Smoking and projected cardiovascular risk in an HIV-positive Asian regional cohort

OBJECTIVES

The aim of the study was to assess the prevalence and characteristics associated with current smoking in an Asian HIV-positive cohort, to calculate the predictive risks of cardiovascular disease (CVD), coronary heart disease (CHD) and myocardial infarction (MI), and to identify the impact that simulated interventions may have.

METHODS

Logistic regression analysis was used to distinguish associated current smoking characteristics. Five-year predictive risks of CVD, CHD and MI and the impact of simulated interventions were calculated utilizing the Data Collection on Adverse Effects of Anti-HIV Drugs Study (D:A:D) algorithm.

RESULTS

Smoking status data were collected from 4274 participants and 1496 of these had sufficient data for simulated intervention calculations. Current smoking prevalence in these two groups was similar (23.2% vs. 19.9%, respectively). Characteristics associated with current smoking included age > 50 years compared with 30-39 years [odds ratio (OR) 0.65; 95% confidence interval (CI) 0.51-0.83], HIV exposure through injecting drug use compared with heterosexual exposure (OR 3.03; 95% CI 2.25-4.07), and receiving antiretroviral therapy (ART) at study sites in Singapore, South Korea, Malaysia, Japan and Vietnam in comparison to Thailand (all OR > 2). Women were less likely to smoke than men (OR 0.11; 95% CI 0.08-0.14). In simulated interventions, smoking cessation demonstrated the greatest impact in reducing CVD and CHD risk and closely approximated the impact of switching from abacavir to an alternate antiretroviral in the reduction of 5-year MI risk.

CONCLUSIONS

Multiple interventions could reduce CVD, CHD and MI risk in Asian HIV-positive patients, with smoking cessation potentially being the most influential.

High-dose bee venom exposure induces similar tolerogenic B-cell responses in allergic patients and healthy beekeepers

BACKGROUND

The involvement of B cells in allergen tolerance induction remains largely unexplored. This study investigates the role of B cells in this process, by comparing B-cell responses in allergic patients before and during allergen immunotherapy (AIT) and naturally exposed healthy beekeepers before and during the beekeeping season.

METHODS

Circulating B cells were characterized by flow cytometry. Phospholipase A2 (PLA)-specific B cells were identified using dual-color staining with fluorescently labeled PLA. Expression of regulatory B-cell-associated surface markers, interleukin-10, chemokine receptors, and immunoglobulin heavy-chain isotypes, was measured. Specific and total IgG1, IgG4, IgA, and IgE from plasma as well as culture supernatants of PLA-specific cells were measured by ELISA.

RESULTS

Strikingly, similar responses were observed in allergic patients and beekeepers after venom exposure. Both groups showed increased frequencies of plasmablasts, PLA-specific memory B cells, and IL-10-secreting CD73^- CD25⁺ CD71⁺ B_R 1 cells. Phospholipase A2-specific IgG4-switched memory B cells expanded after bee venom exposure. Interestingly, PLA-specific B cells showed increased CCR5 expression after high-dose allergen exposure while CXCR4, CXCR5, CCR6, and CCR7 expression remained unaffected.

CONCLUSIONS

This study provides the first detailed characterization of allergen-specific B cells before and after bee venom tolerance induction. The observed B-cell responses in both venom immunotherapy-treated patients and naturally exposed beekeepers suggest a similar functional immunoregulatory role for B cells in allergen tolerance in both groups. These findings can be investigated in other AIT models to determine their potential as biomarkers of early and successful AIT responses.

The minor house dust mite allergen Der p 13 is a fatty acid-binding protein and an activator of a TLR2-mediated innate immune response

BACKGROUND

The house dust mite (HDM) allergen Der p 13 could be a lipid-binding protein able to activate key innate signaling pathways in the initiation of the allergic response. We investigated the IgE reactivity of recombinant Der p 13 (rDer p 13), its lipid-binding activities, and its capacity to stimulate airway epithelium cells.

METHODS

Purified rDer p 13 was characterized by mass spectrometry, circular dichroism, fluorescence-based lipid-binding assays, and in silico structural prediction. IgE-binding activity and allergenic potential of Der p 13 were examined by ELISA, basophil degranulation assays, and in vitro airway epithelial cell activation assays.

RESULTS

Protein modeling and biophysical analysis indicated that Der p 13 adopts a β-barrel structure with a predominately apolar pocket representing a potential binding site for hydrophobic ligands. Fluorescent lipid-binding assays confirmed that the protein is highly selective for ligands and that it binds a fatty acid with a dissociation constant typical of lipid transporter proteins. The low IgE-binding frequency (7%, n = 224) in Thai HDM-allergic patients as well as the limited propensity to activate basophil degranulation classifies Der p 13 as a minor HDM allergen. Nevertheless, the protein with its presumptively associated lipid(s) triggered the production of IL-8 and GM-CSF in respiratory epithelial cells through a TLR2-, MyD88-, NF-kB-, and MAPK-dependent signaling pathway.

CONCLUSIONS

Although a minor allergen, Der p 13 may, through its lipid-binding capacity, play a role in the initiation of the HDM-allergic response through TLR2 activation.

Life expectancy of HIV-positive people after starting combination antiretroviral therapy: a meta-analysis

OBJECTIVES

Life expectancy is an important indicator informing decision making in policies relating to HIV-infected people. Studies estimating life expectancy after starting combination antiretroviral therapy (cART) have noted differences between income regions. The objective of our study was to perform a meta-analysis to assess life expectancy of HIV-positive people after starting cART, and to quantify differences between low/middle- and high-income countries.

METHODS

Eight cohort studies estimating life expectancy in HIV-positive people initiating cART aged ≥ 14 years using the abridged life table method were identified. Random effects meta-analysis was used to pool estimated outcomes, overall and by income region. Heterogeneity between studies was assessed with the I² statistic. We estimated additional years of life expected after starting cART at ages 20 and 35 years.

RESULTS

Overall life expectancy in high-income countries was an additional 43.3 years [95% confidence interval (CI) 42.5-44.2 years] and 32.2 years (95% CI 30.9-33.5 years) at ages 20 and 35 years, respectively, and 28.3 (95% CI 23.3-33.3) and 25.6 (95% CI 22.1-29.2) additional years, respectively, in low/middle-income countries. In low/middle-income countries, life expectancy after starting cART at age 20 years was an additional 22.9 years (95% CI 18.4-27.5 years) for men and 33.0 years (95% CI 30.4-35.6 years) for women, but was similar in the two sexes in high-income countries. In all income regions, life expectancy after starting cART increased over calendar time.

CONCLUSIONS

Our results suggest that the life expectancy of HIV-positive people after starting cART has improved over time. Monitoring life expectancy into the future is important to assess how changes to cART guidelines will affect patient long-term outcomes.

Longitudinal analysis of integrase N155H variants in heavily treated patients failing raltegravir-based regimens

OBJECTIVES

The mechanism of raltegravir (RAL)-resistant evolutions has not already been elucidated. Because the emergence of RAL resistance is usually initiated by the N155H mutant, we assessed the role of minor N155H-mutated variants in circulating RNA and archived DNA in five heavily treated patients experiencing long-term RAL therapy failure and harbouring three different resistance profiles determined by standard genotyping.

METHODS

Allele-specific polymerase chain reaction (AS-PCR) was used to detect N155H mutants in longitudinal stored plasma and whole-blood samples before, during and after RAL-based regimens in five patients infected with the HIV-1 B subtype.

RESULTS

No minor N155H-mutated variant was found by AS-PCR in either plasma or whole-blood samples collected at baseline and after RAL withdrawal in any of the five patients. During RAL failure, the mutation N155H was detected at different levels in three patients displaying the N155H pathway and gradually declined when the double mutant Q148H+G140S was selected in one patient. In two patients with the Q148H resistance pathway, no N155H variant was identified by AS-PCR in either viral RNA or DNA.

CONCLUSIONS

The N155H mutation present at various levels from minority to majority showed no relationship with the three RAL-associated resistance profiles, suggesting that this mutant may not play a role in determining different resistance profiles. Moreover, pre-existing N155H is very infrequent and, if selected during RAL failure, the N155H mutant disappears quickly after RAL withdrawal.

Assessing adherence in Thai patients taking combination antiretroviral therapy

In settings where medications and viral load (VL) monitoring are limited by cost, clinicians need reliable ways to assess patient adherence to therapy. We assessed sensitivity and specificity of two self-reported adherence tools (a visual analogue scale [VAS] and the CASE [Center for Adherence Support Evaluation] adherence index), against a standard of detectable VL, with 288 patients from three sites in Thailand. We also assessed predictors of non-adherence. The sensitivity and specificity of the VAS <95% and CASE adherence index ≤11 against a VL >50 copies/mL were 26% and 90%, 19% and 95%, respectively. Against a VL ≥1000 copies/mL sensitivities increased to 55% and 36%, respectively, and specificities were unchanged. Attending a clinic not staffed by HIV specialists (odds ratio [OR] 3.14; 95% confidence interval [CI] 1.19-8.34) and being educated to primary school level or less (OR 2.24; 95% CI 1.01-4.94) were associated with self-reported adherence <95% on the VAS in multivariate analysis. Adherence assessed by the VAS was a more accurate predictor of detectable VL. Policy-makers in resource-limited settings should ensure that treatment centres are staffed with well-trained personnel aware of the importance of good patient adherence.

The values of nasal provocation test and basophil activation test in the different patterns of ASA/NSAID hypersensitivity

BACKGROUND

The oral provocation test (OPT) is the current gold standard to diagnose aspirin hypersensitivity syndrome although it is time-consuming and contains some systemic risks. Other reliable methods with lower side effects and shorter test duration are being investigated.

OBJECTIVE

The purpose of this study was to evaluate the efficacy of the nasal provocation test (NPT) and the basophil activation test (BAT) in the diagnosis of different subtypes of aspirin sensitivity.

METHODS

Thirty aspirin sensitivity patients with cutaneous and respiratory manifestations underwent NPT and BAT with lysine-ASA. NPT result was interpreted as recommended in EAACI/GA2LEN guidelines and receiver operating characteristic analysis of BAT was performed by using 15 NSAIDs tolerant volunteers as a control group.

RESULTS

NPT was positive in 60% (18/30) of patients and BAT was positive in 76.7% (23/30) of patients. The incubation of basophils with 0.31 mg/ml of lysine-aspirin and using 4.6% activated basophils gives the best predictive values to diagnose aspirin sensitivity. The combination of both tests yielded positive results in 80% and 93.3% of aspirin-induced cutaneous and respiratory patterns. The agreement between NPT and BAT results was 63.3%.

CONCLUSIONS

NPT and BAT are beneficial to detect patients with aspirin sensitivity. The combination of both tests have additional diagnostic values; less time-consuming than OPT and their complications are negligible. A reliable alternative method with minimum side effects is needed to diagnose aspirin sensitivity in suspected patients who have contraindications for OPT.

Genital shedding of HIV after scheduled treatment interruption

This study assessed genital shedding of HIV in patients on intermittent combination antiretroviral therapy (cART) and assessed predictors of having detectable genital HIV RNA in 156 Thai patients with CD4 > 350 cells/μL and HIV RNA ≤50 copies/mL who were randomized to continuous therapy (CT, n = 65) or CD4-guided cART (n = 91). There were 383 matched genital and plasma HIV RNA samples (CT: 158, CD4 guided: 225). In 14 samples collected within eight weeks of treatment interruption, detectable HIV RNA was present in 29% of genital samples and 71% of plasma samples. In 55 samples collected after eight weeks of treatment interruption, detectable HIV RNA was present in 60% of genital samples and 98% of plasma samples. In 110 samples collected up to 96 weeks after treatment re-initiation, detectable genital HIV RNA was found in 8% of samples and all of these were within the first 17 weeks. Independent predictors of detectable genital HIV RNA were increasing age and increasing concentrations of HIV RNA in plasma. These findings support the role of cART in maintaining undetectable HIV RNA in genital secretions.

Cardiovascular risk assessment in persons with HIV infection in the developing world: comparing three risk equations in a cohort of HIV-infected Thais

OBJECTIVE

There is growing concern regarding cardiovascular disease in HIV-infected individuals in developing countries such as Thailand. We evaluated the 10-year risk of coronary heart disease (CHD) in a Thai HIV-infected cohort using three cardiovascular risk equations, and assessed the level of agreement among their predictions.

METHODS

We carried out a cross-sectional analysis of data on 785 Thai subjects followed prospectively in the HIV Netherlands Australia Thailand Collaboration (HIV-NAT) cohort study from 1996 to 2009. Cardiovascular risk factor history, along with relevant laboratory and clinical data, was collected at follow-up clinic visits. Ten-year risks of CHD were calculated using the Framingham, Ramathibodi-Electricity Generating Authority of Thailand (Rama-EGAT) and Data Collection on Adverse Effects of Anti-HIV Drugs (D:A:D) risk equations.

RESULTS

The mean age of the patients was 41.0 years; 55% of the subjects were male. The mean duration of antiretroviral therapy was 7.7 years. The prevalence of cardiovascular risk factors was low, with the most common risk factor being low high-density lipoprotein (HDL) (36.3%). The prevalence of high cardiovascular risk scores (defined as 10-year risk of CHD≥10%) was also low: 9.9, 2.1 and 0.8%, by the Framingham, Rama-EGAT and D:A:D scoring systems, respectively. Only eight subjects (1.0%) had a history of CHD. Bland-Altman plots showed that the Framingham equation predicted a higher risk of CVD compared with the Rama-EGAT and D:A:D equations, which agreed relatively well.

CONCLUSION

The predicted cardiovascular risk in this HIV-infected Thai cohort was relatively low. The agreement among the Rama-EGAT and D:A:D risk scores suggests that both equations may be appropriate estimators of cardiovascular risk in this population.

Production and immunogenicity of hypoallergenic codon-optimized DNA vaccine encoding mature Der p 1 allergen

BACKGROUND

Genetic vaccination with plasmid DNA encoding allergens is a promising potential approach for the treatment or prevention of allergy. Nonetheless, because the allergens expressed can display immunoglobulin (Ig) E reactivity, methods to deliver hypoallergenic variants can minimize the risk of type 2 helper (T(H)2) cell priming after DNA immunization.

METHODS

A humanized synthetic gene encoding mature Dermatophagoides pteronyssinus group 1 (Der p 1) allergen was cloned into the pHIS expression vector carrying unmethylated CpG 2006 (CpG 2006) motif but devoid of signal sequence. The immunogenicity of this DNA construct was compared in naïve mice with that of recombinant ProDer p 1 protein adjuvanted with alum.

RESULTS

Codon optimization of the cDNA encoding mature Der p 1 markedly improved allergen expression. Mature Der p 1, expressed intracellularly in Human Embryonic Kidney 293 cells (HEK 293 cells) transfected with codon-optimized Der p 1 cDNA (pHIS-mHuDer p 1), was shown to be hypoallergenic as it displayed no IgE reactivity. Intradermal vaccinations of naïve Balb/C mice with pHIS-mHuDer p 1 elicited an allergen-specific T(H)1 response characterized by the production of specific IgG2a, a very low amount of specific IgG1, and no specific IgE. Lipoplex formulation with cationic liposome composed of lecithin, N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium methylsulfate (DOTAP) and cholesterol not only accelerated the induction of T(H)1 response but also increased its intensity.

CONCLUSION

A codon-optimized DNA vaccine encoding mature Der p 1 in a lipoplex formulation could represent a promising hypoallergenic vaccine candidate for safer immunotherapy against house dust mite allergy.

Anal squamous intraepithelial lesions among HIV positive and HIV negative men who have sex with men in Thailand

OBJECTIVES

To evaluate the prevalence and risk factors of anal squamous intraepithelial lesions (ASIL), the putative anal cancer precursor, in Asian HIV positive and HIV negative men who have sex with men (MSM).

METHODS

Men who underwent anal Pap smear reported clinical, sociodemographic and behavioural information collected through questionnaire and interview between January 2007 and April 2008. Chi(2) and logistic regression were used to evaluate ASIL prevalence and risk factors among HIV positive and HIV negative MSM.

RESULTS

Of the 174 MSM (mean age 32.1 years), 118 (67.8%) were HIV positive. Overall, 27% had abnormal anal cytology: 13.2% had atypical squamous cells of undetermined significance (ASC-US), 11.5% had low-grade squamous intraepithelial lesion (LSIL) and 2.3% had high-grade squamous intraepithelial lesion (HSIL). Prevalence of ASIL was higher among HIV positive than HIV negative MSM (33.9% vs 12.5%; p = 0.003). Among HIV positive MSM, 16.1% had ASC-US, 14.4% had LSIL and 3.4% had HSIL and 7.1%, 5.4% and 0% in HIV negative MSM, respectively. Anal condyloma was detected in 22% of HIV positive and 16.1% (9/56) of HIV negative MSM (p = 0.5). In HIV positive MSM, anal condyloma (OR 3.42, 95% CI 1.29 to 9.04; p = 0.01) was a significant risk factor for ASIL. Highly active antiretroviral therapy use and CD4+ T cell count were not associated with ASIL.

CONCLUSIONS

One-third of HIV positive and 12.5% of HIV negative MSM had ASIL. Thus, as greater numbers of HIV positive MSM live longer due to increasing access to HAART worldwide, effective strategies to screen and manage anal precancerous lesions are needed.

Impact of reverse transcriptase resistance on the efficacy of TMC125 (etravirine) with two nucleoside reverse transcriptase inhibitors in protease inhibitor-naïve, nonnucleoside reverse transcriptase inhibitor-experienced patients: study TMC125-C227

OBJECTIVES

TMC125-C227, an exploratory phase II, randomized, controlled, open-label trial, compared the efficacy and safety of TMC125 (etravirine) with an investigator-selected protease inhibitor (PI) in nonnucleoside reverse transcriptase inhibitor (NNRTI)-resistant, protease inhibitor-naïve, HIV-1-infected patients.

METHODS

Patients were randomized to TMC125 800 mg twice a day (bid) (phase II formulation; n=59) or the control PI (n=57), plus two nucleoside reverse transcriptase inhibitors (NRTIs).

RESULTS

In an unplanned interim analysis, patients receiving TMC125 demonstrated suboptimal virological responses relative to the control PI. Therefore, trial enrolment was stopped prematurely and TMC125 treatment discontinued after a median of 14.3 weeks. In this first-line NNRTI-failure population, baseline NRTI and NNRTI resistance was high and reduced virological responses were observed relative to the control PI. No statistically significant relationship was observed between TMC125 exposure and virological response at week 12. TMC125 was better tolerated than a boosted PI for gastrointestinal-, lipid- and liver-related events.

CONCLUSIONS

In a PI-naïve population, with baseline NRTI and NNRTI resistance and NRTI recycling, TMC125 was not as effective as first use of a PI. Therefore the use of TMC125 plus NRTIs alone may not be optimal in PI-naïve patients with first-line virological failure on an NNRTI-based regimen. Baseline two-class resistance, rather than pharmacokinetics or other factors, was the most likely reason for suboptimal responses.

Ferritin levels during structured treatment interruption of highly active antiretroviral therapy

OBJECTIVE

The aim of the study was to investigate the influence of highly active antiretroviral therapy (HAART) on iron status and, conversely, the influence of iron status on the response to HAART.

METHODS

Ferritin levels were retrospectively determined in stored plasma from 138 HAART-naïve, moderately immunosuppressed HIV-infected Thai patients participating in a structured treatment interruption trial. Ferritin levels were determined at three predefined time-points: (1) HAART initiation; (2) HAART discontinuation; and (3) HAART resumption.

RESULTS

At baseline, 31% and 16% of the HIV-infected patients included in the study had high (>200 ng/mL) and low (<30 ng/mL) ferritin levels, respectively. Ninety-five per cent of patients with low ferritin levels were female. Ferritin decreased significantly during the interruption phase of HAART (-8.8 ng/mL; P=0.0005) but remained elevated in 62% of the patients with high baseline levels. A low baseline ferritin level was associated with a shorter time (P=0.041) to reach the CD4 cell target for HAART interruption (350 cells/microL), compared with a normal or high baseline ferritin level. Moreover, in a multivariate model, the relative risk (RR) of arriving at this CD4 cell target was significantly higher [RR 1.81; 95% confidence interval (CI) 1.05-3.14] in patients with low baseline ferritin. It is unlikely that inflammation affected ferritin in our patients, as mean levels of C-reactive protein were not elevated in patients with either high or low ferritin levels.

CONCLUSIONS

Both high and low ferritin levels were highly prevalent in moderately immunosuppressed HIV-positive Thai patients. Structured treatment interruption of HAART resulted in a significant decrease in overall ferritin levels. Furthermore, subjects with low baseline ferritin levels had a faster and greater CD4 response to HAART, suggesting a potential beneficial effect of iron deficiency on immunological recovery after initiation of HAART.

Predictive factors for immunological and virological endpoints in Thai patients receiving combination antiretroviral treatment

BACKGROUND

Routine CD4 count and HIV viral load monitoring is a financial barrier in developing countries.

METHODS

We assessed factors associated with CD4 counts < or =200 cells/microL and detectable viral load in Thai HIV-infected patients receiving antiretroviral therapy (ART) at the HIV Netherlands Australia Thailand Research Collaboration and the Thai Red Cross AIDS Research Centre (HIV-NAT). Univariate and multivariate Cox proportional hazards models for multiple treatment failures were used to determine factors related to CD4 counts < or =200 cells/microL and detectable viral load. Multivariate Cox proportional hazards models for CD4 counts < or =200 cells/microL were developed with and without viral load in order to build models applicable to contexts in which viral load is not available.

RESULTS

Four hundred and seventeen patients were included in the study. Fifty-four per cent were male, and the median CD4 count and log(10) viral load at baseline were 283 cells/microL and 4.3 log(10) HIV-1 RNA copies/mL, respectively. Independent factors related to CD4 count < or =200 cells/microL were CD4 count at baseline [hazards ratio (HR) 0.20/100 cells/microL; 95% confidence interval (CI) 0.17-0.23] and changes in CD4 count (HR 0.22/100 cells/microL; 95% CI 0.17-0.28). Factors in multivariate models (in which viral load was considered for inclusion) were CD4 count at baseline (HR 0.21/100 cells/microL; 95% CI 0.18-0.24), changes in CD4 count (HR 0.25/100 cells/microL; 95% CI 0.19-0.32) and detectable viral load (HR 1.94; 95% CI 1.20-3.13). Predictive factors (independent of viral load) were triple ART or highly active antiretroviral therapy (HAART) (HR 0.28; 95% CI 0.22-0.36) and detectable viral load at baseline (HR 2.96; 95% CI 2.24-3.91). Conclusions CD4 count at baseline and changes in CD4 count were important in predicting CD4 counts < or =200 cells/microL. Triple ART and detectable viral load at baseline were important in predicting detectable viral load.

Indinavir/ritonavir 800/100 mg bid and efavirenz 600 mg qd in patients failing treatment with combination nucleoside reverse transcriptase inhibitors: 96-week outcomes of HIV-NAT 009

OBJECTIVE

Nucleoside reverse transcriptase (NRTI) sparing is a favourable option for patients with NRTI failure or toxicity.

METHODS

Patients judged to be failing NRTI therapy were enrolled in a single-arm, open-label study of indinavir/ritonavir (IDV/r) 800/100 mg twice a day (bid)+efavirenz (EFV) 600 mg once a day (qd). The primary endpoint was the change in time-weighted average HIV RNA from baseline. The initial 48-week protocol was extended to 96 weeks by a single amendment. Analysis was by intention to treat.

RESULTS

Sixty-one patients (23 female) were enrolled in the study. Baseline median inter-quartile range (IQR) NRTI exposure was 4.4 (3.9-4.7) years; baseline median viral load was 4.09 log(10) HIV-1 RNA copies/mL (range 3.75-4.61 log(10) copies/mL); baseline median CD4 count was 169 cells/microL (range 60-277 cells/microL). The mean (SD) change in time-weighted average HIV RNA from baseline at 48 and 96 weeks was -2.1 (0.7) and -2.1 (0.8) log(10) copies/mL respectively, resulting in 87% and 69% of patients with HIV RNA <50 copies/mL. Sixteen per cent of patients permanently ceased therapy and 26% underwent temporary drug interruptions because of study drug-related adverse events. Fasted-lipid values rose significantly over the 96 weeks of study, as did median blood glucose and median serum creatinine levels. Twelve (20%) patients underwent IDV dose reduction, mainly because of nephrotoxicity (nine of 12 patients). Blood pressure values deteriorated following switch, but markers of nucleoside toxicity improved.

CONCLUSIONS

IDV/r 800/100 mg bid+EFV 600 mg qd gave a potent, durable response in these NRTI failures and was reasonably well tolerated. However, we observed adverse effects on renal, metabolic and blood pressure parameters. Lower doses of boosted IDV might improve toxicity while maintaining efficacy, and this possibility warrants further investigation.

The 48-week efficacy of once-daily saquinavir/ritonavir in patients with undetectable viral load after 3 years of antiretroviral therapy

OBJECTIVES

To evaluate the efficacy and safety of once-daily saquinavir-soft-gel-capsules/ritonavir (SQV-SGC/RTV) 1600 mg/100 mg plus dual nucleoside reverse transcriptase inhibitors (NRTIs) in HIV-infected patients with plasma viral load (pVL) <50 HIV-1 RNA copies/mL following 3 years of antiretroviral therapy.

METHODS

A total of 69 patients with pVL <50 copies/mL after 162 weeks of antiretroviral treatment started SQV-SGC/RTV 1600 mg/100 mg once-daily while continuing dual NRTIs. Previous treatment consisted of 66 weeks of treatment with a half/full dose of zidovudine (ZDV)/zalcitabine (ddC), followed by 2 years of SQV-SGC twice a day (bid) plus ZDV/lamivudine (3TC) or didanosine (ddI)/stavudine (d4T). Efficacy (pVL), safety and immunological changes (CD4 cell counts) were evaluated after 48 weeks in this open-label, single-arm prospective study.

RESULTS

SQV-SGC/RTV once-daily was well tolerated. No patient changed regimens or was lost to follow-up. After 48 weeks, 63 of 69 patients (91%) had pVL <50 copies/mL (five of the six remaining patients had pVL <400 copies/mL, and one patient had an unexplained rise to 39 500 copies/mL, which decreased to <50 copies/mL 12 weeks later). Median CD4 count increased from 534 cells/muL at the start of the SQV-SGC/RTV once-daily treatment to 664 cells/muL (P<0.001). Compared to the preceding 48 weeks on bid SQV-SGC, the CD4 cell count improved significantly on once-daily SQV-SGC/RTV (P<0.001).

CONCLUSIONS

These data support the use of SQV-SGC/RTV 1600 mg/100 mg once-daily with two NRTIs as a convenient, safe and cost-saving regimen to maintain viral suppression and CD4 counts for 48 weeks in this preselected cohort on highly active antiretroviral therapy (HAART) with pVL <50 copies/mL. The CD4 count rise may be a result of continued immune reconstitution in patients with well-controlled infection.

Pharmacokinetic study of saquinavir hard gel caps/ritonavir in HIV-1-infected patients: 1600/100 mg once-daily compared with 2000/100 mg once-daily and 1000/100 mg twice-daily

OBJECTIVES

A pharmacokinetic comparison of three dosing regimens of saquinavir/ritonavir was carried out: 1600/100 mg once-daily with 1000/100 mg twice-daily, and 1600/100 mg once-daily with 2000/100 mg once-daily.

METHODS

Twenty patients on saquinavir hard gel caps/ritonavir 1600/100 mg once-daily in combination with two nucleoside reverse transcriptase inhibitors for at least 4 weeks were enrolled and randomized to either saquinavir hard gel caps/ritonavir 1000/100 mg twice-daily or 2000/100 mg once-daily. Two pharmacokinetic curves were plotted, at baseline (day 0) and 7 days after the switch. Plasma concentrations were measured at 0, 2, 4, 6, 8, 10, 12 (and 24 for once-daily dosing) hours after drug intake by validated high-performance liquid chromatographic assay (HPLC). The area under the plasma concentration-time curve (AUC0-24 or AUC0-12), maximum and minimum concentration (Cmax and Cmin) and elimination half-life were calculated using a non-compartmental model.

RESULTS

Compared with saquinavir/ritonavir 1600/100 mg once-daily dosing, the saquinavir AUC and Cmin improved significantly when dosed as 1000/100 mg twice-daily (53% and 299%, respectively), and as 2000/100 mg once-daily (71% and 65%, respectively). Low Cmin in three subjects at baseline was corrected after switch to the other dosages. Saquinavir/ritonavir 2000/100 mg once-daily was also associated with a significant increase in saquinavir Cmax (52%) compared with saquinavir/ritonavir 1600/100 mg once-daily.

CONCLUSIONS

Saquinavir/ritonavir when dosed as 2000/100 mg once-daily or 1000/100 mg twice-daily achieves higher saquinavir plasma levels compared with saquinavir/ritonavir 1600/100 mg once-daily. Taking the convenience of once-daily dosing into consideration, dosage of 2000/100 mg once-daily may be preferred.

Comparison of first-line antiretroviral therapy with regimens including nevirapine, efavirenz, or both drugs, plus stavudine and lamivudine: a randomised open-label trial, the 2NN Study

BACKGROUND

The 2NN Study was a randomised comparison of the non-nucleoside reverse-transcriptase inhibitors (NNRTI) nevirapine and efavirenz.

METHODS

In this multicentre, open-label, randomised trial, 1216 antiretroviral-therapy-naive patients were assigned nevirapine 400 mg once daily, nevirapine 200 mg twice daily, efavirenz 600 mg once daily, or nevirapine (400 mg) and efavirenz (800 mg) once daily, plus stavudine and lamivudine, for 48 weeks. The primary endpoint was the proportion of patients with treatment failure (less than 1 log(10) decline in plasma HIV-1 RNA in the first 12 weeks or two consecutive measurements of more than 50 copies per mL from week 24 onwards, disease progression [new Centers for Disease Control and Prevention grade C event or death], or change of allocated treatment). Analyses were by intention to treat.

FINDINGS

Treatment failure occurred in 96 (43.6%) of 220 patients assigned nevirapine once daily, 169 (43.7%) of 387 assigned nevirapine twice daily, 151 (37.8%) of 400 assigned efavirenz, and 111 (53.1%) of 209 assigned nevirapine plus efavirenz. The difference between nevirapine twice daily and efavirenz was 5.9% (95% CI -0.9 to 12.8). There were no significant differences among the study groups in the proportions with plasma HIV-1 RNA concentrations below 50 copies per mL at week 48 (p=0.193) or the increases in CD4-positive cells (p=0.800). Nevirapine plus efavirenz was associated with the highest frequency of clinical adverse events, and nevirapine once daily with significantly more hepatobiliary laboratory toxicities than efavirenz. Of 25 observed deaths, two were attributed to nevirapine.

INTERPRETATION

Antiretroviral therapy with nevirapine or efavirenz showed similar efficacy, so triple-drug regimens with either NNRTI are valid for first-line treatment. There are, however, differences in safety profiles. Combination of nevirapine and efavirenz did not improve efficacy but caused more adverse events.

Pharmacokinetics of stavudine and didanosine coadministered with nelfinavir in human immunodeficiency virus-exposed neonates

We evaluated the pharmacokinetics of stavudine (d4T) and didanosine (ddI) in neonates. Eight neonates born to human immunodeficiency virus-infected mothers were enrolled to receive 1 mg of d4T per kg of body weight twice daily and 100 mg of ddI per m(2) once daily in combination with nelfinavir for 4 weeks after birth. Pharmacokinetic evaluations were performed at 14 and 28 days of age. For d4T, on days 14 and 28, the median areas under the concentration-time curves from 0 to 12 h (AUC(0-12)s) were 1,866 and 1,603, ng x h/ml, respectively, and the median peak concentrations (C(max)s) were 463 and 507 ng/ml, respectively. For ddI, on days 14 and 28, the median AUC(0-10)s were 1,573 and 1,562 h x ng/ml, respectively, and the median C(max)s were 627 and 687 ng/ml, respectively. Systemic levels of exposure to d4T were comparable to those seen in children, suggesting that the pediatric dose of 1 mg/kg twice daily is appropriate for neonates at 2 to 4 weeks of age. Levels of exposure to ddI were modestly higher than those seen in children. Whether this observation warrants a reduction of the ddI dose in neonates is unclear.

Intrapartum and neonatal zidovudine treatment in reduction of perinatal HIV-1 transmission in Bangkok

OBJECTIVE

To evaluate the efficacy of zidovudine (ZDV) administered during labor and to the infants in the first 6 weeks of life in reduction of perinatal HIV-1 transmission.

DESIGN

Open label clinical trial. SITE: King Chulalongkorn Memorial Hospital, Bangkok, Thailand.

MATERIAL AND METHOD

One hundred asymptomatic, antiretroviral naive HIV-1 infected pregnant women who had either late or no prenatal care were recruited from the obstetric service of King Chulalongkorn Memorial Hospital, Bangkok, Thailand. They were given ZDV 300 mg orally every 3 hours during the intrapartum period until delivery. ZDV syrup 2 mg/kg orally every 6 hours were given to the infants immediately after birth for 6 weeks. Breast feeding was not allowed. Infant's blood for HIV-1 PCR test was obtained at age 1 day, and 1, 3 and 6 months. HIV-antibody test was determined at age 18 months. Infants with at least one positive HIV-1 PCR test performed at or after 1 month of age or positive HIV-antibody test at age 18 months were classified as HIV-1 infected infants.

RESULTS

There were 100 healthy infants delivered without complication. Fourteen infants were excluded due to; 13 lost to follow-up and 1 drug intolerance. Of the remaining 86 infants who were followed-up, 27 infants (31.4%) did not receive intrapartum ZDV treatment and 9 infants were HIV-1 infected. The perinatal transmission rate was 10.5 per cent, (95% CI 3.9, 17.1).

CONCLUSION

The result of this study suggests that intrapartum oral ZDV treatment in asymptomatic HIV-1 infected mothers together with ZDV treatment in the neonates for 6 weeks can reduce the rate of perinatal HIV-1 transmission. This regimen may be an alternative treatment for prevention of HIV-1 infection in infants born to HIV-1 seropositive mothers who have had either late or no prenatal care.

Survey of reverse transcriptase from the heterosexual epidemic of human immunodeficiency virus type 1 CRF01_AE in Thailand from 1990 to 2000

Genetic diversity of the HIV-1 envelope gene has shown a steady increase over time in the Thai and other regional epidemics. A serial survey of subtype CRF01_AE polymerase gene (RT) diversity in Thailand was performed, using 48 novel and 15 reported sequences covering the period 1990--2000. These sequences were gathered from individuals whose sole risk factor for infection was heterosexual contact. By contrast to envelope, diversity was low and, despite a 40% increase early in the epidemic, has remained static since 1996. These results indicate that epidemic HIV-1 may be constrained within defined limits of genetic diversity at least in some genomic regions.

Short course zidovudine maternal treatment in HIV-1 vertical transmission: randomized controlled multicenter trial

A multicenter randomized, double blind, placebo-controlled clinical trial was conducted to evaluate the effectiveness of a short course of oral zidovudine (ZDV) treatment in HIV-1 infected pregnant women, starting at 38 weeks of gestation plus ZDV infusion during labor until delivery, to reduce HIV-1 vertical transmission in non-breast fed infants. One hundred and eighty two asymptomatic antiretroviral naïve HIV-1 infected pregnant women were enrolled. Each patient was randomly allocated into either the ZDV or placebo group. The ZDV group received 250 mg ZDV orally twice a day initiated at 38 weeks' gestation until the onset of labor. During the intrapartum period, ZDV infusion at the rate of 2 mg/kg was administered within the first hour and then continuously infused at the rate of 1 mg/kg/h until delivery. The placebo group received an identical capsule during pregnancy and normal saline infusion during labor until delivery. HIV-1 transmission was documented by nested polymerase chain reaction in infants at birth and at 1, 3 and, 6 months of age. The estimated HIV-1 vertical transmission rate was 14.9 per cent (95% CI = 11.1 to 18.7) and 16.3 per cent (95% CI = 12.3 to 20.9) in ZDV and placebo group, respectively (p > 0.05). The short course ZDV in antiretroviral naïve pregnant women initiated at 38 weeks' gestation plus intrapartum ZDV infusion without treatment in the infants was not effective to prevent HIV-1 vertical transmission.

Update on HIV/AIDS in Thailand

Thailand experienced its first case of AIDS in 1984. Approximately 800,000 Thais were infected with HIV in 1995 and 1 million Thais became infected by the year 2000. There have been 5 major epidemic waves: among male homosexuals (started 1984-5), intravenous drug users (started 1988), female commercial sex workers (started 1989), male clients (started 1990), and housewives and the newborn (started 1991). Approximately 96 per cent of HIV-1 infected Thais carried recombinant subtype A/E, the rest carried B'. In a male seroconvertors cohort of 235 cases, median time to show CD4 <200 cells/microL was 6.8 years. Five years survival was significantly lower than that of the other subtype B seroconvertors study, i.e., 82 per cent compared to 90 per cent. Interestingly, 13.5 per cent of seronegative Thais showed homozygous SDF1-3'A polymorphism, which suggests that approximately one-tenth of Thais may become long-term non-progressors after HIV-1 infection. Primary HIV infection syndrome is rare among Thai patients (1.1%). In contrast, it was 50-90 per cent in Western cohorts. In early symptomatic patients, one-third developed pruritic pappular eruptions (PPEs). In advanced stage, disseminated tuberculosis, Pneumocystis carinii pneumonia (PCP), cryptococcosis, and esophageal candidiasis are commonly found. In Northern Thailand, however, Penicillium marneffei infection or penicillosis is more common than cryptococcosis. The recent understanding of HIV pathogenesis suggests that HIV eradication is unlikely to be achievable with current strategies. Several National HIV treatment guidelines including the Thai guideline have been recommended treatment with triple antiretroviral regimen when patients become symptomatics or CD4+ <200. Current development of antiretroviral therapy which includes new agents, new formulas, and pharmacokinetic enhancements, is directed to better potency, higher genetic resistant barrier, less pill burden, and once a day dosing. These will ultimately improve the adherence and the long-term effectiveness of antiretroviral treatment. In reality, however, although the cost of triple regimen is dramatically declining, many patients still can not afford it. Primary prophylaxis and early diagnosis and treatment of opportunistic infection should be considered in patients with CD4+ <200 cells/microL. Modified short course ZDV studies and donation campaigns for preventing mother-to-child transmission, clinical trials to investigate the best use of expensive anti HIV medications in a poor resource setting have been or are being conducted. Nine phase I/II HIV-1 vaccine trial protocols have been or are being tested. A phase III trial of gp120 subtype B/E (AIDSVAX, VaxGen) was started in 1999, a total of 2,500 volunteers will be enrolled, and interim analysis is planned for August 2002. Thai investigators are also participating in pre-clinical development of recombinant BCG and DNA vaccines. Multidisciplinary and multi-level approaches, both by the government and private sectors, have had a positive impact on the HIV epidemic as shown by the declining seroprevalence of HIV infection in Thai male conscripts, and of major sexually transmitted diseases in men. Nevertheless, more effort at the grass roots level is needed to ensure further success and sustainability of the control of the HIV epidemic in Thailand.

A randomized, open-label, comparative trial of zidovudine plus lamivudine versus zidovudine plus lamivudine plus didanosine in antiretroviral-naive HIV-1-infected Thai patients

OBJECTIVE

To assess the efficacy and tolerability of a triple nucleoside reverse transcriptase inhibitor combination of zidovudine, lamivudine, and didanosine therapy.

DESIGN

A randomized open-label trial.

PATIENTS

Antiretroviral-naive HIV-infected patients with CD4+ cell counts of 100 to 500 cells/microl.

METHODS

A total of 106 patients were randomly assigned to 300 mg of zidovudine (200 mg for body weight <60 kg) twice daily plus 150 mg of lamivudine twice daily plus 200 mg of didanosine (125 mg for body weight <60 kg) twice daily (n = 53) or to zidovudine plus lamivudine (n = 53) for 48 weeks.

MAIN OUTCOME MEASURES

Degree and duration of reduction of HIV-1 RNA load and increase in CD4+ cell counts from baseline and development of drug-related toxicities.

RESULTS

At 48 weeks, triple drug therapy showed greater declines in plasma HIV-RNA levels from the beginning of treatment than double drug therapy (1.86 vs. 1.15 log10 copies/ml, respectively; p <.001). The proportions of patients with HIV-RNA <50 copies/ml in an intention-to-treat analysis were 54.7% (29 of 53 patients) and 11.3% (6 of 53 patients) in the triple and double drug therapy, respectively (p =.001). There was no significant difference in increase of CD4 count.

CONCLUSION

Triple drug therapy with zidovudine, lamivudine, and didanosine was significantly more effective in inducing sustained immunologic and virologic responses than the double combination of zidovudine and lamivudine.

Intrapartum zidovudine infusion alone failed to reduce both maternal HIV-1 viral load and HIV-1 infection in infant

A pilot clinical trial to assess the efficacy of intrapartum zidovudine (ZDV) infusion alone in the reduction of maternal viral load and its potential role in preventing vertical transmission of HIV-1. Twenty six, asymptomatic antiretroviral naïve HIV-1 infected pregnant women who had no prior antenatal care and were in labor were enrolled. Each patient received ZDV infusion at the rate of 2 mg/kg within the first hour. ZDV was then continuously infused at 1 mg/kg/h until delivery. Maternal plasma HIV-1 RNA prior to the commencement of ZDV infusion and within an hour after delivery were measured. HIV-1 transmission was documented by nested polymerase chain reaction in infants at six months of age. Median maternal plasma HIV-1 RNA prior to the ZDV infusion and after delivery was 29,401 and 32,555 copies/ml respectively, (p>0.05). The estimated HIV-1 transmission rate was 19.2 per cent (95% CI = 4-34). This result suggested that in asymptomatic HIV-1 infected pregnant women who were antiretroviral naïve and had no prior antenatal care, intrapartum ZDV infusion alone failed to reduce maternal HIV-1 viremia and the transmission rate of HIV-1.

Interleukin-1beta level in gingival crevicular fluid of patients with active periodontitis

Previous studies revealed that interleukin-1beta (IL-1beta) was detectable in gingival crevicular fluid (GCF) of patients with periodontitis, and the level was increased in level in gingival tissue extracts of active periodontal disease sites (defined as attachment loss > or = 2.5 mm over the preceding 2 months) compared to inactive sites or healthy sites. The present study evaluated the relationship of IL-1beta level in GCF and periodontal disease status. GCF was collected with Periopaper strips from 34 disease-active and 45 disease-inactive teeth in 11 untreated periodontitis patients and from 60 teeth in 15 healthy control subjects. Disease activity was defined as attachment loss of > or = 2.5 mm in at least one site of a tooth as determined by sequential probing. The absorbed GCF volume was determined using a Periotron 6000 and the crevicular IL-1beta level was determined using IL-1beta monoclonal antibody (Otsuka Pharmaceutical, Japan). IL-1beta was below the detection level of the assay (6 pg/ml) in the healthy control group but was detected in most teeth of the periodontitis group. However, disease-active teeth had higher IL-1beta level (Mann-Whitney U-test, p < 0.05) than disease-inactive teeth (mean total IL-1beta of 5.89 +/- 7.88 pg/tooth and 1.72 +/- 2.28 pg/tooth; mean concentration of 1.6 +/- 2.5 ng/ml and 0.6 +/- 0.83 ng/ml, respectively). The level of IL-1beta showed no correlation with probing depth, but had significant correlation (p < 0.05) with the extent of attachment loss. This study suggests that the level of IL-1beta in GCF may have a predictive value for determining active and inactive periodontal status.

Immune responses to measles immunization and the impacts on HIV-infected children

This prospective cohort study was conducted to determine the seroconversion rate and the pattern of antibody response to measles vaccine administered at age 9 months in HIV infected and non-infected children born to HIV-1 seropositive mothers. Thirty children born to HIV-1 seropositive mothers and 3 born to HIV-1 seronegative mothers were recruited. One single dose of Schwarz strain of measles virus vaccine (Rouvax) was given to every child at 9 months of age. Clinical status and measles antibody levels were evaluated at the time just before vaccination, 2 and 12 weeks post-vaccination. Antibody was measured by an enzyme immunoassay commercial kit (Enzygnost, Dade Behring Manufacturer, Germany). Children were classified into 3 groups, groups 1 and 2 were children with and without HIV infection respectively. Group 3 children were those born to HIV-1 seronegative mothers. Of the 33 enrolled children, 16, 14 and 3 were classified as groups 1, 2 and 3 respectively. Four children, 2 of each, in groups 1 and 3 did not complete the study. Group 3 was excluded due to the small number of children recruited. There was no short term complication and no measles infection noted during the course of study. None of the children had pre-existing antibodies. The median (range) of CD4 count and CD4/CD8 ratio measured at the time of vaccination were statistically different between groups 1 and 2 children. Group 2 children had better antibody response than group 1 in terms of seroconversion rate and median of antibody levels at 12 weeks post-vaccination. Only 7 of 29 children (24.1%) had detectable measles antibodies at 2 weeks post-vaccination. A decrease in antibody was noted in 2 symptomatic HIV infected children as their disease had progressed. Various potential predictors of measles vaccine responses in HIV infected children including CD4 count and CD4/CD8 ratio were not statistically different between the responders and non-responders. All 4 asymptomatic HIV infected children were responders. This study demonstrated that all of the children had already lost their maternal acquired antibodies at age 9 months. HIV infected children had a poorerantibody response to measles vaccine than the non-infected children.

A randomized, controlled 24-week study of intermittent subcutaneous interleukin-2 in HIV-1 infected patients in Thailand

OBJECTIVES

To assess the immunological and virological effects, safety profile and feasibility of subcutaneous interleukin-2 (scIL-2) therapy in an HIV-infected Thai population.

DESIGN

Seventy-two patients with baseline CD4 cell count of > or = 350 x 10(6)/l and no history of opportunistic infection were randomized to receive antiretroviral therapy plus scIL-2 (scIL-2 group) or antiretroviral therapy alone (control group). scIL-2 was administered at one of three doses for at least 24 weeks. The main measure of treatment efficacy was change in CD4 cell count.

RESULTS

The time-weighted mean change in CD4 cell count from baseline to week 24 was + 252 x 10(6)/l for the scIL-2 group compared with + 42 x 10(6)/l for the control group (P< 0.0001). Changes in plasma HIV RNA were not significantly different between the groups over the same time period: there was a 0.83 log10 copies/ml decrease for the scIL-2 group and a 0.70 log copies/ml decrease for the control group (P= 0.362).

CONCLUSIONS

This study provides the most extensive experience of scIL-2 therapy in HIV-1 infected women and Asians, and demonstrates the immunological efficacy, tolerability and feasability of scIL-2 therapy in this population. Data from this study were instrumental in guiding the selection of the scIL-2 dosing regimen for ongoing phase III trials.