Platelet-Rich Plasma for Parosmia

Overseen By Homer Abaya, BS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Stanford University

Must not be taking: Blood thinners

Disqualifiers: Pregnancy, Nasal abnormalities, Trauma, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 5

Duration: 6 weeks

40 Participants Needed

Trial Summary

What is the purpose of this trial?

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.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, if you are on blood thinners like coumadin or plavix, you cannot participate in the trial.

What data supports the effectiveness of the treatment Platelet-rich Plasma (PRP) for parosmia?

Research shows that Platelet-rich Plasma (PRP) has been used to help regenerate the sense of smell in conditions like anosmia (loss of smell) and hyposmia (reduced sense of smell) due to its anti-inflammatory and neuroprotective effects. PRP contains growth factors that aid in tissue healing and regeneration, which have been beneficial in other medical areas such as wound healing and surgery. ^{1 2 3 4 5}

Is platelet-rich plasma (PRP) generally safe for use in humans?

Platelet-rich plasma (PRP) is generally considered safe for use in humans, as it is an autologous product (made from a person's own blood), which reduces the risk of allergic reactions or disease transmission. Studies have shown its safety in various applications, including tissue regeneration and wound healing. ^{1 2 5 6 7}

How is the treatment Platelet-Rich Plasma (PRP) unique for parosmia?

Platelet-Rich Plasma (PRP) is unique because it uses a concentration of platelets from the patient's own blood, which are rich in growth factors that help repair and regenerate tissues. This approach is different from standard treatments as it leverages the body's natural healing processes, and there are no established treatments specifically for parosmia. ^{4 8 9 10 11}

Research Team

Zara Patel, MD

Principal Investigator

Stanford Otolaryngology - Head and Neck Surgery

Eligibility Criteria

This trial is for individuals experiencing parosmia, a condition where the sense of smell is distorted. Participants should have this condition and be interested in trying an intranasal treatment derived from their own blood.

Inclusion Criteria

Patients must be able to read and understand English

Quantitative score under the 10th percentile on the SSParoT (HedRang and HedDir)

I am 18 years old or older.

Exclusion Criteria

I have a bleeding disorder or am taking blood thinners like coumadin or plavix.

I am over 18, not pregnant, and have no nasal structure issues.

I have lost my sense of smell due to injury, sinus issues, growths, or a brain condition for over 2 years.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive intranasal injections of either PRP or saline into the olfactory cleft three times, separated by two weeks each

6 weeks

3 visits (in-person)

Follow-up

Participants are monitored for changes in olfactory function using the Sniffin Sticks Parosmia Test and QOD scale score

3 months

2 visits (in-person)

Treatment Details

Interventions

• Platelet-rich Plasma (PRP)

Trial Overview The study tests if injecting Platelet-rich Plasma (PRP), made from a patient's own blood, into the nasal cavity can help treat parosmia. PRP has shown promise in healing tissues. Patients will either receive PRP or saline (a placebo) to compare effects.

Participant Groups

Group I: Saline Active Control 1 Intervention

Participants receive saline injections into the olfactory cleft three times, separated by two weeks each. (Sham/placebo injections).

Group II: Platelet Rich Plasma (PRP) Active Control 1 Intervention

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.

Platelet-rich Plasma (PRP) is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Platelet-rich Plasma for:

• Orthopedic conditions (e.g., tendonitis, osteoarthritis)
• Dermatological conditions (e.g., androgenic alopecia, wound healing)
• Sports medicine injuries

Approved in European Union as Platelet-rich Plasma for:

• Orthopedic conditions (e.g., tendonitis, osteoarthritis)
• Dermatological conditions (e.g., androgenic alopecia, wound healing)
• Sports medicine injuries

Approved in Canada as Platelet-rich Plasma for:

• Orthopedic conditions (e.g., tendonitis, osteoarthritis)
• Dermatological conditions (e.g., androgenic alopecia, wound healing)
• Sports medicine injuries

Who Is Running the Clinical Trial?

Stanford University

Lead Sponsor

Trials

2,527

Recruited

17,430,000+

Findings from Research

In a pilot study involving 7 patients with long-term olfactory loss, a single intranasal injection of platelet-rich plasma (PRP) was found to be safe and resulted in subjective improvements in smell for all participants shortly after treatment.

At the 3-month follow-up, 60% of patients with moderate olfactory loss showed significant improvement, with some achieving normal olfactory function, indicating potential efficacy of PRP for treating hyposmia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The use of platelet-rich plasma in treatment of olfactory dysfunction: A pilot study. Yan, CH., Mundy, DC., Patel, ZM.[2022]

In a study of 54 patients with long-term anosmia, platelet-rich plasma (PRP) injections were found to be safe and led to subjective improvements in smell, with 16 patients showing significant improvement after a single injection and 19 after double injections.

The study suggests that PRP may have potential efficacy in treating olfactory loss, particularly for patients with persistent anosmia, although further research is needed to optimize treatment frequency and duration.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Platelet-rich Plasma in Management of Anosmia (Single Versus Double Injections). Shawky, MA., Hadeya, AM.[2023]

In a study involving 16 male mice, platelet-rich plasma (PRP) significantly improved olfactory function in a model of anosmia, as shown by better food-finding test scores compared to a saline control over 21 days.

Histopathological analysis revealed that PRP treatment resulted in less epithelial damage and greater epithelial thickness in the olfactory neuroepithelium, indicating a potential curative effect on olfactory functions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effectiveness of platelet-rich plasma in an anosmia-induced mice model. Yasak, AG., Yigit, O., Araz Server, E., et al.[2018]

Platelet-rich plasma (PRP) preparations are rich in growth factors that play crucial roles in healing and tissue regeneration, making them valuable for clinical applications in various fields such as orthopedic surgery and wound treatment.

The effectiveness of PRP is largely determined by the concentration of platelets and their growth factors, which enhance processes like tissue healing and regeneration through autocrine and paracrine signaling mechanisms.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Growth factor content in PRP and their applicability in medicine. Lubkowska, A., Dolegowska, B., Banfi, G.[2022]

A systematic review of nine randomized controlled trials involving 325 participants found no significant difference in the healing of chronic wounds when comparing autologous platelet-rich plasma (PRP) to standard treatments or placebo.

While some results showed a higher percentage of wound area healed with PRP in mixed chronic wounds, overall evidence does not support the efficacy of PRP for chronic wound treatment, highlighting the need for more robust clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Autologous platelet-rich plasma for treating chronic wounds. Martinez-Zapata, MJ., Martí-Carvajal, AJ., Solà, I., et al.[2022]

Autologous plasma rich in platelets (PRP) has shown to improve gingival recession in chronic periodontitis, with a significant effect size (SMD of 0.54) based on data from four randomized controlled trials.

The efficacy of PRP in promoting complete healing of chronic skin ulcers remains inconclusive, and while adverse effects were reported, there were no significant differences between treatment groups, indicating a need for further research on its safety.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy and safety of the use of autologous plasma rich in platelets for tissue regeneration: a systematic review. Martínez-Zapata, MJ., Martí-Carvajal, A., Solà, I., et al.[2018]

In a study of 140 high-risk women undergoing cesarean sections, the use of autologous platelet-rich plasma (PRP) significantly improved wound healing compared to standard care, with an 85.5% reduction in the REEDA score for the PRP group versus 72% for the control group.

Patients receiving PRP also reported greater pain relief, with a 93% reduction in the visual analog scale (VAS) score compared to 79% in the control group, indicating that PRP not only enhances healing but also improves patient comfort post-surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Application of Autologous Platelet-Rich Plasma (PRP) on Wound Healing After Caesarean Section in High-Risk Patients. Tehranian, A., Esfehani-Mehr, B., Pirjani, R., et al.[2022]

Platelet-rich plasma (PRP) obtained from healthy adult cats using the PRGF®-Endoret® technology showed a significant increase in platelet concentration (1.5 times higher) compared to whole blood, while reducing red and white blood cell counts by over 99%.

The study demonstrated that PRP contains higher levels of platelet-derived growth factor BB (PDGF-BB) compared to platelet-poor plasma (PPP), indicating its potential for promoting tissue repair, although further research is needed to assess its clinical efficacy in treating various conditions in cats.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluation of a Standardized Protocol for Plasma Rich in Growth Factors Obtention in Cats: A Prospective Study. Miguel-Pastor, L., Satué, K., Chicharro, D., et al.[2022]

In a study involving 126 patients with knee joint cartilage injuries and degenerative meniscus lesions, platelet-rich plasma (PRP) treatment showed significant improvement in knee function and pain relief three months after administration, with effects remaining stable at six months.

PRP therapy is a promising method for short-term pain reduction in knee injuries, but further research is necessary to establish its long-term effectiveness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intra-articular Platelet-Rich Plasma Injections for Treating Knee Pain Associated with Articular Cartilage and Degenerative Meniscal Lesions. Mitev, K., Longurov, A.[2020]

Platelet-rich plasma (PRP) contains a high concentration of platelets and growth factors, making it useful in oral and maxillofacial surgery as well as orthopedics for repairing bone, cartilage, and soft tissues.

Key growth factors in PRP, such as PDGF and TGF-beta, are crucial for promoting healing and tissue regeneration during various stages of recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Research progress of the mechanism of repairing bone defect with PRP]. Chen, S., Zhang, N., Chen, WS., et al.[2012]

Platelet-rich plasma (PRP) significantly enhances the proliferation of human adipose-derived stem cells (hASCs), primarily through the action of platelet-derived growth factor (PDGF)-BB.

The proliferation induced by PRP is mediated via specific signaling pathways, including ERK1/2, PI3K/Akt, and JNK, while inhibitors like imatinib and sorafenib can effectively block this process.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Platelet-rich plasma enhances the proliferation of human adipose stem cells through multiple signaling pathways. Lai, F., Kakudo, N., Morimoto, N., et al.[2022]

References

1. United States pubmed.ncbi.nlm.nih.gov

The use of platelet-rich plasma in treatment of olfactory dysfunction: A pilot study. [2022]

2. India pubmed.ncbi.nlm.nih.gov

Platelet-rich Plasma in Management of Anosmia (Single Versus Double Injections). [2023]

3. United States pubmed.ncbi.nlm.nih.gov

The effectiveness of platelet-rich plasma in an anosmia-induced mice model. [2018]

4. Italy pubmed.ncbi.nlm.nih.gov

Growth factor content in PRP and their applicability in medicine. [2022]

5. England pubmed.ncbi.nlm.nih.gov

Autologous platelet-rich plasma for treating chronic wounds. [2022]

6. United States pubmed.ncbi.nlm.nih.gov

Efficacy and safety of the use of autologous plasma rich in platelets for tissue regeneration: a systematic review. [2018]

7. Estonia pubmed.ncbi.nlm.nih.gov

Application of Autologous Platelet-Rich Plasma (PRP) on Wound Healing After Caesarean Section in High-Risk Patients. [2022]

8. Switzerland pubmed.ncbi.nlm.nih.gov

Evaluation of a Standardized Protocol for Plasma Rich in Growth Factors Obtention in Cats: A Prospective Study. [2022]

9. North Macedonia pubmed.ncbi.nlm.nih.gov

Intra-articular Platelet-Rich Plasma Injections for Treating Knee Pain Associated with Articular Cartilage and Degenerative Meniscal Lesions. [2020]

10. China pubmed.ncbi.nlm.nih.gov

[Research progress of the mechanism of repairing bone defect with PRP]. [2012]

11. England pubmed.ncbi.nlm.nih.gov

Platelet-rich plasma enhances the proliferation of human adipose stem cells through multiple signaling pathways. [2022]