title: B-cell-activating factor in rituximab-treated patients with anti-MAG polyneuropathy.
abstract: BACKGROUND
  Antimyelin-associated glycoprotein (MAG) polyneuropathy is a slowly progressive distal form of mixed motor-sensory polyneuropathy that is scarcely responsive to conventional immunosuppressive therapy. Rituximab, a B-cell depleting antibody, is a promising therapeutic choice for anti-MAG polyneuropathy, and the evaluation of factors, such as B-cell-activating factor (BAFF), that control B-cell homeostasis is important to understand how this drug works.
  
  
  METHODS
  Using an ELISA method, the authors measured serum BAFF concentrations in 23 patients with anti-MAG polyneuropathy, before and after rituximab therapy, in 20 neurological controls and in 14 healthy subjects. The patients were followed up over a mean period of 38±12 months and categorised as responders/non-responders, and, between the responders, as relapsing/non-relapsing.
  
  
  RESULTS
  Pretherapy serum BAFF concentrations in non-responders were higher than in responders (cut-off 1665 pg/ml; sensitivity 71.4%; specificity 93.7%; likelihood ratio 11.4), with the highest post-therapy increases in responders. In the responders who relapsed, relapses occurred when serum BAFF concentrations returned to baseline values, 1-2 years after blood B-cell reappearance.
  
  
  CONCLUSIONS
  Before and during therapy, measurements of serum BAFF in rituximab-treated patients with anti-MAG polyneuropathy may help predict the response to the therapy. The findings in this study also provide information about rituximab-induced modifications on B-cell homeostatic regulation.
authors.affiliation: Department of Neurology,Osp. S. Andrea, La Spezia, Italy.
authors.forename: Luana
authors.initials: L
authors.lastname: Benedetti
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Zardini
authors.forename: Chiara
authors.initials: C
authors.lastname: Briani
authors.forename: Alessandro
authors.initials: A
authors.lastname: Beronio
authors.forename: Stefania
authors.initials: S
authors.lastname: Gastaldi
authors.forename: Sven
authors.initials: S
authors.lastname: Jarius
authors.forename: Gian Luigi
authors.initials: GL
authors.lastname: Mancardi
authors.forename: Angelo
authors.initials: A
authors.lastname: Schenone
authors.forename: Diego
authors.initials: D
authors.lastname: Franciotta
mesh_terms: D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use*; D053264:B-Cell Activating Factor / Q000378:metabolism*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D018992:Myelin-Associated Glycoprotein / Q000276:immunology*; D011115:Polyneuropathies / Q000188:drug therapy / Q000276:immunology / Q000473:pathology*; D012008:Recurrence; D000069283:Rituximab; D013997:Time Factors
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D053264:B-Cell Activating Factor; D018992:Myelin-Associated Glycoprotein; D000069283:Rituximab