A cross-sectional study to evaluate the association of hyperbilirubinaemia on markers of cardiovascular disease, neurocognitive function, bone mineral density and renal markers in HIV-1 infected subjects on protease inhibitors.

BACKGROUND: Ongoing inflammation in controlled HIV infection contributes to non-AIDS comorbidities. High bilirubin appears to exhibit an anti-inflammatory effect in vivo. We therefore examined whether increased bilirubin in persons with HIV was associated with differences in markers of inflammation and cardiovascular, bone, renal disease, and neurocognitive (NC) impairment. METHODS: This cross-sectional study examined inflammatory markers in individuals with stable HIV infection treated with two nucleoside reverse transcriptase inhibitors and a boosted protease inhibitor. Individuals recruited were those with a normal bilirubin (NBR; 0-17 µmol/L) or high bilirubin (>2.5 × upper limit of normal). Demographic and anthropological data were recorded. Blood and urine samples were taken for analyses. Pulse wave velocity (PWV) measurement, carotid intimal thickness (CIT), and calcaneal stiffness (CSI) were measured. Males were asked to answer a questionnaire about sexual function; NC testing was performed using CogState. RESULTS: 101 patients were screened, 78 enrolled (43 NBR and 35 HBR). Atazanavir use was significantly higher in HBR. Whilst a trend for lower CIT was seen in those with HBR, no significant differences were seen in PWV, bone markers, calculated cardiovascular risk (Framingham), or erectile dysfunction score. VCAM-1 levels were significantly lower in the HBR group. HBR was associated with lower LDL and triglyceride levels. NBR was associated with a calculated FRAX significantly lower than HBR although no associations were found after adjusting for tenofovir use. No difference in renal markers was observed. Component tests of NC testing revealed differences favouring HBR but overall composite scores were similar. DISCUSSION: High bilirubin in the context of boosted PI therapy was found not to be associated with differences in with the markers examined in this study. Some trends were noted and, on the basis of these, a larger, clinical end point study is warranted.

Low-dose growth hormone for 40 weeks induces HIV-1-specific T cell responses in patients on effective combination anti-retroviral therapy.

Recombinant human growth hormone (rhGH) administered to combination anti-retroviral therapy (cART)-treated human immunodeficiency virus-1 (HIV-1)-infected individuals has been found to reverse thymic involution, increase total and naive CD4 T cell counts and reduce the expression of activation and apoptosis markers. To date, such studies have used high, pharmacological doses of rhGH. In this substudy, samples from treated HIV-1(+) subjects, randomized to receive either a physiological dose (0·7 mg) of rhGH (n = 21) or placebo (n = 15) daily for 40 weeks, were assessed. Peptide-based enzyme-linked immunospot (ELISPOT) assays were used to enumerate HIV-1-specific interferon (IFN)-γ-producing T cells at baseline and week 40. Individuals who received rhGH demonstrated increased responses to HIV-1 Gag overlapping 20mer and Gag 9mer peptide pools at week 40 compared to baseline, whereas subjects who received placebo showed no functional changes. Subjects with the most robust responses in the ELISPOT assays had improved thymic function following rhGH administration, as determined using CD4(+) T cell receptor rearrangement excision circle (TREC ) and thymic density data from the original study. T cells from these robust responders were characterized further phenotypically, and showed decreased expression of activation and apoptosis markers at week 40 compared to baseline. Furthermore, CD4 and CD8 T cell populations were found to be shifted towards an effector and central memory phenotype, respectively. Here we report that administration of low-dose rhGH over 40 weeks with effective cART resulted in greater improvement of T lymphocyte function than observed with cART alone, and provide further evidence that such an approach could also reduce levels of immune activation.

Screening for chronic comorbid diseases in people with HIV: the need for a strategic approach.

Among people living with HIV, the proportion of deaths attributed to chronic noninfectious comorbid diseases has increased over the past 15 years. This is partly a result of increased longevity in the era of highly active antiretroviral therapy (HAART), and also because HIV infection is related, causally or otherwise, to several chronic conditions. These comorbidities include conditions that are strongly associated with modifiable risk factors, such as cardiovascular disease (CVD), diabetes, and renal and bone diseases, and increasingly management guidelines for HIV recommend risk evaluation for these conditions. The uptake of these screening approaches is often limited by the resources required for their application, and hence the management of risk reduction in most HIV-infected populations falls below a reasonable standard. The situation is compounded by the fact that few risk calculators have been adjusted for specific use in HIV infection. There is substantial overlap of risk factors for the four common comorbid diseases listed above that are especially relevant in HIV infection, and this offers an opportunity to develop a simple screening approach that encompasses the key risk factors for lifestyle-related chronic disease in people with HIV infection. This would identify those patients who require more in-depth investigation, and facilitate a stepwise approach to targeted management. Such a tool could improve communication between patient and clinician. A significant proportion of people with HIV are sufficiently engaged with their care to participate in health promotion and take the lead in using patient-centric screening measures. Health-based social networking offers a mechanism for dissemination of such a tool and is able to embed educational messages and support within the process.

Longer prior exposure to zidovudine/lamivudine-containing combination antiretroviral therapy, age, and male gender are each associated with reduced subcutaneous adipose tissue.

OBJECTIVES: Whether zidovudine (AZT)-associated lipoatrophy occurrence differs by concomitant exposure to protease (PIs) or non-nucleoside reverse transcriptase inhibitors (NNRTIs) remains unclear. Baseline body composition data from a randomized trial in subjects stable on first-line AZT-based therapy were used to explore this issue. METHODS: In this substudy of the PREPARE trial, centrally read baseline whole-body dual energy x-ray aborptiometry (DXA) and single-slice abdominal CT scans were analyzed with respect to duration and type of prior AZT/lamivudine (3TC) combination antiretroviral therapy (cART), including by multivariate linear regression adjusted for age, gender, ethnicity, body mass index (BMI), and nadir CD4. RESULTS: DXA and CT, from 134 and 136 patients, respectively [87% male; 82% Caucasian; mean (SD) age, 45.6 years (10); BMI, 24.3 kg/m² (3.2)], were analyzed. Prior AZT/3TC cART exposure was 5.5 (2.2) years. Seventy-eight and 27 patients had concomitantly and exclusively used NNRTIs and PIs, respectively. AZT/3TC cART, AZT/3TC/NNRTI, and AZT/3TC/PI, respectively, were associated with the presence of a mean (95% CI) of 247 g (-438 to -56; P = .012), 267 g (-467 to -66; P = .010), and 216 g (-430 to -1.7; P = .048) less baseline limb fat per additional year of prior exposure. Although abdominal subcutaneous (SAT) adipose tissue was likewise less with longer AZT/3TC cART, this was only significant for AZT/3TC/ NNRTI but not AZT/3TC/PI. Visceral adipose tissue (VAT) amount was not clearly associated to prior treatment. Increased age and male gender were independently associated with lower limb fat and SAT, but more VAT. CONCLUSIONS: Longer exposure to AZT/3TC, regardless of whether in combination with PI or NNRTI, as well as increased age and male gender are independently associated with lower limb fat mass.

Randomized comparison of metabolic and renal effects of saquinavir/r or atazanavir/r plus tenofovir/emtricitabine in treatment-naïve HIV-1-infected patients.

OBJECTIVES: The aim of the study was to compare the effects on lipids, body composition and renal function of once-daily ritonavir-boosted saquinavir (SQV/r) or atazanavir (ATV/r) in combination with tenofovir/emtricitabine (TDF/FTC) over 48 weeks. METHODS: An investigator-initiated, randomized, open-label, multinational trial comparing SQV/r 2000/100 mg and ATV/r 300/100 mg once daily, both in combination with TDF/FTC, in 123 treatment-naïve HIV-1-infected adults was carried out. The primary endpoint was to demonstrate noninferiority of SQV/r compared with ATV/r with respect to the change in fasting cholesterol after 24 weeks. Secondary outcome measures were changes in metabolic abnormalities, body composition, renal function, and virological and immunological efficacy over 48 weeks. Patients who had used at least one dose of trial drug were included in the analysis. RESULTS: Data for 118 patients were analysed (57 patients on SQV/r and 61 on ATV/r). At week 24, changes in lipids were modest, without increases in triglycerides, including a significant rise in high-density lipoprotein (HDL) cholesterol and a nonsignificant decrease in the total:HDL cholesterol ratio in both arms with no significant difference between arms. Lipid changes at week 48 were similar to the changes observed up to week 24, with no significant change in the homeostasis model assessment (HOMA) index. Adipose tissue increased regardless of the regimen, particularly in the peripheral compartment and to a lesser extent in the central abdominal compartment, with an increase in adipose tissue reaching statistical significance in the ATV/r arm. A slight decline in the estimated glomerular filtration rate (eGFR) was observed in both arms during the first 24 weeks, with no progression thereafter. The immunological and virological responses were similar over the 48 weeks. CONCLUSIONS: Combined with TDF/FTC, both SQV/r 2000/100 mg and ATV/r 300/100 mg had comparable modest effects on lipids, had little effect on glucose metabolism, conserved adipose tissue, and similarly reduced eGFR. The virological efficacy was similar.

Persistence of episomal HIV-1 infection intermediates in patients on highly active anti-retroviral therapy.

Treatment of HIV-1-infected individuals with a combination of anti-retroviral agents results in sustained suppression of HIV-1 replication, as evidenced by a reduction in plasma viral RNA to levels below the limit of detection of available assays. However, even in patients whose plasma viral RNA levels have been suppressed to below detectable levels for up to 30 months, replication-competent virus can routinely be recovered from patient peripheral blood mononuclear cells and from semen. A reservoir of latently infected cells established early in infection may be involved in the maintenance of viral persistence despite highly active anti-retroviral therapy. However, whether virus replication persists in such patients is unknown. HIV-1 cDNA episomes are labile products of virus infection and indicative of recent infection events. Using episome-specific PCR, we demonstrate here ongoing virus replication in a large percentage of infected individuals on highly active anti-retroviral therapy, despite sustained undetectable levels of plasma viral RNA. The presence of a reservoir of 'covert' virus replication in patients on highly active anti-retroviral therapy has important implications for the clinical management of HIV-1-infected individuals and for the development of virus eradication strategies.

Injuries across a pre-professional ballet and contemporary dance tertiary training program: A retrospective cohort study.

OBJECTIVES: The study aims to analyse the incidence of medical attention injuries, subsequent injuries, and the median time to injury, across tertiary ballet and contemporary dance training programs. DESIGN: Retrospective cohort. METHODS: Consenting ballet and contemporary dance students completing the third/final year of two tertiary programs were included. The three-year programs consisted of six semesters. Access was granted to onsite physiotherapy notes, timetables, and academic enrolment. Injury was defined as requiring medical attention. Injury and exposure data were extracted, injuries coded for location and tissue, and subsequent injuries, occurring after an initial index injury, categorised. Mean, standard deviation, range, injury incidence, risk and rate ratios, proportions and Kaplan-Meier curves were calculated to report participant characteristics, and injury patterns across three years of the dance program. RESULTS: All 17 students (mean age=20.7 years; standard deviation=1.32) from one program consented to participate, of which all were injured across the three-year program, with 2.71 (95% confidence interval: 2.22, 3.20) injury incidence rate per 1000h, and increasing injury incidences seen across the program. The most injured site and tissue were the ankle (17.65%) and muscle (23.53%) respectively. 74.86% of subsequent injuries were different (affecting a different location and tissue), and 4.88% reinjuries (affecting the same location, tissue, and structure after recovery). The median time to the first injury was seven weeks in the first semester, and later in subsequent year levels. CONCLUSIONS: Increasing injury incidences were seen across the program. Most subsequent injuries were different from previous injuries in this cohort. Future research should use exposure measures beyond hours (i.e. intensity) and consider subsequent injuries.

Injuries during transition periods across the year in pre-professional and professional ballet and contemporary dancers: A systematic review and meta-analysis.

OBJECTIVE: To consider the association of injuries with transition periods in the dance year, i.e., when dancers return at the start of the year, and when they transition from rehearsal to performance periods. METHODS: Six electronic databases were searched to November 2019. All English language peer-reviewed studies, of any study design investigating ballet and contemporary pre-professional and professional dance populations were included. Only those studies reporting on the timing of injury were included. RESULTS: Fifteen cohort and two case-series studies were included. A meta-analysis of seven studies revealed the rate of injuries to be significantly higher for the second and third months (1.52; 95% confidence interval [CI]:1.11-2.08; 1.26; 95%CI:1.07-1.48 respectively) after the return to dance. Two further studies report more injuries up to Week 13 of the year. One study showed an increase in injured dancers at three and four weeks after transition from rehearsals to a performance season. Four studies show an increase in injuries at performance times. CONCLUSIONS: Meta-analyses of seven studies shows the second and third months after returning to dance have a significantly higher rate of injuries. More research is needed to quantify training loads in dance. Practitioners should be cognisant of the higher injury rates during periods of transition and consider modifying load, as it is a potential contributing factor.

Improvements in cheek volume in lipoatrophic individuals switching away from thymidine nucleoside reverse transcriptase inhibitors.

BACKGROUND: Thymidine nucleoside reverse transcriptase inhibitors (NRTIs) are associated with subcutaneous fat loss. Facial changes cannot be assessed by dual-energy X-ray absorptiometry (DEXA) scans. There are limited objective data on the reversibility of facial lipoatrophy. METHODS: We performed a facial volume substudy of a randomized thymidine NRTI replacement study carried out in HIV-infected subjects with moderate to severe lipoatrophy. Facial volume changes were assessed using validated 3D laser imaging. Changes in body composition were measured using DEXA scans. The association between changes in facial volume and body composition parameters at 48 weeks was measured using Spearman's rank correlation. RESULTS: Forty-seven individuals (46 male), 11 receiving zidovudine and 36 receiving stavudine, switched to either tenofovir disoproxil fumarate (DF) (n=23) or abacavir (ABC) (n=24). Thirty-nine of these 47 patients (84.8%) reported facial lipoatrophy at baseline. The median volume increase in both cheeks from baseline was 1857.3 mm(3). These volume changes and increases in limb fat at 48 weeks were similar in the two groups and correlated significantly (Spearman's r=0.41, P=0.004). CONCLUSIONS: Facial volume in lipoatrophic individuals was found to increase after thymidine NRTI replacement. We demonstrated a significant correlation between improvements in facial and limb fat parameters. Switching from thymidine NRTIs in patients with facial lipoatrophy could potentially reduce the need for cosmetic interventions.

Impacts of dance on cognition, psychological symptoms and quality of life in Parkinson's disease.

BACKGROUND: While dance may improve motor features in Parkinson's disease (PD), it is not yet clear if the benefits extend to non-motor features. OBJECTIVE: To determine whether dance classes based on Dance for PD®, improve cognition, psychological symptoms and Quality of Life (QoL) in PD. METHODS: Participants were allocated to a Dance Group (DG; n = 17) or Control Group (CG: n = 16). Participants had early-stage PD (Hoehn & Yahr: DG = 1.6±0.7, CG = 1.5±0.8) with no cognitive impairment (Addenbrooke's score: DG = 93.2±3.6, CG = 92.6±4.3). The DG undertook a one-hour class, twice weekly for 12 weeks, while the CG had treatment as usual. Both groups were assessed for disease severity (MDS-UPDRS), cognition (NIH Toolbox® cognition battery, Trail Making Test), psychological symptoms (Hospital Anxiety and Depression Scale, MDS-UPDRS-I) and QoL (PDQ-39, MDS-UPDRS-II). RESULTS: Group comparison of pre-post change scores showed that selected cognitive skills (executive function and episodic memory), psychological symptoms (anxiety and depression) as well as QoL (PDQ-39 summary index) were significantly improved by the intervention (DG > CG, p's < 0.05, Cohen's d > 0.8). DISCUSSIONS AND CONCLUSION: Dance classes had a clear benefit on psychological symptoms, QoL and a limited cognitive benefit. Follow-up assessment is required to confirm the durability of these effects.

Switching from twice-daily abacavir and lamivudine to the once-daily fixed-dose combination tablet of abacavir and lamivudine improves patient adherence and satisfaction with therapy.

BACKGROUND: Patients prefer fewer pills and once-daily (qd) dosing without food restrictions. We assessed the impact on adherence [by Medication Event Monitoring System (MEMS) cap monitoring] of switching from abacavir (ABC) and lamivudine (3TC) twice daily (bid) to ABC/3TC fixed-dose formulation (FDC, Kivexa) qd to achieve a qd regimen. METHODS: A randomized, open-label, 8-week study comparing adherence, efficacy and safety of immediate vs. delayed switching from ABC/3TC to FDC qd. RESULTS: Ninety-four patients were dosed. Significantly improved adherence was observed at week 4 with qd ABC/3TC across all three adherence variables: taking compliance 99.2% (90.7-100%) vs. 96.6% (60.0-100%) (P=0.017); dosing compliance 97.1% (64.3-100%) vs. 91.9% (33.3-100%) (P=0.016); and timing compliance 95.5% (53.8-100%) vs. 86.3% (4.3-100%) (P=0.006). Treatment satisfaction increased significantly at week 4 with ABC/3TC qd [92% (82-99%) vs. 85% (75-93%) (P=0.004)]. Two patients were withdrawn from the study because of intolerance to ABC/3TC. CONCLUSIONS: Switching from ABC and 3TC bid to ABC/3TC FDC qd significantly improved adherence by MEMS cap monitoring at week 4 and improved patient satisfaction with therapy. The results remain to be confirmed over a longer follow-up. Use of qd regimens supports adherence and improves treatment satisfaction relative to bid regimens.

Low levels of neurocognitive impairment detected in screening HIV-infected men who have sex with men: The MSM Neurocog Study.

This study aimed to determine the prevalence of HIV neurocognitive impairment in HIV-infected men who have sex with men aged 18-50 years, using a simple battery of screening tests in routine clinical appointments. Those with suspected abnormalities were referred on for further assessment. The cohort was also followed up over time to look at evolving changes. HIV-infected participants were recruited at three clinical sites in London during from routine clinical visits. They could be clinician or self-referred and did not need to be symptomatic. They completed questionnaires on anxiety, depression, and memory. They were then screened using the Brief Neurocognitive Screen (BNCS) and International HIV Dementia Scale (IHDS). Two hundred and five HIV-infected subjects were recruited. Of these, 59 patients were excluded as having a mood disorder and two patients were excluded due to insufficient data, leaving 144 patients for analysis. One hundred and twenty-four (86.1%) had a normal composite z score (within 1 SD of mean) calculated for their scores on the three component tests of the BNCS. Twenty (13.9%) had an abnormal z score, of which seven (35%) were symptomatic and 13 (65%) asymptomatic. Current employment and previous educational level were significantly associated with BNCS scores. Of those referred onwards for diagnostic testing, only one participant was found to have impairment likely related to HIV infection. We were able to easily screen for mood disorders and cognitive impairment in routine clinical practice. We identified a high level of depression and anxiety in our cohort. Using simple screening tests in clinic and an onward referral process for further testing, we were not able to identify neurocognitive impairment in this cohort at levels consistent with published data.

Psychological predictors of injury among elite athletes.

OBJECTIVES: To establish injury rates among a population of elite athletes, to provide normative data for psychological variables hypothesised to be predictive of sport injuries, and to establish relations between measures of mood, perceived life stress, and injury characteristics as a precursor to introducing a psychological intervention to ameliorate the injury problem. METHODS: As part of annual screening procedures, athletes at the Queensland Academy of Sport report medical and psychological status. Data from 845 screenings (433 female and 412 male athletes) were reviewed. Population specific tables of normative data were established for the Brunel mood scale and the perceived stress scale. RESULTS: About 67% of athletes were injured each year, and about 18% were injured at the time of screening. Fifty percent of variance in stress scores could be predicted from mood scores, especially for vigour, depression, and tension. Mood and stress scores collectively had significant utility in predicting injury characteristics. Injury status (current, healed, no injury) was correctly classified with 39% accuracy, and back pain with 48% accuracy. Among a subset of 233 uninjured athletes (116 female and 117 male), five mood dimensions (anger, confusion, fatigue, tension, depression) were significantly related to orthopaedic incidents over the preceding 12 months, with each mood dimension explaining 6-7% of the variance. No sex differences in these relations were found. CONCLUSIONS: The findings support suggestions that psychological measures have utility in predicting athletic injury, although the relatively modest explained variance highlights the need to also include underlying physiological indicators of allostatic load, such as stress hormones, in predictive models.

Quality of life outcomes of combination zalcitabine-zidovudine, saquinavir-zidovudine, and saquinavir-zalcitabine-zidovudine therapy for HIV-infected adults with CD4 cell counts between 50 and 350 per cubic millimeter. PISCES (SV14604) Study Group.

BACKGROUND: This double-blind study evaluated treatment with zalcitabine-zidovudine, saquinavir-zidovudine, or saquinavir-zalcitabine-zidovudine on the health-related quality of life of HIV-infected adults with CD4 cell counts between 50 and 350 cells/mm3. METHODS: Nine hundred and ninety-three HIV-infected male or female quality of life substudy patients aged 18 years or older, with CD4 cell counts between 50 and 350 cells/mm3 naïve to antiretroviral therapy or with less than 16 weeks of zidovudine therapy, were randomly assigned to one of three daily regimens: zalcitabine 0.75 mg and zidovudine 200 mg every 8 h (ddC/ZDV); saquinavir 600 mg and zidovudine 200 mg every 8 h (SQV/ZDV); or saquinavir 600 mg, zalcitabine 0.75 mg and zidovudine 200 mg every 8 h (SQV/ddC/ZDV). The health-related quality of life was measured using the Medical Outcome Study HIV (MOS-HIV) Health Survey subscale and physical and mental health summary scores, and a global visual analogue scale (VAS) score. The primary health-related quality of life endpoints were the MOS-HIV physical and mental health summary scores. RESULTS: After 24 weeks of treatment, no statistically significant differences were observed between the three treatment groups on physical health and mental health summary scores (global test P = 0.118). After 48 weeks of treatment, statistically significant differences among the groups were observed for physical health and mental health summary scores (global test P = 0.020); no change in physical health summary scores from the baseline were seen in the triple combination therapy, whereas the ddC/ZDV combination therapy group showed decreases from baseline in physical health summary scores (P = 0.008). Six of the 10 individual MOS-HIV subscale scores and the VAS scores showed results consistent with the physical health summary endpoints after 48 weeks of therapy. No statistically significant differences in baseline to 48 week changes in MOS-HIV subscale or summary scores were seen between the ddC/ZDV and SQV/ZDV groups (P > 0.05). CONCLUSIONS: Patients on triple combination therapy maintained their quality of life over 48 weeks compared with significant decreases in the quality of life for ddC/ZDV combination therapy.

Dietary advice with or without pravastatin for the management of hypercholesterolaemia associated with protease inhibitor therapy.

BACKGROUND: Therapy with a HIV protease inhibitor is associated with elevations in cholesterol and triglycerides. HMG-CoA reductase inhibitors ('statins') are the established therapy for persons with primary hypercholesterolaemia. Because of drug interactions, pravastatin may represent the preferred choice in those taking HIV protease inhibitors. DESIGN: A randomized, open-label comparative 24 week trial of dietary advice alone or with pravastatin in 31 male patients established on protease inhibitor-based regimens for greater than 12 weeks with viral load < 500 copies/ml and cholesterol > 6.5 mmol/l. RESULTS: There were no significant clinical or laboratory events and no patient discontinuation secondary to adverse effects. Viral rebound did not occur. Relative to baseline, total cholesterol at week 24 fell significantly in the pravastatin (1.2 mmol/l; 17.3%) (P < 0.05) but not in the dietary advice (0.3 mmol/l; 4%) group. The difference between the two groups approached significance at week 24 (P = 0.051). This fall was accounted for entirely by a reduction in low density lipoprotein [calculated change 1.24 mmol/l (19%) and 0.07 mmol (5.5%) in pravastatin and dietary advice groups, respectively] as high density lipoprotein rose non-significantly by 0.6 mmol/l in both groups. Weight, basal metabolic rate, fasting glucose and triglycerides did not change significantly in either group. CONCLUSIONS: Dietary advice plus pravastatin significantly reduced total cholesterol in HIV-positive individuals taking protease inhibitors, without significant adverse effects. The inclusion of pravastatin substantially increases the magnitude of the change, which is comparable with changes achieved in endogenous hyperlipidaemia.

Progressive CD4 cell depletion and death in zidovudine-treated patients.

Preliminary evidence suggests that a CD4 cell count < 50 cells/mm3 is associated with a particularly poor short-term prognosis, and is both necessary and sufficient for death associated with HIV infection. We sought to validate these findings in a cohort of 1,415 zidovudine (ZDV)-treated patients, with advanced HIV infection, and to examine more closely the profile of CD4 cell decline over the 2 years prior to death. As of December 31, 1991, 432 patients had died. The cumulative 2 year survival of patients once their CD4 cell count fell to < or = 50 cells/mm3 (median survival = 17.3 months) was substantially shorter at 25.7%, than from when their CD4 cell counts first fell within the range 51-100/mm3 (51.4%); 101-150/mm3 (67.3%); or 151-200/mm3 (76.5%). The percent of patients with a CD4 count < 50 cells/mm3, increased from 33% at 24 months prior to death to 58% at 12 months and 86% at 1 month. Patients with a CD4 count > or = 50 cells/mm3 in the month prior to death, were significantly older (p < 0.001) and had higher CD4 cell counts (p < 0.05) at initiation of ZDV compared to those with a CD4 count < 50 cells/mm3. There were no important differences in HIV risk category, duration of ZDV therapy or use of PCP prophylaxis between the two groups. These findings highlight the importance of more intensive monitoring of patients with CD4 counts < 50 cells/mm3, since life-threatening opportunistic infections are more likely to supervene at this stage. A CD4 count < 50 may also be a useful surrogate endpoint for survival in clinical trials.

Finding a role for zalcitabine in the HAART era.

Zalcitabine (ddC) is a nucleoside analogue reverse transcriptase inhibitor with demonstrated clinical benefit in combination use. More widespread use of zalcitabine has been limited by a number of factors including peripheral neuropathy and three times daily dosing. However, screening for the risk factors for peripheral neuropathy may enable a reduction in the incidence of neuropathy to below 10%. Additionally, new data on the use of zalcitabine twice daily suggest, based on the long intracellular half-life of the active triphosphate, that this is feasible. Additionally, while limited data exist for zalcitabine in true HAART combinations, data from small trials suggest a similar proportion of responders to standard HAART regimens.

The role of didanosine in the management of HIV-1 infection.

Large-scale clinical end point studies comparing antiretroviral therapy with zidovudine alone, didanosine alone, and zidovudine combined with didanosine indicate that both didanosine alone and zidovudine/didanosine provide a better clinical outcome than zidovudine alone in patients with human immunodeficiency virus (HIV) infection. The superiority of combination didanosine/zidovudine therapy over zidovudine monotherapy was most significant in treatment-naive patients, but benefit was also seen in patients who had previously received zidovudine and also in all stages of disease. Activity marker data from other studies suggest that double or triple combination therapies that include didanosine and nucleoside analogues other than zidovudine, non-nucleoside reverse transcriptase inhibitors or protease inhibitors result in powerful suppression of viral replication that will provide additional clinical benefits. Apart from mostly mild gastrointestinal disturbances, didanosine alone and in various combination therapies has been generally well tolerated. Thus, didanosine represents a potent, versatile nucleoside analogue with potential benefits in both current and future antiretroviral regimens for HIV infection.

The role of stavudine in the management of adults with HIV infection.

Combinations of two nucleoside analogue reverse transcriptase inhibitors plus a third agent represent the current standard for antiretroviral therapy. Stavudine is a nucleoside analogue that demonstrates in vitro activity against human immunodeficiency virus type 1 (HIV-1) and HIV-2 within an acceptable therapeutic index in a range of T lymphocyte and haematopoietic precursor cell lines. It is additive or synergistic in vitro with a number of other antiretrovirals including protease inhibitors in two and three way combinations and is active against zidovudine-resistant virus. It exhibits excellent oral bioavailability, with CSF penetration. In clinical use, stavudine exhibits antiretroviral activity as a monotherapy similar to zidovudine, and is of proven clinical benefit in zidovudine-pretreated patients. In combination with didanosine and/or nelfinavir it results in more substantial and durable responses in immunological and virological markers than reported with either drug alone. Comparative trials in zidovudine-experienced patients suggest a similar frequency of adverse events to that observed with zidovudine. Peripheral neuropathy is the most common dose-limiting toxicity with haematological and hepatic function disturbance being infrequent. Reasons for stavudine failure are not established, with no consistent genotypic pattern being associated with changes in stavudine sensitivity in vitro or in vivo. The role of stavudine is as a component of triple therapy regimens both in initial therapy and in patients with prior zidovudine experience.