Occhigrossi F, Mosca J, Varrassi G et al. — Role of Pulsed Radiofrequency on the Immunological System in Chronic Pain Patients: A Narrative Review
Exploration of Immunology, January 2026
This is the most recent paper in the collection — published in 2026 — and provides a comprehensive narrative review of PRF's immunological mechanisms, synthesizing 12 key studies selected from an initial pool of 126 articles. It is notable for being published in an immunology journal, reflecting PRF's expanding identity beyond pain medicine.
Key findings:
- Cytokine modulation: PRF normalizes pro-inflammatory markers (TNF-α, IL-6, IL-17, IFN-γ, IRF8) while upregulating anti-inflammatory signals (IL-10), acting across the DRG, spinal cord, and peripheral nerves
- Microglial regulation: PRF suppresses microglial hyperactivity by downregulating IRF8, p38 MAPK, BDNF, PI3K, and p-ERK — with effects persisting up to 14 days after a single treatment
- Autophagy promotion: High-voltage PRF stimulates autophagic clearance of damaged cells in the dorsal column, facilitating neuronal recovery — a newly identified mechanism linking PRF to tissue regeneration
- GRK2/p38 pathway modulation: PRF applied to the DRG reduces hippocampal neuroinflammation, with demonstrated benefits for both pain and associated depressive symptoms — extending PRF's relevance to neuropsychiatric comorbidities
- Redox and epigenetic effects: The review integrates the Sluijter et al. radical pair hypothesis and adds that PRF-induced cellular improvements may be encoded epigenetically, potentially explaining the prolonged duration of therapeutic benefit
Broader context and future directions:
The review explicitly acknowledges that most existing evidence is of low methodological quality — preclinical, observational, or underpowered — and calls for multicenter RCTs and standardized protocols. It identifies several forward-looking priorities: MAPK/PI3K-Akt pathway elucidation, predictive biomarker development, PRF + orthobiologics combination, and AI-assisted personalization of PRF parameters (voltage, pulse duration, frequency) as an emerging frontier.
Genetic polymorphisms (TNF-α, IL-6, COMT) are highlighted as underexplored modulators of PRF response — pointing toward patient stratification as a future priority.
Significance: This review directly cites Brasil et al. (2020), Sluijter et al. (2023), Michno/Kirkor (2020), and Jorge et al. (2022) — all previously summarized papers — positioning them as foundational references in a growing immunological evidence base. The paper strengthens the scientific narrative around RedoxPRF and transcutaneous application, and its publication in an immunology journal signals PRF's transition from a niche pain procedure toward a recognized immunomodulatory therapy.