Detection of Mycobacterium tuberculosis from paraffin-embedded tissues by INNO-LiPA Rif.TB assay: retrospective analyses of Health Protection Agency National Mycobacterium Reference Laboratory data.
Molecular diagnostic methods are of potential value in identifying tuberculosis (TB) and drug resistance where tissue specimens have been submitted for histology but not for microbiological culture. All paraffin-embedded tissue (PET) specimens (n=60) referred to a single national centre over a 42 month study period were analysed using the INNO-LiPA Rif.TB assay; 29/60 patients had been reported to the UK Enhanced Tuberculosis Surveillance database with a diagnosis of TB based on clinical, radiological and histological evidence. Mycobacterium tuberculosis (MTB) DNA was detectable in 5 out of 29 reported TB cases (17.2 %); 12 out of 29 of the reported TB cases had a positive MTB culture from a secondary clinical specimen and MTB DNA was detectable in 2 of the 12 (16.7 %) laboratory-confirmed TB cases. Referring clinicians should be aware of the limitations of this assay on PETs, and should request molecular testing only in patients with a high clinical probability of TB and when acid-fast bacilli are seen in tissue specimens.
Health Protection Agency National Mycobacterium Reference Laboratory, Institute of Cell and Molecular Science, 2 Newark Street, London E1 2AT, UK.
Srinivasulu
S
Reddy
Health Protection Agency National Mycobacterium Reference Laboratory, Institute of Cell and Molecular Science, 2 Newark Street, London E1 2AT, UK.
Timothy
T
Brown
Health Protection Agency National Mycobacterium Reference Laboratory, Institute of Cell and Molecular Science, 2 Newark Street, London E1 2AT, UK.
Francis
F
Drobniewski
D001426:Bacterial Proteins / Q000235:genetics*; D024881:Drug Resistance, Bacterial; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D016612:Paraffin Embedding; D057089:Pathology, Molecular / Q000379:methods*; D011933:Reagent Kits, Diagnostic; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology; D006113:United Kingdom
D001426:Bacterial Proteins; C079999:LipA protein, Bacteria; D011933:Reagent Kits, Diagnostic