Dominant T-cell clones of unknown significance in patients with idiopathic sensory neuropathies.
OBJECTIVE
To determine whether idiopathic sensory neuropathies could be associated with circulating dominant T-cell clones, a T-cell equivalent to monoclonal gammopathy of unknown significance.


BACKGROUND
A number of predominantly sensory neuropathies remain of unknown etiology. Circulating dominant T-cell clones may be observed in the elderly, in autoimmune disorders, and in chronic viral infections.


METHODS
Twenty patients with chronic sensory or predominantly sensory neuropathies considered idiopathic after intensive investigation were evaluated for the presence of dominant T-cell clones in blood using PCR amplification of the variable region of the T-cell receptor gamma-chain gene. They were classified as chronic idiopathic axonal polyneuropathy (CIAP) or sensory neuronopathy, i.e., chronic idiopathic ataxic neuropathy (CIAN), according to clinical and electrophysiologic criteria.


RESULTS
Occurrence of clonal expansions of T cells was strikingly high in patients with idiopathic sensory neuropathies (16/20, 80%), with a similar proportion in CIAP (12/15, 80%) and CIAN (4/5, 80%), as compared with elderly normal controls (2/10, 20%), elderly controls with degenerative neurologic diseases (2/10, 20%), and elderly patients with idiopathic chronic inflammatory demyelinating polyneuropathy (2/10, 20%) (all p < 0.005).


CONCLUSIONS
Both CIAN and CIAP are associated with dominant T-cell clones of unknown significance that cannot simply be attributed to the age of patients. Relevance of T-cell clones to the pathogenesis of idiopathic sensory neuropathies remains to be determined.
Groupe d'Etude et de Recherche sur le Muscle et le Nerf (GERMEN, EA2347 de l'Université Paris XII), Hôpital Henri Mondor, Créteil, France.
R K
RK
Gherardi
J P
JP
Farcet
A
A
Créange
P
P
Claudepierre
D
D
Malapert
F J
FJ
Authier
M H
MH
Delfau-Larue
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002999:Clone Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010523:Peripheral Nervous System Diseases / Q000209:etiology*; D016133:Polymerase Chain Reaction; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D012678:Sensation Disorders / Q000209:etiology*; D013601:T-Lymphocytes / Q000473:pathology*
D016692:Receptors, Antigen, T-Cell, gamma-delta