Image analysis quantification of sustance P immunoreactivity in FM and MPS

[Guest guest]

Image analysis quantification of sustance P immunoreactivity

in FM and MPS

Image analysis quantification of sustance P immunoreactivity in the

trapezius muscle of patients with fibromyalgia and myofascial pain

syndrome.

J Rheumatol 2000 Dec;27(12):2906-10

De Stefano R, Selvi E, Villanova M, Frati E, Manganelli S, Franceschini

E, Biasi G, Marcolongo R

Institute of Rheumatology, University of Siena, Italy.

PMID: 11128684, UI: 21011300

OBJECTIVE: Substance P (SP), a neurotransmitter stored within the

afferent nociceptive fibers, is likely to be involved in the pathogenesis

of musculoskeletal pain. We investigated SP immunoreactive (SP-ir) nerve fibers

in the upper trapezius of patients with fibromyalgia (FM) and

myofascial pain syndrome (MPS) by immunochemistry.

METHODS: Trapezius muscle obtained from tender points of 9 women with primary

FM, from trigger points of 9 women with regional myofascial pain, and from 9

control women were immunostained with anti-SP sera. Quantitative evaluation was

performed by computerized image analysis.

RESULTS: No significant differences in the number of SP-ir areas were

detected between groups (one way ANOVA: p = 0.2); in contrast, mean

optical density (OD) of SP-ir showed a significant difference comparing

the groups (one way ANOVA: p < 0.0001). Mean OD of the immunostaining for

SP was statistically greater in trapezius muscle of patients with MPS

(0.594 +/- 0.096) compared to specimens from patients with FM (0.436 +/-

0.140) (p < 0.05) and controls (0.314 +/- 0.105) (p < 0.05); mean OD of

immunostaining for SP was greater in FM specimens than in controls (p <0.05).

CONCLUSION: Our results point to a peripheral hyperactivity of the

peptidergic nervous system in FM as well as in MPS. These findings

support the notion of pathogenetic involvement of the afferent nervous

system in the development and perception of myofascial pain.