title: Modulatory effects on axonal function after intravenous immunoglobulin therapy in chronic inflammatory demyelinating polyneuropathy.
abstract: OBJECTIVE
  To investigate the immediate and longitudinal mechanisms of action of intravenous immunoglobulin (IVIg) on axonal function in chronic inflammatory demyelinating polyneuropathy (CIDP).
  
  
  METHODS
  Prospective single-center study.
  
  
  METHODS
  Hospitals and outpatient clinics.
  
  
  METHODS
  Clinical and functional assessment, nerve conduction studies, and 526 motor excitability studies were undertaken in 27 patients, matched before and immediately after infusion and followed up longitudinally.
  
  
  METHODS
  Axonal excitability variables were measured before and immediately after infusion and compared with matched studies and findings in healthy controls.
  
  
  RESULTS
  Immediately after infusion, patients demonstrated decreased threshold, with significant reduction in strength-duration time constant (P = .003), reduction in accommodation to depolarization (P = .04), and reduced threshold change during hyperpolarization (P = .003), accompanied by significant decreases in superexcitability (P = .03) and subexcitability (P = .02). In contrast, changes were absent in disease controls, confirming a specific IVIg action in CIDP patients. Longitudinally, changes correlated with clinical improvement (mean [SE] increase in the Medical Research Council sum score, 2.7 [0.7]; P = .005). Increased compound muscle action potential amplitude was associated with reduction in terminal latency (correlation coefficient, -0.65; P = .02). In addition, these changes translated into improvement in functional assessment with the adjusted Inflammatory Neuropathy Cause and Treatment score, which demonstrated a significant correlation with nerve excitability variables longitudinally (P = .01).
  
  
  CONCLUSIONS
  Findings from the present series establish a modulatory effect of IVIg on axonal function in CIDP patients, suggesting that IVIg stabilizes axonal membrane potential and promotes axonal recovery.
authors: Faculty of Medicine, School of Medical Science, University of New South Wales, Sydney, New South Wales, Australia. c.lin@unsw.edu.au
authors: Cindy Shin-Yi
authors: CS
authors: Lin
authors: Arun V
authors: AV
authors: Krishnan
authors: Susanna B
authors: SB
authors: Park
authors: Matthew C
authors: MC
authors: Kiernan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001369:Axons / Q000187:drug effects* / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D007155:Immunologic Factors / Q000627:therapeutic use*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009424:Nervous System Physiological Phenomena / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000188:drug therapy*; D011930:Reaction Time
chemical_list: D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors