0

TNF-alpha Expression in Painful and Nonpainful Neuropathies

M Empl, S Renaud, B Erne, P Fuhr, A Straube, N Schaeren-Wiemers, A J Steck

Neurology. 2001 May 22;56(10):1371-7.

PMID: 11376190

Abstract:

Objective:
To determine whether the cytokine tumor necrosis factor alpha (TNF-alpha) acts as a pain mediator in neuropathic pain in humans.
Background:
In animal models, inflammatory cytokines such as TNF-alpha have been shown to facilitate neuropathic pain.
Methods:
The expression of TNF-alpha was analyzed immunohistochemically in 20 human nerve biopsy specimens of patients with painful (n = 10) and nonpainful (n = 10) neuropathies. Additionally, serum soluble TNF-alpha receptor I (sTNF-RI) levels were determined in 24 patients with neuropathies, 16 of which were painful and 8 that were painless.
Results:
Colocalization studies by confocal fluorescence microscopy for S-100 and TNF-alpha showed expression of TNF-alpha in human Schwann cells. Patients with painful neuropathies showed a stronger TNF-alpha immunoreactivity in myelinating Schwann cells relative to the epineurial background staining compared with patients with nonpainful neuropathy (0.949 +/- 0.047 vs 1.010 +/- 0.053, p < 0.05). Although there was no difference in sTNF-RI levels between painful (n = 16) and nonpainful (n = 8) neuropathies (sTNF-RI: 1412 +/- 545 pg/mL vs 1,318 +/- 175 pg/mL), patients with a mechanical allodynia (n = 9) had elevated serum sTNF-RI (1627 +/- 645 pg/mL vs 1233 +/- 192 pg/mL, p < 0.05) compared with patients without allodynia (n = 15).
Conclusions:
TNF-alpha expression of human Schwann cells may be up-regulated in painful neuropathies. The elevation of sTNF-RI in patients with centrally mediated mechanical allodynia suggests that systemic sTNF-RI levels may influence central pain processing mechanisms.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
IAR42413754 sTNF-RI human sTNF-RI human Price
qrcode