity for the discussion of key issues such as ethics, acceptability, access, and community involvement.In this conference report we provide brief summaries of recent advancements made and challenges experienced in microbicide research and development, including updates on basic and clinical science, social and behavioural science, and community mobilisation and advocacy activities pertaining to clinical trials.

HIV-2 diagnosis and quantification in high-risk patients

2008-08-14

Current diagnostic assays for HIV-1 do not always test for the presence of HIV-2 in the United States. We present the case of a patient from Cape Verde, who was admitted to our hospital with rapidly deteriorating neurological function and multiple white matter lesions on MRI likely secondary to progressive multifocal leukoencephalopathy (PML). Initially, the patient had a positive EIA for HIV, but a negative HIV-1 Western Blot and no viral load detected on a branched-DNA assay. A repeat viral load by reverse transcriptase methodology (RT-DNA) detected 121,000 copies and an HIV-2 Western Blot was positive. The case highlights an extremely rare presentation of HIV-2 with severe neurological disease. We discuss the different tests available for the diagnosis and monitoring of HIV-2 in the United States.

The feasibility of preventing mother-to-child transmission of HIV using peer counselors in Zimbabwe

2008-08-01

Background: Prevention of mother-to-child transmission of HIV (PMTCT) is a major public health challenge in Zimbabwe. Methods: Using trained peer counselors, a nevirapine (NVP)-based PMTCT program was implemented as part of routine care in urban antenatal clinics. Results: Between October 2002 and December 2004, a total of 19,279 women presented for antenatal care. Of these, 18,817 (98%) underwent pre-test counseling; 10,513 (56%) accepted HIV testing, of whom 1986 (19%) were HIV-infected. Overall, 9696 (92%) of women collected results and received individual post-test counseling. Only 288 men opted for HIV testing. Of the 1807 HIV-infected women who received posttest counseling, 1387 (77%) collected NVP tablet and 727 (40%) delivered at the clinics. Of the 1986 HIV-infected women, 691 (35%) received NVPsd at onset of labor, and 615 (31%) infants received NVPsd. Of the 727 HIV-infected women who delivered in the clinics, only 396 women returned to the clinic with their infants for the 6-week follow-up visit; of these mothers, 258 (59%) joined support groups and 234 (53%) opted for contraception. By the end of the study period, 209 (53%) of mother-infant pairs (n = 396) came to the clinic for at least 3 follow-up visits. Conclusion: Despite considerable challenges and limited resources, it was feasible to implement a PMTCT program using peer counselors in urban clinics in Zimbabwe.

Stable gene transfer of CCR5 and CXCR4 siRNAs by sleeping beauty transposon system to confer HIV-1 resistance

Mayur Tamhane and Ramesh Akkina — 2008-07-30

Background: Thus far gene therapy strategies for HIV/AIDS have used either conventional retroviral vectors or lentiviral vectors for gene transfer. Although highly efficient, their use poses a certain degree of risk in terms of viral mediated oncogenesis. Sleeping Beauty (SB) transposon system offers a non-viral method of gene transfer to avoid this possible risk. With respect to conferring HIV resistance, stable knock down of HIV-1 coreceptors CCR5 and CXCR4 by the use of lentiviral vector delivered siRNAs has proved to be a promising strategy to protect cells from HIV-1 infection. In the current studies our aim is to evaluate the utility of SB system for stable gene transfer of CCR5 and CXCR4 siRNA genes to derive HIV resistant cells as a first step towards using this system for gene therapy. Results: Two well characterized siRNAs against the HIV-1 coreceptors CCR5 and CXCR4 were chosen based on their previous efficacy for the SB transposon gene delivery. The siRNA transgenes were incorporated individually into a modified SB transfer plasmid containing a FACS sortable red fluorescence protein (RFP) reporter and a drug selectable neomycin resistance gene. Gene transfer was achieved by co-delivery with a construct expressing a hyperactive transposase (HSB5) into the GHOST-R3/X4/R5 cell line, which expresses the major HIV receptor CD4 and and the co-receptors CCR5 and CXCR4. SB constructs expressing CCR5 or CXCR4 siRNAs were also transfected into MAGI-CCR5 or MAGI-CXCR4 cell lines, respectively. Near complete downregulation of CCR5 and CXCR4 surface expression was observed in transfected cells. During viral challenge with X4-tropic (NL4.3) or R5-tropic (BaL) HIV-1 strains, the respective transposed cells showed marked viral resistance. Conclusion: SB transposon system can be used to deliver siRNA genes for stable gene transfer. The siRNA genes against HIV-1 coreceptors CCR5 and CXCR4 are able to downregulate the respective cell surface proteins and thus confer resistance against viral infection by restricting viral entry. These studies have demonstrated for the first time the utility of the non-viral SB system in conferring stable resistance against HIV infection and paved the way for the use of this system for HIV gene therapy studies.

The Iranian female high school students' attitude towards people with HIV/AIDS: a cross-sectional study

Kamyar Ghabili, Mohammadali M Shoja and Pooya Kamran — 2008-07-22

Background: Acquired Immunodeficiency Syndrome (AIDS) has become an important public health hazard in Iran. It is believed that AIDS-related knowledge does not necessarily translate into behavior modification. Hence, it has been suggested that culturally appropriate educational campaigns should be implemented to obtain satisfactory outcomes. Here, we evaluated the female high school students' attitude towards HIV/AIDS in Tabriz, Iran to assess the cultural needs for the related educational programs and to discover sources of information about AIDS. Results: Anonymous, self-administered questionnaires were filled by the young female students. Among 300 students, 91% agreed that being an HIV carrier should not be an obstacle to obtaining education and employment. Moreover, 72.5% of the students declared that the community should be informed of HIV-positive people. In addition, one-tenth declared that they would feel extremely uncomfortable towards their HIV infected classmate. In addition, only 16% of the students stated that they would continue to shop at HIV infected grocer's store. The mass media and the experts were the major source and the most reliable source of information about AIDS, respectively. Conclusion: Tabrizian female students have overall negative attitudes towards HIV/AIDS. HIV/AIDS related educational campaigns should target the students, society and the families with emphasizing the leading roles of health staff.