Delayed Hypersensitivity Skin Testing in the Thai Adult Population
Torpong Thongngarm MD*, Apichart M Valyasevi MD*, Kowit Pattanapanyasat PhD**, Suthipol Udompunturak MS***
Affiliation : * Division of Allergy and Clinical Immunology, Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University ** Division of Instruments for Research, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University *** Clinical Epidemiology Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University
Objective : The present study was carried out in healthy Thai subjects to determine the types and concentra-
tions of standard antigens used in delayed-type hypersensitivity (DTH) skin testing as an evaluation of cell-
mediated immunity.
Materials and Methods : One hundred subjects were tested with three antigens including tuberculin (purified
protein derivative), tetanus toxoid, 1:10 and 1:100 dilutions, and Candida albicans, 1:10 and 1:100 dilutions.
Results : We found that 92% of the subjects responded to tuberculin and/or tetanus toxoid at a 1:10 dilution,
77% responded to tetanus toxoid at a 1:10 dilution, and 35% responded to a 1:100 dilution. There was only
one subject who responded to Candida albicans at a 1:10 dilution, and none to a 1:100 dilution. The size of
tuberculin reactions varied from 5 mm to over 20 mm without any evidence of active tuberculosis.
Conclusion : Tuberculin and tetanus toxoid at a 1:10 dilution are probably sufficient to be used in DTH skin
testing to evaluate T-cell function.
Keywords : Delayed-type hypersensitivity, Skin testing, T-cell function, Cell-mediated immunity, Tuberculin, Tetanus toxoid
