Chronic inflammatory axonal polyneuropathy

Abstract

ObjectivesChronic inflammatory axonal polyneuropathy (CIAP) is defined on the basis of the clinical, electrophysiological and nerve biopsy findings and therapeutic responses of ‘immunotherapy responding chronic axonal polyneuropathy (IR-CAP)’.MethodsThe diagnosis of IR-CAP was made when all of three of the following mandatory criterion were met: (1) acquired, chronic progressive or relapsing symmetrical or asymmetrical polyneuropathy with duration of progression >2 months; (2) electrophysiological evidence of axonal neuropathy in at least two nerves without any evidence of ‘strict criteria of demyelination’; and (3) definite responsiveness to immunotherapy.ResultsThirty-three patients with IR-CAP showed similar clinical features of chronic inflammatory demyelinating polyneuropathy (CIDP) except ‘motor neuropathy subtype’. High spinal fluid protein was found in 27/32 (78%) cases. ‘Inflammatory axonal neuropathy’ was proven in 14 (45%) of 31 sural nerve biopsies.DiscussionsIR-CAP could well be ‘axonal CIDP’ in view of clinical similarity, but not proven as yet. Thus, IR-CAP is best described as CIAP, a distinct entity that deserves its recognition in view of responsiveness to immunotherapy.ConclusionDiagnosis of CIAP can be made by additional documentation of ‘inflammation’ by high spinal fluid protein or nerve biopsy in addition to the first two diagnostic criteria of IR-CAP.

Chronic Inflammatory or Chronic Inflammatory Demyelinating Polyradiculoneuropathy?

“…In 1982, Dyck et al used, for the first time, the term “CIDP” ( 4 ), by analogy with “Acute Inflammatory Demyelinating Polyradiculoneuropathy” (AIDP), and demonstrated its sensitivity to steroids. CIDP (CIP) progressively develops over more than 8 weeks, distinguishing this condition from “Guillain-Barré Syndrome” (GBS) which has an acute onset (<4 weeks) ( 6 , 7 ); both conditions (GBS and CIDP) are thought to have an auto-immune basis. Electrophysiologically, criteria of segmental demyelination (such as slowing of nerve conduction velocities, prolongations of distal latencies, conduction blocks and temporal dispersion mainly of motor fibers) are identified, although they are not invariable findings in CIP ( 1 ).…”

“…Although these patients do not meet electrodiagnostic criteria for demyelination, it is of great interest that the EAN/PNS diagnostic criteria now allow confirming the diagnosis of CIP, using clinical characteristics and response to treatment. Recently, Oh et al presented diagnostic criteria, which they proposed to be characteristic of another type of auto-immune peripheral neuropathy, which they call “ Chronic Inflammatory Axonal Polyneuropathy ” (CIAP) ( 7 ); nevertheless, this entity has to be confirmed by independent studies.…”

Pure sensitive chronic inflammatory axonal polyneuropathy following Pfizer COVID-19 vaccine

“…CIAP represents an uncommon variant of chronic inflammatory demyelinating polyneuropathy (CIDP) and is mainly characterized by progressive course (at least 2 months), electrophysiological evidence of axonal neuropathy in at least two nerves, and good response to immunotherapy. The presence of a high CSF protein concentration represents a supportive criterion for the diagnosis [ 5 ]. To the best of our knowledge, to date, no cases of chronic inflammatory polyneuropathy, neither CIAP nor CIDP, following COVID-19 vaccine have been reported.…”

Pathology of Initial Axon Segments in Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Related Disorders

“…Oh et al presented diagnostic criteria they proposed specific to another type of autoimmune neuropathy, called “Chronic Inflammatory Axonal Polyneuropathy” (CIAP). Nevertheless, this entity needs to be confirmed by independent studies [ 6 ].…”