Our five year follow up study showed that the long term prognosis of Japanese CIDP patients was generally favourable; 87% of the 38 patients were able to walk five years later, and 26% experienced complete remission lasting for more than two years without treatment. However, 39% of the patients still required immune treatments, and 13% had severe disability. Further follow up for six to 15 years showed similar results, suggesting that the prognosis of CIDP may be determined by the course and response to treatment in the first five years.
CIDP patients with complete remission more often had subacute
onset, symmetrical symptoms, a good response to initial
treatment with corticosteroids, and nerve conduction
abnormalities predominant in the distal nerve terminals than the
other patients. These factors can be predictors of long term
outcome. Mode of onset or progression time from onset to nadir
is an important prognostic factor. All 10 patients with complete
remission had a subacute onset. The possibility that these
patients had acute inflammatory demyelinating polyneuropathy (Guillain–Barré
syndrome) could be eliminated because they definitely had a
progression time of over two months. Moreover, nine of the 10
patients were obviously responsive to corticosteroids, and this
is not the case for Guillain–Barré syndrome.