Xpert MTB/RIF for diagnosis of tuberculous cervical lymphadenitis in HIV-infected patients.

Abstract

The World Health Organization endorsed the Xpert MTB/RIF assay for the diagnosis of pulmonary tuberculosis (TB), but there is limited information about the utility of this assay for the diagnosis of TB lymphadenitis. Therefore, the objective of this study was to assess the diagnostic accuracy of Xpert MTB/RIF assay in HIV-infected patients with palpable cervical lymph nodes. Prospective, diagnostic test study. Consecutive patients with cervical lymphadenopathy were prospectively enrolled between January 2011 and March 2013. Lymph node specimens were obtained through fine-needle aspiration or excisional biopsy. Mycobacterial culture was considered as the gold standard. Mycobacterium TB was cultured from 15 of 68 specimens (22.05%), and 53 specimens had negative cultures (77.94%). The sensitivity of Xpert MTB/RIF was 100% (95% CI, 74.65%-100%), and the specificity was 100% (95% CI, 91.58%-100%). Smear microscopy had a lower diagnostic performance. Although based on a limited sample size, our study indicates that Xpert MTB/RIF is a useful method for the diagnosis of cervical TB lymphadenitis in HIV-infected patients, regardless of the bacillary load in smear-positive samples or the CD4 T cell count. The sensitivity, specificity, positive predictive value, and negative predictive value were similar to gold-standard culture. N/A.