Randomized Clinical Trial of Intranasal Injection of Platelet-Rich Plasma for Treatment of Parosmia

Not Applicable

Recruiting

• Conditions: Paraosmia
• Interventions: Other: Platelet-rich Plasma (PRP); Other: Saline

• Registration Number: NCT06283745
• Lead Sponsor: Stanford University

Brief Summary

This randomized clinical trial will evaluate the benefit of platelet-rich plasma (PRP) in the treatment of qualitative olfactory dysfunction (parosmia). PRP can be isolated from a patient's own blood and has been found in previous studies to have anti-inflammatory and pro-regenerative properties. It has been used across multiple specialties, such as Orthopedics, Facial Plastics, Dermatology, Neurology in injected form to treat a wide variety of tissues to encourage the body's inherent regenerative capacity. The investigators have completed a randomized controlled trial here, ending in 2022, evaluating it's use in post-SARS-CoV-2 olfactory loss which demonstrated safety and efficacy. Therefore, the investigators aim to assess the ability of PRP to improve olfactory function in patients with parosmia.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2024-02-21
• Study First Submitted QC: 2024-02-27
• Study First Posted: 2024-02-28
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-20
• Last Update Posted: 2024-11-22
• Study Start: 2024-11-23
• Primary Completion: 2027-03-22
• Study Completion: 2027-03-22

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

• Patients >= 18 years of age
• Patients who have qualitative olfactory distortion
• Etiology of qualitative olfactory distortion is due to upper respiratory infection
• Quantitative score under the 10th percentile on the SSParoT (HedRang and HedDir)
• Quantitative score ≥ 8 on the QOD.
• At least 6 months of parosmia but less than 24 months
• Patients can have been previously treated with oral and topical steroids but this is not a requirement
• Patients will receive concurrent olfactory training - the practice of smelling strong odors (standard of care)
• Be able to read and understand English
• Be able and willing to provide Informed Consent

Exclusion Criteria

• Patients < 18 years of age, pregnant females, patients who have structural abnormalities on nasal endoscopy or radiographic imaging that would prevent injection into the olfactory cleft
• Olfactory loss due to trauma, chronic sinusitis / inflammation / polyps, neoplasms, or neurodegenerative diseases or patients who have had olfactory loss > 24 months
• Patients with bleeding disorders or on blood thinners such as coumadin and plavix

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Platelet Rich Plasma (PRP)	Platelet-rich Plasma (PRP)	Participants receive PRP intranasal injection into the olfactory cleft three times, separated by two weeks each. Blood is drawn from the patient. This is placed in a centrifuge and using a specialized PRP kit (Emcyte), the sequential spinning process isolates the platelet-rich plasma portion of the blood and we inject that back into the patient within the nasal cavity.
Saline	Saline	Participants receive saline injections into the olfactory cleft three times, separated by two weeks each. (Sham/placebo injections).

Primary Outcome Measures

Name	Time	Method
Change in Sniffin Sticks Parosmia Test (SSParoT)	Assessed at baseline, 1 month, and 3 months	The test consists of a total of 22 sticks, 11 of which are pleasant odors and 11 of which are unpleasant odors. In this test, the test subject is offered a pair of sticks, 1 with an unpleasant odor and 1 with a pleasant odor.; The SSParoT is the first test to measure qualitative olfactory function. This test uses hedonic estimates of two oppositely odors (pleasant and unpleasant) to assess the Hedonic Range (HR) and Hedonic Direction (HD). These values represent the qualitative olfactory perception.
Change in questionnaire of olfactory disorders (QOD) scale score	Assessed at baseline, 1 month, and 3 months	The QOD is a 25-item validated instrument in the measurement of olfactory-specific QOL (total score on 75) described by Hummel et al. Patients will undergo nasal endoscopy as part of their initial standard of care appointment to exclude structural causes of smell loss including mass or tumor, as well as ensuring there is no structural obstruction to the olfactory cleft such as severe septal deviation.

Trial Locations

Locations (1)

Stanford Sinus Center / Stanford University School of Medicine; 🇺🇸 Palo Alto, California, United States