Evaluation of immunochromatographic point-of-care testing in diagnosis of pulmonary tuberculosis

Abstract

Despite the global significance of tuberculosis (TB), its diagnosis continues to rely on tests that have several limitations. Accurate point-of-care test has not yet been successfully developed. The objective of the present study is to evaluate the efficacy of detecting specific immunoglobulin against 38-kDa and 16-kDa proteins in the TB diagnosis compared to smear staining, culture, and tuberculin skin test (TST). This study was conducted on 41 patients with pulmonary tuberculosis (PTB) and 35 healthy blood donors as control group. In addition to TST, sputum stained smear and TB culture, sera from patients and control groups were tested for reactivity against anti-38-16 kDa proteins with immunochromatographic point-of-care test. The number of culture proven, smear positive patients and TST reactors were 32 (78%), 25 (61%), and 32 (78%) respectively. Only 14 (34.1%) patients had positive results with anti-38-16 kDa antibodies detection test, while all control sera were negative. The sensitivity, specificity, PPV, NPV, and accuracy of anti-38-16 kDa antibodies detection test were 31.3, 55.6, 71.4, 18.5, and 36.6%, respectively with poor agreement with culture and TST results (Kappa = −0.077). The diagnostic value of anti-38-16 kDa TB screening test for routine diagnosis of PTB is restricted and cannot replace sputum smear or culture and can only used as an adjunct test.