Serial testing of interferon-gamma-release assays for the diagnosis of latent tuberculosis in hemodialysis patients.
BACKGROUND
The performance of serial interferon-gamma-release assays (IGRAs) for the diagnosis of latent tuberculosis has not been studied in hemodialysis patients.


METHODS
The QuantiFERON-TB-Gold In-Tube test (QFT) and T-SPOT-TB test (TSPOT) were performed 1 year after initial testing at a hemodialysis center.


RESULTS
Ninety-eight patients were included in the final analysis. Positive rates for the initial tuberculin skin test (TST), QFT and TSPOT were 26.5%, 43.9% and 58.2%, respectively. The follow-up QFT and TSPOT showed positive responses in 52.0% and 53.1%. Conversion rates of the QFT and TSPOT were 20.0% and 26.8%. Reversion rates of the QFT and TSPOT were 16.3% and 29.8%; however, they decreased to 0.0% and 4.8% in patients with a concordantly positive response at the initial TST. A group at high risk for latent tuberculosis increased the risk for the TSPOT conversion [odds ratio (95% confidence interval), 7.76 (1.27-47.40)] and showed a trend of increasing the risk for the QFT conversion [1.97 (0.45-8.71)]. Reversion of both the QFT [18.92 (2.01-178.65)] and TSPOT [6.16 (1.57-24.19)] occurred more frequently in the group at low risk.


CONCLUSIONS
Both conversion and reversion of the IGRAs were associated with the risk for latent tuberculosis in hemodialysis patients. However, serial IGRAs results should be interpreted cautiously due to their high variability.
Chung
Woo Kyung
WK
Department of Internal Medicine, Gachon University of Medicine and Science, Incheon, Republic of Korea.
Zheng
Zhen Long
ZL
Kim
Hyung-Soo
HS
Park
Jin-Woong
JW
Lee
Hyun Joo
HJ
Chang
Jae Hyun
JH
Jeong
Ji Yong
JY
Kim
Sejoong
S
Lee
Hyun Hee
HH
Yang
Jaeseok
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001431:Bacteriological Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007371:Interferon-gamma / Q000378:metabolism*; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D051437:Renal Insufficiency / Q000150:complications* / Q000628:therapy*; D055815:Young Adult
D007371:Interferon-gamma