Quantitation of HIV-1 RNA in dried blood and plasma spots.

Dried blood spots (DBSs) and dried plasma spots (DPSs) are an attractive method for serological and molecular diagnosis of HIV infection. Recently, Youngpairoj et al. [Youngpairoj, A.S., Masciotra, S., Garrido, C., Zahonero, N., de Mendoza, C., Garcia-Lerma, J.G., 2008. HIV-1 drug resistance genotyping from dried blood spots stored for 1 year at 4 degrees C. J. Antimicrob. Chemother. 61, 1217-1220] showed that HIV-1 can be genotyped efficiently from DBS specimens stored at 4 degrees C for 1 year. The viral load obtained from DBS and DPS samples was compared with that obtained from plasma samples. A total of 86 samples was prepared from people infected with HIV subtype B or non-B and spotted on 903 filter papers stored with desiccant at 4 degrees C. RNA was extracted using the QIAamp Viral RNA mini kit (Qiagen, Courtaboeuf, France). RNA from DBS or DPS samples was quantified in accordance with the Agence Nationale de Recherche sur le SIDA (ANRS, AC11, Paris, France) assay for HIV-1 quantitation. When the mean viral load of plasma samples and DPS samples or plasma samples and DBS samples were compared, there were no significant differences. The overall data showed that although the sensitivity threshold of the assays was different, there was a correlation between the three specimen types and that DBS and DPS samples can be routinely used for viral load quantification particularly in resource-limited settings.

Comparison of capillary electrophoresis sequencing with the new CEQ 2000 DNA Analysis System to conventional gel based systems for HIV drug resistance analysis.

To date the majority of sequencing technologies have been based on use of gel plates. In this study sequencing by capillary electrophoresis for HIV-1 genotyping on the CEQ 2000 sequencer (Beckman Coulter Inc.) has been investigated and compared to an 'in house' protocol on the Prism-377 sequencer (Applied Biosystems) and to the HIV-1 TruGene kit (Visible Genetics Inc.), two gel plate-based systems. Plasma from 20 HAART-treated patients with virological failure were analyzed for protease (PR) and reverse transcriptase (RT) genes. A total of 520 RT codons (26/patient) and 360 PR codons (18/patient) related to antiretroviral drug resistance were evaluated. The overall agreement between CEQ 2000 and Prism-377 results was 100% for the RT and PR primary and secondary mutations. The overall agreement between CEQ 2000 and TruGene was 100% for primary and > or =97% for secondary mutations. Discrepant results would have never led to errors in genotype interpretation. Performances for a 24 patients/week/one technician genotyping throughput were analyzed. For Prism-377, TruGene and CEQ 2000, manual processing required 5, 4 and 2,5 days, sequence data analysis needed additional 3, 1 and 2 days and cost/patient was approximately 49, 214 and 39 $, respectively. The CEQ 2000 sequencer offers a reliable alternative for fast and cost effective HIV drug resistance analysis.

Sequence analysis of env C2/V3, gag p17/p24, and pol protease regions of 25 HIV type 1 isolates from Ho Chi Minh City, Vietnam.

Env C2/V3, gag p17/p24, pol protease, and RT regions of HIV-1 isolates recently obtained from 25 HIV-1 seropositive individuals from Ho Chi Minh City (Vietnam) were studied, and genes subtypes were determined by DNA sequence analyses. Twenty-three isolates out of 25 were identified as belonging to subtype E, now recognized as circulating recombinant form 1 (CRF01_AE). The motif at the top of the V3 loop (generally GPGQ) was then preceded by an isoleucine or a methionine (M) residue; the M residue might be a local signature of Vietnamese E isolates compared to Thai E viruses. Two isolates (8%) were shown to be intersubtype recombinants: one E/B and one CRF02_AG(IBNG)/D. The polymorphism of pol protease was considered only for CRF01_AE isolates and is clearly different from that recorded for B viruses with substitutions at positions 13, 35, 36, 41, 69, and 89.

New molecular assays to predict occurrence of cytomegalovirus disease in renal transplant recipients.

Thirty renal transplant recipients, after transplantation, were tested weekly with the following assays: cytomegalovirus (CMV) antigenemia (pp65 Ag), plasma qualitative Amplicor CMV (P-AMP), plasma and peripheral blood leukocyte quantitative Amplicor CMV monitor (P- and PBL-CMM), peripheral blood leukocyte (PBL) quantitative Quantiplex bDNA CMV, version 2.0 (bDNA), and whole-blood Nuclisens pp67 CMV (pp67). Eleven patients developed symptomatic CMV disease, and 7 developed asymptomatic CMV infection. For prediction of CMV disease, the sensitivity, specificity, and positive and negative predictive values, respectively, were as follows: 100%, 63%, 61%, and 100% for pp65 Ag; 100%, 42%, 50%, and 100% for bDNA; 91%, 47%, 50%, and 90% for PBL-CMM; 55%, 74%, 55%, and 74% for P-AMP; 55%, 74%, 55%, and 74% for P-CMM; and 64%, 79%, 64%, and 79% for pp67. First positive results in PBL were obtained 9-10 days before symptoms of CMV disease, compared with 5-6 days in plasma and 0 days in whole blood. PBL assays appear to be more appropriate than plasma assays when pre-emptive therapy is required to prevent the rapid progression from the first detection of the virus to CMV disease.

Cell-associated HIV-1-DNA quantitation after highly active antiretroviral therapy-treated primary infection in patients with persistently undetectable plasma HIV-1 RNA.

OBJECTIVE: To determine the usefulness of cell-associated HIV-1-DNA quantification during the follow-up of highly active antiretroviral therapy (HAART)-treated primary-infected patients with persistently undetectable plasma RNA loads. PATIENTS AND METHODS: In 27 patients given HAART within a median of 24 days after symptomatic primary HIV infection, plasma and peripheral blood mononuclear cell (PBMC) HIV-1 RNA were less than 50 copies/ml and less than 50 copies/10(6) cells after 18 months of treatment. HIV-1 RNA and DNA were quantified every 6 months in PBMC in these 27 patients, 14 of whom accepted excision lymph node biopsy after month 18 for HIV-1-RNA and -DNA quantification in lymph node mononuclear cells (LNMC). RESULTS: The median decreases in plasma HIV-1 RNA, PBMC HIV-1 RNA and DNA over the 18 months of follow-up were 3.6 log (P< 0.005), 1.1 log (P< 0.05), and 1.0 log (P<0.001), respectively. HIV-1 DNA was detected in 92.3% of PBMC samples at baseline and at month 18. In LNMC, 100% of samples were detectable for HIV-1 DNA. CONCLUSION: In this highly selected population of patients with excellent plasma virological response under HAART, HIV-1 DNA showed a progressive decrease but was still detectable in 92.3% of samples at month 18, whereas all LNMC samples tested scored positive for HIV-1 DNA. The utility of proviral HIV-1-DNA monitoring was not clearly demonstrated in this 18-month follow-up of HAART-treated primary-infected patients. However, this finding could be reconsidered when using other therapeutic strategies such as structured treatment interruptions, reinforced treatment or additive immunotherapy.

Analysis of HIV-1 expression in vivo with in situ hybridization and the polymerase chain reaction.

The objective of the present study was to compare the data of in situ hybridization (ISH), RNA polymerase chain reaction (PCR/RNA) and p24 core antigen (p24 Ag) enzyme immunoassay (EIA) for the detection of HIV-1 expression in peripheral blood mononuclear cells (PBMCs) and in plasma of infected patients at various CDC stages. PBMCs of 24 patients mostly of CDC stage II were obtained from heparinized blood samples, cytocentrifuged and hybridized with a (35S) labelled single-stranded RNA probe specific for gag-pol of LAVBru HIV-1 allowing the detection of genomic and/or messenger RNA. The corresponding plasma samples were used for the determination of p24 Ag by EIA and detection of HIV-1 genomic RNA by RT-PCR using specific primers in the LTR, gag and env regions. Whereas p24 was detected in only six out of 24 patients, both ISH and PCR/RNA enabled the detection of viral RNAs in more than 60% of the patients; cumulation of positive results of ISH and RT-PCR showed that 100% of patients at stage IV and 83% of patients at stages II/III have molecular signs of HIV expression therefore indicating that transcription of the provirus is a highly frequent event, even in the early stages of the disease, and, pleading for undertaking a very early antiviral chemotherapy.