The effect of protease inhibitor-based dual antiretroviral regimens on CD4/CD8 ratio during the first year of therapy in ART-naïve patients with HIV-infection.

OBJECTIVES: To assess the effect of protease inhibitor (PI)-based dual therapy on CD4/CD8 ratio during the first year of therapy in antiretroviral therapy (ART)-naïve patients using data from randomized controlled clinical trials. METHODS: We pooled data from the GARDEL and ANDES studies, both randomized controlled clinical trials that recruited ART-naïve people living with HIV and randomly assigned them to receive PI-based dual therapy (DT) or triple therapy (TT) aiming to compare viral efficacy. We compared median CD4/CD8 ratios and the proportion of patients with CD4/CD8 ratio > 1 at 48 weeks after ART initiation in both treatment arms using the Mann-Whitney U-test and the χ2 test. We performed subgroup analysis for patients > 50 years old, with baseline CD4 counts ≤ 200 cells/µL, viral load > 100 000 HIV RNA copies/mL, and ritonavir-boosted lopinavir-based therapy. RESULTS: We analysed data from 571 patients: 292 on DT and 279 on TT. No differences were observed in CD4/CD8 ratio (0.632 vs. 0.617, P = 0.729) or in the proportion of patients with CD4/CD8 ratio > 1 (17.9% vs. 19.3%, P = 0.678) 48 weeks after ART initiation. Subgroup analysis showed no further differences. CONCLUSION: The impact of PI-based DT regimens on the CD4/CD8 ratio during the first year of treatment for ART-naïve patients is similar to that of TT.

Etravirine in treatment-experienced, HIV-1-infected children and adolescents: 48-week safety, efficacy and resistance analysis of the phase II PIANO study.

OBJECTIVES: PIANO (Paediatric study of Intelence As an NNRTI Option; TMC125-C213; NCT00665847) assessed the safety/tolerability, antiviral activity and pharmacokinetics of etravirine plus an optimized background regimen (OBR) in treatment-experienced, HIV-1-infected children (≥ 6 to < 12 years) and adolescents (≥ 12 to < 18 years) over 48 weeks. METHODS: In a phase II, open-label, single-arm study, 101 treatment-experienced patients (41 children; 60 adolescents) with screening viral load (VL) ≥ 500 HIV-1 RNA copies/mL received etravirine 5.2 mg/kg (maximum dose 200 mg) twice a day (bid) plus OBR. RESULTS: Sixty-seven per cent of patients had previously used efavirenz or nevirapine. At week 48, the most common treatment-related grade ≥ 2 adverse event (AE) was rash (13%); 12% experienced grade 3 AEs. Only two grade 4 AEs occurred (both thrombocytopaenia, not etravirine related). At week 48, 56% of patients (68% children; 48% adolescents) achieved a virological response (VL<50 copies/mL; intent-to-treat, noncompleter=failure). Factors predictive of response were adherence > 95%, male sex, low baseline etravirine weighted genotypic score and high etravirine trough concentration (C0h ). Seventy-six patients (75%) completed the trial; most discontinuations occurred because of protocol noncompliance or AEs (8% each). Sixty-five per cent of patients were > 95% adherent by questionnaire and 39% by pill count. Forty-one patients experienced virological failure (VF; time-to-loss-of-virological-response non-VF-censored algorithm) (29 nonresponders; 12 rebounders). Of 30 patients with VF with paired baseline/endpoint genotypes, 18 (60%) developed nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations, most commonly Y181C. Mean etravirine area under the plasma concentration-time curve over 12 h (AUC0-12h ; 5216 ng h/mL) and C0h (346 ng/mL) were comparable to adult target values. CONCLUSIONS: Results with etravirine 5.2 mg/kg bid (with OBR) in this treatment-experienced paediatric population and etravirine 200 mg bid in treatment-experienced adults were comparable. Etravirine is an NNRTI option for treatment-experienced paediatric patients.

The immunomodulatory nutritional intervention NR100157 reduced CD4+ T-cell decline and immune activation: a 1-year multicenter randomized controlled double-blind trial in HIV-infected persons not receiving antiretroviral therapy (The BITE Study).

BACKGROUND: The immunomodulatory nutritional product NR100157 was developed for human immunodeficiency virus (HIV)-infected individuals. We hypothesized that targeting the compromised gastrointestinal tract of HIV-infected individuals would result in systemic immunological benefits. METHODS: In a multicenter, randomized, controlled, double-blind trial, 340 HIV-1-positive adults not on antiretroviral therapy, with CD4(+) T-cell counts <800/µL, were given either NR100157 or an isocaloric and isonitrogenous control for 52 weeks. Primary outcome was CD4(+) T-cell count. Secondary outcomes included plasma viral load (pVL), safety, and tolerability. In a pilot study (n = 20), levels of CD4(+)CD25(+) and CD8(+)CD38(+) activation were measured (n = 20). The trial is registered at the Dutch Trial Register (NTR886) and ISRCTN81868024. RESULTS: At 52 weeks, CD4(+) T-cell decline showed a 40-cell/µL difference (P = .03) in the intention-to-treat population in favor of the immunomodulatory NR100157 (control vs active, -68 ± 15 vs -28 ± 16 cells/µL/year). The change in pVL from baseline was similar between groups (P = .81). In the pilot study, the percentage of CD4(+)CD25(+) was lower in the active group (P < .05) and correlated with changes in CD4(+) T-cell count (r = -0.55, P < .05). The percentage of CD8(+)CD38(+) levels was unaffected. CONCLUSIONS: The specific immunonutritional product NR100157 significantly reduces CD4(+) decline in HIV-1-infected individuals, and this is associated with decreased levels of CD4(+)CD25(+). (This nutritional intervention is likely to affect local gut integrity and gut-associated lymphoid tissue homeostasis, which in turn translates positively to systemic effects.) Clinical Trials Registration. ISRCTN81868024.

Subgroup analysis of virological response rates with once- and twice-daily darunavir/ritonavir in treatment-experienced patients without darunavir resistance-associated mutations in the ODIN trial.

BACKGROUND: ODIN (once-daily darunavir in treatment-experienced patients) was a 48-week, phase III, randomized, open-label trial comparing once-daily (qd) darunavir/ritonavir (DRV/r) 800/100 mg with twice-daily (bid) DRV/r 600/100 mg, both with an optimized background regimen [OBR; at least two nucleoside reverse transcriptase inhibitors (NRTIs)], in treatment-experienced, HIV-1-infected adults with no DRV resistance-associated mutations (RAMs) at screening. Week 48 analyses of virological response by subgroups are reported. METHODS: A total of 590 patients were randomized to receive qd (n=294) or bid (n=296) DRV/r. Virological response (HIV-1 RNA <50 copies/mL) was assessed according to: screening HIV-1 RNA (≥ or <50000 copies/mL), CD4 cell count, prior protease inhibitor (PI) use, number of active NRTIs in the OBR, presence of mutations (primary PI mutations, PI RAMs or M184V/I), gender, age, race, HIV-1 clade and adherence. RESULTS: Baseline characteristics were well balanced between arms and across subgroups. Response rates were comparable between qd and bid DRV/r treatments for all subgroups examined. Response rates were 78.4 and 76.8% in the qd and bid treatment arms, respectively, in patients with baseline HIV-1 RNA ≤ 50000 copies/mL and 52.8% in both arms in those with > 50000 copies/mL. Response rates for the qd and bid treatment arms by baseline CD4 cell count were also similar (69.6 vs. 65.2% for <200 cells/µL; 72.2 vs. 74.8% for 200- <350 cells/µL; 77.0 vs. 74.3% for ≥ 350 cells/µL). CONCLUSIONS: DRV/r administered either qd or bid provided effective treatment for antiretroviral treatment-experienced patients with no DRV RAMs, with comparable response rates across all subgroups studied. Low patient numbers in specific subgroups may limit interpretation of these specific subgroup results.

Analysis of sequences of hepatitis C virus NS5A genotype 1 in HIV-coinfected patients with a null response to nitazoxanide or peg-interferon plus ribavirin.

Even though new drugs have been approved for treatment of hepatitis C virus (HCV) infection, the risk of drug-drug interactions and concern about overlapping toxicities has hindered the development of studies in HIV/HCV-coinfected individuals. Traditional treatment with pegylated interferon plus ribavirin (peg-IFN + RBV) is very expensive and has a low rate of sustained virological response in coinfected patients, especially if they are infected with HCV genotype 1. Nitazoxanide (NTZ) is a drug that is being evaluated for the treatment of chronic HCV infection, both in HCV-monoinfected and HIV/HCV-coinfected patients. Understanding the NTZ resistance mechanism could allow the development of resistance to be minimized and would expand the treatment options, mainly in special populations such as HIV/HCV-coinfected patients. Similarly to IFN, NTZ increases the activity of the cellular protein kinase activated by double-stranded RNA (PKR), a key kinase in the innate antiviral response. In order to elucidate whether sequence heterogeneity in the PKR-binding domain of HCV NS5A genotype 1 could influence the antiviral activity of either NTZ monotherapy or peg-IFN + RBV, baseline and end-of-therapy plasma samples from two groups of eleven non-responder HIV/HCV-coinfected patients that had received NTZ or peg-IFN + RBV were studied. Most of the HCV NS5A sequences examined at the end of therapy did not change from the baseline, even after 30 days course of antiviral therapy. An extensive comparison of HCV NS5A genotype 1 and 4 sequences from the database with reported IFN therapy outcome was performed in order to infer their phylogenetic relationships. The HCV genotype 1 NS5A nucleotide sequences from therapy-non-responder patients were intermingled amongst those from the database, irrespective of their IFN-therapy outcome. When comparing NS5A-PKRBD amino acid sequences, significant differences were observed in genotype 4, but not in genotype 1 (p < 0.0001 and p > 0.05, respectively). In conclusion, despite IFN and NTZ sharing the protein kinase activated by double-stranded RNA as their cellular target, the HCV genotype 1 strategy to counteract the IFN action mediated by NS5A ISDR/PKRBD does not explain drug resistance in HIV/HCV-coinfected patients. Other viral factors that are possibly involved are discussed as well.

Antiviral activity of apricitabine in treatment-experienced HIV-1-infected patients with M184V who are failing combination therapy.

OBJECTIVES: Apricitabine (ATC) is a novel deoxycytidine analogue nucleoside reverse transcriptase inhibitor (NRTI) with significant antiviral activity in vitro, including activity against HIV-1 with reverse transcriptase mutations that confer resistance to other NRTIs. ATC has shown promising antiviral activity and good tolerability when given as monotherapy for 10 days in treatment-naïve HIV-1-infected patients. METHODS: In this Phase II randomized, double-blind study, 51 treatment-experienced HIV-1-infected patients with the reverse transcriptase mutation M184V who were failing therapy which included lamivudine (3TC) were randomized to receive twice-daily 600 mg ATC, 800 mg ATC or 150 mg 3TC for 21 days. Patients remained on their existing background regimen until day 21, when background therapy could be optimized according to genotype at screening. RESULTS: At day 21, the mean change in viral load was -0.71 and -0.90 log(10) HIV-1 RNA copies/mL in the 600 and 800 mg ATC groups, respectively, compared with a -0.03 log(10) change in the 3TC group. In patients with at least three thymidine analogue mutations (TAMs) at baseline, greater reductions in viral load were observed in the 800 mg ATC group at day 21 than in the 600 mg ATC group. Few genotypic changes were detected at day 21 [two patients (600 mg ATC) lost and three patients (800 mg ATC) gained a TAM] and all patients with detectable virus retained the M184V mutation. The safety profiles of the two ATC doses were similar to that of 3TC. CONCLUSIONS: Over the 21-day treatment period, ATC showed promising antiviral activity and was well tolerated in treatment-experienced patients with M184V, with or without additional TAMs.

Prioritising prevention strategies for patients in antiretroviral treatment programmes in resource-limited settings.

Expanded access to antiretroviral therapy (ART) offers opportunities to strengthen HIV prevention in resource-limited settings. We invited 27 ART programmes from urban settings in Africa, Asia and South America to participate in a survey, with the aim to examine what preventive services had been integrated in ART programmes. Twenty-two programmes participated; eight (36%) from South Africa, two from Brazil, two from Zambia and one each from Argentina, India, Thailand, Botswana, Ivory Coast, Malawi, Morocco, Uganda and Zimbabwe and one occupational programme of a brewery company included five countries (Nigeria, Republic of Congo, Democratic Republic of Congo, Rwanda and Burundi). Twenty-one sites (96%) provided health education and social support, and 18 (82%) provided HIV testing and counselling. All sites encouraged disclosure of HIV infection to spouses and partners, but only 11 (50%) had a protocol for partner notification. Twenty-one sites (96%) supplied male condoms, seven (32%) female condoms and 20 (91%) provided prophylactic ART for the prevention of mother-to child transmission. Seven sites (33%) regularly screened for sexually transmitted infections (STI). Twelve sites (55%) were involved in activities aimed at women or adolescents, and 10 sites (46%) in activities aimed at serodiscordant couples. Stigma and discrimination, gender roles and funding constraints were perceived as the main obstacles to effective prevention in ART programmes. We conclude that preventive services in ART programmes in lower income countries focus on health education and the provision of social support and male condoms. Strategies that might be equally or more important in this setting, including partner notification, prompt diagnosis and treatment of STI and reduction of stigma in the community, have not been implemented widely.

Bioinformatic analysis of post-transmission viral readaptation in Argentine patients with acute HIV-1 infection.

During the acute phase of HIV-1 infection, a strong readaptation occurs in the viral population. Our objective was to analyze the post-transmission mutations associated with escape to the cytotoxic immune response and its relationship with the progression of the infection. In this study, a total of 17 patients were enrolled during acute/early primary HIV infection and 8 subjects that were the HIV positive partner resulting in 8 transmission pairs. Genotyping of the genetic polymorphisms of HLA class I A and B was performed using PCR-SSOP. Viral RNA extraction was from plasma. 570 single Gag-gene amplifications were obtained by limiting-dilution RT-PCR. Epitope prediction was performed with NetMHC CBS prediction server for the 19 HLA-A and B alleles. Cytotoxic response prediction was performed by using the IEDB Analysis Resource. From our results, we deduce that the transmitted CTL / gag escape frequency in the founder virus was at least double compared to the post-transmission events. Additionally, by means of an algorithm that combines these frequencies, we observed that the founder viruses better adapted to the HLA A / B alleles of the recipient could contribute to a greater progression of the infection. Our results suggest that there is a large adaptation of HIV-1 to the HLA A / B alleles prevalent in our population. However, despite this adaptive advantage, the virus needs to make "readjustments" through new escape and compensatory mutations. Interestingly, according to our results, this readaptation could have a role in the progression of the infection.

Use of darunavir and enfuvirtide in a pregnant woman.

SUMMARY: A 41-year-old pregnant woman with multiple virological failures started darunavir, enfuvirtide, zidovudine and lamivudine at week 28 of pregnancy. During week 38, the patient had a viral load <400 copies/mL and a CD4 count of 180 cells/mm(3) (13%). The child was found to be in good health, with negative HIV-polymerase chain reactions at birth, at two and at six months.

Hepatitis B virus genotype distribution and its lamivudine-resistant mutants in HIV-coinfected patients with chronic and occult hepatitis B.

Hepatitis B virus (HBV) genotypes were examined in HIV-infected patients with chronic and occult HBV infection. From a total population of 593 HIV-infected patients, 22 individuals (prevalence 3.7%) were found to be HBsAg while 72 (12.1%) were found to be anti-HBc alone. From them, 20 and 4 were HBV DNA positive, respectively. These last four patients are therefore considered to be HBV infected in an occult form. The genotypes could be determined in all 24 HBV-infected patients. HBV-A was the most common (20/24; 83.3%), followed by HBV-D (2/24; 8.3%) and HBV-F (1/24; 4.2%). The remaining sample exhibited mixed infection involving genotypes A and D as pure ones, thus also forming part of three intergenotypic recombinant forms exhibiting different mosaic S gene patterns. The sexual route of transmission was predominant among HBV genotype A-infected patients. Among the 24 HBV DNA-positive patients, point mutations related to lamivudine resistance were found in four strains. These viral strains showed a methionine-to-valine substitution at codon 204 (rtM204V) in association with an upstream B-domain change at rtL180M. Additionally, two of them exhibited the additional rtV173L mutation. The value of HBV molecular monitoring including both HBV viral genomic characterization and genotypic resistance profile in HIV-HBV-coinfected individuals is discussed.

Bayesian network analysis of resistance pathways against HIV-1 protease inhibitors.

Interpretation of Human Immunodeficiency Virus 1 (HIV-1) genotypic drug resistance is still a major challenge in the follow-up of antiviral therapy in infected patients. Because of the high degree of HIV-1 natural variation, complex interactions and stochastic behaviour of evolution, the role of resistance mutations is in many cases not well understood. Using Bayesian network learning of HIV-1 sequence data from diverse subtypes (A, B, C, F and G), we could determine the specific role of many resistance mutations against the protease inhibitors (PIs) nelfinavir (NFV), indinavir (IDV), and saquinavir (SQV). Such networks visualize relationships between treatment, selection of resistance mutations and presence of polymorphisms in a graphical way. The analysis identified 30N, 88S, and 90M for nelfinavir, 90M for saquinavir, and 82A/T and 46I/L for indinavir as most probable major resistance mutations. Moreover we found striking similarities for the role of many mutations against all of these drugs. For example, for all three inhibitors, we found that the novel mutation 89I was minor and associated with mutations at positions 90 and 71. Bayesian network learning provides an autonomous method to gain insight in the role of resistance mutations and the influence of HIV-1 natural variation. We successfully applied the method to three protease inhibitors. The analysis shows differences with current knowledge especially concerning resistance development in several non-B subtypes.

HCV genotype distribution among HIV co-infected individuals in Argentina: relationship with host and viral factors.

Coinfection with hepatitis C virus (HCV) in individuals infected with HIV is associated with a higher incidence of liver injury hepatic decompensation, and decreased survival than that observed in an HIV-monoinfected population. While prevalence studies on HIV/HCV coinfection have been performed in the U.S. and in some European countries, little is known about HCV genotype distribution in Latin America. The main objective was to evaluate the HCV prevalence and genotypes among HIV co-infected patients, and their relationship with HCV viral load, serum ALT level and T lymphocyte CD4+ cell count. These data pursue to increase the knowledge from South America about a pressing problem from HIV-infected patients. Retrospectively collected specimens from 593 HIV-positive individuals in Argentina were tested for anti-HCV These were analyzed for HCV-RNA qualitatively and quantitatively. The HCV genotype was determined by the RFLP method. One hundred and twenty-nine (21.7%) HIV-infected individuals were anti-HCV positive; 65.9% of them exhibited detectable HCV-RNA. Genotype 1 (43, la/c; 9, 1b; and 5, 1a/c+1b) was present in 57, while 1, 14 and 13 were infected with genotype 2, 3 or a mix, respectively. Co-infected individuals were more likely to be male, without significant differences in age and CD4+ cell counts than HIV-monoinfected individuals. HCV infection prevalence in patients co-infected with HIV highlights the impending public health impact of this problem. Considering the increasing rate of HCV genotypes with lower response rates to treatment among HIV co-infected patients, antiretroviral therapy success might be jeopardized by HCV coinfection.

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.

Abacavir compared to protease inhibitors as part of HAART regimens for treatment of HIV infection: patient satisfaction and implications for adherence.

The purpose of this study was to compare treatment satisfaction with triple nucleoside reverse transcriptase inhibitor (NRTI) highly active antiretroviral treatment (HAART) regimens including abacavir (ABC) to HAART regimens that include protease inhibitors (PIs) and to estimate the relationship between patient satisfaction and adherence to HAART. Three open-label clinical trials comparing ABC-including HAART regimens with PI-including HAART regimens were completed, two with patients previously untreated with antiretroviral therapy and one with patients successfully treated with PI-including HAART regimens. The HIV Treatment Satisfaction Questionnaire (HIVTSQ) was completed at several time points during each trial. Levels of patient satisfaction with the ABC and PI regimens were compared for all three trials. The correlation between adherence and patient satisfaction scores was measured using data from an adherence questionnaire in one of the studies. In all three clinical trials, patient satisfaction scores were significantly higher with an ABC-including triple NRTI HAART regimen than with a PI-including HAART regimen. The difference was apparent by week 4 of the trial and was maintained throughout the trial time period. Inspection of the item responses in the patient satisfaction questionnaire indicated that treatment convenience, flexibility, impact on lifestyle, and side effects were key factors in the difference in satisfaction between the treatment groups. In addition, patient satisfaction was shown to be significantly correlated with adherence defined as taking 95% or more of prescribed doses. Greater satisfaction was reported by patients given an ABC-including HAART regimen than those given a PI-including HAART regimen. Patient satisfaction may be an indicator for better treatment adherence.

Comparative studies of two-times-daily versus three-times-daily indinavir in combination with zidovudine and lamivudine.

OBJECTIVES: To compare the efficacy and safety of two-times-daily versus three-times-daily indinavir in combination with zidovudine and lamivudine. DESIGN: Two multicenter, open-label, randomized 24-week studies. METHODS: Adults HIV-1 infection, HIV-1 RNA greater than 10000 copies/ml, and no prior lamivudine or protease inhibitor therapy were eligible. In a pilot study (Study A), patients received indinavir at 800 mg every 8 h, 1000 mg every 12 h, or 1200 mg every 12 h. In a subsequent study (Study B), patients received indinavir at 800 mg every 8 h or 1200 mg every 12 h. All subjects received zidovudine (300 mg) and lamivudine (150 mg) every 12 h. An intent-to-treat analysis was used. RESULTS: In Study A, which enrolled 88 patients, neither HIV-1 RNA nor CD4 cell responses differed significantly between treatment groups at 24 weeks when corrected for multiple comparisons. Study B enrolled 433 patients, but was prematurely discontinued when interim analysis suggested greater efficacy of three-times-daily indinavir. Of the first 87 patients reaching week 24, HIV-1 RNA was less than 400 copies/ml in 91% receiving three-times-daily versus 64% receiving two-times-daily indinavir (P < 0.01). CONCLUSION: Three-times-daily indinavir appears more efficacious than two-times-daily dosing when administered with zidovudine and lamivudine. Two-times-daily indinavir dosing should only be considered in situations characterized by favorable pharmacokinetic drug-drug interactions.

Brain-stem auditory evoked potentials in human immunodeficiency virus-seropositive patients with and without acquired immunodeficiency syndrome.

Brain-stem auditory evoked potentials were recorded in 35 human immunodeficiency virus (HIV)-seropositive subjects from the Centers for Disease Control groups III and IV, 24 HIV-negative drug abusers, and 62 normal healthy controls. None of the patients had evidence of neurological complications. History of alcohol consumption was an exclusion criterion. The values of central conduction times I-V and III-V showed significant differences between the HIV-seropositive subjects and normal healthy controls, as well as between the HIV-seropositive subjects and HIV-negative drug abusers. Central conduction times I-III showed no differences between groups, except in the left ear of Centers for Disease Control group IV compared with controls. No statistical differences were found in the central conduction times between HIV-negative drug abusers and normal healthy controls. The results suggest a subclinical involvement of the upper brain stem in HIV infection. It could be produced by direct action of the virus on central nervous system structures.

Treatment of primary HIV infection: a pilot study of stavudine and didanosine plus nevirapine with or without hydroxyurea.

Treatment of primary human immunodeficiency virus (HIV) infection (PHI) may provide an opportunity to achieve a long lasting suppression of viral replication. Although there is growing evidence of the benefit of treating PHI, clinical data are still very limited. Special therapeutic considerations in this clinical setting include the prevalence of resistant viruses in the community, complexity of regimens and their long-term toxicity. In addition, adjunctive therapies aimed at exploring the role of immune modulation and intensification of antiretroviral therapy are becoming areas of great interest. In this regard, the role of hydroxyurea, a cytostatic agent that potentiates the antiviral effect of didanosine, and possibly of stavudine is being investigated. A pilot study to assess the antiviral effect of a combination of didanosine plus stavudine plus nevirapine with or without hydroxyurea in the treatment of PHI is currently under way. Preliminary results on 22 patients who completed at least 36 weeks of therapy suggest that the combination is safe, well tolerated and effective for the treatment of PHI.

Resistance profiles to antiretroviral drugs in HIV-1 drug-naive patients in Argentina.

The drug resistance profile of treatment-naive HIV-infected individuals living in Buenos Aires, Argentina, was studied. Samples taken from 94 drug-naive individuals with established HIV infection and 13 patients with primary HIV infection were assessed by nucleotide sequencing and LIPA. The prevalence of drug-associated primary mutations in individuals with established infection was very low. In the viral protease region, 1/86 (1.2%) individuals carried the D30N mutation, whereas 1/85 (1.2%) had the M41L mutation in the reverse transcriptase (RT) region. Secondary mutations in both the protease and RT regions were found in almost 90% of the individuals. In individuals with primary infection, primary mutations were detected in 2/13 (15.4%) patients, one of them carrying M461 mutation in the protease while the other patient had a mutation at codon 184 of the RT. In accordance with current drug resistance testing guidelines, the results of this study suggest that susceptibility tests need not be performed at this time prior to initiation of antiretroviral therapy in HIV-1-infected people in Argentina. However, the public health implications of this subject warrant follow-up studies that will examine a larger number of drug-naive patients, not only in Buenos Aires but also in other major Argentinian cities and in rural areas.

AIDS in Latin America.

The epidemic in Latin America has placed an unexpected additional burden on the health care systems and national economies, already weak and affected by severe problems. Specific regional diseases in addition to common opportunistic infections, and particularly the high incidence of TB, produce a different picture compared with the United States and Europe. Access to ARV therapy is far from being universal in Latin America; nevertheless, some countries are providing HAART to all eligible patients, showing that it is not impossible to improve quality of care for people living with HIV infection in the region. Before assuming as definitive and irreversible that at least one or two generations will be sacrificed on the altar of inequity of our uneven world, we as acting scientists should join the struggle of millions of human beings claiming their right to be treated with the best drugs that science can offer today.

[Diarrhea and AIDS: more complex diagnostic techniques; better therapeutic results]. / Diarrea y SIDA: técnicas diagnósticas más complejas; mejores resultados terapéuticos.

During 17 months, 73 HIV-positive patients with diarrhea lasting at least for 14 days, were studied prospectively. The patients had stool specimen examinations negative for enteric pathogens, or positive for one of them, but with no response to specific treatment. All patients were subcomitted to digestive endoscopy and biopsies were taken for microbiological and histological studies. The etiology of the diarrhea could be established in 48 patients (66%). In 45, the cause was an enteric infection. There was association of 2 pathogens in 11 patients, and of 3 in 1 patient. The agents found were: Cryptosporidium (24%), MAI (16%), Giardia lambila (12%), isospora belli (5%), Shigella (5%), Salmonella (5%); Entamoeba histolytica (3%), HSV (3%), tuberculosis (2%), adherent bacteria (2%) and spirochetes (2%). In 3 patients the etiology was not infection, their diagnoses were coeliac disease, lymphoma and idiophatic colonic ulcers, respectively. In 51% of the cases only the examination of endoscopic biopsy specimens could identify the cause of the diarrhea. These results justify the use of these methods to improve diagnosis and therapeutic attempts in these patients.