An interventional study of olfactory testing and Odor stimulation in Alzheimer Disease, Smell Loss and Smell Dysfunction, sponsored by Duke University. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-12.
Sponsored by Duke University · Not applicable, Interventional, and Basic science
This research study aims to investigate the function of the olfactory lining in the nasal cavity and its potential alterations in both healthy and diseased conditions. The olfactory lining is involved in the sense of smell.
The purpose of this study is to collect tissue from the nasal cavity.
The purpose of this study is to analyze cell populations active in human olfactory tissue in health and disease. This is a prospective study. Healthy participants or participants with known disease processes that may impact olfaction, such as Alzheimer's, inflammatory conditions, aging, or post-viral smell loss, will be included. Olfaction will be measured using standard psychophysical testing. Biopsies of the olfactory lining in the nasal cavity may be obtained in the otolaryngology clinic or the operating room, if the patient is having an unrelated endoscopic nasal surgery, and may be obtained using a punch technique or a cytology brush. Before biopsies, some patients may be asked to sniff an odor substance (such as lavender, mint, citrus, or cloves) briefly, to stimulate olfactory cells. Biopsies will be processed for assays in the PI's lab, including histology, primary culture assays, flow cytometry assays, or transcriptomic profiling.
3,965 studies on the registry are indexed under Alzheimer Disease; 926 are open to participants now.
This study's planned enrollment of 125 is above the median of 70 across 3,019 interventional studies indexed under Alzheimer Disease.
Browse Alzheimer Disease studies →Duke University is the lead sponsor of 2,063 studies on the registry; 273 are open to participants now.
Of its 204 completed or terminated interventional studies of FDA-regulated products, 167 (82%) have results posted.
Counted across the registry records on this site, refreshed daily.
Group 1: Alzheimer's study
Inclusion Criteria:
Exclusion Criteria:
Group 2: Act-seq study or Non-AD controls
Inclusion Criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Olfactory function will be assessed using the Smell Identification Test (SIT, Sensonics, Inc) or Sniffin' Sticks Test. Using topical intranasal decongestion/anesthetic (oxymetazoline/lidocaine), a cytology brush biopsy will be obtained from the olfactory cleft region of the nose in clinic exam room using a nasal endoscope.
Diagnostic Test: olfactory testing · Other: Odor stimulation · Procedure: Olfactory biopsy
Olfactory function will be measured using established psychophysical testing via the Smell Identification Test or Sniffin' Sticks. Researchers will obtain biopsies from (1) normosmic subjects with or without odor stimulation, and (2) hyposmic subjects with history of upper respiratory infection (URI) as likely cause of the smell loss (such as COVID19) with or without odor stimulation.
Diagnostic Test: olfactory testing · Other: Odor stimulation · Procedure: Olfactory biopsy
Patients will undergo smell testing, using the Smell Identification Test (Sensonics), a validated widely-used 40-item "scratch-and-sniff" style psychophysical test to determine olfactory function.
subset of patients will be asked to sniff a specific odor for about an hour, using commercially available "odor pens" (Sniffin' Sticks or Sensonics). These odor pens are widely used for olfactory training therapy, a treatment designed to help people with some forms of smell loss; they are also used in psychophysical olfactory testing.
Biopsy involves a simple cytology brush technique of the lining of the nose in a region called the olfactory cleft, using a nasal endoscope, and can be done in clinic or in the operating room at the time of a nasal surgery. Topical oxymetazoline and tetracaine spray is applied to the nasal cavity, a rigid nasal endoscopy (0-degree 4 mm endoscope, Karl Storz) is performed to visualize the olfactory cleft, and a small nasal cytology brush biopsy (Hobbs Medical)is performed by swabbing and rotating brush gently in the olfactory cleft. Cytology sample is placed into a buffer (Hibernate-E, Thermo Fisher)on ice for transport to the research lab.
Transcription state changes in olfactory cells
Using single cell RNA-sequencing, olfactory epithelial cell populations will be analyzed for changes in coherent gene expression programs from subjects in different environmental conditions.
Time frame: study is planned for completion over 5 years
Plan to share: No
No publications or documents are linked to this record.
Started Jan 2025 (actual). Primary completion is estimated for Apr 2029, 51 months after the start.
Of 882 non-industry interventional studies with no phase under Alzheimer Disease, half reached primary completion within 30 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 51. This study's planned 51 months is above that.
Counting every sponsor, half of 959 studies reached it within 29 months; a quarter within 15 and three quarters within 51.
How these figures are worked out, and which studies are left out of them.
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