[Tuberculin reactivity in the elderly. Comparison of PPD-RT23 and PPD-CT68].
BACKGROUND
Tuberculin reactivity varies on the basis of the PPD lot and the population studied.


OBJECTIVE
To compare tuberculin reactivity in the elderly following successive applications of PPD from 2 different lots.


METHODS
Elderly nursing-home residents, from the province of Guadalajara, Spain.


METHODS
The elderly were randomly selected and administered with a first Mantoux intradermoreaction of 2 UT of PPD-RT23 or 2 UT of PPD-CT68. The study was performed in a scaled basis, eliminating the reactors (transversal induration > or = 5 mm at 72 h). The non reactors were restudied with a second and third test in alternative arms at a 7-day interval with the same lot and initial dosis of PPD. At one year the scaled study was repeated with 2 UT of PPD-CT68.


RESULTS
Eight hundred and thirty elderly persons (79 +/- 9 years) were studied, with 410 receiving PPD-RT23 and 420 receiving PPD-CT68. No differences were observed in the percentage of initial reactors (31% vs 29%; p = 0.26) or in the booster reactors (23% vs 20%; p = 0.16). The PPD-RT23 was found to trigger more intensive reactions than the PPD-CT68 leading to a greater frequency of indurations > 14 mm. After one year, the percentage of stable reactions was similar in both groups (50.5% vs 49.5%; NS).


CONCLUSIONS
1) In elderly nursing-home residents 2 UT of PPD-RT23 and 2 UT of PPD-CT68 showed similar results in regard to the number of reactors and the frequency of booster reactions. 2) The proportion of intense reactions was greater with 2 UT of PPD-RT23 than with 2 UT of PPD-CT68. 3) The stability of the reactions at one year was independent of the lot used in the first phase.
Ussetti
P
P
Hospital General del INSALUD, Guadalajara.
Urbina
J
J
Pantoja
C
C
Sidne
J
J
Martínez
J A
JA
Martínez
M A
MA
Sánchez
I
I
Cobos
J
J
Rojas
O
O
D000368:Aged; D015331:Cohort Studies; D005260:Female; D006707:Homes for the Aged / Q000706:statistics & numerical data; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D011446:Prospective Studies; D013030:Spain / Q000453:epidemiology; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology / Q000276:immunology*
Reactividad tuberculínica en el anciano. Comparación entre el PPD-RT23 y el PPD-CT68.