Underestimation of Mycobacterium tuberculosis infection in HIV-infected subjects using reactivity to tuberculin and anergy panel.
BACKGROUND
This study aimed to evaluate purified protein derivative (PPD) reactivity and its interrelationship with anergy panel and CD4+ lymphocytes in HIV-infected subjects as compared to PPD reactivity in HIV-uninfected individuals in a tuberculosis endemic and high Bacillus Calmette-Guérin (BCG) coverage environment.


METHODS
Clients of four Mexico City HIV detection centres were screened for HIV-1 antibodies (ELISA or haemagglutination, Western Blot); reactivity to PPD (Mantoux PPD, 5TU RT-23), Candida (1:1000, 0.1 ml), and tetanus toxoid (10Lf, 0.1 ml); and CD4+ T cells. Active tuberculosis was excluded. Informed consent was obtained.


RESULTS
From 5130 clients 1168 subjects were enrolled; of these 801 (68.6%) were HIV positive. Reactivity to PPD among HIV-positive subjects was found in 174 (22%), 261 (32.6%), and 296 (37%), at PPD cutoff levels of > or =10 mm, > or =5 mm, and > or =2 mm as compared to 224 (61%) of 367 HIV-negative individuals' reactors to PPD (> or =10 mm) (P < 0.001). After exclusion of anergic individuals using two cutoff levels for cutaneous allergens (< or =2 mm and < or =5 mm), PPD reactivity between HIV-infected and uninfected individuals continued to be significantly different. Only HIV-infected individuals with CD4+ T cells > or =500 cells/mm3 had similar reactivity to PPD as HIV-uninfected individuals. Variables associated with PPD reactivity were CD4+ T cell counts, BCG scar, HIV infection and age.


CONCLUSIONS
PPD reactivity was useful to diagnose tuberculosis infection only among HIV-infected individuals with CD4+ counts > or =500 cells/mm3. Among individuals with lower counts, lowering cutoff levels or using anergy panel did not permit comparable reactivity as that observed among HIV-uninfected individuals.
García-García
M L
ML
Instituto Nacional de Salud Pública, Cuernavaca, M éxico.
Valdespino-Gómez
J L
JL
García-Sancho
C
C
Mayar-Maya
M E
ME
Palacios-Martínez
M
M
Balandrano-Campos
S
S
Escobar-Gutiérrez
A
A
Peruga
A
A
Weissenbacher
M
M
Daniels
E
E
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D001500:BCG Vaccine / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D005260:Female; D015483:HIV Antibodies / Q000032:analysis; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D015995:Prevalence; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D014505:Urban Population
D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D001500:BCG Vaccine; D015483:HIV Antibodies