TABLE 1.

Summary of select clinical studies in solid organ transplant recipients assessing clinical utility of QFN-CMV assay

Transplant recipient cohort	CMV serological status of transplant recipients	QFN-CMV assay time point(s)	Clinical study conclusion	Reference
SOTa (heart/lung and kidney) (n = 25)	D+/R+ = 17, D+/R− = 8	Various	All seropositive transplant recipients showed positive reactivity in QFN-CMV assay, while seronegative recipients showed negative reactivity	15
SOT (lung) (n = 39)	D+/R+ = 18, D+/R− = 8, D−/R+ = 6, D−/R− = 7	0.5, 1, 2, 3, 6, 9, 12, and 18 mo posttransplant	QFN-CMV assay accurately tracks the development of de novo CMV immunity; a striking decrease was seen in the QFN-CMV reactivity prior to the episode of CMV reactivation	35
SOT (kidney, pancreas, lung, heart, liver, and other) (n = 108)	D+/R+ = 39, D−/R+ = 34, D+/R− = 35	Monthly for 4 mo after completion of prophylaxis	Monitoring of CMV T cell immunity using QFN-CMV assay may be useful for predicting late-onset CMV disease	34
SOT (kidney) (n = 14)	D−/R+ = 1, D+/R+ = 11, D+/R− = 2	Various	QFN-CMV assay is a sensitive and specific test to detect a virus-specific T-cell response; this assay, in combination with viral DNA load estimates, may prove to be useful to stratify patients at risk of CMV disease	33
SOT (kidney, lung, heart, liver, and combined) (n = 37)	D+/R+ and D−/R+ = 30, D+/R− = 7	Monitoring initiated at the onset of CMV viremia	Monitoring of CMV T cell immunity using QFN-CMV assay after the onset of CMV viremia may be useful to predict progression vs spontaneous viral clearance, thereby helping guide in determining the best antiviral therapy and refining current preemptive strategies	8
SOT (lung) (n = 67)	D−/R+ = 11, D+/R+ = 28, D+/R− = 17, D−/R− = 11	Monitoring monthly for 1 year	A standardized measurement of CD8+ T cell immunity using QFN-CMV assay might contribute to monitoring the immune status of lung transplant recipients	27
SOT (kidney, pancreas, lung, heart, liver, and other) (n = 127)	D+/R− = 127	3–6 mo (at completion of prophylaxis) and 1 and 2 mo after completion of prophylaxis	QFN-CMV assay may be useful to predict if patients are at low, intermediate, or high risk for the development of subsequent CMV disease after prophylaxis	28
SOT (lung and kidney) (n = 113 [55 evaluated])	D+R+ = 33, D−R+ = 11, D+R− = 8, D−R− = 3	Pretransplant and posttransplant	Monitoring of CMV T cell immunity using QFN-CMV assay prior to transplantation is useful in informing the risk of posttransplant CMV replication in SOT recipients	36
SOT (lung, liver, kidney) (n = 114)	R+ = 114, R− = 27	Various	QFN-CMV assay assessment is recommended for non-HLA A1- and HLA A2-seropositive transplant recipients	37
SOT (liver, lung, kidney) (n = 68)	D+/R− = 68	Not specified	Transplant recipients with positive reactivity in QFN-CMV assay had a higher percentage of late-differentiated CD8+ T cells than patients lacking this response	24
SOT (kidney) (n = 25)	D+/R+ = 13, D+/R− = 9, D−/R− = 1, D−/R+ = 2	4.38 ± 2.73 mo posttransplant	An indeterminate result of QFN-CMV assay seems to be related to impaired immunity; the QFN-CMV assay appears to be useful in identifying the transplant recipients with increased risk of infectious complications who may benefit from immunosuppression reduction and maintenance of antiviral prophylaxis	23
SOT (kidney) (n = 124)	D+/R+ = 124	Pretransplant and 1 mo and 3 mo posttransplant	QFN-CMV assay reactivity is not associated with DNAemia	18
SOT (kidney and lung) (n = 55)	D+/R+ = 33, D+/R− = 8, D−/R+ = 11, D−/R− = 3	Pretransplant and 3 or 6 mo and 12 mo posttransplant	D−/R− recipients remained nonreactive in QFN-CMV assay both at pretransplant and posttransplant; D+/R− recipients showed lower reactivity in QFN-CMV assay than D+/R+ or D−/R+ patients	22
SOT (kidney, liver, lung, and combined) (n = 27)	D+/R− = 12, R+ = 13, D−/R− = 1, unknown = 1	Every 2 wks until 3 mo after completion of prophylaxis	QFN-CMV assay can be used to guide changes to the management of CMV infection	20

^aSOT, solid organ transplant.