SP823SCREENING OF LATENT TUBERCULOSIS USING QUANTIFERON GOLD TEST AMONG SAUDI KIDNEY TRANSPLANT PATIENTS

Abstract

Introduction and Aims: Screening and targeted testing for tuberculosis is a key strategy for controlling infection. This study aimed to detect latent tuberculosis among renal transplant patients. Methods: Multicenter prospective study investigated all kidney transplant patients seen and treated at two tertiary hospitals in Riyadh, Saudi Arabia. Whole blood samples were taken for Quantiferon-TB Gold In-Tube Test (QFT) Tuberculin test (TST) was done in all patients. Demographics, laboratory tests, chest radiography and BCG vaccination status were collected. Patients followed-up for 2 years Results: 141 participants. Age 44.5 (SD 12.8) years Male Gender (%) 102 (72) Eleven (7.9%) reported previous TB, and 7 (5.2%) reported TB exposure. BCG vaccination was reported by 69 (50.4%) while the BCG scar was fond in 99 (76.7%). DM (%) 50 (35.5);12 patient had HCV infection, prevalence of latent TB using the QFT-GIT in 24 participants (17%); positive TST was found in 17 (12.2%) participants. There was no significant association and poor agreement found between QFT and TST (p=0.405, κ= -0.053). Previous TB was reported with lower frequency in QFT positive (2 [18.2] vs 9 [81.8], p=0.595), BCG vaccination was reported with lower frequency among QFT positive (18 [18.2%] vs 81 [81.8%]) No participants with reported TB contact had a positive QFT or TST result. Smoking, and cough all remained significant a of positive QFT fter controlling for confounding factors ( p=0.02;; p=0.041, respectively) Patients with HCV had a lower frequency of positive QFT (p=0.342) Sensitivity, Specificity, LTBI prevalence, positive predictive value (PPV), and negative predictive value (NPV) for QFT. Sensitivity (95% CI) QFT-GIT 31.82% (14-55%) Specificity (95% CI) 85.71%(78-91.5) PPV (95% CI) 29.17% (12.7-51%) NPV (95% CI) 87.18(80-92.6%) Sensitivity, Specificity, LTBI prevalence, positive predictive value (PPV), and negative predictive value (NPV) for TST Sensitivity (95% CI) Conclusions: Due to low of Quantiferon TB Gold in-tube test sensitivity and low positive predictive value (PPV) , we recommend its use for its negative predictive value (NPV and to use either TST or QFT in screening latent TB.