The diagnostic value of urinary culture filtrate protein-10antigen in childhood tuberculosis

Introduction and Aim:Childhood tuberculosis (TB) remains a major problem worldwide.However, diagnosis of tuberculosis in children is often complicated by the difficulty in obtaining a proper sputum specimens and low sensitivity of the gold standard diagnostic test to confirm the presence of Mycobacterium tuberculosis(M.tb)in this age group. Recently, M.tbantigen detection in urinaryspecimenshas become a popular method. It is non-invasiveand handling of specimen is simple. It was reported that urinary CFP-10, a specific protein of M.tb, has emerged as a potential biomarker in the future. However, its diagnostic value as a new biomarker in childhood TB remains poorly understood.The aim of the study is to determine the diagnostic value of urinary CFP-10 in childhood TB.   Methods: Seventy children with suspected pulmonary or extrapulmonary TB were enrolled. Tuberculosis was diagnosed by performingTuberculin skin test, chest x-ray, microscopic examination, and microbiological cultureobtainedfrom sputum or gastric lavage specimen. The level ofurinary CFP-10 antigen was analyzedbyELISA (Elabscience, China). Statistical analyseswereperformed using SPSS 21.0 and p-values of <0.05 were consideredstatistically significant.   Results: The levels of urinary CFP-10 in subjects diagnosed with TB was higher than that of the non-TB subjects, 4.13(0.62) vs 0.43(0.14) pg/mL, p=0.005. The cut-off value forurinary CFP-10 level reached 0.39 pg/mL (sensitivity 65% and specificity 67%). This value became0.54 pg/mL (sensitivity 61% and specificity 62%)in microbiologically confirmed cases.   Conclusion: The urinary CFP-10 level has moderate diagnostic value for diagnosing childhood TB.