Diagnosis of abdominal tuberculosis by T-cell-based assays on peripheral blood and peritoneal fluid mononuclear cells.
OBJECTIVE
Diagnosing abdominal tuberculosis (TB) remains a challenge. A recently developed RD-1 gene-based assay for diagnosing tuberculosis infection shows promising results. We evaluated the diagnostic usefulness of this assay compared with conventional tests in patients with suspected abdominal TB in clinical practice.


METHODS
All patients with suspected abdominal TB were prospectively enrolled in a tertiary hospital during a 1-year period. In addition to the conventional tests for diagnosing TB, the IFN-gamma-producing T-cell response to ESAT-6 and CFP-10 by ELISPOT assay using peripheral blood mononuclear cells (PBMC) and peritoneal fluid mononuclear cells (PF-MC) were performed.


RESULTS
Forty eight patients with suspected abdominal TB were enrolled. Of these patients, 30 (63%) were classified as abdominal TB including 14 TB peritonitis (12 confirmed + 1 probable + 1 possible), 6 abdominal TB lymphadenitis (3 confirmed + 3 probable), 4 hepatic TB (3 confirmed + 1 possible), 2 intestinal TB (1 confirmed + 1 probable), 3 renal TB (1 confirmed + 2 probable), and 1 pancreatic TB (1 confirmed). Eighteen (38%) were classified as not TB. ELISPOT assay using PBMC was performed on samples from all 48 subjects. The sensitivity and specificity of the PBMC ELISPOT assay were 89% (95% CI, 71-98%) and 78% (95% CI, 52-94%), respectively. In the 11 patients in whom PF-MC ELISPOT assay was performed, it was positive in 5 of 6 patients with TB peritonitis, and negative in all 5 patients with not TB.


CONCLUSIONS
The ELISPOT assay using PBMC and PF-MC is a useful adjunct to the current tests for diagnosing abdominal TB.
Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736, Republic of Korea.
Sung-Han
SH
Kim
Oh-Hyun
OH
Cho
Su Jin
SJ
Park
Byong Duk
BD
Ye
Heungsup
H
Sung
Mi-Na
MN
Kim
Sang-Oh
SO
Lee
Sang-Ho
SH
Choi
Jun Hee
JH
Woo
Yang Soo
YS
Kim
D000005:Abdomen; D000328:Adult; D000368:Aged; D001202:Ascitic Fluid / Q000166:cytology / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D014376:Tuberculosis / Q000175:diagnosis*