Diagnostic value of inducible protein-10 in pulmonary tuberculosis

Abstract

There is increased need for alternative biomarkers in diagnosis, prognosis and follow up of patients with pulmonary tuberculosis and for differentiation between active and latent tuberculosis.The aim of this work is to evaluate the efficacy of inducible protein-10 (IP-10) as a biomarker in the diagnosis of pulmonary tuberculosis as well as to elucidate its ability in distinguishing between active and latent tuberculosis.This study was carried out on 20 apparently healthy subjects (group I), 20 active pulmonary tuberculosis (TB) patients (group II) and 20 latent TB patients (group III). They were matched in age and sex. Group II were sub-classified into three subgroups according to the radiological extent of the pulmonary lesion into: (Minimal, moderately advanced and far advanced lesions).Blood samples were obtained and the determination of serum IP-10 levels by enzyme linked immunosorbent assay methods were done (Sandwich) ELISA.Tuberculin skin test (TST) was significantly higher in group II and III compared to group I and it was significantly higher in group II compared to group III.Serum IP-10 level was significantly higher in group II and III as compared with group I and higher in group II compared to group III, and it was also, significantly higher in far advanced lesions and moderately advanced lesions than minimal lesions.Significant positive correlations were found between serum IP-10 level and both TST and blood lymphocyte%.IP-10 showed sensitivity 88.9%, specificity 100% and accuracy 95.5% with positive predictive value 100% and negative predictive value – 75% in diagnosis of active pulmonary and latent tuberculosis.It was concluded that IP=10 could be used as a diagnostic biomarker in the diagnosis of active pulmonary and latent tuberculosis and it correlates well with disease severity.