Neuropatias associadas aos mecanismos de desmínagem

NEUROPATHIES RELATED TO DYSIMMUNE MECHANISMS

The demonstration of inflammatory changes in the peripheral

nerves of patients with proximal lower limb motor

neuropathy or those with superimposed CIDP has raised the

possibility of the use of immunomodulatory treatment.

There have been reports of the successful treatment of

patients with the former condition with intravenous human

immunoglobulin, plasma exchange, corticosteroids, or cytotoxic

drugs (cyclophosphamide, azathioprine) either alone

or in combination.24 However, the natural history of this disorder

is often one of spontaneous improvement and a

controlled clinical trial is now clearly needed.

Non-diabetic patients with CIDP may benefit from similar

treatment and studies on limited numbers of cases have

so far indicated that this also applies to CIDP in diabetic

subjects.21 24 Inflammatory lesions are known to be present in

autonomic ganglia and nerve trunks in patients with severe

autonomic neuropathy,25 again suggesting a superimposed

autoimmune process. Whether immunomodulatory measures

would be beneficial in such cases is unknown.

POSSIBLE USE OF GROWTH FACTORS

Studies on animal models of diabetes indicate that IGF I

enhances regeneration and nerve growth factor (NGF) has

been shown to have a beneficial effect in other experimental

neuropathies. Preliminary evidence from phase II clinical

trials of human recombinant NGF has indicated that

this agent may benefit symptoms related to dysfunction of

small sensory fibres.26 The results of phase III trials are

therefore awaited with interest. Diabetes affects fibres of all

sizes, both myelinated and unmyelinated, but the neurotrophic

effect of NGF is mainly on small myelinated and

unmyelinated axons. If the use of NGF is shown to be

helpful, future treatment regimes may require combinations

of growth factors—for example, with the addition of

brain derived neurotrophic factor (BDNF)—so that the

large fibre neuropathy is also targeted.

P K THOMAS

Correspondence to: Professor P K Thomas, University Department of Clinical

Neurosciences, Royal Free and University College Medical School, Royal Free

Campus, Rowland Hill Street, London NW3 2PF, UK. Telephone [phone]

794 0500; fax [phone].

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6 Giannini C, Dyck PJ. Basement membrane reduplication and pericyte

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