Use of the QuantiFERON Monitor Assay to Predict Clinical Outcomes in Solid Organ and Hematopoietic Cell Transplant Recipients: A Scoping Review.

Background: QuantiFERON Monitor (QFM) is an interferon-gamma release assay designed to provide a global measure of innate and adaptive cell-mediated immune function. We performed a scoping review to explore published evidence on the ability of QFM to predict clinical outcomes in solid organ transplant (SOT) and allogeneic hematopoietic cell transplant (HCT) recipients.

Methods: A literature search was conducted using Embase, Cochrane, and PubMed databases and included studies reporting QFM values and the incidence of infection and/or organ rejection or graft-versus-host disease (GvHD).

Results: Thirteen publications (9 SOT, 4 HCT) were included. Among SOT studies, infection (n = 8), rejection (n = 3), mortality (n = 2), and immunosuppression regimens (n = 7) were assessed as outcomes; low QFM values were associated with increased infection risk in 7/8 studies. Correlations were also identified between immunosuppression regimens and QFM results in 6/7 studies. No clear relationships between QFM values and rejection or mortality could be determined, possibly due to the low number of events reported. Infection (n = 4), GvHD (n = 3), and mortality (n = 1) were assessed in the HCT studies, with 3/4 reporting an association between low QFM values and infection. There was a high degree of heterogeneity in the transplant populations, outcome measures and definitions, QFM thresholds, and timing of sample collection.

Conclusions: The available data suggest that QFM may be able to identify overly immunosuppressed individuals at higher risk of infection; additional studies are needed to further evaluate its predictive utility in transplant and other settings.