Blood and urine IP-10 associate with active TB in HIV-infected patients

INTRODUCTION: IP-10 has been proposed as a tuberculosis (TB) biomarker for adults. Moreover, urine IP-10 is detected in adults with pulmonary diseases including active TB and its level decreases after successful therapy. AIM: To evaluate blood and urine IP-10 levels in prospectively enrolled active TB patients in Uganda, with or without HIV-infection. The results are evaluated in relationship to clinical/microbiological parameters. RESULTS: 39 patients with active TB and 33 healthy donors (HD) were enrolled. Among the active TB patients, 24 were HIV-uninfected and 15 HIV-infected. Blood IP-10 levels were significantly higher in active TB compared to HD in both HIV-infected (p≤0.0001) and -uninfected subjects (p≤0.0001). Urine IP-10 levels were significantly increased in HIV-infected active TB patients compared to HD (p=0.03). A significant but low positive correlation between urine and blood IP-10 was found in active TB (r s =0.31, p=0.0004) and in HIV-infected active TB patients (r s =0.44, p s = -0.56, p CONCLUSION: Blood IP-10 levels associate to active TB status independently of HIV infection. Urine IP-10 levels associate to active TB status in HIV-infected patients whereas IP-10 is only increased in the HIV-uninfected patients. These findings, besides opening new strategies to detect markers in districts different from blood, suggest the potentials of IP-10 as TB biomarker for the immune-compromised population in high TB and HIV endemic countries.