Peripheral neuropathy associated with chronic natural killer cell lymphocytosis.
We report a patient with steroid-responsive peripheral neuropathy which developed with chronic natural killer cell lymphocytosis (CNKL). A 70-year-old female with a 2-week history of progressive motor and sensory neuropathy showed a marked increase of natural killer (NK) cells in the blood, and was diagnosed as having CNKL. Nerve conduction studies (NCS) revealed a mixed axonal and demyelinating neuropathy. A sural nerve biopsy revealed infiltration of NK cells into the nerve fascicles, and demyelinating changes with axonal degeneration. The infiltrating NK cells were adjacent to myelinated fibers, showing damage of Schwann cell membrane. Treatment with oral prednisolone resulted in rapid improvement of the sensory disturbance and weakness with a significant decrease of NK cells in the blood and disappearance of the conduction blocks in NCS. This is the first case of CNKL associated neuropathy in which infiltration of NK cells was demonstrated in the nerve fascicles. Our observations suggest that the infiltrating NK cells may directly damage myelin and Schwann cells, thus causing demyelination.
Noguchi
Moeko
M
Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, 13-1 Takara-machi, Kanazawa 920-8641, Japan. noguchim@med.kanazawa-u.ac.jp
Yoshita
Mitsuhiro
M
Sakai
Kenji
K
Matsumoto
Yasuko
Y
Arahata
Masahisa
M
Ontachi
Yasuo
Y
Takami
Akiyoshi
A
Nakao
Shinji
S
Sato
Katsuaki
K
Yamada
Masahito
M
D000200:Action Potentials / Q000502:physiology; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D003711:Demyelinating Diseases / Q000473:pathology; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural; D018655:Lymphocyte Count; D008218:Lymphocytosis / Q000150:complications* / Q000473:pathology; D009431:Neural Conduction; D009460:Neurologic Examination; D010523:Peripheral Nervous System Diseases / Q000209:etiology* / Q000473:pathology; D011241:Prednisone / Q000627:therapeutic use; D013497:Sural Nerve / Q000473:pathology
D000893:Anti-Inflammatory Agents; D011241:Prednisone