title: Diagnostic value of IgM deposition at the dermo-epidermal junction.
abstract: BACKGROUND
  Granular immunoglobulin M (IgM) deposits at the dermo-epidermal junction (DEJ) are common in lupus erythematosus (LE); however, weak, interrupted, linear and granular patterns of IgM at the DEJ have been reported in sun-exposed skin in normal adults and in a heterogeneous group of diseases.
  
  
  METHODS
  We analyzed 200 patients with positive IgM direct tissue immunofluorescence deposition at the DEJ, alone or in combination with other immunoreactants, in order to determine the diagnostic significant of IgM deposition at the DEJ.
  
  
  RESULTS
  IgM deposition at the DEJ, commonly in combination with other immunoreactants, was associated with LE in 57.5% of patients. In cases with IgM deposition alone at the DEJ, only 12% had LE (strong intensities). IgM deposition at the DEJ was associated with other dermatoses in 42.5% of patients. In non-lupus patients, IgM deposition was the sole finding in 59% of cases, and was weaker and more focal than in LE patients.
  
  
  CONCLUSIONS
  IgM deposition at the DEJ in patients with LE tends to exhibit a strong intensity and is commonly detected in combination with other immunoreactants. IgM deposition alone at the DEJ, especially of weak intensity or focal in pattern, is noted in non-lupus patients, and has less diagnostic significance.
authors.affiliation: Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: K
authors.initials: K
authors.lastname: Kulthanan
authors.forename: S
authors.initials: S
authors.lastname: Pinkaew
authors.forename: P
authors.initials: P
authors.lastname: Suthipinittharm
mesh_terms: D003937:Diagnosis, Differential; D004817:Epidermis / Q000276:immunology; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000276:immunology; D011237:Predictive Value of Tests; D012867:Skin / Q000276:immunology*
chemical_list: D007075:Immunoglobulin M