title: Impaired interferon production by leukocytes from patients with Bell palsy and lack of findings suggestive for a systemic viral involvement.
abstract: OBJECTIVE
  This study aimed to test the hypothesis that viral and other microbial infections cause Bell palsy and to use the interferon (IFN) alpha/beta-induced MxA protein as an indicator of systemic viral infection.
  
  
  BACKGROUND
  Bell palsy has been previously associated with several viral infections. Recently, after this study was completed, herpes simplex virus DNA was detected in the endoneurial fluid of some patients with Bell palsy.
  
  
  METHODS
  Serum and blood mononuclear cells were obtained from 30 patients with Bell palsy and 12 control subjects. The sera were tested for antibodies to 21 microbes. Mononuclear cells were assayed for (a) MxA protein using immunoblotting and (b) capacity to produce IFN in short-term culture after stimulation with influenza A virus.
  
  
  RESULTS
  No significant differences were seen in serum antibodies or MxA protein between the patients and controls. The geometric mean of leukocyte IFN production in the convalescent phase of Bell palsy patients was higher than in the acute phase but remained still at significantly lower levels as compared with the control group (p < 0.05). In three patients there was no detectable IFN production.
  
  
  CONCLUSIONS
  These results provide no evidence for a systemic viral involvement in Bell palsy, but the observed decreased IFN-producing capacity at the onset of Bell palsy could be a sign of transient immunosuppression or of an abnormal frequency of leukocyte subpopulations in the disease.
authors.affiliation: Department of Otolaryngology, Helsinki University Hospital, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Pitkäranta
authors.forename: T
authors.initials: T
authors.lastname: Hovi
authors.forename: M
authors.initials: M
authors.lastname: Peltomaa
authors.forename: I
authors.initials: I
authors.lastname: Pyykkö
authors.forename: I
authors.initials: I
authors.lastname: Julkunen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood / Q000276:immunology; D004279:DNA, Viral / Q000276:immunology; D005158:Facial Paralysis / Q000209:etiology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007165:Immunosuppression Therapy; D016898:Interferon-alpha / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009975:Orthomyxoviridae / Q000276:immunology; D014764:Viral Proteins / Q000276:immunology
chemical_list: D000906:Antibodies; D004279:DNA, Viral; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016898:Interferon-alpha; D014764:Viral Proteins