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Updated: Jul 15, 2026

The MODS method for diagnosis of tuberculosis and multidrug resistant tuberculosis
Published on: August 11, 2008
Early diagnosis of subclinical multidrug-resistant tuberculosis
Luca Richeldi1, Katie Ewer, Monica Losi
1University of Modena and Reggio Emilia and Azienda Ospedaliera Policlinico di Modena, Modena, Italy.
Background:
Tuberculosis control hinges on prompt diagnosis of active cases and screening of contacts by tuberculin skin testing. Rapid blood tests for Mycobacterium tuberculosis infection are a new alternative to the tuberculin skin test, but whether they improve clinical outcomes is unknown.
Objective:
To describe how a novel T-cell-based test for M. tuberculosis infection helped diagnose tuberculosis in an asymptomatic, immunosuppressed adult with a negative result on a tuberculin skin test.
Design:
Case report.
Setting:
Household contact.
Patients:
Asymptomatic man receiving maintenance azathioprine therapy for Crohn disease whose wife had multidrug-resistant pulmonary tuberculosis.
Measurements:
Enzyme-linked immunospot (ELISPOT) assay, computed tomography, and bronchoalveolar lavage cultures.
Results:
The man had a negative tuberculin skin test result and a positive ELISPOT assay result. High-resolution computed tomography of the chest showed consolidation with early cavitation. Bronchoalveolar lavage and culture confirmed multidrug-resistant tuberculosis.
Limitations:
This single case report is a proof of concept and is not a formal evaluation of clinical utility.
Conclusions:
A positive ELISPOT assay result helped diagnose subclinical active tuberculosis in an immunosuppressed patient with a false-negative tuberculin skin test result. Large prospective studies that compare benefits and costs of this alternative to tuberculin skin testing are needed.
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