Abstract
The aim of this study was to evaluate the support to tuberculosis diagnosis of a new immunological tool, an enzyme-linked immunospot (ELISPOT) assay for interferon-γ, in diabetic patients. From March 2007 to January 2008, diabetic patients with suspected pulmonary tuberculosis were enrolled in a tertiary care hospital. Data on clinical characteristics of the patients and conventional laboratory results were collected and blood samples were obtained for ELISPOT assay (T SPOT-TB; Oxford Immunotec Ltd, Oxford, UK). A total of 84 patients with suspected pulmonary tuberculosis were recruited. Fifty-one (60.7%) of these patients were considered to have pulmonary tuberculosis, including 42 (50%) with confirmed tuberculosis and 9 (10.7%) with probable tuberculosis. The overall (confirmed and probable tuberculosis) sensitivity, specificity, positive predictive value and negative predictive value of the ELISPOT assay were 84.3%, 66.7%, 79.6%, and 73.3%, respectively. The negative predictive value of the ELISPOT assay was significantly higher in patients with adequate glycaemic control (90% vs 56.3%). In conclusion, the ELISPOT assay can provide useful support in diagnosing pulmonary tuberculosis in diabetic patients, especially those with adequate glycaemic control.
Acknowledgements
This study was partly supported by the Institute for Biotechnology and Medicine Industry (DOH97-DC-1501).
Declaration of interest: No conflict of interest.