320 research outputs found
CD4 count in HIV infection is positively correlated to interferon-gamma and negatively correlated to interleukin-10 in vitro production
No full textGenotypic resistance tests for the management of the HIV-infected patient with non-B viral isolates
No full textWitness for the prosecution: The dominating HIV-1 subtype in Europe and in the USA is the B subtype, but the prevalence of circulating recombinant forms and non-B subtypes (nBS) in Europe has increased. HIV-1 group O strains are spontaneously resistant to non-nucleoside analogue reverse transcriptase inhibitors (NNRTI) and little is known about the antiretroviral (ARV) drug susceptibility of nBS clinical isolates. Controlled randomized trials showing a clinical benefit of a treatment guided by HIV-1 resistance testing at virological failure have been conducted on subtype B. Thus, the result cannot be simply extended to nBS. In nBS, the frequency or amplification failure is increased, but retesting failed samples with an alternative set of polymerase chain reaction primers improves the success of amplification. The major problem is the reliability of genotypic resistance tests (GRT) owing to misinterpretation of the obtained amino acid mutations, the background sequence in nBS being different from the standard used in the commercial kits or in the web-based HIV-1 resistance interpretation tools. At the moment, no nBS database is available to help in the interpretation of the protease and RT sequence results. Furthermore, the mutational pattern of specific ARV drugs may be different, in particular with subtype C and G. In conclusion, in patients with nBS the indication to for at virological failure may exists, even in the absence of clinical evidence, but the results have to be interpreted by experts with particular caution. Witness for the defence: The extensive variability of HIV-1 has a potential impact on epidemiology, diagnosis, therapy and the prevention of infection. Nine different major subtypes of group M (A-D, F-H, J and K) circulate to varying extents in populations around the globe together with the circulating recombinant forms (CRF) owing to intersubtype recombinations. Although viruses belonging to the HIV-1 B clade are still predominant in Europe, the USA and Australia, an increasing prevalence of non-clade B subtypes and CRF has been reported by several surveys in previously homogeneous clade B countries. As current ARV have been designed using subtype B strains and resistance mutations have been characterized on this subtype, the increasing global spread of HIV subtypes highlights the need to determine the activity of anti-HIV drugs against subtypes or CRF other than subtype B
L'intervento nutrizionale in soggetti sovrappeso ipercolesterolemici. Riduzione della colesterolemia con terapia dietetica guidata.
No full textSubtype assignment and phylogenetic analysis of HIV type 1 strains in patients from Swaziland.
No full textAim of this study was to assess HIV-1 subtype distribution and prevalence of transmitted mutations related to antiretroviral drugs in Swaziland. According to the WHO guidelines, 47 plasma samples from naive patients stored at HIV/AIDS National Reference Laboratory in Mbabane between 2002 and 2003, before the introduction of antiretroviral therapy in the country, were studied. HIV-1 RNA was extracted from the plasma samples, RT and protease regions of pol gene were amplified and sequenced. The mutations associated to drug resistance were defined as major or minor on the basis of the recommendations of the International AIDS Society - USA panel. A mutation associated to non nucleoside inhibitors (Y181I) was found in one case showing a prevalence of transmitted drug resistance <5 in Swaziland. No major mutations conferring resistance to protease and nucleoside RT inhibitors were found. Clade assignment was performed by phylogenetic analysis of pol gene. The general time-reversible model of substitution was used to study the phylogenetic relationships between sequences obtained from Swazi patients and sequences from neighbor countries. All patients were found to carry a C subtype. No phylogenetic relationships were detected within Swazi sequences, indicating the absence of epidemiological relationships among patients in study. Although local variants of subtype C have been recently recognized, phylogenetic analysis did not reveal the presence of significant cluster of Swaziland sequences within African variants. This finding may be explained by multiple introduction of C strains
Low CD4 counts rather than superantigenic-like effects account for differences in expressed T-cell receptor (TCR) repertoires between HIV-1 seropositive long-term non-progressors and individuals with progressive disease
No full textAnalysis of HIV-infected individuals who have stable CD4 counts many years after seroconversion may provide an insight as to how the host's immune system can successfully control HIV infection. In this study we analysed the T-cell receptor (TCR) Vbeta repertoire in 13 HIV+ individuals, seven of whom were classed as long-term non-progressors (LTNP), using a technique which couples anchor PCR (AnPCR) amplification of beta-chain cDNA to differential probe hybridization with non-radioactively labelled Vbeta family specific oligonucleotide probes. There were no significant differences in the expressed TCR repertoires between the LTNP group and the other HIV-infected individuals. However, there was a statistically significant inverse correlation between CD4 count and the number of Vbeta family-specific perturbations in the recent seroconverters (SC) and those with progressive infection (PI), consistent with other shared features of clinical disease progression (Th1/Th2 switch and high frequency of viral isolation). We conclude that long-term clinical non-progression in HIV-1 infection is not associated with the loss or expansion of a particular Vbeta family; instead, low CD4 count in the PI and SC individuals was correlated with increased number of Vbeta family-specific perturbations relative to the LTNP group and that it is hence unlikely that HIV encodes a superantigen
Persisting HIV-1 replication triggered by acute hepatitis A virus infection
No full textWe report the case of two patients in whom acute hepatitis A was associated with a marked and prolonged increase in human immunodeficiency virus type 1 (HIV-1) viral load. Although in one patient the rise in HIV-1 RNA might also have been related to the interruption of antiretroviral therapy, we also observed a similar pattern in the other patient who had a stable undetectable plasma viraemia prior to acute hepatitis and never received treatment with anti-retrovirals. Our observation supports the hypothesis that immune activation that is induced by acute hepatitis A virus (HAV) infection may trigger HIV-1 replication. This highlights the importance of maintaining antiretroviral therapy throughout the acute phase of hepatitis A and of preventing HAV infection through active immunization
Increasing prevalence of non-clade B HIV strains in heterosexual men and women, as monitored by analysis of reverse transcriptase and protease sequences.
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