Quantiferon conversions and reversions among HIV patients on antiretroviral therapy

BACKGROUND: Tuberculosis (TB) remains a major global public health problem. Recent guidelines recommend screening of high-risk patients for latent TB infection, with the preferential use of interferon gamma release assays (IGRA) over PPD. However, there are several reports of reversions and conversion of quantiferon TB tests (QTF). METHODS: The primary aim of this retrospective review among HIV positive patients, >18 years of age, performed from January 2011 to April 2017, was to measure the occurrence of QTF conversions (negative to positive) and reversions (positive to negative) during routine clinical care. Continuous variables will be presented as mean, standard deviation. Categorical variables will be presented as the number and percentage of subjects in each category. RESULTS: There were a total of 381 cases, with an average age of 52.8 (±12) years of age. From those 249 patients had at least one QTF performed during the study period and 98 patients had 2 or more tests. 196 had a PPD test performed. From the patients that were initially QTF negative (N = 100), 7 converted to positive. There were a total of 10 patients who’s QTF was positive and were retested, and from those 7 reversed to negative (see Table 1). Most cases that reversed were considered to be low positives (5/6 of those where initial values available). There were 21 patients had a history of positive PPD and 16 of those had negative QTF. CONCLUSION: Reversions were common among HIV positive patients with high CD counts. Most reversions occurred with initial low positive QTF results. Providers should consider confirmatory testing among patients with QTF conversion and no history of TB exposure in low-risk settings. Future studies must be done to confirm these findings. DISCLOSURES: All authors: No reported disclosures.