Usefulness of Adenosine Deaminase Assay in Diagnosis of Patients with HIV Infection and Pleural Tuberculosis

The utility of the adenosine deaminase (ADA) assay in the diagnosis of patients with pleural tuberculosis (TB) and human immunodeficiency virus (HIV) infection is controversial. Forty-eight HIV positive patients with pleural effusion were evaluated; ADA assay was obtained in forty-three of them. Twenty-five patients presented diagnosis of TB. Patients with diagnosis of TB showed a median value of ADA of 70 IU/L (interquartile range (IQR) 41⁻89) and the non-TB group a median of 27.5 IU/L (IQR 13.5⁻52). Patients with diagnosis of TB had a median cluster of differentiation 4 (CD4) count of 174 (IQR 86⁻274) and the non-TB group had a median of 134 (IQR 71⁻371). Receiver operating characteristic curve was performed with an area under the curve of 0.79. The best cut-off obtained was 35 IU/L with a sensibility of 80% and a specificity of 66%. There was no correlation between CD4 lymphocytes count and the value of ADA in the TB patient group.