Serum concentrations of retinol, alpha-tocopherol and the carotenoids are influenced by diet, race and obesity in a sample of healthy adolescents

An important part of understanding the functions of vitamin A, vitamin E and the carotenoids in nutritional status assessment, health promotion and disease prevention is knowledge of factors that influence their distribution in human tissues. Our objective was to examine serum concentrations of these nutrients and compounds in a sample of 285 healthy participants, 12-17 y old, from three U. S. cities. Pearson correlations between diet measured with a food frequency questionnaire and serum nutrient concentrations among these adolescents (adjusted for total serum cholesterol, age, sex, race and body mass index) were as follows: retinol, 0.23; alpha-tocopherol, 0.16; alpha-carotene, 0.31; beta-carotene, 0.15; beta-cryptoxanthin, 0.38; lycopene, 0.08; and lutein + zeaxanthin, 0.25. Multivariate linear regression modeled associations of demographic, dietary and physiologic variables with serum concentrations of these nutrients. African-American participants had significantly lower concentrations of serum retinol (P < 0.001), alpha-tocopherol (P < 0.01) and alpha-carotene (P < 0.02), but higher concentrations of lutein + zeaxanthin (P = 0.001) compared with Caucasians. Obese participants had serum nutrient concentrations that were 2-10% (P < 0.05) lower than normal weight participants. Dietary intake was a significant predictor of all serum analytes (P < 0.01) except lycopene. These models explained 20% of the variability in serum retinol, 28% of the variability in serum alpha-tocopherol, and 14-24% of the variability in serum carotenoids.

HIV-associated lipodystrophy

The HIV associated lipodystrophy syndrome is characterized by fat loss from the periphery, fat accumulation in the abdominal, dorsocervical regions and breasts, and hyperlipidaemia, insulin resistance and lactic acidaemia. Although several mechanisms have been proposed to explain these abnormalities, the exact aetiology of the condition remains unclear and will likely prove to be complex. The principal clinical concerns that arise from this disorder are possible increased risks of premature atherosclerosis and cardiovascular disease. A variety of therapeutic interventions, designed to limit these risks, are under evaluation.

High exposure to nevirapine in plasma is associated with an improved virological response in HIV-1-infected individuals

OBJECTIVE

To explore relationships between exposure to nevirapine and the virological response in HIV-1-infected individuals participating in the INCAS trial.

METHODS

The elimination rate constant of plasma HIV-1 RNA (k) was calculated during the first 2 weeks of treatment with nevirapine, zidovudine and didanosine in 51 antiretroviral-naive HIV-1-infected patients. The relationships between the value of k, the time to reach an undetectable HIV-1 RNA concentration in plasma (< 20 copies/ml) and the success of therapy after 52 weeks of treatment as dependent variables and the exposure to nevirapine, baseline HIV-1 RNA and baseline CD4 cell count as independent variables, were explored using linear regression analyses, proportional hazard models and logistic analyses, respectively.

RESULTS

The value of k for HIV-1 RNA in plasma was positively and significantly associated with the mean plasma nevirapine concentration during the first 2 weeks of therapy (P = 0.011) and the baseline HIV-1 RNA (P = 0.008). Patients with a higher exposure to nevirapine reached undetectable levels of HIV-1 RNA in plasma more rapidly (P = 0.03). From 12 weeks on, the median nevirapine plasma concentration was significantly correlated with success of therapy after 52 weeks (P < 0.02).

CONCLUSIONS

A high exposure to nevirapine (in a twice daily regimen) is significantly associated with improved virological response in the short as well as in the long term. These findings suggest that optimization of nevirapine concentration might be used as a tool to improve virological outcome in (antiretroviral-naive) patients treated with nevirapine.

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.

Osteopenia in HIV-infected men: association with asymptomatic lactic acidemia and lower weight pre-antiretroviral therapy

BACKGROUND

Osteopenia has been associated with antiretroviral therapy, particularly with protease inhibitors. Osteopenia in HIV-uninfected men is associated with mitochondrial defects.

METHODS

Bone density was assessed by dual-energy X-ray absorptiometry (DEXA) in 221 HIV-infected men (mean age 43 years) recruited to a lipodystrophy prevalence survey. Additional parameters assessed were demographics, exercise, smoking, type(s) and duration of all antiretroviral therapy, lipodystrophy (overall and by region), CD4 counts, HIV RNA, fasting metabolic parameters (lipid, glycaemic, lactate, liver enzymes, testosterone) and regional body fat and lean mass (DEXA and L4 abdominal computed tomographic scan).

RESULTS

Thirty-two patients were drug-naive; 42 were receiving nucleoside analogue reverse transcriptase inhibitors (NRTI) and 147 were receiving these plus protease inhibitors. Osteoporosis (t-score < -2.5 SD below normal) was found in seven (3%) and osteopenia (t-score -1.0 to -2.5 SD) in 44 (22%). No patient had had a fracture since being infected with HIV. The only factors independently associated on logistic regression with osteopenia or osteoporosis were higher lactate levels, even if asymptomatic [odds ratio (OR) 2.39 per 1 mmol/l increase; 95% confidence interval (CI) 1.39-4.11; P = 0.002), and lower weight prior to commencing antiretroviral therapy (OR 1.06 per 1 kg decrease; 95% CI 1.02-1.11; P = 0.006). There was no independent association with any other parameter, including type or duration of antiretroviral therapy and lipodystrophy at any site. Lower total bone mineral density was associated with lower weight prior to commencing antiretroviral therapy whereas lower spinal bone mineral density was associated mostly with higher lactate.

CONCLUSION

Osteopenia in HIV-infected men is common, asymptomatic and is associated with asymptomatic NRTI-related lactic acidemia and lower weight pre-antiretroviral therapy.

Impact of HIV type 1 protease, reverse transcriptase, cleavage site, and p6 mutations on the virological response to quadruple therapy with saquinavir, ritonavir, and two nucleoside analogs

Genotype alterations of HIV-1 protease, reverse transcriptase, cleavage sites p7/p1 and p1/p6, as well as p6(gag) and transframe protein p6* were studied in an observational cohort of 42 individuals who received antiretroviral therapy consisting of saquinavir, ritonavir, and two nucleoside analogs. In a multivariate logistic regression analysis, the prior protease inhibitor experience (odds ratio, 6.20; 95% CI, 1.22-31.38) and the presence of primary protease mutations (odds ratio, 9.99; 95% CI, 1.05-94.72) were independently associated with virological failure. Moreover, a trend was observed in that individuals with N-terminal amino acid insertions in the proline-rich motif of the p6(gag) protein were less likely to experience virological failure (OR, 0.17; 95% CI, 0.02-1.35; p = 0.09). In contrast, the presence of secondary protease, reverse transcriptase, or cleavage site mutations was not independently associated with treatment failure. However, mutations at cleavage site p7/p1 (p = 0.01) and C-terminal p6* mutations (p = 0.02) were both associated with primary protease mutations. In conclusion, the presence of primary protease mutations was the most important predictor of the subsequent virological response. Moreover, there is some evidence that insertions in the proline-rich area of the p6(gag) protein may affect the virological response. The relationship between mutations of cleavage sites or C-terminal p6* residues and protease mutations suggests that these alterations may serve a compensatory role, increasing viral fitness.

Macular pigment optical density in a midwestern sample

OBJECTIVE

To assess the distribution of the macular pigments (MPs) lutein (L) and zeaxanthin (Z) in a healthy sample more representative of the general population than past studies and to determine which dietary factors and personal characteristics might explain the large interindividual differences in the density of these MPs.

DESIGN

Prevalence study in a self-selected population.

PARTICIPANTS

Two hundred eighty healthy adult volunteers, consisting of 138 men and 142 women, between the ages of 18 and 50 years, recruited from the general population.

METHODS

MP optical density was measured psychophysically at 460 nm by use of a 1 degrees test field. Serum was analyzed for carotenoid and vitamin E content with reversed-phase high-performance liquid chromatography. Usual intakes of nutrients over the past year were determined by means of a food frequency questionnaire.

MAIN OUTCOME MEASURES

MP optical density.

RESULTS

Mean MP optical density measured 0.211 +/- 0.13, which is approximately 40% lower than the average reported in smaller, less representative studies. MP density was 44% lower in the bottom versus the top quintile of serum L and Z concentrations. Similarly, MP density was 33% lower in the bottom compared with the top quintile of L and Z intake. MP density was 19% lower in blue-grey-eyed subjects than in subjects with brown-black irises. When all variables were considered together in a general linear model of determinants of MP, statistically significant (P < 0.05) relationships were found between MP density and serum L and Z, dietary L and Z intake, fiber intake, and iris color.

CONCLUSIONS

These data suggest that MP values in this healthy adult population are lower than in smaller select samples. Moreover, these data indicate that MP is related to serum L and Z, dietary L and Z intake, fiber intake, and iris color.

Increased turnover of CCR5+ and redistribution of CCR5- CD4 T lymphocytes during primary human immunodeficiency virus type 1 infection

CCR5 is the major coreceptor for human immunodeficiency virus (HIV) type 1 during primary infection. CCR5+ CD4 T lymphocytes were studied in subjects with primary HIV-1 infection (PHI) or acute Epstein-Barr virus (EBV) infection and in HIV-uninfected controls. The early decline of CD4 T lymphocytes during PHI resulted from depletion of CCR5- CD4 T lymphocytes. After antiretroviral therapy, Ki-67- CCR5- CD4 T cell counts rapidly increased in the circulation, which suggests that the initial decrease was due to an alteration in trafficking and/or sequestration. In the CCR5+ subset of CD4 T cells, there was an elevation in the proliferative (Ki-67+) fraction during PHI, yet their total number remained in the normal range. In contrast, in acute EBV infection, proliferating CCR5+ CD4 T cells accumulated to very high levels, suggesting they have an important role in the early antiviral response, which may be impaired in HIV-1 infection.

Hyperlipidemia and inhibitors of HIV protease

HIV protease inhibitors have been successfully incorporated into therapy for patients with HIV. These otherwise efficacious treatments present with multiple metabolic side-effects and body habitus changes known as the lipodystrophy syndrome. Direct associations of the lipid abnormalities with protease inhibitor use have been described, and ongoing studies are focused on describing mechanisms for future intervention. Mechanisms based on the molecular identity of the protease inhibitor target with human proteins, interference with aspects critical to lipoprotein production, and interference with adipocyte differentiation have been described. This review highlights the complexities of this syndrome, and discusses putative mechanisms whereby protease inhibitors cause hyperlipidemia.

Avanti 3: A Randomized, Double-Blind Trial to Compare the Efficacy and Safety of Lamivudine plus Zidovudine versus Lamivudine plus Zidovudine plus Nelfinavir in HIV-1-Infected Antiretroviral-Naive Patients

The objective of our randomized, multicentre, double-blind, placebo-controlled study was to investigate the safety, tolerability, and antiretroviral and immunological effect of double and triple combination therapy regimens. A total of 105 antiretroviral therapy-naive patients were randomized to receive either zidovudine (300 mg twice per day) plus lamivudine (150 mg twice per day) plus nelfinavir placebo (three times per day) ( n=52), or zidovudine/lamivudine (dose as before) plus nelfinavir (750 mg three times per day) ( n=53) for 28 weeks. After this time, patients were allowed to switch to open-label zidovudine/lamivudine/nelfinavir. The overall log10 reduction from baseline in plasma HIV-1 RNA was significantly greater in the zidovudine/lamivudine/nelfinavir group than the zidovudine/lamivudine group ( P=0.001; median treatment difference, –1.01 log10 copies/ml; 95% confidence interval –1.23 to –0.79), as measured by the average area under the curve minus baseline over 28weeks. Increases from baseline in CD4 cell counts were statistically significantly greater in the zidovudine/lamivudine/nelfinavir group (101.5 cells/ml) than the zidovudine/lamivudine group (47.0 cells/ml; P=0.027) at week 28.

Of note, the addition of nelfinavir from weeks 28–52 led to an increase in the proportion of subjects with plasma HIV-1 RNA <400 copies/ml from 17% (9/52 patients on zidovudine/lamivudine) to 50% (13/26 patients who switched to zidovudine/lamivudine/nelfinavir). Incidence of drug-related adverse events was similar in the two groups, except for nausea (more common in zidovudine/lamivudine group; 40 versus 17%) and diarrhoea (more common in zidovudine/lamivudine/nelfinavir group; 45 versus 14%). In conclusion, our study confirms the efficacy of triple combination therapy with two nucleoside analogues and a protease inhibitor compared with double-nucleoside therapy. Interestingly, the addition of nelfinavir to zidovudine/lamivudine, even after 6 months of double nucleoside therapy, led to a substantial virological benefit that was sustained over 24weeks in a subset of patients.

Relative significance of different pathways of immune reconstitution in HIV type 1 infection as estimated by mathematical modeling

A major goal of antiretroviral HIV-1 therapy is the reversal of HIV-1-associated immunological dysfunction. However, the pathogenetic mechanisms involved and their significance are largely unknown. On the basis of the life cycle of naive, activated, and memory CD4(+) T cell subsets, a mathematical model of immune reconstitution was developed and applied to data for T cell subsets in individuals with acute or chronic HIV-1 infection receiving antiretroviral therapy. The final model that most accurately fitted the data, and resulted in realistic estimates for CD4(+) T cell turnover, considered three pathways of immune reconstitution for naive cells, including thymic production, peripheral expansion, and redistribution of naive cells from lymphoid tissue. The reconstitution of the memory compartment was fitted through differentiation and expansion of naive cells and peripheral expansion of memory cells as well as redistribution of memory cells trapped in the lymphoid tissue. Estimated median half-lives for naive and memory CD4(+) T cells were 114 and 21 days, while total production rates were 9.1 x 10(7) and 2.4 x 10(9) cells/day, respectively. Peripheral expansion and thymic production contributed equally to the regeneration of naive cells, but peripheral expansion of memory cells was larger than production of these cells by differentiation of naive cells. A comparison of immune reconstitution in acute and chronic HIV-1 infection revealed that, after adjustment for age, the main difference was the more rapid release of a larger number of naive cells in treated acute HIV-1 infection. Thymic function and peripheral expansion rates, however, were similar in both cohorts.

Rapid restoration of CD4 T cell subsets in subjects receiving antiretroviral therapy during primary HIV-1 infection

OBJECTIVE

To compare the effect of highly active antiretroviral therapy on immune reconstitution in subjects with acute and chronic HIV-1 infection.

DESIGN

Prospective study including 58 treatment-naive subjects who commenced indinavir or nelfinavir and two nucleosides during primary (PHI; n = 28) or chronic HIV-1 infection (CHI; n = 30).

METHODS

Naive (CD45RA+ 62L+), memory (CD45RA-) and activated (CD38+ HLA-DR+) T cell subsets were quantified at 1-2 monthly time intervals using 4-colour flow cytometry.

RESULTS

At 1 year, HIV-1 RNA declined in both cohorts to undetectable levels (< 50 copies/ml), while median CD4 lymphocyte count increased from 470 to 758 x 10(6) cells/l in PHI and from 204 to 310 x 10(6) cells/l in CHI, reaching > 500 x 10(6) cells/l in 93% of PHI, but only in 37% of CHI subjects (P < 0.001). Naive CD4 lymphocytes increased from 106 to 176 x 10(6) cells/l in PHI and from 41 to 44 x 10(6) cells/l in CHI (PHI versus CHI at 12 months: P = 0.003), while memory cells rose from 368 to 573 x 10(6) cells/l in PHI and from 148 to 223 x 10(6) cells/l in CHI (P < 0.001). Early increases (< 3 months) of CD4 lymphocytes were larger in subjects with PHI, consisting of naive CD45RA+ CD62L+ as well as memory CD45RA- CD62L+ cells (P = 0.001). CD4 activation declined from 5 to 2% in PHI and from 13 to 6% in CHI (P = 0.001), while CD8 cell activation was reduced from 33 to 15% in PHI and from 42 to 19% in CHI (P = 0.02).

CONCLUSION

Immune reconstitution was more complete, occurred earlier and comprised both naive and memory CD4 T lymphocytes in subjects who commenced antiretroviral therapy during primary HIV-1 infection.

Adverse effects of antiretroviral therapy

Antiretroviral toxicity is an increasingly important issue in the management of HIV-infected patients. With the sustained major declines in opportunistic complications, HIV infection is a more chronic disease, and so more drugs are being used in more patients for longer periods. This review focuses on the pathogenesis, clinical features, and management of the principal toxicities of the 15 licensed antiretroviral drugs, including mitochondrial toxicity, hypersensitivity, and lipodystrophy, as well as more drug-specific adverse effects and special clinical settings.

Antiretroviral therapy of HIV-1 infection: established treatment strategies and new therapeutic options

Recently, studies have shown that non-nucleoside reverse transcriptase inhibitors, such as efavirenz or nevirapine, in combination with two nucleoside analogues have an antiretroviral potency comparable to protease inhibitor containing regimens. Triple combination therapy that includes a non-nucleoside reverse transcriptase inhibitor can therefore be regarded as an effective alternative first-line treatment of HIV-1 infection.

Evidence for independent development of resistance to HIV-1 reverse transcriptase inhibitors in the cerebrospinal fluid

OBJECTIVES

To delineate and compare the nature and frequency of mutations known to confer resistance to HIV-1 nucleoside reverse transcriptase inhibitors in the cerebrospinal fluid (CSF) and blood compartments.

METHODS

Fifty-three paired CSF and plasma specimens had been prospectively collected and stored from 49 HIV-1 infected patients. These were tested using a commercially available line probe assay which allows the simultaneous detection of wild-type and drug selected variants conferring resistance to one or more drugs: zidovudine, didanosine, zalcitabine, and lamivudine.

RESULTS

Of the 53 (58%) paired samples, 31 could be amplified by nested PCR. The current assay's limitation for use with CSF is highlighted as 91% of blood samples amplified compared with 60% of CSF samples showing the assays inability to amplify viral loads below 1000 copies/ml. Of the 31 patients 21 (68%) had identical resistance patterns in the CSF and plasma; the other 10 (32%) patients had a resistance profile in the CSF that was different from that in their plasma. Of these, three samples demonstrated amino acid changes associated with high level zidovudine resistance in the CSF but the blood sample remained genotypically sensitive. Nine samples demonstrated resistance in blood but remained wild-type in the CSF. Resistant genotypes were detected in CSF for all nucleosides except didanosine.

CONCLUSIONS

Differences in the positions and frequencies of wild-type and drug selected variants in specimens derived from the CSF and blood compartments were detected in a significant number of patients; this argues for the independent development of drug resistance in the CNS in some patients. These findings may have important implications in guiding antiretroviral therapy in HIV-1 infection.

Hepatitis C virus core mutations reduce the sensitivity of a fluorescence enzyme immunoassay

Four of 107 samples obtained from hepatitis C virus (HCV) carriers showed lower HCV core antigen levels in a fluorescence enzyme immunoassay (FEIA) than expected from corresponding HCV RNA levels. Nucleotide sequencing revealed a mutation in the HCV core region (Thr49Pro) that appears to have reduced the FEIA sensitivity.

Virological and immunological effects of combination antiretroviral therapy with zidovudine, lamivudine, and indinavir during primary human immunodeficiency virus type 1 infection

Forty-seven patients presenting with primary human immunodeficiency virus (HIV) infection were treated with zidovudine 200 mg 3 times a day, lamivudine 150 mg 2 times a day, and indinavir 800 mg 3 times a day for 1 year. From a mean pretreatment viral RNA level of 4.93 log(10) copies/mL, the proportions of patients having <500 copies/mL at 24 and 52 weeks were 92.0% and 89.2%, respectively. For the 35 patients with data available at 24 and 52 weeks, the corresponding proportions for the <50 copies/mL analysis were 86.6% and 79.3%, respectively. The change in virus load was -2.19 and -2.41 log(10) copies/mL at weeks 8 and 52, respectively. CD4 cell counts increased, from a mean of 546 cells/mm(3), by 142 cells/mm(3) at week 24 and by 210 cells/mm(3) at week 52. Three patients discontinued the study because of drug-related toxicity. Six (12.8%) patients had adverse experiences associated with nephrolithiasis. Combination therapy with zidovudine, lamivudine, and indinavir during primary HIV infection results in a profound and sustained reduction in virus load with concurrent recovery of the CD4 cell population.

Pooled analysis of 3 randomized, controlled trials of interleukin-2 therapy in adult human immunodeficiency virus type 1 disease

We collected human immunodeficiency virus (HIV) disease progression, survival, most recent CD4 cell count, and plasma HIV RNA levels from patients (n=157) who participated in randomized clinical trials of interleukin (IL)-2 that commenced before 1995. Data were available for 155 (99%) patients. Statistical analyses were based on the intention-to-treat principle. Median follow-up was 28 months and 30 months for control and IL-2 patients, respectively. Twenty-five (16%) patients developed AIDS or died during follow-up (16 control patients vs. 9 IL-2 patients; R2=0.57; P=.22). Mean change from baseline CD4 cell count was significantly higher in patients randomized to receive IL-2 (368 vs. 153 cells/microL; P=.003). Mean change from baseline plasma HIV RNA was significantly lower in patients randomized to receive IL-2 (-0.98 vs. -0.63 log copies/mL; P=.004). Significant improvements in CD4 cell count and plasma HIV RNA in recipients of IL-2 relative to control patients were associated with a nonsignificant trend toward improved clinical outcome.

A randomized, double-blind trial of half versus standard dose of zidovudine plus zalcitabine in Thai HIV-1-infected patients (study HIV-NAT 001). HIV Netherlands Australia Thailand Research Collaboration

BACKGROUND

Triple combination antiretroviral therapy, recommended as standard of care, is unaffordable for much of the developing world.

OBJECTIVES

To establish whether half doses of zidovudine (AZT) and zalcitabine (ddC) are as effective as standard doses in a Thai population with lower body weight than Western populations and predominantly infected with HIV-1 subtype E.

METHODS

A group of 116 antiretroviral naive patients, with CD4 cell counts 100-500 x 10(6) cells/l, were randomized to: AZT 200 mg three times daily plus ddC 0.75 mg three times daily versus AZT 100 mg three times daily plus ddC 0.375 mg three times daily and followed-up regularly for 48 weeks.

RESULTS

The study enrolled 111 patients: 59 men and 52 women, body weight (mean +/- standard deviation) 56.4 +/- 12.3 kg, mean CD4 cell count 324 x 10(6) cells/l, mean HIV RNA 4.7 log10 copies/ml. There were no significant differences between the two groups. Twelve patients discontinued, including two deaths that were unrelated to study medication. No significant differences in adverse events were seen. Week 48 data for the standard dose and half dose arms, respectively, were mean CD4 cell count increases of 52 and 78 x 10(6) cells/l (P = 0.34), mean plasma HIV-1 RNA reduction of 1.4 and 1.1 log10 copies/ml (P = 0.10), HIV RNA of < 400 copies/ml in 52 and 20%[ (P = 0.001). Participants with higher than mean baseline CD8 cell counts (mean 1062 x 10(6) cells/l) showed greater decline in CD8 cells on standard doses. Further analysis showed improved reduction in HIV RNA (P < 0.0001) and in the percentage with undetectable HIV RNA (P = 0.0137) in the standard dose arm, corrected for baseline HIV RNA, which if < 4.75 log10 copies/ml significantly correlated with HIV RNA < 400 copies/ml at week 48.

CONCLUSION

At week 48, the proportion with HIV RNA < 400 copies/ml was significantly higher in the standard dose arm; lower baseline HIV RNA correlated with better HIV RNA outcome at 48 weeks. The arms did not differ in CD4 cell response but standard doses correlated with greater CD8 cell decline.

A randomized, dose-finding study with didanosine plus stavudine versus didanosine alone in antiviral-naive, HIV-infected Thai patients

OBJECTIVES

To evaluate the safety and efficacy of four different regimens of didanosine (ddI) + stavudine (d4T) in HIV-infected Thais.

DESIGN

Prospective, open-label, randomized study.

METHODS

Patients were randomized to four regimens of high and low doses of ddI and d4T or to ddI alone. D4T was added to the ddI-alone arm after week 24. The duration of study was 48 weeks.

RESULTS

Seventy-eight patients were randomized (mean CD4 cell count, 255 x 10(6)/l; mean plasma HIV-1 RNA; 4.3 log10 copies/ml). In the intent-to-treat analysis, 78% of patients in the pooled combination arms and 20% of the patients in the ddI alone arm (to which d4T was added after 24 weeks) showed plasma HIV-1 RNA < 500 copies/ml at week 24 (P < 0.001), and 59% versus 53% at week 48, respectively. In addition, the proportion of patients with < 50 HIV-1 RNA copies/ml was 13% versus 7% at week 24 (P = 0.5) and 17% versus 20% at week 48 respectively. At week 24, median CD4 cell count increases from baseline were 101 x 10(6)/l in the pooled combination versus 76 x 10(6)/l in the ddI alone arm (P = 0.78). Logistic regression modeling suggested a correlation between receiving high dose ddI and achieving HIV-1 RNA < 500 copies/ml at week 48 (P = 0.07).

CONCLUSIONS

The d4T/ddI combination was superior to ddI alone in producing HIV-1 viral suppression. At week 48, > 60% of patients treated with this combination reached HIV-1 RNA levels < 500 copies/ml. Receiving high dose ddI but not d4T may correlate with a better viral suppression.

Incubation time of acute human immunodeficiency virus (HIV) infection and duration of acute HIV infection are independent prognostic factors of progression to AIDS

The severity and the duration of acute human immunodeficiency virus (HIV) infection (AHI) are associated with a faster rate of progression to AIDS, but the prognostic value of the length of incubation time of AHI (IncAHI), defined as the time between HIV infection and AHI, on progression to AIDS has not been assessed. We explored this issue prospectively in 70 individuals with documented AHI and a known date of HIV infection. The median IncAHI was 21.5 days (range, 5-70 days), and the median duration of AHI was 15.5 days (range, 3-67 days). The adjusted relative hazard of progression to AIDS or to a CD4(+) count <200x103/mL was 4.23 (95% confidence interval [CI], 1.40-12.73; P=.01) for the patients with an IncAHI <21.5 days, compared with those with longer IncAHI, and was 3.53 (95% CI, 1.09-11.36; P=.03) for the patients with a duration of AHI >15.5 days, compared with those with shorter duration. Both IncAHI and duration of AHI were independent predictors of progression. This suggests that early pathogenic events before the onset of AHI influence the rate of HIV disease progression.

A randomised, open-label comparison of three highly active antiretroviral therapy regimens including two nucleoside analogues and indinavir for previously untreated HIV-1 infection: the OzCombo1 study

BACKGROUND

Highly active antiretroviral therapy (HAART) including two nucleoside analogues and a potent protease inhibitor is standard of care initial therapy for HIV-infected adults. The best-tolerated and most potent initial HAART regimen is unknown and was investigated in this study.

METHODS

One hundred and nine HIV-infected adults with no prior antiretroviral therapy, and CD4 lymphocyte counts < 500 x 10(6) cells/l or plasma HIV RNA > 30,000 copies/ml were randomized to zidovudine-lamivudine-indinavir (ZDV-3TC-IDV), stavudine-lamivudine-indinavir (d4T-3TC-IDV) or stavudine-didanosine-indinavir (d4T-ddI-IDV) for 52 weeks. The primary endpoints were plasma HIV RNA and drug-related adverse events. Other assessments were overall safety, adherence and adverse events, CD4 lymphocyte counts, cutaneous delayed type hypersensitivity (DTH) responses and quality of life (Euroqol).

RESULTS

Only 58% patients had HIV RNA < 50 copies/ml plasma at 12 months, with no significant difference between the three regimes (P = 0.34). Drug-related adverse events sufficiently severe to warrant drug discontinuation were less common (P = 0.06) in patients receiving d4T-3TC-IDV (18%) than in those receiving ZDV-3TC-IDV (34%) or d4T-ddI-IDV (41%). The percentages of patients who remained on their assigned therapy with plasma HIV RNA < 50 copies/ml at 52 weeks were 60% with d4T-3TC-IDV, 53% with ZDV-3TC-IDV and 35% with d4T-ddI-IDV. Virological failure at 52 weeks was more likely in those whose adherence was estimated to be < 100% in the first 4 weeks of therapy (P = 0.02), but not in those who developed grade 3 or 4 drug-related adverse events. At 52 weeks, the mean CD4 lymphocyte count increase was 200 x 10(6) cells/l with only 7% of patients having counts lower than at baseline; DTH responses improved but remained clinically impaired in most patients. Quality of life improved significantly in all groups.

CONCLUSIONS

Initial HAART regimens including IDV failed to suppress plasma HIV RNA to < 50 copies/ml in > 40% patients after only 12 months of therapy although there was significant overall improvement immunologically and in quality of life. The type of dual nucleoside combination used was less important in predicting virological failure than was imperfect adherence early in therapy. Consideration should be given to modifying a HAART regimen relatively early in non-adherent patients.

Long-term immunological response in HIV-1-infected subjects receiving potent antiretroviral therapy

OBJECTIVE

To determine the long-term T-lymphocyte response to highly active antiretroviral therapy (HAART) and to define predictors of the immunological response.

DESIGN

Cohort study, including 135 HIV-1-infected subjects at a city general practice who commenced HAART between 1996 and 1998.

METHODS

Collection of plasma HIV-1 RNA, CD4+ and CD8+ T-lymphocyte data at 3-6 monthly time intervals over 2 years.

RESULTS

Seventy-three subjects (54%) achieved suppression of plasma HIV-1 RNA to levels below 400 copies/ml during the observation period, 31 individuals (23%) had detectable plasma HIV-1 RNA below 10,000 copies/ml and 31 subjects (23%) had virological failures with viral loads above 10,000 copies/mL. Median CD4+ T lymphocytes increased from 246 to 463 x 10(6) cells/l, showing a median rise of 20 x 10(6) cells/l per month in the first 3 months and 7 x 10(6) cells/l per month thereafter. The proportion of individuals who reached CD4+ cell counts above 500 x 10(6) cells/l increased from 8% at baseline to 54% at 2 years. Treatment-naïve individuals, subjects with a large reduction of HIV-1 RNA or a large early CD8+ increase had better early CD4+ responses. Long-term CD4+ T-cell increases were inversely correlated with mean plasma HIV-1 RNA levels. Baseline CD4+ T-cell count was the most important determinant of reaching CD4+ cell counts above 500 x 10(6) cells/l. Nineteen per cent of subjects had no further CD4+ T-cell increases in the second year of therapy despite undetectable viral load.

CONCLUSIONS

Immune reconstitution is a slow process, showing a large individual variability. The virological response to HAART was the most important determinant of the immunological short- and long-term response.