title: Rapid and specific diagnosis of tuberculous pleuritis with immunohistochemistry by detecting Mycobacterium tuberculosis complex specific antigen MPT64 in patients from a HIV endemic area.
abstract: OBJECTIVE
  The aim of the study was to evaluate the diagnostic potential of immunohistochemistry using an antibody to the secreted mycobacterial antigen MPT64, specific for Mycobacterium tuberculosis complex organisms, on formalin-fixed biopsies from patients with pleural tuberculosis (TB) from a high TB and HIV endemic area.
  
  
  RESULTS
  Pleural biopsies from 25 TB cases and 11 non-TB cases were studied. Ziehl-Neelsen staining for acid-fast bacilli and immunohistochemistry with anti-MPT64 and anti-Bacille Calmette-Guérin (BCG) antibodies was performed. Nested polymerase chain reaction (N-PCR) for IS6110 was performed for comparison. Acid-fast bacilli were detected in only 2 cases and 3 biopsies showed granulomas with caseous necrosis. Immunostaining with anti-MPT64, anti-BCG, and N-PCR were positive in 20 (80%), 12 (48%), and 16 (64%) of the cases, and 0, 3 (27%), and 2 (18%) of the non-TB controls, respectively. The diagnostic validity of immunohistochemistry was calculated by comparison with N-PCR-positive TB cases and N-PCR-negative non-TB controls. The sensitivity of immunohistochemistry with anti-MPT64 and anti-BCG were 81% and 56% respectively, and the corresponding specificities were 100% and 78%.
  
  
  CONCLUSIONS
  Detection of the MPT64 antigen by immunohistochemistry improves the diagnosis of TB pleuritis caused by M. tuberculosis complex organisms in patients living in HIV-endemic areas with atypical histology and negative staining for acid-fast bacilli.
authors.affiliation: Institute of Medicine, University of Bergen, Haukeland University Hospital, Bergen, Norway.
authors.forename: Kamaldeen
authors.initials: K
authors.lastname: Baba
authors.forename: Anne Margarita
authors.initials: AM
authors.lastname: Dyrhol-Riise
authors.forename: Lisbet
authors.initials: L
authors.lastname: Sviland
authors.forename: Nina
authors.initials: N
authors.lastname: Langeland
authors.forename: Anwar A
authors.initials: AA
authors.lastname: Hoosen
authors.forename: Harald G
authors.initials: HG
authors.lastname: Wiker
authors.forename: Tehmina
authors.initials: T
authors.lastname: Mustafa
mesh_terms: D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D019353:Endemic Diseases / Q000517:prevention & control; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D015497:HIV-1; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011237:Predictive Value of Tests; D013019:South Africa; D014396:Tuberculosis, Pleural / Q000150:complications* / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; C510537:MPT64 protein, Mycobacterium tuberculosis