Effectiveness and Safety of Platelet Rich Plasma (PRP) on Persistent Olfactory Dysfunction Related to COVID-19

Study Overview
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Brief Summary
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Olfactory dysfunction (OD) is a well know symptom of coronavirus disease 2019 (COVID-19), accounting for 48 to 85% of patients. In 1 to 10% of cases, patients develop a chronic olfactory dysfunction (COD,) lasting more than 6 months. Recently, platelet-rich plasma (PRP) was used in patients with non-COVID-19 COD and authors reported encouraging results. In the present study, the investigators investigated the usefulness and safety of PRP injection in 56 patients with COVID-19 COD. Our results showed that PRP in the olfactory cleft can increase the olfactory threshold one month after the injection. Moreover, our results suggest that timing of treatment may be an important factor and that PRP is a safe treatment because no adverse effects were reported throughout the study

Official Title
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Effectiveness and Safety of Platelet Rich Plasma (PRP) on Persistent Olfactory Dysfunction Related to COVID-19: Towards a New Therapeutic Hope

Conditions
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Anosmia, COVID-19

Intervention / Treatment
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* Drug: Platelet rich plasma (PRP)
* Other: olfactory training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient chronic olfactory dysfunction lasting more than 6 months after an infection of COVID-19 Exclusion Criteria: Patient under 18 years old Patient with blood disorder Blood thinner user Patient with abnormal findings on nasal endoscopy (e.g., polyposis, rhinosinusitis)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: control group<br>Patient underwent simple olfactive training for one month. | Other: olfactory training<br>* The investigators compare the result of the PRP group to a control group how underwent simple olfactive training for one month. The control group matched for age, gender and olfactory score at baseline. The patients had a sniffing stick test at the beginning and also after one month of olfactory training.<br>|
| Experimental: PRP injected group<br>Patient had one injection in each olfactory cleft. | Drug: Platelet rich plasma (PRP)<br>* PRP injections were performed in each olfactory cleft by nasal endoscopy and under local anesthesia, a sniffing stick test was performed before the injection and one month after<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| efficity of 1 injection of PRP by Sniffing Sick test compare to a simple olfactory training |  | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PRP, Anosmia, COVID-19