Clinicopathologic findings and prognosis of chronic inflammatory demyelinating polyneuropathy

Objective: To evaluate the clinicopathologic features and prognostic factors of 100 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: Comparison of clinical and biopsy findings with functional score evaluated an average of 6 years after referral. Results: CIDP followed a relapsing course in 14% of the patients and a progressive course in 45%. After progressive onset, little change was noted during follow-up in the others. Five patients had symptomatic involvement of the CNS. Teased fiber preparations of nerve biopsy specimens showed that 68 patients had purely demyelinative lesions, 20 had mixed axonal and demyelinative lesions, and 5 had predominantly axonal lesions. Axonal loss was a common finding, with 47% of the patients retaining less than half of the normal density of fibers. Inflammatory infiltrates, found in 18 samples, were prominent only in 4. Of the 83 patients evaluated an average of 6 years after onset, 56 were in good condition; 24 had deteriorated and failed to respond to treatment, including 9 patients who died as a consequence of their neurologic deficit. Progressive course, CNS involvement, high proportion of fibers showing active demyelination on nerve biopsy, and axonal loss overall correlated with higher disability. Conclusion: Axonal loss is the major long-term pejorative prognostic factor in CIDP.