I. Van Rhijn et al., Expression of accessory molecules for T-cell activation in peripheral nerve of patients with CIDP and vasculitic neuropathy, BRAIN, 123, 2000, pp. 2020-2029
Vasculitic neuropathy and chronic inflammatory demyelinating polyneuropathy
(CIDP) are neuropathies characterized by a T-lymphocyte infiltrate in the
peripheral nerves. The microenvironment in which these T cells become activ
ated, and the molecules and cells that play a role in this process are inco
mpletely understood. Using immunohistochemical analysis, we studied the eff
ect of the presence of adhesion, costimulatory and antigen-presenting molec
ules on different cell types as a precondition for local T-cell activation
in human sural nerve biopsies of seven patients with CIDP, three patients w
ith vasculitic neuropathy and three healthy controls. In biopsies from CIDP
and vasculitic neuropathy patients, but not in those from healthy controls
, Schwann cells expressed the adhesion/T-cell stimulatory molecule CD58 (LF
A-3). The CD58 molecule was also present on endothelial cells of all vascul
itic neuropathy patients and one CIDP patient. In biopsies from normal cont
rols and patients, CD54 (ICAM-1) expression was detectable on microvascular
endothelial cells. In addition, expression of the costimulatory molecule C
D86 was detected on vascular tissue in patients with vasculitic neuropathy.
Although macrophages were always present in all subjects, expression of th
e major histocompatibility complex (MHC)-like molecule CD1a by macrophages
was restricted to biopsies from two CIDP patients and one vasculitic neurop
athy patient. Unexpectedly, Schwann cells of a single vasculitis patient st
rongly expressed CD1b, a molecule involved in the presentation of self-glyc
olipids to T cells. Schwann cells in biopsies from patients and normal cont
rols expressed high levels of the invariant chain, CD74, a molecule involve
d in the intracellular sorting of MHC class II molecules, There was no evid
ence for the presence of dendritic cells in sural nerve biopsies. These fin
dings support a model in which T-cell activation can be initiated and/or pe
rpetuated locally in sural nerve biopsies of patients with CIDP and vasculi
tic neuropathy, and predict an important role for Schwann cells and endothe
lial cells.