Pu rp o s e : Recently in Korea since 1998, 2TU has been used instead of 5TU, which
caused a confusion in interpreting tuberculin skin tests. We compared the tuberculin skin reaction
to PPD(purified protein derivatives) 1TU, 2TU and 5TU.
Me th ods : We studied tuberculin skin reaction to PPD 1TU, 2TU and 5TU on 92 infants
who were vaccinated with percutaneous multiple puncture BCG vaccine(Tokyo 172 strain, Japan
BCG Laboratory Co.) in neonatal period. Diameters of indurations were measured in
millimeters 48∼72 hours after the intradermal injection of PPD 1TU, 2TU and 5TU.
Re s ul t s : Among 92 infants(male : 56, female : 36), 1TU was used on 31 infants, 2TU on
31 infants and 5TU on 30 infants for tuberculin skin test. The mean diameter of induration
for PPD 1TU, 2TU and 5TU were 5.7±4.2 mm, 7.1±3.7 mm, and 9.2±4.2 mm, respectively.
There was no statistical difference in mean diameter of induration between 1TU and
2TU. However, when tested with 5TU, the diameter of induration was significantly larger
than those of PPD 1TU and 2TU(P<0.05). Six subjects(19.4%) tested with 1TU, 9 subjects
(29%) tested with 2TU and 16 subjects(53.3%) tested with 5TU had diameter of 10 mm or
more. There was no statistical difference between 1TU and 2TU but for 5TU, number of
subjects with diameter of 10 mm or more was significantly higher than PPD 1TU and 2TU
(P<0.05). Number of subjects with induration diameter of 5 mm or more for 1TU, 2TU and
5TU was 19(61.3%), 22(71.0%) and 26(86.7%), respectively. However, there was no statistical
difference.
Co n c lu s i on : A new standard criteria for interpreting the tuberculin skin test with PPD
2TU should be established for clinical diagnosis of tuberculosis.
Pu rp o s e : Recently in Korea since 1998, 2TU has been used instead of 5TU, which
caused a confusion in interpreting tuberculin skin tests. We compared the tuberculin skin reaction
to PPD(purified protein derivatives) 1TU, 2TU and 5TU.
Me th ods : We studied tuberculin skin reaction to PPD 1TU, 2TU and 5TU on 92 infants
who were vaccinated with percutaneous multiple puncture BCG vaccine(Tokyo 172 strain, Japan
BCG Laboratory Co.) in neonatal period. Diameters of indurations were measured in
millimeters 48∼72 hours after the intradermal injection of PPD 1TU, 2TU and 5TU.
Re s ul t s : Among 92 infants(male : 56, female : 36), 1TU was used on 31 infants, 2TU on
31 infants and 5TU on 30 infants for tuberculin skin test. The mean diameter of induration
for PPD 1TU, 2TU and 5TU were 5.7±4.2 mm, 7.1±3.7 mm, and 9.2±4.2 mm, respectively.
There was no statistical difference in mean diameter of induration between 1TU and
2TU. However, when tested with 5TU, the diameter of induration was significantly larger
than those of PPD 1TU and 2TU(P<0.05). Six subjects(19.4%) tested with 1TU, 9 subjects
(29%) tested with 2TU and 16 subjects(53.3%) tested with 5TU had diameter of 10 mm or
more. There was no statistical difference between 1TU and 2TU but for 5TU, number of
subjects with diameter of 10 mm or more was significantly higher than PPD 1TU and 2TU
(P<0.05). Number of subjects with induration diameter of 5 mm or more for 1TU, 2TU and
5TU was 19(61.3%), 22(71.0%) and 26(86.7%), respectively. However, there was no statistical
difference.
Co n c lu s i on : A new standard criteria for interpreting the tuberculin skin test with PPD
2TU should be established for clinical diagnosis of tuberculosis.