Diagnostic evaluation of urinary lipoarabinomannan at an Ethiopian tuberculosis centre

Direct capture enzyme-linked immunosorbent assay (ELISA) for lipoarabinoman nan (LAM) was performed on urine samples from 200 tuberculosis (TB) patient s and 800 non-TB patients routinely diagnosed among consecutive suspects in an Ethiopian TB centre, 50 healthy Ethiopians, 50 healthy individuals and 100 non-TB patients from Norway served as controls. Of the TB patients, 139 (69.5%) were positive for acid-fast bacilli (AFB). In the remaining cases the diagnosis was based on suggestive clinical findings. All Ethiopian non- TB patients were AFB negative and showed no clinical evidence of TB. In the Ethiopian groups, 138 (74%) of the TB patients, 105 (13.1%) of the non-TB patients and 5 (10%) of the healthy controls were positive by the LAM-ELISA . 113 (81.3%) of AFB positives and 35 (57.4%) of AFB-negatire TB patients h ad positive LAM-ELISA. In the Norwegian groups all were LAM negative. The s ensitivity and specificity of the LAM-ELISA for TB patients versus Ethiopia n non-TB patients were 74% and 86.9%, respectively; the positive and negati ve predictive values were 58.5% and 93.0%. This study suggests that detecti on of LAM in the urine of TB patients may improve case finding and that dia gnostic tests based on this principle may serve as valuable supplemental to ols in TB control.