Soluble Urokinase-Type Plasminogen Activator Receptor as a Biomarker of Treatment Response in Childhood Tuberculosis

Background: Childhood tuberculosis (TB) is a major health problem worldwide, especially in developing countries. In 2015, there are estimated 950,000 cases of childhood TB. Since most TB in children is paucibacillary, this gives rise not only to problem in diagnosing but also in monitoring the response to anti-TB treatment as well. Soluble urokinase-type plasminogen activator receptor (suPAR), a glycosylphosphatidylinositol-linked membrane protein of various cells of immune system, is one of the potential biomarkers to be used in the management of TB. The objective of this study is to study the decrease of scrum suPAR level after anti-TB treatment in children with TB and its association with patient characteristics. Methods: We conducted a prospective study on children suspected of having TB due to a history of contact with active TB case and symptoms such as coughing, fever, and enlarged lymph nodes. The diagnosis of TB is established by history, physical examination including anthropometric examination. Tuberculin skin test using PPD RT-23 and interferon-gamma releasing assay with Quantiferon TB-Gold Plus was performed. Chest X-rays were read by two independent radiologists. Microbiological examination was perfonned using microscopic examination and Xpert MTB/RIF. The level of suPAR before and after anti-TB treatment was examined with the Elisa method. Results: There was no significant difference of serum suPAR levels before and after anti-TB treatment (mean 0.71 [standard deviation 0.585] ng/mL; P = 0.072). There was no association between ages (P = 0.112), nutritional status (P = 0.228), diagnosis of pulmonary or extrapulmonary TB (P = 0.956), and radiological feature (P = 0.810) with serum suPAR levels decrease. Conclusion: There is no suPAR serum level decrease 2 months after treatment with anti-TB and there is no association with age, nutritional status, pulmonary or extrapulmonary TB diagnosis, and radiological feature.