The significance of the tuberculin test using bioequivalent PPD.
The biological reactivity of two commercially available tuberculin preparations was measured in 168 subjects (9 with active tuberculosis; 98 with inactive tuberculosis; and 61 general population). One tuberculin had 5 tuberculin units (TU) per 0-1 ml dose relative to a stabilized solution of PPD-S, whereas the other preparation was bioequivalent to 5 TU per 0-1 ml dose of unstabilized PPD-S, and was therefore of lower potency. Differences between the tuberculins were more evident when an induration of larger than or equal to 10 mm was considered as positive. Using a criterion of larger than or equal to 5 mm the differences were smaller, but the frequency of non-tuberculous responders was increased using this criterion. The average difference between the tuberculins was of the order of 5 mm regardless of the criterion of postivity. The use of chemoprophylaxis based on reaction size necessitates that the physician should know which of these two commercially available tuberculins is being used.
D003951:Diagnostic Errors; D004305:Dose-Response Relationship, Drug; D006801:Humans; D014373:Tuberculin / Q000592:standards*; D014374:Tuberculin Test
D014373:Tuberculin