Clinical and radiological features in relation to urinary excretion of lipoarabinomannan in Ethiopian tuberculosis patients

Abstract

We have previously reported on the diagnostic potential of urinary lipoarabinomannan (LAM) detection in active tuberculosis (TB). In this study, we identified clinical and radiological parameters that were significantly associated with urine LAM positivity in a clinical sample of 931 patients attending a TB control center in Addis Ababa, Ethiopa. These parameters were attributed weights and used in a diagnostic score (DS) system. Using urinary LAM as a reference, this DS system showed a sensitivity of 65.4% and a specificity of 82.9%. The positive and negative predictive values were 56.8% and 87.4%, respectively. HIV or other coinfections or deficiencies may have blurred the clinical manifestations of pulmonary TB (PTB) and thereby contributed to the relatively high number of false-positive DS results obtained. Although additional markers may be required to improve the sensitivity of the DS system, the relatively high specificity of this simple approach may be of some practical use in the field. Thus, in PTB-suspected, DS-negative cases, the likelihood of ongoing PTB is < 20%.