Daily sampling of an HIV-1 patient with slowly progressing disease displays persistence of multiple env subpopulations consistent with neutrality.

The molecular evolution of HIV-1 is characterized by frequent substitutions, indels and recombination events. In addition, a HIV-1 population may adapt through frequency changes of its variants. To reveal such population dynamics we analyzed HIV-1 subpopulation frequencies in an untreated patient with stable, low plasma HIV-1 RNA levels and close to normal CD4+ T-cell levels. The patient was intensively sampled during a 32-day period as well as approximately 1.5 years before and after this period (days -664, 1, 2, 3, 11, 18, 25, 32 and 522). 77 sequences of HIV-1 env (approximately 3100 nucleotides) were obtained from plasma by limiting dilution with 7-11 sequences per time point, except day -664. Phylogenetic analysis using maximum likelihood methods showed that the sequences clustered in six distinct subpopulations. We devised a method that took into account the relatively coarse sampling of the population. Data from days 1 through 32 were consistent with constant within-patient subpopulation frequencies. However, over longer time periods, i.e. between days 1...32 and 522, there were significant changes in subpopulation frequencies, which were consistent with evolutionarily neutral fluctuations. We found no clear signal of natural selection within the subpopulations over the study period, but positive selection was evident on the long branches that connected the subpopulations, which corresponds to >3 years as the subpopulations already were established when we started the study. Thus, selective forces may have been involved when the subpopulations were established. Genetic drift within subpopulations caused by de novo substitutions could be resolved after approximately one month. Overall, we conclude that subpopulation frequencies within this patient changed significantly over a time period of 1.5 years, but that this does not imply directional or balancing selection. We show that the short-term evolution we study here is likely representative for many patients of slow and normal disease progression.

Cost-effectiveness of atazanavir/ritonavir compared with lopinavir/ritonavir in treatment-naïve human immunodeficiency virus-1 patients in Sweden.

OBJECTIVE: The aim of this study was to estimate the cost-effectiveness of atazanavir/ritonavir (atazanavir/r) versus lopinavir/ritonavir (lopinavir/r) in treatment-naïve human immunodeficiency virus-1 (HIV-1) patients in Sweden for whom efavirenz is not suitable. METHODS: A Markov model was developed to predict the lifetime outcomes of atazanavir/r and lopinavir/r in terms of quality-adjusted life years (QALYs) and total costs. The model was structured to focus on treatment lines--how patients progress from first- to second-, and then to third-line treatment. Model inputs were derived directly from clinical trials, such as the CASTLE study (a 96-week head-to-head trial in first-line therapy), and from the Framingham risk-equation. The analysis was conducted from a payer perspective and included extensive scenario and probabilistic sensitivity analyses. RESULTS: The model predicted atazanavir/r to save 0.16 (95% confidence interval (CI) 0.00 to 0.33) QALYs and reduce total costs by -202,896 SEK (95% CI -332,156 to -81,644 SEK) over a lifetime horizon. Probabilistic sensitivity analyses showed that atazanavir/r had a 100% probability to be cost-effective at a willingness to pay of 200,000 SEK per QALY. CONCLUSION: The results indicate that atazanavir/r is cost-saving and more effective compared to lopinavir/r for patients who have previously not been exposed to antiretroviral drugs in Sweden.

IP-10 predicts the first phase decline of HCV RNA and overall viral response to therapy in patients co-infected with chronic hepatitis C virus infection and HIV.

The aim of this study was to investigate the utility of baseline plasma interferon-gamma inducible protein-10 (IP-10) levels in human immunodeficiency virus (HIV)-hepatitis C virus (HCV) co-infected patients. Baseline IP-10 was monitored during HCV combination therapy in 21 HIV-HCV co-infected patients (HCV genotype 1 (n = 16), 2 (n = 2), and 3 (n = 3)). Lower baseline IP-10 was significantly associated with a rapid decline in HCV RNA, in particular with the first phase reduction, and similar cut-off levels (< 150 and > 600 pg/ml) as in HCV mono-infected patients apply. In conclusion, baseline IP-10 < 150 pg/ml is predictive of a favourable viral response to HCV therapy in HIV-HCV co-infected patients, and may thus be useful in encouraging such difficult-to-treat patients to initiate therapy.

HCV/HIV co-infection at a large HIV outpatient clinic in Sweden: feasibility and results of hepatitis C treatment.

We investigated the prevalence of hepatitis C virus (HCV) co-infection in HIV-infected patients at a large Swedish outpatient clinic. We also evaluated the feasibility of treating this patient group with pegylated-interferon alpha-2a and ribavirin (RBV) and found that only a small fraction of the HCV/HIV co-infected patients met the criteria for HCV treatment when following international guidelines. Thus, 11 patients were treated, and HCV kinetics were measured during early treatment. The overall treatment response rate was surprisingly high (73%) and correlated to early virological response.

Expansion of functionally skewed CD56-negative NK cells in chronic hepatitis C virus infection: correlation with outcome of pegylated IFN-alpha and ribavirin treatment.

NK cells are important innate immune effector cells, normally characterized as CD56(+)CD3(-) lymphocytes. In this study, we report that CD56(-)CD16(+) NK cells expand in many patients with chronic hepatitis C virus infection. These CD56(-) NK cells were functionally impaired with respect to cytokine production upon target cell recognition, in comparison to CD56(dim) and CD56(bright) NK cell subsets. In particular, CD56(-) NK cells were strikingly defective in their polyfunctional response as measured by the coexpression of MIP-1beta, IFN-gamma, TNF-alpha, and CD107a degranulation. The ability of these cells to mediate three or four of these functions was poor; expression of MIP-1beta alone dominated their response. CD56(-) NK cells retained expression of receptors such as the natural cytotoxicity receptors and NKG2D, whereas the expression of CD57 and perforin was lower when compared with CD56(dim) NK cells. Interestingly, pretreatment levels of CD56(-) NK cells correlated with the outcome of pegylated IFN-alpha and ribavirin treatment. In patients with CD56(-) NK cells in the range of healthy subjects, 80% reached a sustained virological response to treatment, whereas only 25% of patients with levels clearly above those in healthy subjects experienced a sustained virological response. Thus, chronic hepatitis C virus infection is associated with an expansion of CD56(-) NK cells functionally skewed toward MIP-1beta production only. Furthermore, high levels of these cells reveal a disturbance in innate cellular immunity that is associated with an impaired ability to respond to antiviral treatment with IFN-alpha and ribavirin.

High levels of chronic immune activation in the T-cell compartments of patients coinfected with hepatitis C virus and human immunodeficiency virus type 1 and on highly active antiretroviral therapy are reverted by alpha interferon and ribavirin treatment.

Chronic immune activation is a driver of human immunodeficiency virus type 1 (HIV-1) disease progression. Here, we describe that subjects with chronic hepatitis C virus (HCV)/HIV-1 coinfection display sharply elevated immune activation as determined by CD38 expression in T cells. This occurs, despite effective antiretroviral therapy, in both CD8 and CD4 T cells and is more pronounced than in the appropriate monoinfected control groups. Interestingly, the suppression of HCV by pegylated alpha interferon and ribavirin treatment reduces activation. High HCV loads and elevated levels of chronic immune activation may contribute to the high rates of viral disease progression observed in HCV/HIV-1-coinfected patients.

Elevated numbers of Fc gamma RIIIA+ (CD16+) effector CD8 T cells with NK cell-like function in chronic hepatitis C virus infection.

CTL are crucial in the defense against viral infections. In the course of investigating peripheral blood and intrahepatic CD8 T cells in patients with chronic hepatitis C virus (HCV) infection, we observed a significant population of CD8 T cells expressing the FcgammaRIIIA (CD16) receptor. This observation led us to characterize these cells with respect to their phenotype and function in a cohort of patients with chronic HCV infection as well as in healthy blood donors. On average, 10% of peripheral blood CD8 T cells from HCV-infected patients expressed CD16 compared with only a few percent in healthy donors. CD16(+) CD8 T cells displayed a late-stage effector phenotype with high levels of perforin. These cells exhibited a restricted TCR profile suggesting underlying clonal expansion. Stimulation of CD16 on CD8 T cells evoked a vigorous response similar to that of CD16 stimulation in NK cells. Our data suggest that CD8 T cells, during chronic HCV infection in humans, continue to differentiate beyond defined stages of terminal effector cells, acquiring CD16 and NK cell-like functional properties.

Expansion of CD56- NK cells in chronic HCV/HIV-1 co-infection: reversion by antiviral treatment with pegylated IFNalpha and ribavirin.

Co-infection with HCV and HIV-1 is a problem of increasing importance and the role of innate cellular immunity in this co-infection is incompletely understood. Here, we have observed sharply elevated numbers of CD56(-)CD16(+) perforin(low) NK cells in HCV/HIV-1 co-infected subjects on antiretroviral therapy. Interestingly, this expansion of unconventional CD56(-) NK cells rapidly reverted when HCV was suppressed by IFNalpha and ribavirin treatment, and was not seen in mono-infected control groups. In vitro experiments suggested that this effect of treatment was due to suppression of HCV viremia rather than a direct effect of IFNalpha on these cells. In contrast, the conventional CD56(+) NK cells were largely unchanged in subjects with high HCV loads, although they exhibited slightly decreased perforin expression. With delayed kinetics, the CD56(bright) immuno-regulatory NK cell subset temporarily increased to supranormal levels in response to HCV treatment. In contrast to the NK compartment, the CD1d-restricted NKT cells were severely reduced by the co-infection and not restored by treatment. Together, our data suggest that the high HCV loads in HCV/HIV-1 co-infection alter the NK cell compartment in a way not observed in HCV mono-infection.

Spontaneous HCV clearance in HCV/HIV-1 coinfection associated with normalized CD4 counts, low level of chronic immune activation and high level of T cell function.

BACKGROUND/OBJECTIVE: Spontaneous HCV clearance in HCV/HIV-1 coinfected patients is likely to be very rare given the damage to the immune system caused by HIV-1 infection. The search for immune correlates of spontaneous clearance is important for the understanding of pathogenesis as well as for the development of possible new treatment strategies. STUDY DESIGN/RESULTS: A cohort of HCV/HIV-1 coinfected patients was followed. Plasma HCV viral load was measured and T cell immunity in peripheral blood samples was assessed using multi-color flow cytometry. One HCV/HIV-1 coinfected patient spontaneously became HCV-RNA negative after being positive for several years. This patient displayed a normalized CD4 counts on successful HAART, low level of T cell activation and a high level of T cell function as compared to HCV/HIV-1 coinfected control subjects. CONCLUSIONS: A beneficial immune status including a low level of chronic T cell activation and a high level of T cell function may be one factor that contributes to improved chances of clearance of chronic HCV infection in HIV-1 infected patients.

Therapeutic immunization for HIV.

Vaccines have entered into human clinical trials against infectious diseases and as therapies against cancer. The HIV virus establishes a latent infection at a very early stage and the T cell memory of the infected patient is rapidly destroyed. However, results of immunotherapy after DNA and protein immunization show that vaccine-induced immune responses might be present for a long period of time. Patients subjected to therapeutic immunization appear to do well, and to have a small immunological advantage, which, however, will have to be improved. The vaccine therapy should start early, while adequate reservoirs of appropriate T helper cells are available and still inducible. The DNA vaccines induce a relatively long-lived immunological memory, and gene-based immunization is effective in inducing cytotoxic CD8(+) T cells and CD4+ helper cells. Protein vaccines, on the other hand, primarily give T cell help. It thus appears that DNA and protein approaches to HIV immunization complement each other. A surprisingly broad reactivity to peptides from different subtypes of HIV was identified in individuals infected with several subtypes of HIV.

Impact of HIV type 1 genetic subtype on the outcome of antiretroviral therapy.

The objective of this study was to investigate the short-term virological outcome of antiretroviral combination therapy (ART) in relation to infection with different HIV-1 genetic subtypes. Antiretroviral drug-naive patients in Sweden were prospectively enrolled and followed for 6 months when starting ART in the period from January 1998 to January 2002. Plasma-HIV-1 RNA levels, CD4 counts, and type of ART regimen were recorded. The HIV-1 subtype was determined by direct sequencing of regions of the env or pol genes. Data from 172 patients who harbored subtypes A, B, C, D, G, and CRF01_AE were analyzed (32 A, 44 B, 34 C, 18 D, 5 G, and 19 CRF01_AE). Of all patients 84% had undetectable plasma HIV-1 RNA levels after 6 months of ART. Patients infected with CRF01_AE more often had undetectable HIV-1 RNA plasma levels than patients infected with subtypes A or D. However, the possibility that this difference is due to ethnicity cannot be ruled out. Of patients of African origin, 77% had undetectable viral load after 6 months of treatment, while the corresponding figures for Caucasians and Asians were 91% and 100%, respectively. Thus, we have found an overall good short-term virological outcome after the initiation of ART in a cohort of ARV-naive patients of diverse ethnic background infected with different HIV-1 genetic subtypes. In univariate analysis ethnicity, but not genetic subtype, correlated with virological response. However, the impact of ethnicity was moderate. Patients of African origin, who had the poorest outcome, showed a 77% virological response rate.

Effects of potent antiretroviral therapy on the immune activation marker soluble CD27 in patients infected with HIV-1 subtypes A-D.

HIV-1 genetic subtypes might have a different impact on disease progression and response to antiretroviral therapy (ART). Few data are available on the immune activation profile in patients with different HIV-1 subtypes. We have tested by ELISA the plasma levels of an immune activation marker, soluble CD27 (sCD27), in a cohort of 64 patients infected with HIV-1 subtypes A-D, at baseline and after 1 year of virologically successful ART. Plasma sCD27 was significantly higher in the whole HIV-1-infected population as compared to healthy subjects [522 U/ml (188-1,307) vs. 285 U/ml (174-397), P < 0.001]. Among the four different HIV-1 subtypes, patients with subtype C virus had significantly higher plasma sCD27 [684 U/ml, (188-1228)] as compared to patients with subtype A [428 U/ml (247-1307), P < 0.05] and B [454 (211-925), P < 0.05]. After 1 year of ART, plasma sCD27 significantly decreased in all groups but patients with subtype C viruses had the largest reduction of sCD27 from baseline. The data indicate that a similar immune activation profile is present in patients infected with HIV-1 subtypes A, B, and D and that in presence of successful ART these subtypes respond similarly in terms of immune activation. Intriguingly, subtype C infection seems to be associated with higher levels of plasma sCD27, suggesting that HIV-1 genetic subtype C may have a different impact on disease outcome and response to therapy.

Limited transmission of drug-resistant HIV type 1 in 100 Swedish newly detected and drug-naive patients infected with subtypes A, B, C, D, G, U, and CRF01_AE.

The prevalence of genetic drug resistance in newly diagnosed HIV-1 cases and potential subtype-specific mutation patterns were studied. Samples from 100 newly diagnosed patients were randomly chosen from three HIV clinics in Sweden, prospectively collected during the period June 1998 to August 2001. Viral RNA was extracted from plasma and an approximately 2000-bp fragment covering the protease (PR) and reverse transcriptase (RT) genes was sequenced. Subtypes A, B, C, D, G, U, and CRF01_AE were found. All 100 sequences had mutations reported to be involved in some drug resistance, revealing naturally occurring subtype-specific amino acid patterns. Such patterns may be important to consider when treating patients infected with nonsubtype B viruses. While many drug resistance mutations seem to be naturally occurring, 9% of the newly detected patients in Sweden may have been infected with virus from antiviral-treated patients. Among the individuals infected with resistant virus, the majority were infected with subtype B virus and belonged to the homosexual risk group. It may be important to routinely test for resistance in newly infected cases to improve the choice of drugs for treatment because the virus may revert and resistant forms can become latent.

Chronic hepatitis C: updated Swedish consensus.

In 1999 a Swedish national expert panel published recommendations for the treatment of chronic hepatitis C (HCV) infection. Recently, pegylated interferon (peg-IFN) products have been introduced, and an increased knowledge concerning treatment of acute HCV and HCV-human immunodeficiency virus (HIV) coinfection has been gained. As a result of this, an update of the Swedish recommendations was developed following an expert meeting in October 2002. The panel now recommends the use of peg-IFN together with ribavirin as the standard treatment. Owing to the excellent response rates in HCV genotype 2 and 3 infections, these patients can be treated for 24 weeks without preceding liver biopsy. For patients with genotype 1 infection (with a slightly below 50% sustained response rate after 48 weeks treatment) and only mild histological disease, treatment can be postponed until future better treatment options become available. In patients who fail to achieve a 99% reduction (2 log drop) in viral titre after 12 weeks of treatment, discontinuation of therapy is recommended. Patients previously treated with IFN monotherapy and not having achieved a sustained virological response are recommended the same combination treatment as treatment-naive patients. IFN monotherapy is recommended in patients with acute hepatitis C. For children with chronic HCV infection, combination treatment is mainly recommended in clinical trials. For HCV-HIV coinfected patients, combination treatment is recommended and preferably given when blood CD4 counts are above 350/ml and before antiretroviral treatment (ART) is needed. Concurrent ART or prominent liver fibrosis requires frequent monitoring because of the increased risk for mitochondrial toxicity and liver failure.