This study analysed the sequence of HIV-1 pol gene derived from Zimbabwean infected patients. Sequence analysis, performed on 8 samples, revealed that sequences were classified as subtype C (n=5), ...subtype B (n=2) and CRF01_AE (n=1). Two patients, treated with a therapeutic regimen containing NRTI/NNRTI, harboured drug resistance mutations in HIV-1 DNA. Phylogenetic analysis performed on subtype C sequences showed that our strains were aggregated in different clusters depending on the country of origin.
Recently published studies have highlighted the importance of phylogenetic and phylodynamic analyses in supporting epidemiological investigations to reconstruct the transmission network of human ...immunodeficiency virus. Here, we report a case of sexual transmission of human immunodeficiency virus type 1 between a man and a woman that marks once more the importance of a tightened collaboration between phylogeny and epidemiology.
We describe a case of human immunodeficiency virus type 1 subtype B transmission in a stable Caucasian heterosexual couple. The man was 30 years old and the woman was 21 years old at the time of their presentation to the Department of Public Health and Infectious Diseases of the University of Rome "Sapienza". The couple reported a history of drug abuse.
Phylogenetic analysis is a powerful technique that if properly used can prove valuable in research investigations. In the case presented here, a phylogenetic analysis alongside epidemiological evidence allowed us to determine the most probable source of the human immunodeficiency virus infection. The dated tree allowed us to date the transmission event, the time point, and the direction of transmission based on the phylogeny, which agreed with the presumptive time of infection determined from clinical history-taking.
To evaluate whether an inter-individual variability in the activity of thymidine kinase (TK) and deoxycytidine kinase (dCK), which are involved in the first step of phosphorylation of some nucleoside ...analogues, exists in antiretroviral-naive, HIV-seropositive patients.
Forty-five randomly selected antiretroviral-naive HIV-infected patients were recruited, together with 26 healthy volunteers with no concurrent infection and under no pharmacological treatment.
Peripheral blood mononuclear cells (PBMC) were isolated from venous blood and their TK and dCK activities evaluated. CD4 T cells and HIV-RNA were measured in HIV-infected patients, too.
There was a broad range of variability in TK activity in HIV-infected individuals. Furthermore, the activity in PBMC was significantly higher in HIV-infected individuals than in healthy volunteers. dCK activity in seropositive patients was significantly lower than in healthy volunteers. A marked inter-individual variability in dCK levels was observed in the HIV-infected group. No correlations were found between TK or dCK activities and plasma viral load, CD4 cell count, sex or age of patients.
A marked range of inter-individual variability of TK and dCK activities in PBMC exists in HIV-infected individuals but not in healthy volunteers, indicating that the activity of enzymes with key roles in drug activation could vary greatly from one patient to another. Furthermore, TK expression is greater in HIV-infected individuals than in healthy volunteers. Better understanding of the viral or cellular factors that contribute to this variability, as well as their effect on responses to antiretroviral treatment, may aid optimization of the management of HIV-infected patients.
The goal of the OSCAR programme is to evaluate the performances of genotypic HIV-1 tropism testing in clinical practice using the enhanced sensitivity version of Trofile (ESTA) as reference-assay.
...HIV-1 coreceptor-usage was assessed using plasma samples from 406 HIV-1 infected patients by ESTA and by gp120 V3 population-sequencing followed by Geno2pheno (set at a False Positive Rate FPR of 10% and 5%).
ESTA was successful in 365 (89.9%) samples indicating R5 in 254 (69.6%), and DM/X4 in 111 (30.4% of samples (104 28.5% DM and 7 1.9% X4). Genotypic-testing successfully assessed viral tropism for all 406 samples, including the 41 with undetermined result by ESTA. Genotypic-tropism testing at a FPR of 5% and 10% was 81.1% and 78.4% concordant with ESTA, respectively. Despite a sensitivity of 48.7% and 55.9% at a FPR of 5% and 10%, respectively, a high concordance (specificity: 95.3% for FPR of 5% and 88.2% for FPR of 10%) between genotypic-tropism testing and ESTA was reached in the detection of R5-tropic viruses.
Our results are in line with other European studies, and support the routine use of genotypic tropism testing in clinical-settings for monitoring of HIV-1 infected patients candidate to or failing CCR5-antagonists.
MxA, a protein with selective activity against certain viruses, is an accepted specific indicator of type I interferon (IFN) activity. We have developed an internally controlled ...quantitative-competitive PCR to measure the amounts of MxA mRNA expressed in peripheral blood mononuclear cells (PBMC). This assay is more sensitive, quantitative, and easily applied to serial clinical samples than previously described methods. We have applied this assay retrospectively to 27 patients with chronic active hepatitis C given IFN-alpha2. Most such patients gain no sustained benefit but nevertheless suffer from the side effects, expense, and inconvenience of the treatment. Fourteen of the 27 had been classified on clinical grounds as responders and 13 as nonresponders at the end of a 6 month treatment period. We measured MxA mRNA in PBMC obtained before and after 8 weeks of IFN-alpha2 treatment. All the patients expressed some level of mRNA before treatment began, and after 8 weeks of treatment, the level rose in 19. This increase was significant (p < 0.001) only in patients classified as responders. This strongly suggests that hepatitis C virus (HCV) patients who express increased amounts of MxA mRNA in their PBMC during IFN-alpha treatment are most likely to obtain long-term benefit. If this finding is confirmed in future prospective studies, it will provide an extremely important predictive marker for managing IFN-alpha therapy in patients with HCV.
During acute human immunodeficiency virus (HIV) infection, both virus load (HIV RNA) and infectivity are high (103-107 RNA copies/mL or TCID50/mL) until antibody is produced, which may reduce the HIV ...infectivity. In HIV carriers, the HIV RNA load is elevated (103–105 copies/ mL), but infectivity is low (100–102 TCID50/mL). The low infectivity in carriers could be due to neutralization by antibody in serum, resulting in immune complexes (ICs). We demonstrated that ICs in plasma, prepared with protein A beads, contained HIV RNA (80%–100%) in association with immunoglobulin G (IgG). In comparison, ICs from patients with acute HIV infection and little or no antibody contained virtually no HIV RNA. Moreover, ICs prepared by ultrafiltration contained IgG and specifically and irreversibly neutralized HIV, which indicates that the ICs contained neutralizing antibody. These findings indicate that the HIV RNA in the plasma of carriers is frequently composed of antibody-neutralized HIV as ICs.
It has been demonstrated that HIV infection may affect the levels of thymidine kinase (TK) and deoxycytidine kinase (dCK) in peripheral blood mononuclear cells from HIV infected adults. The aim of ...this study was to examine the effect of HIV infection and/or antiretroviral therapy on the activity of the above enzymes in HIV-infected children. The results showed that an inter-individual variability in TK and dCK activities does exist in both HIV infected and uninfected children. TK and dCK levels in PBMC from HIV infected and non infected children did not significantly differ. Furthermore, the therapeutic regimen, including zidovudine, does not seem to affect TK activity.
The present study was aimed at describing the effect of highly active antiretroviral therapy (HAART) in 10 patients with primary HIV infection (PHI). Clearance rates of HIV RNA and HIV DNA in ...peripheral blood as well as the preexistence and the emergence of drug-resistant strains of HIV were determined over 52 weeks of treatment. The data indicate that HAART is able to induce a suppression of plasma viral load together with a significant decrease, but not a suppression, of peripheral blood mononuclear cell-associated proviral DNA in PHI subjects. Analysis of drug-resistant strains revealed that three PHI patients, showing a complete virologic response, developed mutations in the pol gene, thus suggesting that a persistent residual virus replication exists despite a sustained suppression of plasma viremia.
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