Utility of the T-SPOT®.TB test's borderline category to increase test resolution for results around the cut-off point - 08/03/18
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Abstract |
Background |
Accurate identification of individuals with TB infection, is required to achieve the WHO's End TB Strategy goals. While there is general acceptance that the T-SPOT.TB test borderline category provides an opportunity to increase test resolution of results around the test cut-off point, this has not been investigated.
Methods |
645,947 tests were analyzed to determine frequency of borderline results, effect of age and time between tests and associations between subjects' clinical risk factors and retest results.
Results |
645,947 tests produced 93.5% negatives, 4% positives, 0.6% invalids, and 1.8% borderlines. Within the borderline results, 5044 were repeated, with 59.2%, 20.0% and 20.2% resolving to negative, positive and borderline, respectively. Age of subject did not affect retest results; however, time between tests indicated that retest resolution occurred with greatest frequency after 90 days. TB risk factors were provided for 2640 subjects and 17% of low risk subjects with a high initial borderline resolved to negative while 27.6% of subjects with high risk and an initial low borderline resolved to positive, suggesting that these subjects could have been inappropriately classified if using a single cut-off point test with no borderline category.
Conclusion |
This study demonstrates the utility of the T-SPOT.TB test's borderline category to increase test resolution around the test cut-off point.
Le texte complet de cet article est disponible en PDF.Keywords : Borderline result, Invalid, T-Cell Xtend, TB infection, Pediatric, IGRA, T-SPOT
Plan
☆ | T-SPOT is a trademark of Oxford Immunotec Ltd.|© 2017 Oxford Immunotec Inc. |
Vol 108
P. 178-185 - janvier 2018 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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