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

Stanford University40 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Paraosmia

Interventions

Platelet-rich plasma (PRP) intranasal injection in the treatment of qualitative olfactory dysfunction (parosmia). This is taken from a blog draw from the patient themselves, and thus no external drug/biologic product will be given - only the concentrated plasma portion from the patient's own blood.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Change in Sniffin Sticks Parosmia Test (SSParoT)

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.

Time frame: Assessed at baseline, 1 month, and 3 months

Change in questionnaire of olfactory disorders (QOD) scale score

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.

Time frame: Assessed at baseline, 1 month, and 3 months

Central Contacts

Homer Abaya, BS

CONTACT

(650) 725-6500 habaya@stanford.edu

Maxime Fieux, MD, PhD