Authors

I.N. van Schaik, M.D., Ph.D.
P.A. van Doorn, M.D., Ph.D.

Clinical features
The first patients with CIDP are described already in 1911 by Werthein Salamon. Then the disease was named polyneuritis idiopathica subacuta. In the years to follow more of those patients were described by various neurologist. In 1958 Austin reviewed 32 cases of recurrent polyneuropathy and he pointed at the corticosteroid responsiveness in nine of these cases. 1 Since some of these patients  turned out to be responsive to immunomodulating treatment, an overwhelming research effort has been put into trying to understand the mechanisms of disease, finding more effective and long-lasting therapies, and defining clear and practical criteria for the diagnosis. Read more

Natural course and prognosis
The prognosis of CIDP is worse than GBS. More than 80 per cent of patients fail to make a spontaneous recovery. There is a need to improve therapy, because CIDP causes prolonged periods of disability and occasionally death. Many patients complaint about fatigue despite relatively normal muscle strength.⁴⁶

Epidemiology
CIDP can occur at any age. The estimated incidence of CIDP is approximately 0.15/100.000 annually. CIDP is a chronic disorder which causes disability for many years. The prevalence is estimated to be between 1,2 and 1,9/100 000.^44;45 These figures will vary depending on the diagnostic criteria used.

Pathophysiology / etiology
Breakdown of myelin, a characteristic of the demyelinating neuropathies, is thought to result from an autoimmune reaction towards nerve components. Since most patients respond well to treatment with high dose intravenous IgG (IVIg) or plasma exchange, circulating autoantibodies are presumably involved in these disorders. 22 Yan et al. have shown that passive transfer of demyelination is possible by serum or IgG from CIDP patients, supporting a role for autoantibodies in the pathogenesis of CIDP. 23 However, the exact pathogenic nature of the autoimmune response, the identity of autoantigens or mode of action of these treatments remains elusive. Thusfar, no in vitro assays are available to monitor disease activity, allowing adjustment of treatment and prognosis after therapy. Characterization of the autoreactive target epitopes or factors eliciting the autoimmune response is therefore needed. Read more

Differential diagnosis
CIDP has to be distinguished from Guillain-Barré syndrome (GBS), the inherited demyelinating polyneuropathies, metabolic neuropathies (associated with diabetes, uraemia, acromegaly, hepatitis, amyloidosis, and hypothyroidism), paraneoplastic neuropathies, neuropathies associated with monoclonal gammopathies, neuropathies associated with human immunodeficiency virus or Lyme’s disease, and multifocal motor neuropathy. Lewis and Sumner have described patients with a multifocal sensorimotor demyelinating polyneuropathy but this disorder should probably be considered as a variant of CIDP. 13;14 CIDP is often considered to be a chronic variant of GBS. Read more

Ancillary investigations
The diagnosis of CIDP is based on the clinical, electrophysiological, cerebrospinal fluid features and, to a limited degree, on histopathology. Cerebrospinal fluid protein levels are generally elevated without cellular reaction.⁴ Electrophysiologically, the disease is characterised by reduced nerve conduction velocities, abnormal temporal dispersion and conduction block.^3;19;20 The pathological findings include multifocal demyelination, mononuclear cells in close approximation to demyelinated axons, remyelination, fibre loss and only sometimes 'onion bulbs'.^3;4 Lymphocytic infiltration can be found in sural nerve biopsies, but, as may be expected from a predominantly motor neuropathy with multifocal involvement, biopsies are frequently normal and in general not necessary to make the diagnosis.^9;21

Therapy
A beneficial effect of immunosuppressive therapy (e.g. corticosteroids) and plasma exchange has been demonstrated in randomised clinical trials. 47-53 Several uncontrolled studies have suggested a beneficial effect of intravenous immunoglobulin. 19;20;54-57 As a result, a number of randomised trials with IVIg in CIDP have been undertaken. 58-63 The efficacy and safety of intravenous immunoglobulin (IVIg) in CIDP has been reviewed and compared with plasma exchange and prednisolone in a Cochrane systematic review. 64;65 Six randomised controlled trials were considered eligible for review including 170 patients. Read more

References
¹ Austin JH. Recurrent polyneuropathies and their corticosteroid treatment. With Read more