PANDORA: Evaluation of Platelet-rich Plasma in Non-tumoural Odour Disorders: a Descriptive Pilot Study.

PANDORA: Evaluation of Platelet-rich Plasma in Non-tumoural Odour Disorders: a Descriptive Pilot Study.

This is a prospective, single-center, single-arm, non-comparative descriptive pilot study evaluating autologous platelet-rich plasma (PRP) injections in adults with persistent (>6 months) non-tumoural olfactory dysfunction, either age-related degenerative olfactory dysfunction (DOD) or post-traumatic olfactory dysfunction (DOPT). Participants receive three PRP injections over 4 weeks (Day 0, Day 14, Day 28), with follow-up visits at Month 3 and Month 6 after the first injection. Olfactory function is assessed using the Sniffin' Sticks Test (TDI score). Patient-reported outcomes include SNOT-22 and a visual analog scale (VAS) for perceived olfactory impairment. Safety is assessed through adverse event collection.

Prospective consecutive recruitment in an ENT department at Hôpital Lyon Sud (Hospices Civils de Lyon). Eligible participants are enrolled into one of two diagnostic cohorts (DOD or DOPT), and analyses are performed separately by cohort. PRP is prepared from autologous venous blood using a standardized preparation system and injected under endoscopic guidance in the olfactory cleft area (superior nasal septum mucosa). Follow-up assessments are performed at baseline and at Months 3 and 6 after the first injection.

Inclusion Criteria

• Adults with persistent (>6 months) non-tumoural olfactory dysfunction: age-related degenerative olfactory dysfunction (DOD) or post-traumatic olfactory dysfunction (DOPT).
• Objective olfactory impairment confirmed by Sniffin' Sticks Test (TDI ≤ 30.5/48).
• MRI within the last 6 months after onset excluding tumoural etiology or central cause.
• Normal nasal endoscopy.
• Affiliated to a social security system (or equivalent).
• Written informed consent.

Exclusion Criteria

• Inflammatory rhinosinus disease (e.g., nasal polyposis) or granulomatosis with polyangiitis.
• Coagulation disorder.
• Brain radiotherapy history or ongoing chemotherapy.
• Olfactory disorder temporally linked to SARS-CoV-2 infection (delay <1 month).
• History of sinus or skull base surgery (except septoplasty/turbinoplasty/rhinoseptoplasty).
• Therapeutic-dose anticoagulants.
• Refusal to discontinue chronic NSAID use if applicable.
• Pregnancy/labor/breastfeeding.
• Vulnerable persons (deprived of liberty; legal protection; etc.).
• Participation in another interventional study with ongoing exclusion period.