Small fibre involvement in neuropathy associated with IgG, IgA and IgM monoclonal gammopathy.
A delta and C fibre function has been investigated in 18 patients affected by neuropathies associated with monoclonal gammopathies. Warm, cold and heat pain thresholds have been determined by means of a Somedic Thermotest, operating on the Peltier principle, in a room at constant temperature. Our results indicate that: 1) there is an involvement of A delta and C fibres in these neuropathies that might be difficult to quantitate only on clinical grounds 2) in IgG and IgA patients, all affected by a subclinical or mild axonal neuropathy, small fibres of both types are always involved 3) in IgM anti-MAG positive severe cases, A delta fibre involvement, suggestive of demyelination is evident, while in one anti-MAG negative patient only C fibres are damaged, probably reflecting a different pathogenetic mechanism.
Barbieri
S
S
Institute of Clinical Neurology, Dino Ferrari Centre, University of Milan, Italy.
Sandroni
P
P
Nobile-Orazio
E
E
Cappellari
A
A
Cavestro
C
C
Baldini
L
L
Scarlato
G
G
D000368:Aged; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology*; D009422:Nervous System Diseases / Q000276:immunology / Q000503:physiopathology*; D009431:Neural Conduction / Q000502:physiology; D010265:Paraproteinemias / Q000150:complications / Q000503:physiopathology*
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M