en Diagnostic/screening methods and protocols Diagnostic/screening methods and protocols Original article Original article <span style="font-size:11pt"><span style="line-height:normal"><span style="tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt"><span sans-serif="" style="font-family:Calibri,"><b><span lang="EN" style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Introduction</span></span></b><span lang="EN" style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">: latent tuberculosis infections (LTBI) are not detectable by a single-stage tuberculin test and maybe detected after repeating tests 7-21 days later. This phenomenon, called the boosting phenomenon, supports a two-stage test to identify false negatives in a single-stage test. The present study investigates the value of a two-stage tuberculin test in diabetic patients.<b> Methods</b>: We performed a tuberculin test for 195 diabetic patients. The patients with induration > 10 mm were subjected to a second tuberculin test 7-21 days later. <b>Results</b>: Of 195 patients, 115 came for measuring the tuberculin test induration, which was positive in 3 out of 115 patients (2.61%). Of the remaining 112 patients, 53 patients were subjected to the second test, and 38</span></span> <span lang="EN" style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">patients came back for measuring the induration, which became positive in 4 (10.52%) patients.<b> Conclusion</b>: The increased LTBI rate from 2.61% to 10.52% following the second tuberculin test indicates a boosting phenomenon due to a delayed hypersensitivity reaction.</span></span> <span lang="EN" style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Hence, patients with latent tuberculosis who had a false negative test in the first stage were identified.</span></span></span></span></span></span><br> &nbsp; Tuberculosis, Latent tuberculosis, Type 2 diabetes mellitus, Two-stage tuberculin test, Boosting phenomenon 75 79 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-372-1&slc_lang=en&sid=1 Mahshad Mousavi mahshad.mosavi.94@gmail.com 0000-0002-9158-4069 No Student Research Committee, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran Nazanin Mousavi nazanin.mosavi.94@gmail.com 0000-0003-0186-6052 No Student Research Committee, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran Seyyed Amir Yasin Ahmadi yasin_ahmadi73@yahoo.com 0000-0001-9274-7408 No Student Research Committee, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran Mozhgan Kaviani kavianim29@yahoo.com 0000-0003-2774-6091 Yes Department of Internal Medicine, School of Medicine, Lorestan University of Medical Science, Khorramabad, Iran