Effectiveness of platelet-rich plasma on post-COVID chronic olfactory dysfunction

Platelet-Rich Plasma for Treating COVID-19-Related Anosmia, Hyposmia, and Parosmia: A Controlled Longitudinal Study

OBJECTIVE

To investigate the effectiveness of platelet-rich plasma (PRP) injection into the olfactory clefts of coronavirus disease 2019 (COVID-19) patients with persistent anosmia, hyposmia, and parosmia.

STUDY DESIGN

Controlled study.

SETTING

Multicenter study.

METHODS

From March 2022 to July 2024, 514 COVID-19 patients undergoing PRP injection and olfactory training versus olfactory training (controls) for a persistent olfactory dysfunction (OD) were consecutively recruited from two medical centers. Subjects were evaluated from pre- to 3 months post-injection with the olfactory disorder questionnaire (ODQ) and the threshold, discrimination, and identification (TDI) test. Olfactory outcomes were compared between controls and patients considering the type of OD (anosmia, hyposmia, and parosmia).

RESULTS

The PRP group was composed of 416 patients with anosmia (N = 111; 26.7%), hyposmia (N = 160; 38.5%), and parosmia (N = 145; 34.9%). The baseline ODQ of patients with parosmia was significantly higher than those of the other groups (P = .001). The increase in TDI subscores and total score was significantly higher in all PRP subgroups compared to controls (P = 0.001). The ODQ significantly reduced from pre- to post-PRP injection in hyposmia and parosmia groups (P = 0.001). Patients with parosmia showed a significantly greater reduction in ODQ scores compared to the control group. The 3-month TDI score was negatively influenced by the age of patients (rs = -0.263; P = 0.001) and the duration of OD (rs = -0.213; P = .001).

CONCLUSION

Patients with parosmia experienced a stronger impact of OD on quality of life (QoL), and showed greater QoL improvement following PRP injections compared to other groups.

Short-term efficacy of platelet-rich plasma in the treatment of persistent olfactory dysfunction: systematic review and meta-analysis

PURPOSE

To assess the short-term effects of topical platelet-rich plasma (PRP) injection on persistent refractory olfactory dysfunction.

METHODS

A comprehensive literature search of the PubMed, SCOPUS, EMBASE, Web of Science, Google Scholar, and Cochrane databases was conducted for articles up to November 2023. The search focused on studies that compared the amelioration of olfactory dysfunction between a topical PRP treatment cohort and a control group (receiving either placebo or no treatment), along with pre- and post-treatment comparisons. Subgroup analysis of the evaluation of olfactory function was also performed.

RESULTS

The improvement in olfactory scores 1-3 months post-treatment (standardized mean difference = 1.5354 [95% confidence interval: 0.7992; 2.2716], I2 = 83.8%) was greater in the treatment group than in the control group. In the treatment group, PRP increased the threshold, discrimination, and identification (TDI) score for Sniffin' Sticks by > 5.5 (minimum clinically significant difference; mean difference = 6.1789 [3.9788; 8.3789], I2 = 0.0%), indicating clinically significant improvement based on verified examinations. The rate of significant improvement among patients was 0.6683 [0.5833; 0.7436] after treatment. All TDI subdomains were significantly and similarly improved after treatment.

CONCLUSION

This meta-analysis suggests that injection of PRP into the olfactory fissure or surrounding mucosal areas is an effective treatment for persistent refractory olfactory dysfunction in the short term.

Intranasal insulin for the treatment of olfactory dysfunction: a protocol for a systematic review and meta-analysis

INTRODUCTION

Olfactory dysfunction (OD) is a prevalent nasal affliction that has detrimental effects on the patients' quality of life and safety. Conventional therapeutic strategies have various limitations such as high costs, prolonged treatment durations and adverse side effects. Intranasal insulin is a novel intervention for the management of OD. To date, few systematic reviews have been conducted to evaluate the efficacy of this intervention. This study aims to critically assess the therapeutic efficacy and safety profile of intranasal insulin administration in patients with OD.

METHODS AND ANALYSIS

A systematic literature search will be performed on several databases, including PubMed, the Cochrane Central Register of Controlled Trials, Embase, SinoMed and China National Knowledge Infrastructure (CNKI), to identify studies investigating the efficacy of intranasal insulin in treating OD. The search will span from database inception to 1 April 2024, including publication in Chinese and English languages. Data will be retrieved from the literature by two independent investigators. Subsequently, the data will be processed using RevMan V.5.3.5. The meta-analysis will be performed in line with the Cochrane Handbook guidelines. The clinical efficacy and safety of intranasal insulin for OD will be appraised based on various outcomes, including overall symptom improvement, the Connecticut Chemosensory Clinical Research Center score, variations in serum glucose levels, body mass index variations and the incidence of adverse events.

ETHICS AND DISSEMINATION

This will be a systematic review of available literature; thus, no ethical clearance is required. The results of this study will be shared through journal publication or presented at an academic conference.

TRIAL REGISTRATION NUMBER

According to the guidelines, our systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 16 May 2024 (registration number CRD42024543438).

Treatment of COVID-19 Associated Olfactory Dysfunction: A Systematic Review

PURPOSE OF REVIEW

COVID -19 associated olfactory dysfunction is widespread, yet effective treatment strategies remain unclear. This article aims to provide a comprehensive systematic review of therapeutic approaches and offers evidence-based recommendations for their clinical application.

RECENT FINDINGS

A living Cochrane review, with rigorous inclusion criteria, has so far included 2 studies with a low certainty of evidence. In this systematic review we list clinical data of 36 randomised controlled trials (RCTs) and non-randomised studies published between Jan 1, 2020 and Nov 19, 2023 regarding treatment options for COVID-19 associated olfactory dysfunction. Nine treatment groups were analysed, including olfactory training, local and systemic corticosteroids, platelet-rich plasma (PRP), calcium chelators, vitamin supplements including palmitoylethanolamide with luteolin, insulin, gabapentin and cerebrolysin. Primary objective was the effect of the studied treatments on the delta olfactory function score (OFS) for objective/psychophysical testing. Treatments such as PRP and calcium chelators demonstrated significant improvements on OFS, whereas olfactory training and corticosteroids did not show notable efficacy for COVID-19 associated olfactory dysfunction.

Utilization and efficacy of platelet-rich plasma and platelet-rich fibrin in otolaryngology: a systematic evidence-based review

PURPOSE

To explore utilization and efficacy of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in different sub-specialties of otolaryngology.

METHODS

A systematic search was performed using Cochrane Central Register of Controlled Trials, PubMed, EMBASE, Medline, Clinicaltrials.gov, Scopus, and Google Scholar up to March 2024. English language randomized controlled trials with original data evaluating the use of PRP and PRF in various surgical and non-surgical procedures related to otolaryngologic sub-specialties. Dataset was limited to randomized controlled trials (RCTs) to have the best quality of evidence and possible recommendation.

RESULTS

Our database search resulted in 591 manuscripts. Four hundred twenty-six studies were primarily excluded after reviewing the title and abstract. The remaining 165 articles were studied completely, and 51 articles met the inclusion criteria. All the studies were RCTs and dated from 2001 to 2024. They included 19 studies related to otology, 10 studies related to rhinology, 7 studies related to facial plastic surgery, 6 studies related to head and neck surgery, 3 studies related to general otolaryngology, 3 studies related to pediatrics, 2 studies related to laryngology, and 1 study related to sleep medicine.

CONCLUSION

PRP and PRF are safe, easy to use, and potentially effective treatment options for multiple otolaryngology pathologies. As an autologous material, there is no risk of immune reaction, and thus has been selected as a viable treatment option by many otolaryngologists. Larger studies would be helpful to confirm efficacy and allow for optimized patient selection for this treatment option.

Platelet-Rich Plasma (PRP) in the Treatment of Long COVID Olfactory Disorders: A Comprehensive Review

Background: Long COVID has brought numerous challenges to healthcare, with olfactory dysfunction (OD) being a particularly distressing outcome for many patients. The persistent loss of smell significantly diminishes the affected individual's quality of life. Recent attention has been drawn to the potential of platelet-rich plasma (PRP) therapy as a treatment for OD. This comprehensive review aims to evaluate the effectiveness of PRP therapy in ameliorating OD, especially when associated with long-term COVID-19. Methods: We executed a comprehensive search of the literature, encompassing clinical trials and observational studies that utilized PRP in treating OD limited to COVID-19. We retrieved and comprehensively discussed data such as design, participant demographics, and reported outcomes, focusing on the efficacy and safety of PRP therapy for OD in COVID-19 patients. Results: Our comprehensive analysis interestingly found promising perspectives for PRP in OD following COVID-19 infection. The collective data indicate that PRP therapy contributed to a significant improvement in olfactory function after COVID-19 infection. Conclusions: The evidence amassed suggests that PRP is a promising and safe therapeutic option for OD, including cases attributable to Long COVID-19. The observed uniform enhancement of olfactory function in patients receiving PRP highlights the necessity for well-designed, controlled trials. Such studies would help to refine treatment protocols and more definitively ascertain the efficacy of PRP in a broader, more varied patient cohort.

Efficacy of Platelet-Rich Plasma in the Treatment of Persistent Olfactory Impairment After COVID-19: A Systematic Review and Meta-Analysis

Background and Objectives

This study aimed to evaluate the impact of topical platelet-rich plasma (PRP) injection on persistent refractory olfactory dysfunction after COVID-19 infection.

Methods

A systematic review was conducted, focusing on studies that compared the efficacy of topical PRP treatment with a control group (receiving either placebo or no treatment) in ameliorating olfactory dysfunction. Pre- and post-treatment comparisons were evaluated, along with a subgroup analysis of olfactory function evaluation.

Results

The analysis revealed a significant improvement in olfactory scores between 1 to 3 months post-treatment (standardized mean difference=1.4376; 95% confidence interval [CI]=0.5934-2.2818; I2=84.1%) in the treatment group compared to the control group. Moreover, a notable disparity was observed between the two groups in the incidence of substantial recovery from anosmia or hyposmia (odds ratio=8.6639; 95% CI=2.9752-25.2292; I2=0.0%). PRP treatment led to a clinically significant increase in the threshold, discrimination, and identification (TDI) score for the Sniffin' Sticks test by >5.5 (minimum clinically significant difference; mean difference, 6.3494; 95% CI=4.0605-8.6384; I2=0.0%), as confirmed by verified examinations. The odds ratio for significant improvement among patients after treatment was determined to be 0.7654 (95% CI=0.6612-0.8451). Furthermore, all TDI subdomains exhibited significant and comparable improvements post-treatment.

Conclusion

This meta-analysis indicates that the injection of PRP into the olfactory fissure or surrounding mucosal areas is an effective treatment for persistent refractory olfactory dysfunction.

Platelet-Rich Plasma for Patients with Olfactory Dysfunction: Myth or Reality? A Systematic Review

BACKGROUND

With promising outcomes, platelet-rich plasma (PRP) has recently been suggested as a treatment for olfactory dysfunction (OD).

METHODS

Clinical studies utilizing PRP in OD caused by COVID-19, trauma, anesthetic exposure, viral infection, and chronic rhinosinusitis were included in a systematic review.

RESULTS

Ten clinical studies were qualitatively analyzed. Six of these studies used the PRP for OD caused by COVID-19, one on OD after functional endoscopic sinus surgery, and three on post-infectious or post-trauma OD. The population included 531 patients, ranging in age from 15 to 63.

CONCLUSION

The use of PRP may be a risk-free and efficient therapeutic option with very encouraging outcomes. Indeed, it enhances olfactory perception in patients who not only exhibit COVID-19 infection aftereffects, but also in those who have lost their sense of smell due to trauma, rhinosinusitis, rhinitis, or even surgery. To evaluate the PRP's therapeutic benefits in OD patients and to compare the efficacy of different therapeutic protocols with regard to treatment schedules, there is an urgent need for focused controlled trials.