Use of ligase chain reaction for the rapid diagnosis of lymph node tuberculosis.

Ligase chain reaction amplification (LCx Abbott Laboratories) was used to detect the presence of M. tuberculosis in 101 adenopathy specimens obtained from 98 patients. A total of 30 cases of lymph node tuberculosis were diagnosed, and the data were compared with results obtained using conventional techniques. The sensitivity of auramine staining and culture were 50.0% and 66.7%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the LCx assay were 80.0, 98.6, 96.0, and 92.1% respectively. The results confirm the reliability of ligase chain reaction amplification for the detection of lymph node tuberculosis.