Studies that explore the role of innate immunity and NcP

Study and referenceMechanism involvedNcP condition
Mast cells involvement
Blanco et al. [32]Increased mast cells correlate with pain, fatigueFM patients
Salemi et al. [33]Increased mast cells and mediators such as IL 1, IL 6, TNF-alpha, IL 17FM patients
Murphy et al. [34]Increased mast cells and mediators such as IL 1, IL 6, TNF-alpha, IL 17Chronic pelvic pain patients
Tsilioni et al. [36]Increase in serum substance P which increases mast cell activationFM patients
Liu et al. [41]Higher levels of mucosal leptin, linked to increased levels of mast cells through the induction of IFN and the suppression of IL 4IBS patients
Li et al. [43]Mast cell accumulation, activation, and degranulation in proximity to peptidergic nerve fibers were mediated by substance PCRPS patients
Neutrophils involvement
Caxaria et al. [46]Neutrophils invade sensory ganglia, increasing mechanical hyperalgesia and favouring sensitization of spinal cord neuronsFM patients
Microglia and astrocyte activation
Atta et al. [21]M1/M2 polarization with an augmented pro-inflammatory signature (mediated by the M1 phenotype, which secretes TNF-alpha, IL 1β, and IL 6)FM patients
Ye et al. [54]Glial activation with an increase of pro-inflammatory cytokines and overexpression of purinergic receptorsOrofacial pain patients
Linan-Rico et al. [55]Enteric glia activation, linked to toll-like receptor 4 signalingIBS patient
Dodds et al. [56]Glial activation by toll-like receptors, purinergic receptors, and chemokinesFemale patients with pelvic pain
Lao et al. [57]Microglia activation is mediated by purinergic receptors, TNF-alpha, and IL 1βMale patient with pelvic pain
Tian et al. [58]Astrocytes activation via metalloproteinase pathwayCRPS patients
NK recruitment
Verma et al. [60]NK cells recruitment and pro-inflammatory cytokines spill overFM patients

NcP: nociplastic pain; FM: fibromyalgia; IL: interleukin; TNF: tumor necrosis factor; IBS: irritable bowel syndrome; IFN: interferon; CRPS: complex regional pain syndrome; NK: natural killers. MI/M2 microglia phenotypes (see text for details)