Sera from 50 consecutive
CIDP patients diagnosed in our clinic, 32 patients with
multiple sclerosis, 40 patients with other neuropathies including 26 with
Guillain-Barré syndrome (GBS)/
Fisher syndrome, and 30 healthy controls were measured for anti-NF
antibodies by flow cytometry using HEK293 cell lines stably expressing human NF155 or NF186. Four additional
CIDP patients with anti-NF155
antibodies referred from other clinics were enrolled for clinical characterization.
RESULTS: The positivity rate for anti-NF155
antibodies in
CIDP patients was 18% (9/50), who all showed a predominance of
IgG4 subclass. No other subjects were positive, except one GBS patient harboring
IgG1 anti-NF155
antibodies. No anti-NF155 antibody carriers had anti-NF186
antibodies. Anti-NF155 antibody-positive
CIDP patients had a significantly younger onset age, higher frequency of
drop foot, gait disturbance,
tremor and distal acquired demyelinating symmetric phenotype, greater cervical root diameter on magnetic resonance imaging neurography, higher cerebrospinal fluid
protein levels, and longer distal and F-wave latencies than anti-NF155 antibody-negative patients. Marked symmetric
hypertrophy of cervical and lumbosacral roots/plexuses was present in all anti-NF155 antibody-positive
CIDP patients examined by neurography. Biopsied sural nerves from two patients with anti-NF155
antibodies demonstrated subperineurial
edema and occasional paranodal
demyelination, but no
vasculitis, inflammatory cell infiltrates, or onion bulbs. Among anti-NF155 antibody-positive patients, treatment responders more frequently had daily oral
corticosteroids and/or
immunosuppressants in addition to
intravenous immunoglobulins than nonresponders did.
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