RT Journal
A1 Villarino ME, Burman W, Wang Y, et al
T1 COmparable specificity of 2 commercial tuberculin reagents in persons at low risk for tuberculous infection
JF JAMA
JO JAMA
YR 1999
FD January 13
VO 281
IS 2
SP 169
OP 171
DO 10.1001/jama.281.2.169
UL http://dx.doi.org/10.1001/jama.281.2.169
AB Context 
                  One or both commercial tuberculin skin test reagents
(Aplisol and Tubersol) may have a high rate of false-positive
reactions.Objective 
                  To compare the reaction size and specificity of skin
testing with Aplisol, Tubersol, and the standard purified protein
derivative (PPD-S1).Design 
                  Double-blind trial, conducted between May 14, 1997,
and October 28, 1997, in which each individual received 4 tuberculin
skin reagents at sites assigned at random.Setting 
                  Health departments and universities in 6 US cities.Participants 
                  A total of 1555 persons at low risk of latent
tuberculosis infection.Intervention 
                  Simultaneous skin tests with Aplisol, Tubersol,
PPD-S1, and either a second PPD-S1 or PPD-S2 (a proposed new standard).Main Outcome Measure 
                  Reaction size at each injection site measured
by 2 investigators blinded to type of reagent.Results 
                  Aplisol produced slightly larger reactions than
Tubersol, but this difference did not significantly change skin test
interpretation. The mean ± SD reaction sizes were 3.4 ± 4.2 mm with
Aplisol, 2.1 ± 3.2 mm with Tubersol, and 2.5 ± 3.6 mm with PPD-S1.
Assuming that all participants were uninfected and using a 10-mm
cutoff, the specificities of the tests were high: Aplisol, 98.2%;
Tubersol, 99.2%; and PPD-S1, 98.9%. Significant variability was not
detected in interobserver, host, and lot-to-lot reagent comparisons.Conclusion 
                  Using a cutoff of at least 10 mm, testing with 3
different PPD reagents resulted in similar numbers of uninfected
persons being correctly classified.