One-Year Experience of Cytomegalovirus T Cell Immunity Monitoring in Heart Transplant Recipients

Purpose Guidelines suggest optional use of Cytomegalovirus (CMV) T Cell immunity monitoring (TCell) to guide primary prophylaxis duration or need for secondary prophylaxis after infection. This may help balance the negative implications of CMV (rejection, coronary artery vasculopathy) against those of valganciclovir (expense, leukopenia/neutropenia). We present one year of experience to evaluate the potential utility of this test. Methods CMV TCell was implemented at our center to assess immunity at end of primary prophylaxis (R+ serostatus) and need for secondary prophylaxis after treatment of CMV. Heart transplant recipients with CMV TCell September 2019 to 2020 were retrospectively reviewed. Primary prophylaxis tests were excluded if R- serostatus or within 6 months of rATG. Tests at time of CMV detection prior to treatment were also excluded. Results Table 1 describes requirements for implementation. 24 patients had CMV TCell during study period; 1 never processed. Patients were excluded for: R- serostatus (6), rATG (1), and at time of CMV detection (2). 14 patients were included for analysis; 5 CMV R+ to guide primary prophylaxis discontinuation, 8 for secondary prophylaxis after infection treatment, 1 early for neutropenia. The early test for neutropenia was inconclusive after G-CSF administration. Immunity was noted at first test in 2/5 (40%) of the primary prophylaxis and 4/8 (50%) of the secondary group. Of non-immune in primary prophylaxis group, 2 had inconclusive tests concurrent to non-CMV infection and other in setting of neutropenia. After repeat tests, 9/14 (64%) patients were noted to have immunity. Of those with immunity, 5/9 (55%) had recurrence of low level viremia; 2 treated at detection, 3 self-cleared without treatment. Conclusion Early review of our data suggests CMV TCell may serve a role to identify patients who would benefit from secondary prophylaxis after treatment of CMV infection. Additional data over future years will help better define optimal utilization of this test.