title: Evaluation of real-time polymerase chain reaction, interferon-gamma, adenosine deaminase, and immunoglobulin A for the efficient diagnosis of pleural tuberculosis.
abstract: OBJECTIVE
  Pleural tuberculosis (TB) is a diagnostic challenge because of its non-specific clinical presentation and paucibacillary nature. Conventional diagnosis methods have limitations. We evaluated the real-time polymerase chain reaction (PCR), interferon-gamma (IFN-γ), adenosine deaminase (ADA), and immunoglobulin A (IgA).
  
  
  METHODS
  We assessed 204 cases: 50 were confirmed pleural TB, 104 were probable pleural TB, and 50 formed the non-TB group. IFN-γ and IgA were measured by enzyme-linked immunosorbent assay and ADA was measured by colorimetric assay. Real-time PCR was carried out using the 16S rRNA sequence, pleural biopsy specimens were submitted to histopathologic examination, pleural fluid culture was undertaken using Lowenstein-Jensen and MGIT-BACTEC, and pleural fluid smears were stained with auramine O.
  
  
  RESULTS
  For confirmed and probable pleural TB cases, the area under the curve (AUC) of the receiver operating characteristic (ROC) curve was highest for IFN-γ (0.994 and 0.963, respectively), followed by ADA (0.989 and 0.945, respectively), real-time PCR (0.898 and 0.784, respectively), and IgA (0.817 and 0.784, respectively). For confirmed and probable pleural TB cases, IFN-γ showed the highest sensitivity (98% and 76.9%, respectively), followed by ADA (92% and 73%, respectively), real-time PCR (80% and 57.7%, respectively), and IgA (70% and 57.7%, respectively). With regard to combined positivity, the combination of 'either real-time PCR or IFN-γ' showed the highest sensitivity: 100% in confirmed pleural TB and 96.2% in probable pleural TB.
  
  
  CONCLUSIONS
  IFN-γ showed the highest sensitivity as an individual diagnostic test. When a combination of tests was used, positivity of 'either IFN-γ or real-time PCR' appeared valuable for the diagnosis of pleural TB.
authors.affiliation: Department of Microbiology, Immunology and Molecular Biology, Choithram Hospital and Research Centre, PO Box 131, Manik Bagh Road, Indore, 452014 Madhya Pradesh, India.
authors.forename: Yatiraj
authors.initials: Y
authors.lastname: Kalantri
authors.forename: Nanda
authors.initials: N
authors.lastname: Hemvani
authors.forename: D S
authors.initials: DS
authors.lastname: Chitnis
mesh_terms: D000243:Adenosine Deaminase / Q000378:metabolism*; D000328:Adult; D019540:Area Under Curve; D003124:Colorimetry; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007371:Interferon-gamma / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000276:immunology / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014396:Tuberculosis, Pleural / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D055815:Young Adult
chemical_list: D007070:Immunoglobulin A; D012336:RNA, Ribosomal, 16S; D007371:Interferon-gamma; D000243:Adenosine Deaminase