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Updated: Jan 31, 2026
Amplifying and Quantifying HIV-1 RNA in HIV Infected Individuals with Viral Loads Below the Limit of Detection by Standard Clinical Assays
Published on: September 26, 2011
HIV-1 detection in the olfactory mucosa of HIV-1-infected participants
Luca Bertero1, Sarah Beth Joseph2, Mattia Trunfio3
1Unit of Pathology, Department of Medical Sciences, University of Torino, Torino, Italy.
Objective:
HIV infection chronically affects the central nervous system (CNS). Olfactory mucosa is a unique site in the respiratory tract that is directly connected to the CNS; thus we wanted to evaluate olfactory mucosa as a surrogate of CNS sampling.
Design:
We conducted a preliminary study examining HIV populations and susceptible cells in the olfactory mucosa.
Methods:
Olfactory mucosa was sampled by minimally invasive brushing. Cerebrospinal fluid (CSF) analyses were performed as per routine clinical procedures. Olfactory marker protein, CD4+, CD8+, and trans-activator of transcription (TAT) expressions were assessed by immunohistochemistry. Plasma, CSF, and olfactory mucosa HIV-RNA were quantified using the Cobas AmpliPrep/Cobas TaqMan assay, whereas HIV proviral DNA was evaluated on peripheral blood mononuclear cell and olfactory mucosa. HIV-1 env deep sequencing was performed for phylogenetic analysis.
Results:
Among ART-naive participants, 88.2% (15/17), and among ART-treated participants, 21.4% (6/28) had detectable HIV-RNA in samples from their olfactory mucosa; CSF escape was more common in patients with olfactory mucosa escape (50 vs. 7.9%; P = 0.010). Olfactory mucosa samples contained few cells positive for CD4, CD8, or HIV-DNA, and no HIV TAT-positive cells, indicating that this approach efficiently samples virions in the olfactory mucosa, but not HIV-infected cells. Yet, using a deep sequencing approach to phylogenetically compare partial HIV env genes in five untreated participants, we identified distinct viral lineages in the OM.
Conclusions:
The results of this study suggest that nasal brushing is a well tolerated and useful technique for sampling the olfactory mucosa. HIV-RNA was detected in most naïve and in some treated patients, warranting larger longitudinal studies.
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