title: Difficulties of interpreting Borrelia serology in patients with uveitis.
abstract: OBJECTIVE
  We aimed to review all uveitis patients with a positive Borrelia serology to evaluate positive results in uveitis subtypes. Further we wanted to test a self-assembled Interferon gamma release assay (IGRA) as a possible supplement method in these patients.
  
  
  METHODS
  Patients where serology for Borrelia was ordered from September 2005 to May 2008, were identified by database search. Patients with positive results in ELISA and Western Blot were retested by a self-assembled IGRA. Bayes Theorem was applied.
  
  
  RESULTS
  Testing for Borrelia was ordered for 184 patients. 18 patients (9,8%) showed positive results. 11 were positive for IgG (5,9 %), 3 were positive for IgG and IgM (1,6 %) and 4 for IgM (2,1%). Applying Bayes Theorem, we calculated a posttest-probability of 9% in case of a positive test result. 16 of the 18 patients were retested by IGRA. None of them showed a positive result.
  
  
  CONCLUSIONS
  A positive serology with uveitis as the only clinical symptom is not sufficient to confirm Borreliosis as 5,9 % of patients with uveitis and a positive IgG serology correspond to the normal spread of Borrelia in the population. Looking at posttest-probability shows a lot of false-positive test results when testing all uveitis patients for Borrelia routinely.
authors.affiliation: University of Heidelberg, Interdisciplinary Uveitis Center, Department of Ophthalmology, Heidelberg, Germany. Friederike.Mackensen@med.uni-heidelberg.de
authors.forename: Friederike
authors.initials: F
authors.lastname: Mackensen
authors.forename: Stefan
authors.initials: S
authors.lastname: Zimmermann
authors.forename: Werner
authors.initials: W
authors.lastname: Alle
authors.forename: Regina
authors.initials: R
authors.lastname: Max
authors.forename: Eva
authors.initials: E
authors.lastname: Jakob
authors.forename: Matthias D
authors.initials: MD
authors.lastname: Becker
authors.forename: Dorothea
authors.initials: D
authors.lastname: Thiemeyer
mesh_terms: D001499:Bayes Theorem; D015153:Blotting, Western; D001899:Borrelia Infections / Q000175:diagnosis* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D012698:Serologic Tests; D014605:Uveitis / Q000382:microbiology*
chemical_list: D007371:Interferon-gamma