Genotypic determination of HIV tropism - clinical and methodological recommendations to guide the therapeutic use of CCR5 antagonists

The approval of maraviroc (Selzentri®), the first CCR5 antagonist, with specific antiviral activity against CCR5 (R5)-tropic HIV variants, has promoted the determination of HIV coreceptor usage in the clinical setting. The phenotypic assay Trofile™, which is based on recombinant virus technology, has been the most widely used diagnostic test, given that it was the only assay which provided tropism information in the pivotal maraviroc clinical trials. However, this method displays logistical and technical limitations that make it far from convenient as a diagnostic test in clinical practice. Genotypic methods based on V3 genotyping represent a more feasible alternative and progressively are replacing phenotypic assays. Even though their sensitivity to detect X4-tropic variants is lower compared to Trofile™, recent studies have demonstrated that specific genotypic tools (geno2pheno and PSSM) are comparable to Trofile™ and ES-Trofile™ in predicting virologic response to maraviroc. This review summarizes clinical and methodological recommendations for the genotypic determination of HIV tropism to guide therapeutic decisions with CCR5 antagonists in HIV therapeutics.

[Factors related to non-prescription of tuberculin skin testing in a cohort of HIV-infected people]

INTRODUCTION

Tuberculin skin testing (TST) for tuberculosis (TB) is recommended for all patients with HIV infection because of the known relationship between these two conditions. In this report we analyze the incidence and variables associated with non-prescription of TST in a cohort of HIV-infected people.

PATIENTS AND METHODS

Longitudinal study conducted between 2000 and 2002 at 10 HIV hospital-based clinics. All HIV-infected patients who had not been regularly followed-up previously in dedicated clinics were identified. Data about TST and other variables related to TB were obtained from the clinical records. We calculated the percentage of patients who did not undergo TST and the associated factors, using odds ratios (ORs) and the 95% CI to investigate associations. A multivariate logistic regression analysis was performed.

RESULTS

A total of 1242 patients met the inclusion criteria. TST was not performed in 185 patients (17.6% of those eligible). The fact of being an intravenous drug abuser was associated with a higher probability of TST non-prescription (OR: 2.6, 95% CI 1.1-6.5), whereas being unemployed (OR: 0.6, 95% CI 0.3-1.0), having a CD4 cell count >200 (CD4 200-499: OR 0.5, 95% CI 0.3-0.9. CD4> or =500: OR 0.3, 95% CI 0.2-0.6), and contact with persons with TB (OR 0.2, 95% CI 0.1-0.5) were associated with a lower probability.

CONCLUSIONS

In this study, the percentage of TST non-prescription was quite high. The results suggest that TST non-prescription in this population is related to the clinicians' expectations regarding the results of the test and the patients' adherence to treatment for latent TB infection.

[Clinical manifestations of HIV infection in distinct geographical areas]

The clinical manifestations of HIV infection vary widely in distinct geographical areas. While HIV-related disease has been well characterized in western countries, relatively few publications have described the clinical manifestations of these diseases in tropical areas, where the vast majority of HIV-infected people are concentrated. In addition, HIV infection may alter the natural history of tropical diseases in several ways and tropical diseases influence the course of HIV infection. The present review describes the major opportunistic infections afflicting people with HIV/AIDS in Africa, Latin America, and Asia and discusses the mutual interactions between HIV and the major tropical diseases.

Incidence and risk factors for tuberculosis in HIV-positive subjects by HAART status

OBJECTIVE

To estimate incidence rates and risk factors for tuberculosis (TB) in human immunodeficiency virus seroprevalent subjects.

METHODS

Multicentre, hospital-based cohort study of patients presenting to 10 Spanish hospitals from 1 January 1997 to 31 December 2003. Poisson regression was used and highly active antiretroviral treatment (HAART) was modelled as a time-dependent covariate.

RESULTS

A total of 4268 patients were followed for a median of 3.8 years; 221 TB cases were diagnosed over 16 464 person-years (py). TB rates were higher in HAART-naïve subjects (1.56 per 100 py, 95%CI 1.36-1.79) than those on HAART (0.5/100 py, 95%CI 0.31-0.80). Among HAART-naïves, TB risk factors were: being male, being an injecting drug user (IDU) (RR 2.01, 95%CI 1.28-3.16), having low CD4 counts (P < 0.001) and high viral loads (P < 0.001). HAART was protective (RR 0.26, 95%CI 0.16-0.40) and reductions in TB rates were observed in the last calendar period (RR 0.74, 95%CI 0.55-1.00). For patients on HAART, no differences were observed by category of transmission. Low CD4 counts at entry were associated with higher TB rates (P < 0.001).

CONCLUSIONS

HAART was associated with lower TB rates, and TB risk factors differed according to whether or not patients had received HAART. To further reduce TB rates, additional strategies are needed, such as timely access and adherence to HAART, especially in IDUs.

Prevalence of M. tuberculosis infection and tuberculosis disease among HIV-infected people in Spain

OBJECTIVE

To study the prevalence of Mycobacterium tuberculosis infection (MTBI) and past/current tuberculosis (TB) among human immunodeficiency virus (HIV) infected persons in Spain.

DESIGN

Longitudinal study conducted between 2000 and 2003 at 10 HIV hospital-based clinics. Data were drawn from clinical records. Associations were measured using odds ratios (ORs) and their 95% confidence intervals (95%CI).

RESULTS

Of the 1242 persons who met the eligibility criteria, most were male (75%), aged <40 years (75%) and unemployed (40%). HIV infection occurred through intravenous drug use (53%), heterosexual sex (29%) and sex between men (16%). In the initial evaluation, 315 subjects had evidence of MTBI: 84 (6.8%) had a history of TB, 23 (1.8%) current TB and 208 (16.8%) latent tuberculosis infection (LTBI). MTBI was associated with male sex, age 30-49 years, contact with a TB case, homelessness, poor education, and negatively with CD4 <100 cells/mm(3). Among subjects with MTBI, past/current TB was associated with retirement/disability (OR 6, 95%CI 1.6-22.5), CD4 <200 cells/mm(3) (OR 9.7, 95%CI 3.8-24.6), viral load >55,000 copies (OR 5.3, 95%CI 1.4-20.0), and negatively, with skilled work (OR 0.4, 95%CI 0.1-1.0) or administrative/managerial/professional work (OR 0.05, 95%CI 0.01-0.4).

CONCLUSION

Social context has an impact on the effectiveness of HIV and TB control programmes even in industrialised countries with free access to health care.

[Spanish cohort of naïve HIV-infected patients (CoRIS): rationale, organization and initial results]

OBJECTIVE

To describe the methodology and baseline results of the Spanish cohort of naïve HIV-infected patients included in the Research Network on HIV/AIDS (CoRIS).

METHODS

CoRIS is a multicenter, hospital-based prospective cohort of HIV sero-prevalent, retroviral-naïve subjects, over 13 years old, and seen at 17 hospitals in 8 of the 17 Autonomous Regions in Spain from January 2004 to October 2005. The socio-demographic characteristics, as well as epidemiological, clinical, laboratory and treatment data were recorded, and biological samples were collected at baseline and during follow-up.

RESULTS

A total of 1,591 subjects have been included in CoRIS; 24% are women, median age at cohort entry is 36 years, and 74% were diagnosed during 2004 or 2005. Twenty-seven percent came from countries other than Spain, mainly Latin-America (16%) and sub-Saharan Africa (5%). Thirty-two percent had completed secondary education and 16% university studies. The most frequent categories of transmission were men having sex with men (37%) and heterosexual sex (36%); only 21% were injection drug users. At cohort entry, median CD4 count was 317 cells/mm 3 and median viral load was 52,300 copies/mL; 18% were diagnosed with AIDS. Main AIDS-defining illnesses were Pneumocystis jiroveci pneumonia (6.1%), esophageal candidiasis (3.3%) and tuberculosis (extrapulmonary, 3.0% and pulmonary 2.7%). There were 35 deaths (2.2%). Thirty-three percent of patients gave a baseline sample to the BioBank.

CONCLUSIONS

CoRIS offers relevant information about the current epidemiological profile of HIV infection in Spain, where sexual transmission has become predominant. The type and amount of information obtained from clinical and epidemiological data collection together with biological samples demonstrate the viability of the project, which offers many possibilities for future research.

HIV-infected progressors and long-term non-progressors differ in their capacity to respond to an A-class CpG oligodeoxynucleotide

We used an A-class CpG oligodeoxynucleotide to explore innate immunity in HIV infection and observed that natural killer cells from progressors showed a markedly lower IFN-gamma production in response to the oligonuclotide as compared with long-term non-progressing subjects and healthy HIV-negative individuals. This functional defect was found in patients who showed a long immunological reduction and in those who had had a recent reduction in their CD4 cell counts.

[Paludism due to Plasmodium falciparum in visitors to the Dominican Republic]

We present two cases of P. falciparum malaria in visitors to tourist resorts on the East Coast of the Dominican Republic, traditionally believed to be an area without risk of malaria. In both patients the malaria was severe (with 20% parasitization in one) and there was a long interval between the onset of symptoms and diagnosis. These cases are possibly related (along with a further 17 reports by the Centers for Disease Control and Prevention) to an increase in the population of Anopheles sp as a consequence of increased rainfall and floods provoked by a hurricane in September 2004, as well as to the presence of a semi-immune population (Haitian immigrants working in the construction and tourist sectors). Both physicians and patients should be aware of this outbreak so that adequate precautions can be taken and early diagnoses can be made.

Recomendaciones de GESIDA/Plan Nacional sobre el Sida respecto al tratamiento antirretroviral en pacientes adultos infectados por el VIH (octubre 2004)

OBJECTIVE

This consensus document is an update of antiretroviral therapy (ART) recommendations for adult patients infected with the human immunodeficiency virus (HIV).

METHODS

To formulate these recommendations, a panel composed of members of the Grupo de Estudio de Sida (GESIDA; AIDS Study Group) and the Plan Nacional sobre el Sida (PNS; Spanish AIDS Plan) reviewed the advances in current understanding of the pathophysiology of HIV, the safety and efficacy findings from clinical trials, and the results from cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings over the last years. Three levels of evidence were defined according to the source of the data: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not recommend ART was established in each of these situations.

RESULTS

ART consisting of at least three drugs is currently the initial treatment of choice for chronic HIV infection. These regimens should include 2 NRTI + 1 NNRTI or 2 NRTI + 1 PI. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4+ lymphocyte counts per L and plasma viral load, as follows: 1) Therapy should be started in patients with CD4+ counts of < 200 cells/microL; 2) Therapy should be started in most patients with CD4+ counts of 200-350 cells/microL, although it can be delayed when CD4+ count persists at around 350 cells/microL and viral load is low; and 3) Initiation of therapy can be delayed in patients with CD4+ counts of > 350 cells/microL. The initial objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining the antiviral response. Because of the development of cross resistance, therapeutic options are limited when ART fails. Genotype studies are useful in these cases. Toxicity is a limiting factor in the use of ART, although the benefits outweigh the risks. In addition, the criteria for the use of ART are discussed in situations of acute infection, pregnancy, and post-exposure prophylaxis, and in the management of co-infection of HIV with HCV or HBV.

CONCLUSIONS

CD4+ lymphocyte count is the most important reference factor for initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the possibility to determine viral resistance is leading to a more individualized approach to therapy.

Health-Related Quality of Life in HIV Patients Switching to Twice-Daily Indinavir/Ritonavir Regimen or Continuing with Three-Times-Daily Indinavir-Based Therapy

Objective

To evaluate health-related quality of life (HRQoL) changes in patients treated with indinavir three-times daily after switching to a twice-daily indinavir/ritonavir regimen or continuing with the same regimen.

Methods

Patients on HAART including indinavir three-times-daily with undetectable viral load were randomly assigned to continue with this therapy or to change to a twice-daily indinavir/ritonavir (800/100 mg) regimen. The Medical Outcomes Study HIV Health Survey (MOS-HIV) questionnaire was used as the HRQoL measure.

Results

A total of 118 patients participated in the study, of which 59 (50%) were randomly assigned to continue with the three-times-daily regimen. Patients had a mean age of 39 years and 80% of them were male. At baseline, subjects included in the three-times-daily group presented a significantly greater number of symptoms than subjects in the twice-daily group, but no statistically significant differences were observed in MOS-HIV scores between the groups. In the intention-to-treat (ITT) analysis, a reduction in HRQoL scores was observed in both groups, which was greater in the twice-daily group. In the per protocol analysis, reduction of HRQoL was minimal.

Conclusions

A HRQoL deterioration, greater in the twice-daily group, was observed in this study in the ITT analysis, while HRQoL remained stable in both groups in patients who continued with and tolerated the allocated regimen.

Características epidemiológicas de las nuevas infecciones causadas por el VIH comparadas con los casos de sida. La epidemia de VIH/sida en el País Vasco

OBJECTIVE

To describe the epidemiological characteristics of new cases of HIV infection diagnosed from 1997-2001 and compare them with AIDS cases (1991-2001).

METHODS

Data were retrospectively collected on new cases of HIV infection detected in the Basque Country (1997-2001) and were compared with AIDS cases (1991-2001).

RESULTS

A total of 912 new cases of HIV infection were diagnosed. In 299 of the new cases (32.8%), HIV and AIDS were diagnosed simultaneously. The most common mechanism of transmission was heterosexual transmission, followed by intravenous and homo/bisexual transmission. Significant epidemiological differences (p < 0.001) were found with regard to AIDS cases.

CONCLUSIONS

Sexual transmission has replaced intravenous drug use as the most common mechanism of HIV transmission. A large percentage of patients were simultaneously diagnosed with HIV and AIDS, indicating the need for new prevention strategies.

Consensus conference on chronic viral hepatitis and HIV infection: updated Spanish recommendations

Chronic hepatitis B and C represent a leading cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected patients worldwide. New treatment options against both hepatitis B (HBV) and C (HCV) viruses have prompted us to update previous recommendations for the management of coinfected individuals. Fifteen topics (nine related to HCV, five to HBV and one to both viruses) were selected for this purpose. A panel of Spanish experts in the field was invited to review these areas and propose specific recommendations, which were scored according to the Infectious Disease Society of America (IDSA) grading system. These guidelines represent a comprehensive and updated overview on the management of hepatitis B and C in HIV-infected patients.

[Recommendations of the Spanish AIDS Study Group (GESIDA) and the National Aids Plan (PNS) for antiretroviral treatment in adult patients with human immunodeficiency virus infection in 2002]

OBJECTIVE

To provide an update of recommendation on antiretroviral treatment (ART) in HIV-infected adults.Methods. These recommendations have been agreed by consensus by a committee of the spanish AIDS Study Group (GESIDA) and the National AIDS Plan. To do so, advances in the physiopathology of AIDS and the results on efficacy and safety in clinical trials, cohort and pharmacokinetics studies published in biomedical journals or presented at congresses in the last few years have been reviewed. Three levels of evidence have been defined according to the data source: randomized studies (level A), case-control or cohort studies (level B) and expert opinion (level C). Whether to recommend, consider, or not to recommend ART has been established for each situation.

RESULTS

Currently, ART with combinations of at least three drugs constitutes the treatment of choice in chronic HIV infection. In patients with symptomatic HIV infection, initiation of ART is recommended. In asymptomatic patients initiation of ART should be based on the CD41/mL lymphocyte count and on the plasma viral load (PVL): a) in patients with CD41 lymphocytes < 200 cells/mL, initiation of ART is recommended; b) in patients with CD41 lymphocytes between 200 and 300 cells/mL, initiation of ART should, in most cases, be recommended; however, it could be delayed when the CD41 lymphocyte count remains close to 350 cells/mL and the PVL is low, and c) in patients with CD41 lymphocytes > 350 cells/mL, initiation of ART can be delayed. The aim of ART is to achieve an undetectable PVL. Adherence to ART plays a role in the durability of the antiviral response. Because of the development of cross-resistance, the therapeutic options in treatment failure are limited. In these cases, genotypic analysis is useful. Toxicity limits ART. The criteria for ART in acute infection, pregnancy and postexposure prophylaxis and in the management of coinfection with HIV and hepatitis C and B virus are controversial.

CONCLUSIONS

The current approach to initiating ART is more conservative than in previous recommendations. In asymptomatic patients, the CD41 lymphocyte count is the most important reference factor for initiating ART. Because of the considerable number of drugs available, more sensitive monitoring methods (PVL) and the possibility of determining resistance, therapeutic strategies have become much more individualized.