title: A rapid and non-invasive 2-step algorithm for diagnosing tuberculous peritonitis using a T cell-based assay on peripheral blood and peritoneal fluid mononuclear cells together with peritoneal fluid adenosine deaminase.
abstract: OBJECTIVE
  A recently developed RD-1 gene-based assay for diagnosing tuberculous peritonitis (TBP) has given promising results. We therefore created a clinical algorithm for differentiating TBP from other diagnoses using peripheral blood and peritoneal fluid mononuclear cells (PBMC/PF-MC) along with conventional tests.
  
  
  METHODS
  All adult patients with suspected TBP in whom enzyme-linked immunosorbent spot (ELISPOT) assays were performed both on PBMC and PF-MC were prospectively enrolled over a 6-year period. Confirmed TBP with positive cultures or Mycobacterium tuberculosis PCR, probable TBP with PF changes consistent with TBP, caseating granuloma, and a successful response to anti-TB therapy, as well as possible TBP without exclusion of TBP, were each defined.
  
  
  RESULTS
  A total of 74 patients were enrolled. Of these, 45 (61%) (19 confirmed, 16 probable, and 10 possible) were classified as TBP. The other 29 (39%) patients were classified as not TB. The sensitivity and specificity, respectively, of the tested methods for diagnosing TBP were as follows: PBMC ELISPOT (≥6 spots), 84% and 59%; PF-MC ELISPOT (≥6 spots), 87% and 86%; PF-MC/PBMC ratio (≥3), 69% and 97%; and PF-ADA level (≥21 U/L), 82% and 79%. The areas under the ROC curves were as follows: PF-MC ELISPOT, 0.90; PF-MC/PBMC ratio, 0.82; PBMC ELISPOT, 0.80; and PF-ADA, 0.80, respectively. When a 2-step algorithm ('PBMC ELISPOT ≥6 spots or PF-ADA ≥21 U/L' as a rule-out test and 'PF-MC/PBMC ratio ≥3' as a rule-in test) was applied, 67% (30/45) of the patients with TBP were accurately classified without undergoing invasive procedures.
  
  
  CONCLUSIONS
  A 2-step algorithm using the PBMC/PF-MC ELISPOT assays and PF-ADA appears to be a promising rapid and non-invasive approach for diagnosing TBP.
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Ju Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Sun-Mi
authors.initials: SM
authors.lastname: Kim
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang-Oh
authors.initials: SO
authors.lastname: Lee
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Yang Soo
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Jun Hee
authors.initials: JH
authors.lastname: Woo
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address: kimsunghanmd@hotmail.com.
authors.forename: Sung-Han
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000243:Adenosine Deaminase / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000465:Algorithms; D001202:Ascitic Fluid / Q000166:cytology / Q000201:enzymology; D003937:Diagnosis, Differential; D058501:Enzyme-Linked Immunospot Assay; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D014395:Peritonitis, Tuberculous / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D000243:Adenosine Deaminase
keywords: Diagnosis; ELISPOT; Peritonitis; Tuberculosis