Impact of highly active antiretroviral therapy on incidence and management of human immunodeficiency virus-related opportunistic infections

Forty years of HIV infection and AIDS in Taiwan: Reflection on the past and looking toward the future

We review the epidemiology, policies, and control programs of HIV infection in Taiwan in the past 40 years since the first case of HIV infection was diagnosed in 1984. With the introduction of combination antiretroviral therapy (ART) in Taiwan in 1997, the incidences of HIV-related opportunistic illnesses and mortality have significantly declined. However, despite improved access to HIV testing and treatment, late presentation of HIV infection remains common. Unprotected sex, particularly among men who have sex with men, continues to be the leading risk for HIV transmission after implementation of harm reduction program to control an outbreak of HIV infection among people who inject drugs that occurred in 2003-2007. The sequential introduction of well-tolerated, effective, single-tablet antiretroviral regimens has facilitated the implementation of "treat-all" policy in 2016, rapid ART initiation within 7 days of diagnosis in 2018, and same-day ART initiation in 2021 when immunochromatography was used for rapid confirmation of HIV infection. Government-funded pilot program of pre-exposure prophylaxis for HIV infection, which was launched in 2016 followed by wider enrollment of people at high risk for HIV acquisition in 2018, have contributed to sustained declines of the incidence of HIV infection since 2018, along with high rates of linkage to HIV care, ART initiation, viral suppression, and retention in care in Taiwan. Challenges remain to achieve HIV elimination and long-term successful management of HIV infection, which include stigma and discrimination, late presentation of HIV infection, and accelerated ageing with increasing rates of co-morbidities among people with HIV.

HIV Impairs Alveolar Macrophage Function via MicroRNA-144-Induced Suppression of Nrf2

BACKGROUND

Despite anti-retroviral therapy, HIV-1 infection increases the risk of pneumonia and causes oxidative stress and defective alveolar macrophage (AM) immune function. We have previously determined that HIV-1 proteins inhibit antioxidant defenses and impair AM phagocytosis by suppressing nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Given its known effects on Nrf2, we hypothesize miR-144 mediates the HIV-1 induced suppression of Nrf2.

METHODS

Primary AMs isolated from HIV-1 transgenic (HIV-1 Tg) rats and wild type littermates (WT) as well as human monocyte-derived macrophages (MDMs) infected ex vivo with HIV-1 were used. We modulated miR-144 expression using a miR-144 mimic or an inhibitor to assay its effects on Nrf2/ARE activity and AM functions in vitro and in vivo.

RESULTS

MiR-144 expression was increased in AMs from HIV-1 Tg rats and in HIV-1-infected human MDMs compared to cells from WT rats and non-infected human MDMs, respectively. Increasing miR-144 with a miR-144 mimic inhibited the expression of Nrf2 and its downstream effectors in WT rat macrophages and consequently impaired their bacterial phagocytic capacity and H₂O₂ scavenging ability. These effects on Nrf2 expression and AM function were reversed by antagonizing miR-144 ex vivo or in the airways of HIV-1 Tg rats in vivo, but this protection was abrogated by silencing Nrf2 expression.

CONCLUSIONS

Our results suggest that inhibiting miR-144 or interfering with its deleterious effects on Nrf2 attenuates HIV-1-mediated AM immune dysfunction and improves lung health in individuals with HIV.

Treating progressive disseminated histoplasmosis in people living with HIV

BACKGROUND

Progressive disseminated histoplasmosis (PDH) is a serious fungal infection that affects people living with HIV. The best way to treat the condition is unclear.

OBJECTIVES

We assessed evidence in three areas of equipoise. 1. Induction. To compare efficacy and safety of initial therapy with liposomal amphotericin B versus initial therapy with alternative antifungals. 2. Maintenance. To compare efficacy and safety of maintenance therapy with 12 months of oral antifungal treatment with shorter durations of maintenance therapy. 3. Antiretroviral therapy (ART). To compare the outcomes of early initiation versus delayed initiation of ART.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane CENTRAL; MEDLINE (PubMed); Embase (Ovid); Science Citation Index Expanded, Conference Proceedings Citation Index-Science, and BIOSIS Previews (all three in the Web of Science); the WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and the ISRCTN registry, all up to 20 March 2020.

SELECTION CRITERIA

We evaluated studies assessing the use of liposomal amphotericin B and alternative antifungals for induction therapy; studies assessing the duration of antifungals for maintenance therapy; and studies assessing the timing of ART. We included randomized controlled trials (RCT), single-arm trials, prospective cohort studies, and single-arm cohort studies.

DATA COLLECTION AND ANALYSIS

Two review authors assessed eligibility and risk of bias, extracted data, and assessed certainty of evidence. We used the Cochrane 'Risk of bias' tool to assess risk of bias in randomized studies, and ROBINS-I tool to assess risk of bias in non-randomized studies. We summarized dichotomous outcomes using risk ratios (RRs), with 95% confidence intervals (CI).

MAIN RESULTS

We identified 17 individual studies. We judged eight studies to be at critical risk of bias, and removed these from the analysis. 1. Induction We found one RCT which compared liposomal amphotericin B to deoxycholate amphotericin B. Compared to deoxycholate amphotericin B, liposomal amphotericin B may have higher clinical success rates (RR 1.46, 95% CI 1.01 to 2.11; 1 study, 80 participants; low-certainty evidence). Compared to deoxycholate amphotericin B, liposomal amphotericin B has lower rates of nephrotoxicity (RR 0.25, 95% CI 0.09 to 0.67; 1 study, 77 participants; high-certainty evidence). We found very low-certainty evidence to inform comparisons between amphotericin B formulations and azoles for induction therapy. 2. Maintenance We found no eligible study that compared less than 12 months of oral antifungal treatment to 12 months or greater for maintenance therapy. For both induction and maintenance, fluconazole performed poorly in comparison to other azoles. 3. ART We found one study, in which one out of seven participants in the 'early' arm and none of the three participants in the 'late' arm died.

AUTHORS' CONCLUSIONS

Liposomal amphotericin B appears to be a better choice compared to deoxycholate amphotericin B for treating PDH in people with HIV; and fluconazole performed poorly compared to other azoles. Other treatment choices for induction, maintenance, and when to start ART have no evidence, or very low certainty evidence. PDH needs prospective comparative trials to help inform clinical decisions.

Impact of Strain Competition on Bacterial Resistance in Immunocompromised Populations

Despite the risk of emerging drug resistance that occurs with the frequent use of antimicrobial agents, targeted and prophylactic antibiotics have been considered crucial to opportunistic infection management among the HIV/AIDS-immunocompromised. As we recently demonstrated, the disrupted selective pressures that occur in AIDS-prevalent host populations increase the probability of novel emergence. This effect is concerning, given that bacterial strains unresponsive to first-line antibiotics can be particularly dangerous to hosts whose immune response is insufficient to fight infection in the absence of antibiotic support. While greater host susceptibility within a highly immunocompromised population may offer a fitness advantage to drug-resistant bacterial strains, this advantage could be mitigated by increased morbidity and mortality among the AIDS-immunocompromised. Using a Susceptible-Exposed-Infectious-Recovered (SEIR) epidemiological model parameterized to reflect conditions in an AIDS-prevalent host population, we examine the evolutionary relationship between drug-sensitive and -resistant strains of Mycobacterium tuberculosis. We explore this relationship when the fitness of the resistant strain is varied relative to that of the sensitive strain to investigate the likely long-term multi-strain dynamics of the AIDS-mediated increased emergence of drug resistance.

Impact of chemorophylaxis policy for AIDS-immunocompromised patients on emergence of bacterial resistance

Chemoprophylaxis (antibiotic prophylaxis) is a long relied-upon means of opportunistic infection management among HIV/AIDS patients, but its use represents an evolutionary tradeoff: Despite the benefits of chemoprophylaxis, widespread use of antibiotics creates a selective advantage for drug-resistant bacterial strains. Especially in the developing world, with combined resource limitations, antibiotic misuse, and often-poor infection control, the emergence of antibiotic resistance may pose a critical health risk. Extending previous work that demonstrated that this risk is heightened when a significant proportion of the population is HIV/AIDS-immunocompromised, we work to address the relationship between HIV/AIDS patients' use of antibiotic chemoprophylaxis and the emergence of resistance. We apply an SEIR compartmental model, parameterized to reflect varying percentages of chemoprophylaxis use among HIV/AIDS+ patients in a resource-limited setting, to investigate the magnitude of the risk of prophylaxis-associated emergence versus the individual-level benefits it is presumed to provide. The results from this model suggest that, while still providing tangible benefits to the individual, chemoprophylaxis is associated with negligible decreases in population-wide morbidity and mortality from bacterial infection, and may also fail to provide assumed efficacy in reduction of TB prevalence.

Gastrointestinal Parasitic Infections and Immunological Status of HIV/AIDS Coinfected Individuals in Nigeria

BACKGROUND

Parasitic infections of the gastrointestinal tract is one of the highest causes of morbidity and mortality among HIV infected individuals. This is due to the colonization of the intestinal tract by parasites influenced by induced enteropathy caused by HIV infection. CD+4 t-lymphocytes count is a marker of the immune status of HIV infected individuals.

OBJECTIVE

This study investigated the prevalence of gastrointestinal parasitic infections among HIV coinfected individuals in relation to their immunological status.

METHODS

CD+4 t-lymphocytes count was determined using fluorescence-activated cell sorting (FACS) count system. Parasitological examination of faecal samples was conducted using direct wet mount, modified Z-N and Giemsa stain techniques. All prepared slides were examined under x10 and x40 objectives.

FINDINGS

Out of the 891 HIV seropositive participants on antiretroviral therapy that were studied, 641 (71.9%) had CD+4 counts equals to or greater than 500 cells/mm3. All other seropositive participants had CD+4 counts below 500 cells/mm3. Gastrointestinal parasitic infections were recorded in 187 (20.9%) seropositive participants, with females (n = 108, 12.1%) having more infections than males. Multiple gastrointestinal parasitic infections were recorded in 28 (3.1%) seropositive participants. Out of the 150 seronegative participants, 79 (52.7%) of them had at least one gastrointestinal parasitic infection. Female seronegative participants also accounted for higher infection rate (n = 42, 28.0%) than males (n = 37, 24.7%). Multiple infections were also recorded in 18 (12.0%) seronegative individuals. The overall prevalence rate of infection between both positive and negative individuals was 25.5%. There was statistical significant difference in the infections of Cryptosporidium parvum (p < 0.003), Cyclospora cayetanensis (p < 0.011) and Cystoisospora belli (p < 0.011) between HIV seropositive and HIV seronegative individuals. Also, there was statistical significant difference in the infections of hook worm (p < 0.002) and Trichuris trichiura (p < 0.020) between seronegative and seropositive individuals. Gastrointestinal parasitic infection rate was significantly higher among seropositive participants with CD+4 counts between 200 and 350 cells/mm3 (n = 109, 58.3%).

CONCLUSION

The study shows that HIV infected individuals continue to experience gastrointestinal infections even with antiretroviral treatment, especially those with CD+4 counts below 350 cells/mm3. Health care providers should prioritise routine screening of HIV patients for gastrointestinal parasites and provide prompt treatment. Antiparasitic drugs should also be provided as prophylaxis.

Outcomes of cryptococcosis in renal transplant recipients in a less-resourced health care system

BACKGROUND

Cryptococcosis is the second most common cause of invasive fungal infections in renal transplant recipients in many countries, and data on graft outcome after treatment for this infection is lacking in less-resourced health care settings.

METHODS

Data from 47 renal transplant recipients were retrospectively collected at a single institution during a period of 13 years. Graft dysfunction, graft loss, and mortality rates were evaluated. Predictors of mortality and graft loss were estimated.

RESULTS

A total of 38 (97.4%) patients treated with amphotericin B deoxycholate (AMBd) showed graft dysfunction after antifungal initiation and 8 (18.2%) had kidney graft loss. Graft loss within 30 days after cryptococcosis onset was significantly associated with disseminated infection, greater baseline creatinine levels, and graft dysfunction concomitant to AMBd therapy and an additional nephrotoxic condition. The 30-day mortality rate was 19.2% and it was significantly associated with disseminated and pulmonary infections, somnolence at admission, high CSF opening pressure, positive CSF India ink, creatinine levels greater than 2.0 mg/dL at admission, graft dysfunction in patients treated with AMBd and an additional nephrotoxic condition and graft loss within 30 days.

CONCLUSION

Graft dysfunction was common in renal transplant recipients with cryptococcosis treated with AMBd. The rate of graft loss rate was high, most frequently in patients with concomitant nephrotoxic conditions. Therefore, the clinical focus should be on the use of less nephrotoxic lipid formulations of amphotericin B in this specific population requiring a polyene induction regimen for treatment of severe cryptococcosis in all health care systems caring for transplantation recipients.

Addressing Antiretroviral Therapy-Associated Drug-Drug Interactions in Patients Requiring Treatment for Opportunistic Infections in Low-Income and Resource-Limited Settings

An increasing number of human immunodeficiency virus (HIV)-infected patients are achieving virologic suppression on antiretroviral therapy (ART) limiting the use of primary and secondary antimicrobial prophylaxis. However, in low-income and resource-limited settings, half of those infected with HIV are unaware of their diagnosis, and fewer than 50% of patients on ART achieve virologic suppression. Management of comorbidities and opportunistic infections among patients on ART may lead to inevitable drug-drug interactions (DDIs) and even toxicities. Elderly patients, individuals with multiple comorbidities, those receiving complex ART, and patients living in low-income settings experience higher rates of DDIs. Management of these cytochrome P450-mediated, nonmediated, and drug transport system DDIs is critical in HIV-infected patients, particularly those in resource-limited settings with few options for ART. This article critically analyzes and provides recommendations to manage significant DDIs and drug toxicities in HIV-infected patients receiving ART.

Bloodstream infections in HIV-infected patients

In the combined antiretroviral therapy era, HIV-infected patients remain a vulnerable population for the onset of bloodstream infections (BSI). Worldwide, nontyphoid salmonellae, Streptococcus pneumoniae, Escherichia coli, Staphylococcus aureus and coagulase negative staphylococci are the most important pathogens. Intravenous catheter associated infection, skin-soft tissue infection and endocarditis are associated with Gram-positive bacteremia. Among the Gram-negative, nontyphoidal Salmonella have been previously correlated to sepsis. Other causes of BSI in HIV-infected patients are mycobacteria and fungi. Mycobacteria constitute a major cause of BSI in limited resource countries. Fungal BSI are not frequent and among them Cryptococcus neoformans is the most common life-threatening infection. The degree of immunosuppression remains the key prognostic factor leading to the development of BSI.

Disparities in the Magnitude of Human Immunodeficiency Virus-related Opportunistic Infections Between High and Low/Middle-income Countries: Is Highly Active Antiretroviral Therapy Changing the Trend?

Opportunistic infections (OIs) cause significant morbidity/mortality in human immunodeficiency virus (HIV)-infected individuals globally. Disparities between high-income countries (HICs) and low/middle-income countries (LMICs) in the magnitude of HIV-related OIs in pre-highly active antiretroviral therapy (HAART) populations was reviewed, and HAART-induced decline in OIs was further compared between the two settings. Studies published in English from onset of HIV epidemic up to December 2013 were searched in PubMed, Google, Google Scholar, and African Journal online. An article was included if (a) the study was conducted in HIC or LMIC, (b) the age of the participants was ≥12 years, (c) the HAART status of the participants was stated, and (d) various types of OIs were investigated. In predominantly pre-HAART populations, the incidence and prevalence of overall HIV-related OIs in HIC ranged from 5.5 to 50.0 per 100 person-years (PY) and 27.4-56.7%, respectively. In LMIC, the respective overall incidence and prevalence of OIs were 12.2-93.9 per 100 PY and 32.0-77.7%. Pneumocystis jirovecii pneumonia, candidiasis, Cytomegalovirus disease, Mycobacterium avium complex disease, and Kaposi's sarcoma were the most frequent OIs in HICs while tuberculosis, candidiasis, chronic diarrhea, and cryptococcosis were predominant in LMICs. The introduction of HAART led to substantial reduction in the incidence of OIs with more impressive percentage decline in HICs (43-97%) compared to 30-79% in LMICs. Disparities in the magnitude of HIV-related OIs between HICs and LMICs are evident both in the pre-HAART and post-HAART era. Efforts to optimize HAART-induced decline in HIV-related OIs should become a global health priority irrespective of prevailing socioeconomic circumstances.

Nitric oxide levels in HIV-infected, untreated patients and HIV-infected patients receiving antiretroviral therapy

The role of nitric oxide (NO) in HIV infection is ambiguous; controversy exists around whether the levels of serum NO are increased or decreased in HIV-infected patients. Thus, it is necessary to reassess NO levels in HIV-infected patients. The aim of this study was to investigate the nitrite/nitrate metabolite (NOx) levels in HIV-infected untreated patients and in HIV-infected patients receiving highly active antiretroviral therapy (HAART), compared with HIV-uninfected individuals (control group). The HIV-infected patients enrolled in this study had been receiving HAART for at least 6 months (HIV-treated) or had not received HAART for at least 6 months (HIV-untreated group). New recommendations encourage initiating treatment in HIV-infected adults at a CD4 cell count of 500 cells/mm(3) or less. We also investigated whether levels of NOx were associated with immunophenotypic characteristic of HIV-infected patients. Our results showed a statistically significant increase in NOx levels in the HIV-untreated group (164.0 ± 166.6 μmol/L), compared with both the control (98.9 ± 59.4 μmol/L) and HIV-treated group (71.7 ± 53.3 μmol/L). Multiple regression analysis showed that the differences in NOx level were independent of gender, liver enzyme level, lipid measurement, and hematological parameters. In addition, a lower CD4/CD8 ratio was associated with higher NOx levels in HIV-infected patients. The results further revealed that NOx levels were increased in HIV infection, and that derangement of immune system function was associated with increased NO levels. The levels of NOx were found to decline with the use of HAART, which may contribute to cardiovascular disease in HIV-infected patients.

Response to Pneumococcal Polysaccharide Vaccination in HIV-Positive Individuals on Long Term Highly Active Antiretroviral Therapy

Background and objectives

Streptococcus pneumoniae continues to cause serious infections in HIV-positive individuals in the era of highly active anti-retroviral therapy. This led to the recommendation to revaccinate HIV-positive individuals with PPV23 five years after primary vaccination. The benefits of revaccination and the impact of long term highly active anti-retroviral therapy (HAART) on antigen-specific B cell reconstitution have remained unclear thus far and were investigated.

Design and methods

We assessed antibody levels, opsonophagocytic activity and phenotype of pneumococcal polysaccharide (PPS) specific-B cells post-revaccination in long term HAART cohorts stratified according to CD4 count as group A (CD4>200) and group B (CD4<200). Anti-PPS IgG, IgM and functional antibody response against vaccine serotypes 14 and 23F were measured by ELISA and opsonophagocytic assay followed by phenotypic analysis of PPS14 and 23F-specific B cells using fluorescently labeled PPS.

Results

Significant increases in total and functional antibody titers were noted in groups A and B post-vaccination concomitant with significant rise in PPS-specific IgM memory B cells, a critical B cell subset required for protection against PPS although the overall response remained significantly diminished compared to HIV-negative volunteers.

Conclusion

Comparable increases in opsonophagocytic titers between study groups A and B concomitant with a comparable rise in PPS-specific IgM memory B cells indicate revaccination to be beneficial regardless of the degree of CD4 T cell reconstitution. These findings emphasize the importance of defining effective vaccination practices amongst high-risk individuals.

Morbidity in HIV-1-infected individuals before and after the introduction of antiretroviral therapy: a longitudinal study of a population-based cohort in Uganda

BACKGROUND

We compared morbidities in HIV-1-infected patients before and after the introduction of antiretroviral therapy (ART) in a rural Ugandan cohort followed from 1990 to 2008. ART was introduced in 2004.

METHODS

Random-effects Poisson regression models were used to estimate incidence rates of World Health Organization (WHO) stage-defining diseases in HIV-infected individuals aged 13 years or older with known seroconversion dates, and in an age-stratified sample of HIV-negative individuals.

RESULTS

The most common morbid event was bacterial pneumonia, with an incidence of 7.4/100 person-years (pyr) among 309 HIV seroconverters and 1.3/100 pyr among 348 HIV-negative participants [hazard ratio (HR) 5.64; 95% confidence interval (CI) 3.6-8.8]. Among seroconverters, the incidence of the acquisition of any WHO stage-defining disease rose from 14.4/100 pyr (95% CI 11.1-18.6) in 1990-1998 to 46.0/100 pyr (95% CI 37.7-56.0) in 1999-2003. Following the introduction of ART, the incidence among seroconverters declined to 36.4/100 pyr (95% CI 27.1-48.9) in 2004-2005 and to 28.3/100 pyr (95% CI 21.2-37.8) in 2006-2008. At the individual level, a higher rate of acquiring any WHO stage-defining disease was independently associated with lower CD4 cell count, longer duration of HIV infection and older age. In addition, individuals who had been on ART for longer than 12 months had a substantially lower rate of any WHO stage disease than those not yet on ART (adjusted HR 0.35; 95% CI 0.2-0.6).

CONCLUSION

Morbidity in HIV-positive participants decreased following the introduction of ART, and this decline was more marked with increasing duration on ART. The benefits of decreased HIV-related morbidity from ART lend support to urgent efforts to ensure universal access to early diagnosis of HIV infection and to ART, especially in rural Africa.

Clinical manifestations of treatment-naive patients with acquired immunodeficiency syndrome and responses to highly active antiretroviral therapy in the Taipei Veterans General Hospital: a 5-year prospective study

BACKGROUND

Taipei Veterans General Hospital, one of the medical centers in Taiwan, has provided highly active antiretroviral therapy (HAART) to human immunodeficiency virus/AIDS patients for more than 10 years. Five years ago, we began a prospective follow-up of our patients' clinical manifestations and responses to HAART by collecting their clinical data. In this study, we analyzed the morbidity, mortality, and responses to HAART of treatment-naive AIDS patients. The purpose was to provide local data that may be valuable in Taiwan.

METHODS

Study cases were enrolled from January 1, 2004, to February 28, 2009, with inclusion criteria of newly diagnosed AIDS during hospitalization and being naive to HAART. Antiretroviral therapy was initiated. To evaluate the clinical responses to HAART, we excluded patients who were pregnant, died within 1 month after confirmation of an AIDS diagnosis, failed to initiate HAART, or were lost to follow-up for more than 6 months. Plasma viral loads and CD4(+) counts were quantified by reverse-transcriptase polymerase chain reaction and flow cytometry, respectively. Statistical analysis was performed using SPSS statistical software.

RESULTS

A total of 49 patients were enrolled and 45 patients fulfilled the inclusion criteria for evaluating the efficacy of HAART. At 3 months, 12 months, and 30 months after the initiation of HAART, 64.4% (29 of 45), 88.2% (30 of 34), and 93.8% (15 of 16) had undetectable plasma viral loads, respectively, and 37.8% (17 of 45), 73.5% (25 of 34), and 81.2% (13 of 16) had CD4(+) counts of more than 200 cells/μL, respectively. Median CD4(+) counts increased from baseline at Month 3 by 171 cells/μL and at Month 30 by 375 cells/μL. The overall mortality was 22.4% (11 of 49).

CONCLUSION

The virologic and immunologic responses after initiating HAART in this study demonstrated our achievements in providing care and treatment for AIDS patients during this 5-year period, which provides a strong evidence of the efficacy of HAART.

Pulmonary infections in the HIV-infected patient in the era of highly active antiretroviral therapy: an update

The highly active antiretroviral therapy (HAART) era began in 1996 when the combination of multiple antiretroviral agents was found to improve outcomes in HIV-infected patients. HAART has made a tremendous impact on the progression of HIV and on the morbidity and mortality associated with its opportunistic infections. HIV-positive patients who respond to HAART have a decreased incidence of opportunistic infections. Studies have documented close to a 50% decline in the incidence of pneumocystis pneumonia and bacterial pneumonia with the use of antiretroviral therapy. Primary and secondary prophylaxis for pneumocystis pneumonia can be discontinued in patients who show a sustained response to antiretroviral therapy. Unique to the HAART era, immune reconstitution syndrome is characterized by a paradoxical deterioration of a preexisting infection that is temporally related to the recovery of the immune system. Recently, more and more patients are being admitted for non-AIDS related illnesses in the HAART era.

Long-term exposure to AZT, but not d4T, increases endothelial cell oxidative stress and mitochondrial dysfunction

Nucleoside reverse transcriptase inhibitors (NRTIs), such as zidovudine (AZT) and stavudine (d4T), cause toxicities to numerous tissues, including the liver and vasculature. While much is known about hepatic NRTI toxicity, the mechanism of toxicity in endothelial cells is incompletely understood. Human aortic endothelial and HepG2 liver cells were exposed to 1 muM AZT or d4T for up to 5 weeks. Markers of oxidative stress, mitochondrial function, NRTI phosphorylation, mitochondrial DNA (mtDNA) levels, and cytotoxicity were monitored over time. In endothelial cells, AZT significantly oxidized glutathione redox potential, increased total cellular and mitochondrial-specific superoxide, decreased mitochondrial membrane potential, increased lactate release, and caused cell death from weeks 3 through 5. Toxicity occurred in the absence of di- and tri-phosphorylated AZT and mtDNA depletion. These data show that oxidative stress and mitochondrial dysfunction in endothelial cells occur with a physiologically relevant concentration of AZT, and require long-term exposure to develop. In contrast, d4T did not induce endothelial oxidative stress, mitochondrial dysfunction, or cytotoxicity despite the presence of d4T-triphosphate. Both drugs depleted mtDNA in HepG2 cells without causing cell death. Endothelial cells are more susceptible to AZT-induced toxicity than HepG2 cells, and AZT caused greater endothelial dysfunction than d4T because of its pro-oxidative effects.

HIV-1 transgene expression in rats causes oxidant stress and alveolar epithelial barrier dysfunction

BACKGROUND

HIV-infected individuals are at increased risk for acute and chronic airway disease even though there is no evidence that the virus can infect the lung epithelium. Although HIV-related proteins including gp120 and Tat can directly cause oxidant stress and cellular dysfunction, their effects in the lung are unknown. The goal of this study was to determine the effects of HIV-1 transgene expression in rats on alveolar epithelial barrier function. Alveolar epithelial barrier function was assessed by determining lung liquid clearance in vivo and alveolar epithelial monolayer permeability in vitro. Oxidant stress in the alveolar space was determined by measuring the glutathione redox couple by high performance liquid chromatography, and the expression and membrane localization of key tight junction proteins were assessed. Finally, the direct effects of the HIV-related proteins gp120 and Tat on alveolar epithelial barrier formation and tight junction protein expression were determined.

RESULTS

HIV-1 transgene expression caused oxidant stress within the alveolar space and impaired epithelial barrier function even though there was no evidence of overt inflammation within the airways. The expression and membrane localization of the tight junction proteins zonula occludens-1 and occludin were decreased in alveolar epithelial cells from HIV-1 transgenic rats. Further, treating alveolar epithelial monolayers from wild type rats in vitro with recombinant gp120 or Tat for 24 hours reproduced many of the effects on zonula occludens-1 and occludin expression and membrane localization.

CONCLUSION

Taken together, these data indicate that HIV-related proteins cause oxidant stress and alter the expression of critical tight junction proteins in the alveolar epithelium, resulting in barrier dysfunction.

Cryptococcal lymphadenitis as a manifestation of immune reconstitution inflammatory syndrome in an HIV-positive patient: a case report and review of the literature

Cryptococcus neoformans infections are typically associated with T-cell deficiencies, including acquired immunodeficiency syndrome (AIDS). Although highly active antiretroviral therapy (HAART) has strongly reduced AIDS-related opportunistic infections, the restoration and reactivation of CD4+ cells can induce an immune reconstitution inflammatory syndrome (IRIS), consisting in a deregulated inflammatory response to latent infectious pathogens and/or to their residual antigens. Cryptococcal lymphadenitis has occasionally been documented in IRIS. Here we report a case of histology- and culture-negative cryptococcal lymphadenitis associated with IRIS in an adult AIDS patient with a history of disseminated cryptococcosis, after the start of fully adherent HAART. Appropriate diagnosis was established on nested-PCR and sequence analysis of the interspacer region 2 of C. neoformans ribosomal DNA, and detection of slow-growing blastospores in enrichment cultures of fine-needle lymph node aspirate. Review of recent literature and our case findings suggest that IRIS-associated cryptococcal lymphadenitis is more likely the flare up of a latent infection rather than an immunopathological response to residual antigen of unviable cryptococci.

Seroprevalence of viral hepatitis and sexually transmitted disease among adults with recently diagnosed HIV infection in Southern Taiwan, 2000-2005: upsurge in hepatitis C virus infections among injection drug users

BACKGROUND/PURPOSE

The purpose of this study was to compare the seroprevalence of viral hepatitis and sexually transmitted disease (STD) co-infections among three populations at risk recently diagnosed with HIV infection.

METHODS

A retrospective review of medical records was performed to determine the prevalence of several co-infections among adults recently diagnosed with HIV infection between 2000 and 2005 at National Cheng Kung University Hospital in Tainan, Taiwan.

RESULTS

Among a total of 484 adults, 124 (25.6%) were men having sex with men (MSM), 105 (21.7%) were heterosexual adults, and 255 (52.7%) were injection drug users (IDUs). The case number of adults with recently diagnosed HIV infection increased annually, from 27 in 2000 to 142 in 2005 (p < 0.001). This trend appeared to be attributable to the upsurge in HIV infection among IDUs beginning in 2003. At the time of HIV diagnosis, mean CD4+ counts were significantly higher and plasma HIV-1 RNA loads were lower in the IDU group than the MSM or heterosexual groups. The hepatitis B virus (HBV) carrier rate was similar in all three groups, with an average rate of 16.5%. The prevalence of treponemal antibody and Entamoeba histolytica indirect hemagglutination antibody was higher in MSM (37.5% and 9.4%, respectively) than in heterosexuals (19.6% and 7.3%, respectively) or IDUs (3.2% and 2.1%). The seroprevalence of hepatitis A virus infection increased with age, with 94.2% (97/103) of patients who were older than 40 years. Hepatitis C virus (HCV) or HBV-HCV co-infections were noted more often in IDUs (97.9% and 16.9%, respectively) than in heterosexuals (10.9% and 2.2%, respectively) and MSM (5.3% and 3.6%, respectively).

CONCLUSION

There was a recent upsurge in HIV-HCV co-infected IDUs in southern Taiwan. A higher rate of co-infection with STDs among HIV-infected MSM highlights the need for integrated STD control efforts in current HIV prevention programs.

Vascular oxidative stress and nitric oxide depletion in HIV-1 transgenic rats are reversed by glutathione restoration

Human immunodeficiency virus (HIV)-infected patients have a higher incidence of oxidative stress, endothelial dysfunction, and cardiovascular disease than uninfected individuals. Recent reports have demonstrated that viral proteins upregulate reactive oxygen species, which may contribute to elevated cardiovascular risk in HIV-1 patients. In this study we employed an HIV-1 transgenic rat model to investigate the physiological effects of viral protein expression on the vasculature. Markers of oxidative stress in wild-type and HIV-1 transgenic rats were measured using electron spin resonance, fluorescence microscopy, and various molecular techniques. Relaxation studies were completed on isolated aortic rings, and mRNA and protein were collected to measure changes in expression of nitric oxide (NO) and superoxide sources. HIV-1 transgenic rats displayed significantly less NO-hemoglobin, serum nitrite, serum S-nitrosothiols, aortic tissue NO, and impaired endothelium-dependent vasorelaxation than wild-type rats. NO reduction was not attributed to differences in endothelial NO synthase (eNOS) protein expression, eNOS-Ser1177 phosphorylation, or tetrahydrobiopterin availability. Aortas from HIV-1 transgenic rats had higher levels of superoxide and 3-nitrotyrosine but did not differ in expression of superoxide-generating sources NADPH oxidase or xanthine oxidase. However, transgenic aortas displayed decreased superoxide dismutase and glutathione. Administering the glutathione precursor procysteine decreased superoxide, restored aortic NO levels and NO-hemoglobin, and improved endothelium-dependent relaxation in HIV-1 transgenic rats. These results show that HIV-1 protein expression decreases NO and causes endothelial dysfunction. Diminished antioxidant capacity increases vascular superoxide levels, which reduce NO bioavailability and promote peroxynitrite generation. Restoring glutathione levels reverses HIV-1 protein-mediated effects on superoxide, NO, and vasorelaxation.

HIV-associated Isospora belli infection: incidence and risk factors in the French Hospital Database on HIV

OBJECTIVE

To determine the incidence of Isospora belli infection in HIV-infected patients in France, and to study risk factors.

METHODS

The French Hospital Database on HIV (FHDH) is a prospective cohort study that collects demographic, clinical and therapeutic data on patients managed in 62 hospitals. We reviewed all cases of I. belli infection recorded between 1992 and 2003. We compared the incidence in 1992-1994 [before the use of dual therapy and combination antiretroviral therapy (cART)] and in 1997-2003 (when use of cART was widespread), after stratification for CD4 cell count (< 50, 50-99, 100-199 and > 200 cells/microL).

RESULTS

A total of 164 patients had I. belli infection either at enrollment (n=71) or during follow up (n=93). During the study period, I. belli infection tended to occur less frequently during follow up, and to be diagnosed mainly at database enrollment. The incidence of I. belli infection during follow up fell by 79% [relative hazard (RH) 0.21; 95% confidence interval (CI) 0.13-0.33] in the cART period compared with the pre-cART period; no such change was noted among patients with CD4 cell counts below 50 cells/microL. In multivariable analysis, the risk of I. belli infection was significantly higher among patients from sub-Saharan Africa (RH 4.3; 95% CI 2.6-7.3). After adjustment for CD4 cell count, patients receiving cotrimoxazole prophylaxis were found to be at a lower risk of I. belli infection (RH 0.3; 95% CI 0.2-0.6).

CONCLUSIONS

In France, I. belli infection among HIV-infected patients is now mainly seen in patients from sub-Saharan Africa, who present at an advanced stage.

Concurrent drug therapy for tuberculosis and HIV infection in resource-limited settings: present status and future prospects

Rapid scale-up of antiretroviral treatment (ART) in resource-limited settings where the burden of tuberculosis (TB) is high has resulted in the increasingly frequent need for patients to receive TB treatment and ART concurrently. This presents a major challenge to ART programs in these settings, where the therapeutic options and the healthcare infrastructure to effectively deliver and monitor overlapping treatment are limited. This article reviews the issues of pharmacokinetic interactions, drug cotoxicity and TB immune reconstitution disease. The currently available treatment options and the impact of concurrent treatment on patient outcomes are described. The use of ART in the treatment of HIV-associated multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) is also considered. Finally we discuss how new therapeutic agents currently in development may improve treatment options in the future.

Risk of Recurrent Nontyphoid Salmonella Bacteremia in HIV-Infected Patients in the Era of Highly Active Antiretroviral Therapy and an Increasing Trend of Fluoroquinolone Resistance

BACKGROUND

Risk of recurrent nontyphoid Salmonella (NTS) bacteremia and trends of antimicrobial resistance of NTS remain unknown in human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART).

METHODS

Ninety-three patients who received a diagnosis of NTS bacteremia from June 1994 through June 2006 were prospectively followed up. Incidence of recurrent NTS bacteremia was compared between the pre-HAART era (June 1994-March 1997) and the HAART era (April 1997-June 2006). Prevalence of antimicrobial resistance was compared among the NTS isolates obtained in the pre-HAART era, the early HAART era (April 1997-June 2002), and the late HAART era (July 2002-June 2006).

RESULTS

Compared with patients enrolled in the pre-HAART era, patients who received HAART had an incidence of recurrent NTS bacteremia that was significantly reduced by 96%; the incidence of recurrent NTS bacteremia was 2.56 cases per 100 person-years in the HAART era, compared with 70.56 cases per 100 person-years in the pre-HAART era (rate ratio, 0.036; 95% confidence interval, 0.012-0.114; P<.001). In the HAART era, the incidence of recurrent NTS bacteremia did not increase among patients receiving fluoroquinolone prophylaxis for <or=30 days (1.69 cases per 100 person-years), compared with among patients receiving fluoroquinolones for >30 days (3.95 cases per 100 person-years), with a rate ratio of 0.43 (95% confidence interval, 0.07-2.58). Although resistance to ampicillin, cotrimoxazole, and chloramphenicol decreased, the proportion of NTS isolates resistant to fluoroquinolones increased from 0% in the pre-HAART era to 6.2% in the early HAART era and 34.2% in the late HAART era (P=.002).

CONCLUSIONS

The risk of recurrent NTS bacteremia decreased significantly in the HAART era, although NTS isolates obtained from HIV-infected patients were increasingly resistant to fluoroquinolones.

Asymptomatic oral carriage of Candida species in HIV-infected patients in the highly active antiretroviral therapy era

Oropharyngeal candidiasis is the most common opportunistic fungal infection in individuals infected with human immunodeficiency virus. CD4+ lymphocytes count and the quantification of viral RNA in blood plasma have been found to be the main markers of HIV disease progression. The present study was conducted to evaluate Candida sp. diversity in the oral cavity of HIV-infected patients and to determine whether there was association of CD4+ cell count and viral load with asymptomatic oral Candida carriage. Out of 99 HIV-positive patients studied, 62 (62.6%) had positive culture for Candida (oral carriage) and 37 patients (37.4%) had Candida negative culture (no oral carriage). The etiologic agents most common were C. albicans and C. tropicalis. The range of CD4+ was 6-2305 cells/mm3 in colonized patients and 3-839 cells/mm3 for non-colonized patients, while the viral load was 60-90016 copies/mL for colonized patients and 75-110488 copies/mL for non colonized patients. The viral load was undetectable in 15 colonized patients and in 12 non colonized patients. Our results showed that there was no significant difference of the variables CD4+ cell count and viral load between oral candida carriage and no oral candida carriage patients.

HIV-Related Oral Lesions, Demographic Factors, Clinical Staging and Anti-Retroviral Use

BACKGROUND

The aim of the present study was to compare the prevalence of HIV-related oral lesions (HIV-OL) between two health centers for HIV in Mexico City and to analyze the factors that, in addition to combined antiretroviral therapy (CART) and low CD4(+), may be associated with possible differences in prevalence.

METHODS

A cross-sectional observational study was performed between January 2000 and February 2003 at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), a specialized referral center for HIV/AIDS patients and the Clínica Especializada Condesa (CEC), a primary care center for HIV-infected individuals without social security insurance. A consecutive sample of HIV-infected individuals had an oral examination based on established clinical criteria. Demographic, clinical and laboratory data were obtained. Independent association of each factor with specific HIV-OL was assessed by logistic regression modeling.

RESULTS

Eight hundred fifty individuals were examined (INCMNSZ: 479; CEC: 371). Hairy leukoplakia (HL), periodontal disease (PD) and Kaposi's sarcoma (KS) were independently associated with the study site [odds ratio (OR) = 1.7 (95% confidence interval (CI): 1.1-2.4), OR = 4.2 (95% CI: 1.3-13), OR = 10.1 (95% CI: 2.7-38.2), respectively], being more frequent in CEC patients. HL was independently associated with men having sex with men OR = 1.7 (95% CI: 1.1-2.8). All HIV-OL were independently associated with CD4(+) counts and, with the exception of PD and KS, with time under CART.

CONCLUSIONS

The present comparative study showed that several factors were associated with a difference in prevalence of oral lesions found in two AIDS clinics located in Mexico City. Severe immune suppression, CART duration and the study site were associated with HIV-OL. Further investigation into factors such as socioeconomic determinants associated with HIV-OL is warranted.

HIV-1-induced pulmonary oxidative and nitrosative stress: exacerbated response to endotoxin administration in HIV-1 transgenic mouse model

Human immunodeficiency virus (HIV)-1 causes lung disease by increasing the host's susceptibility to pathogens. HIV-1 also causes an increase in systemic oxidative/nitrosative stress, perhaps enhancing the deleterious effects of secondary infections. Here we examined the ability of HIV-1 proteins to increase lung oxidative/nitrosative stress after lipopolysaccharide (LPS) (endotoxin) administration in an HIV-1 transgenic mouse model. Lung oxidative/nitrosative stress biomarkers studied 3 and 6 h after LPS administration were as follows: lung edema, tissue superoxide, NO metabolites, nitrotyrosine, hydrogen peroxide, and bronchoalveolar lavage fluid (BALF) glutathione (GSH). Blood serum cytokine levels were quantified to verify immune function of our nonimmunocompromised animal model. Results indicate that 3 h after LPS administration, HIV-1 transgenic mouse lung tissue has significantly greater edema and superoxide. Furthermore, NO metabolites are significantly elevated in HIV-1 transgenic mouse BALF, lung tissue, and blood plasma compared with those of wild-type mice. HIV-1 transgenic mice also produce significantly greater lung nitrotyrosine and hydrogen peroxide than wild-type mice. In addition, HIV-1 transgenic mice produce significantly less BALF GSH than wild-type mice 3 h after LPS treatment. Without treatment, serum cytokine levels are similar for HIV-1 transgenic and wild-type mice. After treatment, serum cytokine levels are significantly elevated in both HIV-1 transgenic and wild-type mice. Therefore, HIV-1 transgenic mice have significantly greater lung oxidative/nitrosative stress after endotoxin administration than wild-type mice, independent of immune function. These results indicate that HIV-1 proteins may increase pulmonary complications subsequent to a secondary infection by altering the lung redox potential.

A new model to monitor the virological efficacy of antiretroviral treatment in resource-poor countries

Monitoring the efficacy of antiretroviral treatment in developing countries is difficult because these countries have few laboratory facilities to test viral load and drug resistance. Those that exist are faced with a shortage of trained staff, unreliable electricity supply, and costly reagents. Not only that, but most HIV patients in resource-poor countries do not have access to such testing. We propose a new model for monitoring antiretroviral treatment in resource-limited settings that uses patients' clinical and treatment history, adherence to treatment, and laboratory indices such as haemoglobin level and total lymphocyte count to identify virological treatment failure, and offers patients future treatment options. We believe that this model can make an accurate diagnosis of treatment failure in most patients. However, operational research is needed to assess whether this strategy works in practice.

Drug–drug interactions and tolerance in combining antituberculosis and antiretroviral therapy

Worldwide, tuberculosis (TB) is one of the most important infectious diseases in subjects with HIV infection. Although effective therapy is available for both conditions, there are major problems in the concurrent treatment of HIV and TB co-infection. In this article the knowledge available on drug-drug interactions between anti-HIV and anti-TB compounds is analysed, particularly with regard to pharmacological interactions secondary to interference with cytochrome P450 enzymes. Within the same setting, facts and possible interpretations of the problems encountered in terms of tolerance and safety of the concurrent treatment of TB and HIV are also reviewed. Current guidelines, as well as additional possible strategies to be adopted in this particular co-morbidity setting are discussed.

Infectious lung complications in patients with HIV/AIDS

PURPOSE OF REVIEW

The aim of this article is to review recent observations in the area of infectious lung complications in individuals with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Since the immunodeficiency was first characterized, it has been associated with enhanced susceptibility to opportunistic infection, and life-threatening infections of the lung in particular. In the past few years there have been a large number of reports documenting the changes to this disease profile in the age of highly active antiretroviral therapy (HAART). Furthermore, there have been considerable advances in our understanding of the immunology and vaccinology of many of the pathogens implicated in pulmonary infections in this context, including Mycobacterium tuberculosis, Streptococcus pneumoniae and Pneumocystis pneumonia.

RECENT FINDINGS

In considering the time-course and spectrum of HIV-associated respiratory infections, the field must now be divided into studies undertaken in parts of the world where HAART is accessible and those where it is not. Despite the enormous impact of HAART, it has brought with it a new set of concerns, including the effects of immune restoration disease (IRD), and the complex interplay between HAART and tuberculosis therapy.

SUMMARY

The overriding conclusion from recent experience is that HAART, in those parts of the world where it is readily available, has changed the clinical picture of infections associated with HIV, and needs to be available to patients across the developing world as well. Furthermore there have been important developments in vaccination programs against pathogens involved in HIV-associated pneumonia.

HIV antiretroviral therapy in resource-limited settings: Experiences from Haiti

An unprecedented international effort to expand high activity antiretroviral therapy (HAART) to resource-poor nations has been launched. The World Health Organization (WHO) has created antiretroviral (ARV) treatment guidelines adapted to resource-poor settings. The first-line regimen is two nucleoside reverse transcriptase inhibitors (NsRTIs) and one nonnucleoside reverse transcriptase inhibitor (NNRTI). Therapy is initiated by clinical staging and CD4 T-cell counts when available. Adherence is the responsibility of health care workers. The use of ARV therapy in resource-poor settings faces several challenges, including the poverty of patients, political and social upheavals and violence, social stigma associated with HIV/AIDS, unreliable pharmacy systems, tuberculosis, and lack of trained health care workers. Using our experience in Haiti, we describe how we have addressed these challenges with the goal of increasing access to care for the poor with HIV/AIDS.