title: Evaluation of an immunohistochemical test with polyclonal antibodies raised against mycobacteria used in formalin-fixed tissue compared with mycobacterial specific culture.
abstract: An immunohistochemical (IH) test (commercially available polyclonal antiserum rabbit anti-Myco-bacterium bovis; DAKO A/S) was used to detect the presence of mycobacteria in 65 formalin-fixed, paraffin-embedded tissue blocks from different organs, showing necrotizing caseous granuloma lesions on hematoxylin and eosin sections from 65 patients. These 65 samples were dyed using an acid-fast fluorescent technique and compared using the immunohistochemical method. Both results were also compared with the mycobacterial cultures. The IH test, compared with the culture, showed a sensitivity (S) of 52%, a specificity (Sp) of 76%, a positive predictive value (PV pos) of 61% and a negative predictive value (PV neg) of 69%. We analyze these data and discuss the possible causes of false-positive and -negative results of the IH test. This rapid test on paraffin embedded tissue seems valuable in the period when waiting for the culture results.
authors.affiliation: Department of Pathology, University Hospital, Doce de Octubre, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Carabias
authors.forename: E
authors.initials: E
authors.lastname: Palenque
authors.forename: R
authors.initials: R
authors.lastname: Serrano
authors.forename: J M
authors.initials: JM
authors.lastname: Aguado
authors.forename: C
authors.initials: C
authors.lastname: Ballestín
mesh_terms: D000818:Animals; D005557:Formaldehyde; D006801:Humans; D007150:Immunohistochemistry; D009161:Mycobacterium / Q000276:immunology / Q000302:isolation & purification*; D011817:Rabbits; D016707:Tissue Fixation
chemical_list: D005557:Formaldehyde