CD4 T lymphocyte levels and PPD skin test measurements in adult AIDS patients with pulmonary tuberculosis

ABSTRACT

This pilot study was carried out at the Chonburi General hospital and the zonal tuberculosis [TB] center in Chonburi, Thailand. A total of 22 AIDS patients with pulmonary tuberculosis and 20 HIV seronegative pulmonary tuberculosis patients [Controls] were skin tested with 5 tuberculin units [TU] of PPD. Anergy was observed in 82% of AIDS cases, all with very low CD4 counts. The remaining 18% showed skin reactions ranging between 1 mm and 9 mm. The Pearsons correlation coefficient test showed a good correlation between the PPD induration measurement and the absolute CD4 counts. The coefficient r=0.79 [p< 0.001] with the absolute CD4 counts, and r=0.60[P< 0.001] with the percentage of CD4 lymphocytes. In the control group, no such correlation was found and anergy was not observed in any of the patients. Relationship was established between CD4 counts and the PPD skin induration measurement, though with a larger sample size, the association may be better established and may predict the level of CD4 T lymphocytes and hence disease progression, especially in areas of high case load of AIDS and tuberculosis