title: Intraepidermal nerve fiber densities in chronic inflammatory autoimmune diseases.
abstract: BACKGROUND
  Some patients with systemic lupus erythematosus have selective loss of small-diameter nerve fibers, while larger nerve fibers are unaffected.
  
  
  OBJECTIVE
  To determine intraepidermal nerve fiber densities in patients with different chronic inflammatory autoimmune diseases.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Stavanger University Hospital, Stavanger, and Haukeland University Hospital, Haukeland, Norway.
  
  
  METHODS
  Sixty patients with systemic lupus erythematosus (SLE) (mean +/- SD age, 43.2 +/- 13.5 years), 61 patients with primary Sjögren syndrome (age, 57.1 +/- 14.7 years), and 52 patients with rheumatoid arthritis (age, 57.4 +/- 12.3 years) were compared with 106 healthy subjects (age, 49.0 +/- 19.6 years).
  
  
  METHODS
  Skin biopsy specimens.
  
  
  METHODS
  To evaluate small-diameter nerve fiber loss, intraepidermal nerve fiber densities were measured in skin punch biopsy specimens obtained from the distal part of the leg.
  
  
  RESULTS
  The mean +/- SD densities were 7.5 +/- 3.8 fibers/mm in patients with SLE, 9.2 +/- 3.8 fibers/mm in primary Sjögren syndrome, and 10.9 +/- 5.4 fibers/mm in rheumatoid arthritis vs 12.4 +/- 4.6 fibers/mm in healthy subjects. Densities were significantly less in patients with SLE vs patients with rheumatoid arthritis and vs healthy subjects (P<.001 for both), as well as in patients with primary Sjögren syndrome vs healthy subjects (P<.001). Eight patients (13%) with SLE, 2 patients (3%) with primary Sjögren syndrome, and 2 patients (4%) with rheumatoid arthritis had densities below the lower reference limit of 3.4 fibers/mm, consistent with small-diameter nerve fiber neuropathy.
  
  
  CONCLUSIONS
  The degree of loss of small-diameter nerve fibers differs among patients with these chronic inflammatory autoimmune diseases, likely reflecting differences in pathogenesis and organ affinity of the individual disease entities.
authors.affiliation: Clinical Immunology Unit, Department of Internal Medicine, Stavanger University Hospital, Stavanger, Norway. gola@sus.no
authors.forename: Lasse G
authors.initials: LG
authors.lastname: Gøransson
authors.forename: Johan G
authors.initials: JG
authors.lastname: Brun
authors.forename: Erna
authors.initials: E
authors.lastname: Harboe
authors.forename: Svein I
authors.initials: SI
authors.lastname: Mellgren
authors.forename: Roald
authors.initials: R
authors.lastname: Omdal
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000473:pathology; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000473:pathology*; D001369:Axons / Q000473:pathology; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004817:Epidermis / Q000294:innervation / Q000473:pathology*; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D036421:Nerve Fibers, Unmyelinated / Q000473:pathology; D011984:Sensory Receptor Cells / Q000473:pathology*; D012859:Sjogren's Syndrome / Q000175:diagnosis / Q000473:pathology