Purified protein derivative skin testing on HIV/AIDS patients and logistic regression analysis of its risk factors

ObjectiveTo understand the reactivity of purified protein derivative skin test (PPD test) in HIV-infected persons and to determine the influential factors associated with PPD.Methods174 HIV/AIDS patients registered in the local center for disease control and prevention (CDC) participated this study from April to June in 2006. Questionnaire, CD4 count and thoracic roentgenogram were performed for all participants.ResultsIn this study, response rate of questionnaires was 83.65%. The majority of these participants had a different degree of immunodeficiency that accounted for 93.64%. Female patients had a higher CD4 count than that of males. The total positive rate of PPD was 38. 15%. Analysis of single factor in our study indicated that CD4 count, previous tuberculosis history, tuberculosis contact history and thoracic roentgenogram manifestation of patients were related to their PPD diameters. Further analysis of multiple factors also supports the previous conclusion that CD4 count and previous tuberculosis history of patients were risk factors in the PPD test.ConclusionThe PPD test of HIV/AIDS patients could be affected by several factors. For persons infected with HTV, the confirmation of latent tuberculosis infection (j_TBl) should be considered the combination effect of previous MTB infection and body cellular immune function.